 Sahani and a team of speakers from University of Washington will be taking these sessions for us. So please be there. So let's move on to our prelude sessions for today. The first session will be by Dr. Abhishek Mahajan. He is a consultant geologist at the Clatterbridge Cancer Center NHS Foundation Trust Liverpool UK. On the re-senior lecturer at the University of Liverpool He is an ex-professor of radiology and consultant radiologist at the Tata Hospital in India. His areas of interest are AI, radiogenomics, ion biomarker imaging, neuro, head neck and thoracic imaging. He has more than 392 publications, 200 national international faculty lectures to his credit, associate editor in the frontiers of oncology, frontiers of nuclear medicine, frontiers in radiology. He is a core member of the RISPON consortium, the BRATS Challenge Consortium and the FETS Challenge Consortium, a peer review committee member for DVT International EU India Horizon 2020 Challenge. He has received the AI Innovator of the Year award 2021 by ELETS and IRA and several others. So let's move on to his lecture, which is on MRI of tongue lesions. Moving on to our prelude sessions for today. The first session will be by Dr Abhishek Mahajan. He is a consultant geologist at the Clatterbridge Cancer Center NHS Foundation Trust Liverpool UK. On the re-senior lecturer. Thank you to Dr Patka for giving me this opportunity and I'm very pleased to be on this panel of good radiologists discussing the MR imaging. The topic given to me is imaging of tongue cancer and this particular presentation would take you through the intricate imaging points, which you can actually tell the surgeon before he plans his surgery. The first to begin with, can you see my slides, is all okay? Yes, yes, everything is fine. So first and foremost, we have to understand that which imaging and why it's very important that you choose the right imaging modality and the right imaging modality. I don't think so that any of the radiologists wouldn't agree is MRI because MR scores over CT in terms of the contrast which we get in the muscles. Also that there are very less chances that there is bone involvement. So bone involvement, if at all, if we are suspecting, then we can supplement with CT as a problem solving tool. So due to the superior soft tissue contrast, which is not seen in the CT, MR definitely is the modality of choice for imaging of the tongue. What all MR would help you into assessing while doing an MR of the tongue, it gives you tumor thickness and depth of invasion. The depth of invasion concept is a very important concept because it is the current AGCC 8th guideline for staging the tumor. If you understand the concept of depth of invasion, then you can adequately stage the tumor. The second is the most important is extension across midline because if there's an extension across midline, then you would be looking to along the nose, along the contollateral neck extension into the muscles of the tongue, the deep in the extrinsic muscles and the floor of the mouth. Involvement of the adjacent structure that is the tonsils and the epiglottis and the epiglottis. Invasion of the mandible and invasion of the neurovascular bundle and submandibular gutter. So one has to at least report these important features in while reporting an MR of a tongue cancer. We'll briefly hit on the anatomy and then we'll move on to the imaging findings. So the tongue is divided into oral and the base tongue. The division is done because the treatment of the oral tongue is different from the treatment of the base tongue. The oral tongue tongue is treated with surgery and the base tongue is treated with chemotherapy. This division is actually done by the circumvillate papilla which is seen on clinical examination. However, we do not see the circumvillate papilla on the clinical examination. Hence, there is a imaginary line, the plane which is drawn between the junction of the soft palate and the hard palate over here up to the high white bone. Anything behind the disjunction is the base tongue and anything interior to is is the oral tongue. So once the oral tongue, this particular imaging, the slides would be basically dealing with the oral tongue because that is treated with surgery. Coming to the first and foremost actual section which you see at the level of the tongue is the fern shape pattern with the lingual septum between. This fern shape pattern is the intrinsic muscles which are interdigitating with interdigitating fat. This fern shape pattern should be considered as the uppermost level of the tongue and these are the intrinsic muscles. You have the masticator space over here, the mandible, the medial pterigoid, the masticator muscle, the anterior buccal fat over here, triangular buccal fat and the parotid duct. You have the mandibular cortex which is hypo intense, the alveolar cortex and you have an important structure over here that's the buccinator muscle. The moment you go a little bit down, you will again see that the interdigitating muscles are prominent and the fat has become more prominent because now the insertion of the extrinsic muscle starts. So this is the section which is an important section to understand the extrinsic muscles. The extrinsic muscles usually the most important critical point in the extrinsic muscle is the genial tubercle which is the center point of the mandible. So this is the mandible over here, the center point is the genial tubercle. The genial tubercle gives maximum origins to the muscles. The first and foremost muscle is the geniohybrid muscle. A geniohybrid muscle is an inverted V-shaped muscle which takes origin from the genial tubercle and gets inserted posteriorly. Lateral to the geniohybrid muscle, you will have a fat containing area which is the space of the sublingual gland and the sublingual space. Posteriorly you have an inverted V which are two muscles. One is the medial one which is the hyoglossus muscle and the lateral one which is the mylohybrid muscle. As we go posteriorly, you have the submandibular glands which are just appearing and posteriorly is the lingual tonsil. So the lingual tonsil is also important that the lingual tonsil enhancement should not be considered as a mass. These are normal enhancing structures in the oral cavity. As we go further down, we have the structures which are the floor of the mouth structures that is the anterior belly of the digastric, the two symmetrical structures, the submental space over here, the hyoid bone, the submandibular glands and the fringeococytome muscles. As we go further, we need to see the other muscles and that is the sagittal plane which gives the muscle which forms the back bulk of the tongue. So the tongue predominantly is formed by the genioglossus muscle. It's a fan-shaped muscle, takes origin from the genial tubercle, forms a fan. You can appreciate the fan over here and it gets inserted into the intrinsic muscles of the tongue. This particular muscle forms the bulk and during the glycectomy, genioglossus muscle is the muscle which is predominantly dissected. The floor of the mouth is underneath this muscle. There are two muscles which run horizontally from the genial tubercle to the hyoid bone. So this is the hyper intense signal of the marrow of the hyoid bone. This is the mandible, the genial tubercle over here. You see the genial tubercle is given origin to the first muscle which is getting inserted into the hyoid and this is the geniohyoid muscle. Inferior to the geniohyoid muscle, there is another linear structure muscle which is mylohyoid muscle. So this muscle forms the floor of the mouth. Any disease involving the mylohyoid or going beyond that is the involvement of floor of mouth. Coming to the coronal anatomy, the coronal anatomy is usually done to see the floor of the mouth and the neurovascular bundle assessment. So the mylohyoid muscle which forms the floor of the mouth is a sling shape muscle which runs all along. So you can appreciate the sling over here and the hyoid bone in the center. So this is the mylohyoid sling and you can appreciate the lingual artery flow widths which demarcates the neurovascular bundle. We will see the neurovascular bundle in detail. Coming to another section which is important, this is the lingual septum on the coronal section which form later to it is the root of the tongue which is formed by the genioglossus muscle that I said is the bulk of the lung tongue and then you have the mylohyoid sling and that inferiorly the anterior belly of the digastic muscles. So the neurovascular bundle is appreciated by the lingual artery, the flow within the lingual artery. We per se do not see the lingual nerve but we identify the flow all along its course and try to appreciate the neurovascular bundle. How do you identify the what is where is the lingual nerve? The lingual nerve and the hypoglossal nerve lies lateral to the hyoid glossus muscle. So the lateral one is the hyoid glossus muscle, the lateral one is the lingual nerve and the hyoid glossus muscle to the to the slow way. So treatment plans, so stage one and stage two oral cancers with tongue cancers are treated with single modality, predominantly surgery or radiotherapy and if it's stage three and four they are treated with surgery with post-operative radio and chemotherapy. I was just reading our article on this which gives a comprehensive review of all the imaging modalities but per se I'll be discussing this table in depth. This table helps you into guiding the management. So the first concept is depth. If the depth is more than 10 millimeter, there are two outcomes. So it's important to document your depth in the report. Spread across midline if it is present it means there are contollateral nodal metastasis and plan the contollateral nectis section as well. If there is neurovascular bundle invasion that means there are chances that the patient would need total glossectomy. If there is posterior extension or p-epiglottic space involvement or hyoid bone involvement then it is a relative contendication to chemotherapy surgical management. You give a trial of chemotherapy and see if the retumor is reducing. Posterior split to the masticator space which is advanced disease, it's advanced so it's palliative treatment and bone erosion which decides the mandiblectomy whether it's middle third or the lateral mandiblectomy. So the first concept is tumor thickness and depth of invasion. The two things are different. What we usually used to do in the past was tumor thickness. We used to measure the medial to lateral dimension and that would be the tumor thickness. However the newer concept is depth of invasion which is different and I'll show the diagrammatic line diagrams on that. So tumor thickness if it is more than four millimeter there is incidence of nec nodal metastasis and elective nectis section is recommended. So it means the tumor if it is more than four millimeter medial to lateral all patients should undergo elective nectis section that's the consensus by the N0 trial performed at Atom Memorial Hospital. So let's understand the tongue tumor and how what the tumor thickness and depth of invasion are different. This is an imaginary tumor which has been drawn over here. The tumor can be of three types. It can be exophytic, it can be exo endophytic or it can be only endophytic. So in the exophytic tumor you will draw a mucosal plane which is the boundary of the let's say this is a tumor over here so I am if I draw an imaginary plane for the tongue so it would run something like this and this is the exophytic component and this is the endophytic component. So if you draw the imaginary mucosal plane medial to lateral is the tumor thickness. Again if you draw this imaginary plane excluding the exophytic component the medial to lateral is the depth of invasion and the total one would become tumor thickness. In an endophytic tumor it's very difficult to understand this imaginary plane and whatever is the level left the enhancing tumor left behind that forms the depth of invasion. So depth of invasion and tumor thickness are two different concepts as seen on this case if I draw a line over here imaginary plane of the mucosa outer part will not be included in depth of invasion if you include the total one that will become tumor thickness. So coming to the next important criteria so this tumor is a low volume disease would be resected with the surgery which could be a wide local excision. However in this kind of a low volume disease which is at the level of genial tubercle that means it is involving the most of the origins this patient would need total glass acne or gross dissection total dissection because the the genioblastis muscle origin itself is involved. Then somebody hello is there any disturbance no no sir you can continue So then again as I said like the tumor can be endophytic or it can be exophytic this is an exophytic tumor this is the imaginary plane over here. If I consider this as the imaginary plane this would be the depth of invasion and the total would be tumor thickness. As the tumor reaches close to the lingual raffae the disease becomes T4. So remember when your disease is reaching close to or it's more than 20 millimeter in depth or it is close to lingual raffae it is T4 disease and if there is a spread across the midline start looking for the quanta lateral node. So this is a disease which is extending across the midline it has a node on the epsilon side and a node on the quanta lateral 1b side and then there's a submental node as well. Involvement of neurovascular bundle as I said that you have to identify the lingual r3 flow void and lateral 2s is the the lingual nerve and hypoglossal nerve which if involved would lead to tongue atrophy which is in a sign which is a late presentation but early signs such as hyper intensity within the muscles of the tongue could be represented because of the lingual muscle denervation lingual and nerve denervation. This is quanta lateral neurovascular bundle involvement and in such cases there is need for total glosectomy so if single side is involved partial glosectomy is done and if both the neurovascular bundles are involved the patient is a candidate for total glosectomy. The another important feature to identify submandibular space involvement you have to differentiate submandibular space involvement versus submandibular gland inflammation. The moment there is genial tubercle and the genioglossus muscle involvement that leads to obstruction of the submandibular duct which runs between the genioglossus muscle and this secondary duct duct obstruction leads to enlargement of the gland and should not be confused with submandibular gland involvement. So one has to trace the course of the submandibular duct if the submandibular duct is not involved and there is direct involvement of the submandibular space that means it's a two submandibular space involvement. Bustier extension into the valichila into the pre-apiglottic space and tonsil they are poor prognostic markers in such are the cases which are candidate for chemotherapy again. Mandibular invasion as I said it's only seen in 10% of the cases and it is definitely seen in advanced cases but it's not so common to see hence we rarely made CT as a problem solving tool to identify subtle cortical erosions. So this is the case where the cortex is completely maintained you can see the hypo intense cortex however here there's breakage break of the cortex with marrow invasion and this is in showing mandibular invasion. I'll show some case capsules as to how we can plan the management and I'll discuss the points how to read this particular case. So there's case number one and in this particular case I will start reporting my tongue tumor that there's a right lateral border tongue disease which is enhancing and shows a hypo intense signal on the T2 weighted images. I'll read the measure the depth of invasion and I'll document the depth of invasion in this particular case so that's approximately seven millimeter which will make it a T2 tumor. The disease is far away from the neurovascular bundle very unlikely that it would have involved the neurovascular bundle it's not even close to the lingual graphase so it's just abutting the hyoglyphus muscle so I would not be worried about the contralateral nodal disease and by and large there are no particular nodes seen on this particular imaging and it's showing restricted diffusion so it's a small volume T2 disease probably N0 and I would recommend that no need for doing the chest CT for this particular patient for work up. In this particular case I there's a large volume disease which is crossing the lingual graphase there's contralateral spread of the disease this is definitely a stage T4A disease there's an ipsilateral enhancing nodes some break in the cortex with involvement of the there's an adenyl socket at the level of the tumor which is probably there's involvement of the marrow also and this disease is abutting the anterior cortex with erosions along the anterior cortex as well the disease has gone close to the genital vocal with involvement of the genioblastis muscle the whole fan of the genioblastis muscle is involved and this patient would be a candidate for total voulassectomy and I would recommend to do an ultrasound of the contralateral side to pick up any nodes which might be missed on the MR in this particular case there's definitely a need to do a CT thorax to rule out any metastases in the lung. This is another advanced stage disease presentation so this is a large volume disease on the coronals you can see the neuro vascular bundle being involved on the ipsilateral side the myelohydr sling over here is also involved that means the floor of the mouth is involved and there is direct extension into the submandible gland however you can see the dilated submandible duct also here which is involved the tumor is abutting the lingual graphase and there's ipsilateral necrotic 1b node however there's a contralateral node also which appears to be indeterminate I would say it's highly suspicious and this is the normal submandible gland so you can appreciate that the normal the gland on the ipsilateral side is in large the signal of the myelohydr muscle is lost floor of the mouth is involved and the neuro vascular bundle is important some bit of change along the cortex is seen so if this case might need a CT to evaluate whether the cortex periosteum is eroded or not you can see the same thing reaching over here along the alveolus going on to the next case I forgot to tell you one important point in this case so if you see the axial section then the node is seen over here which was seen here and this node particular node is necrotic if the planes of the nodes are not very good so this is a node which has extra capsule spread and extra capsule spread is again a poor prognostic marker in oral cavity it directly makes the disease n3 so any node which shows necrosis or shows perinodal standing or has loss of planes with the staph muscles is a n3 node directly come into the next case this is a large volume disease eroding the mandible with pathological structure of the mandible there are necrotic nodes on both the sides even at the submental level the whole of the tongue bulk is involved and posterior extension into the vallicle and the posterior pharyngeal wall with extensive large necrotic nodal mass at level 3 this is a gross disease patient is a palliative candidate and he would only receive palliative therapy for the symptomatology let's look at the post therapy imaging post therapy imaging we in our center now follow nyretz categories it's beyond the purview of this particular presentation but for the sake of just to highlight that we report using nyretz and nyretz category two which is very important because it's a submicosal disease usually seen in tongue should be kept in mind primary imaging after surgery is done by MRI at six months and if there is a suspicion you supplement your imaging with pet CCT remember that do not perform pet CCT in the early eight weeks 8 to 12 weeks because there are chances that there will be inflammation and you will get spurious fdg uptake which can lead to misdiagnosis so at eight weeks doing an MR with diffusion with each study is the gold standard of follow-up imaging and if there's a doubt then you can supplement with either direct biopsy or a fdg pet CCT so this is the recommendations by the nyretz if it's nyretz one that means there is no disease routine follow-up if it's nyretz two short interval follow-up or pet CCT or direct inspection nyretz category three is kind of suspicious indeterminate and then you need to do a biopsy and nyretz four is you it's a definitely request and then you plan your decant case either you do upfront surgery with CCT CCT of the thorax or you plan a fdg pet CCT to do out any metastasis and then plan your surgery and this is an example of nyretz category one use in the nyretz category one you see that the normal enhancing palatine tonsil is seen which should not be considered as an abnormal disease as I told no palatine tonsils enhance normally there's no mucosin enhancement and there's no abnormal fdg uptake so this patient is a baby ot case which was treated with chemotherapy and it's nyretz category one usually after after partial restriction you see that the there's retraction though muscle there's loss of muscle mass this is a normal case after post surgery you see that there is loss of the bulk on the operated side and there's retraction of the tonsil tonsil lingual sulcus this retracted tonsil lingual sulcus may at times enhance and should not be considered as recurrent disease in total loss there is reconstruction are performed by the either the by the tram flap or by the pectoralis flap so you will see that the ipsilateral side pectoralis will be deficient and you will see the the the skin and the sub mucosa so this usually will have hair also because this hair might grow if there's the patient is hairy and usually the part is taken where there's no hair and this particular muscle is having subcutaneous fat over here so this is a normal appearance the skin and the subcutaneous fat after total glossectomy with reconstruction and this is an example where there's total glossectomy has been performed and there is suspicious nodular enhancement which either is a postoperative edema with because the patient received radiotherapy also and it could be recurrent so if you perform your diffusion weighted study sequences you can very well differentiate that recurrent tumor and not a postoperative edema case so to conclude I would say that imaging plays an important role in staging of the tongue cancers it depicts depth of invasion which is otherwise very difficult to measure on clinical examination deeper extension which are usually not visualized on clinically clinically and it's very important for radiologists to have an effective checklist which is being adhered and you document the positive and the negative finding so that you don't miss on any of the findings and could report adequately with that I thank you for your kind attention and I recommend reading our article so that was Dr Abhishek Mahajan who spoke on MRI of foundations so moving on to our next session we have Dr Gaurang Shah who's a clinical professor in radiology director of medical student education in neuro radiology but at a clinical functional MRI service in the neuro radiology division of the University of Michigan a special interest in functional MRI and advanced MR applications in neuro his topic is MRI of green limits thanks a lot appreciate the invitation and I think I'll just start my talk right away let me see if I can match it so if I'm going around just let me know that we can see what screen now we can see that right so should I share the screen yeah so it's a sharing well should I let's written hide okay so I should I should click on hide yes okay and we can start okay fantastic thank you very much first of all I thank Dr Parker for inviting me onto this great webinar I'm sure I'm speaking to many old friends and many new friends but there's no way of knowing for me whatever what I'm saying is registering with you so I hope I mean I wish this could be this could have been a two-way session but somehow it is not but let's look at the cranial nose and that's the most interesting topic that fell of them like a clock and it's kind of cranial clock and you know where all the cranial nose can be actually compartmentalized and they can be segmented into different parts so that we can understand them better now this is from Ari Blitz a good friend of mine who is now at the Cleveland Clinic and what he actually has proposed here is the segmenting of the cranial nose and this kind of allows us to to understand the cranial nose much better the first of all segment A is the nucleus so that's something which we do not really identify but because of our knowledge of anatomy we can actually know where the nucleus of the cranial nose is the second one is the pharynchymal posticular part which means the white matter fascicles which actually start from that nucleus going outside and that also is within the brain stem predominantly or brain pharynchyma and we can actually map them out with DTI if we try hard enough but we do not really see that and the third segment which is C which is a cisternal segment is something that we are very very intimately familiar with because that we can see very well getting into the different parts of from the cisternal segment that it comes out from the surface of the brain it goes into the neural cave and the neural cave varies from different cranial now to different cranial now but um that neural cave again is a very important segment let's say for cranial now fights meccals cave to the neural cave from there it goes on to an interdural segment which means that it pierces the dura the outermost layer of the brain and then it enters into a foraminal segment which is the foraminal of the skull base through which it is going to exit the skull and enter the soft tissue of the neck or the skull base and that is the extra foraminal segment so if we actually divide the cranial now into all these different segments and then analyze it it is actually much more easy for us to to analyze and look at the cranial now okay so again you know this is a pretty good graphic which actually explains us how this thing works out so let's say a first segment is within the brain this is the fifth cranial now the mr image on the right side and the ct image on the left side we are actually looking the same it's looking at the same anatomic plane on both ct and mri so this is segment a and b which is within the brainstem this is segment c and d which is actually in the csf and this is the cisternal segment of fifth cranial now let me see we may not be able to see my okay so this is actually the cisternal segment of fifth cranial now and this is segment d which is the neural cave segment this is the mackles cave area and going forward yet then actually you enter the foraminal segment so this one actually outlines the interdural segment in some ways and then the fifth cranial now goes into the cavernous sinus on the lateral margin and that we would see actually much better as we go ahead but i'm just outlining the different parts between them now so and then going forward again is the segment within the bone which is a foraminal segment this is foramando tandem seen on mr as well as on ct and then it actually gets into the pteropyridine fossa and that is the extra foraminal segment that i'm talking about so this is how you kind of divide the different parts of the cranial now and this is uh how would you like to see it so let's start off with the first cranial now which is actually not a cranial now it's more or less um uh in my view it's not a cranial now it's an extension of the brain and to call it a cranial now is fake news as somebody would say but at the same time uh it has been called in for a long time so let's kind of look at it and look at the ct anatomy and the mr anatomy so this is crystal galley in the axial plane of the ct and this is a coronal pin of the ct in the midline is the crystal galley at the bottom are actually the cryptofram plate this is the lateral lamella the vertical segment of the bone and here is the pulviet modalis and on top of that there is csf and as if you can see very well and you will see it much better on the the coronal MRI weighted images is that there is actually just above the cryptofram plate there is a pool of csf and that is known as olfactory sulcus and that olfactory grew which actually communicates with olfactory sulcus contains the olfactory nerves and that is something you will see it very well here so these are the olfactory bulbs and these olfactory bulbs actually are forming from here so if you see here at this picture this is the olfactory bulb that's olfactory now these are the different branches of the olfactory nerve from the world of the nasal cavity and they all kind of communicate and make this thick stalk of the olfactory tract and this is what we see here this is the olfactory tract here and this is olfactory sulcus in which it is flying medial to it is the gyrus vectus and then this olfactory tract will lead it to a an area which is known as the olfactory trigon now most of the fibers of the olfactory now actually turn laterally and they communicate with amygdala and that explains the fact that sometimes we have very visceral reaction to some kind of smell because amygdala is a seed of flight and fright and if you do not like certain smell we don't even think about it but we recoil and we just want to move away that's part of our reptilian brain disconnected with the hippocampal system and the olfactory now communicates directly with the amygdala through which the lateral fibers and that is why it cannot explain a lot of things and again you have the middle stria and intermediate stria and then it communicates with the olfactory now on the other side so looking at some of the pathology this is one of the most well-known pathology of the olfactory now which is the estheticia neuroblastoma you can see it on CT's mildly hyperdense lesion on MRI as intensely enhancing mass which actually is contiguous across the cubiform plate there's a big part within the nasal cavity and across the cubiform plate you can see an extension of that mass getting into the brain but between the mass and the brain there will be a cystic cavity here and that actually is very pathognomic of the estheticia neuroblastoma right here here is a case of 46 year old male with a head trauma and you can see that this is a sequel of that where the gyrus erectus is affected the olfactory now is not very well seen and it's not a surprise that he had an osmium kalman syndrome it's a very rare genetic disorder and you can see that there's congenital absence of the olfactory now so this is normal anatomy and as I showed you earlier this is the olfactory grew this is olfactory sulcus this is a gyrus erectus these two are the olfactory now and this is normal anatomy but in patients with kalman syndrome there is congenital absence of the olfactory nose and again there is a condition called insinid fits and that's the seizure leg activity which takes place in the lateral olfactory area this can produce the hallucination of taste and order so now we move on to the second cranial now which again is fake news that it's a cranial now it's an extension of the brain as you very well know you cannot have any neurofibroma or schwannoma of the arctic now because it's not enough it's more or less an extension of the brain if you look at the different segments of the arctic now it starts off with a small intraocular segment it's pretty tiny like a one millimeter in the length and actually it is you can see it around the region of sclera it's known as lemonic fibrosis right there and this is where the ganglion cells would exit the orbital flow then there is an intra orbital segment which is about two to three centimeters in length and this is something we just seen within the orbital cavity it continues on posteriorly to a segment called intra canalicular segment which is about four to nine millimeter depending on where you are looking at it so this is a coronal CT and just above the superior orbital fissure so this is a superior orbital fissure and here is where you will see the optic canal and up through that canalicular segment and continues on into the intra cranial segment which is about a centimeter long and it actually meets with each other at a structure which we very well know and an optic chism from optic chism there's the acquisition of the lateral fibres of the optic nose and then it goes continues on into the optic tract the optic track again is the x-shaped structure and from optic track again it continues on to the hetero chismal structure so the hetero chismal structures would be from the optic track it will go on to the lateral geniculate a bulk of it will go to the lateral geniculate body a bulk will go to the medial geniculate body and from there the optic radiation will start up and it will go into the perichalkarine area where the primary visual cortex is so this is a functional MRI with visual cortex that you can actually see the the part of the brain with which we are performing the visual function and that part is connected to the orbit through this optic radiation and the lateral geniculate body which are actually the relay points through the optic track through the optic chism through the optic nerves and you can analyze it much better with the DTI and tractography we perform it routinely in all the brain tumors because whenever there's a brain tumor it distorts the normal anatomy the normal landmarks are actually gone and neurosurgeon needs to know where the different prime and eloquent tracks are and for that we perform DTI perfusion diffusion and functional MRI so these are the visual pathways in short the orbits the optic nerves here the optic chism optic tracks and then getting into the lateral geniculate body and this is the optic radiation going to the chalterine sulcus so let's look at some of the pathologies of the optic nerve now those pathologies here would be let's see who am I that switch to no it's not going to get me okay so here is something which we all know this is actually a collection of CSF surrounding the optic nose you can see that in the bilateral intra orbital segments and this is secondary to astrotumor say bright up here you can see a patient who has actually a huge phylocytic astrocytoma of the thalamus and then he had this two bulky fusiform tumors of the optic nose and that's the optic pathway glioma I unfortunately not able to play it because I chose the function of laser pointer so let me see if I can get out of it do nothing I can do it without let me end the show get back and then see if I can back without a pointer so just bear with me for a single second okay sir yeah so let me try to know I think I'll need to display setting has to change and that is much better okay you can see my whole slide correct yes okay excellent so this is my little video here that I can play out and that video shows in the axial plane and it's in a loop that you can see there's a huge phylocytic astrocytoma and the hypothalamus which actually infiltrates into bilateral basal ganglia and then it continues on with the in the orbital cavity as the optic nose the case below that is that of neurominal dysoptica and you can see it again I think I okay and in here you can see that there's an enhancing part of the optic nose you can see the optic chiasm the optic now the optic tracks are enhancing and within this final chord there is this exponential intramural hyperintensity to long segment lesion so that's typical of neurominal dysoptica this one is as we all know it's a huge cellar mass within supracellar extension which has a big mass effect on the optic chiasm and this causes the by temporal hemianopsia yeah it's very typical of picture 3 macronoma and the one here is actually you can see an astrocytoma in the temporal occipital region now as I said earlier we want to know what is its relationship with the optic pathways and that is something which you can do by doing tectography so you can actually perform the tectography make it in the multiple planes and then that was the if you can see that is the mass and you can see that the optic tracks actually is deviated but it's not infiltrated by the mass so there's a lot of things you can do with the modern imaging but the fact remains that the more information you give the neurominal chiasm it's better for you so now let's come to the real cranial nose which starts with the cranial null 3 and we can see that let's see let's look at the segments a and b into the third cranial now so as I said segment a and b they are surrounded by brainstem perinchyma they're not directly visualized and the location of cranial now like you can actually call it 3 a 3 dot a and 3 dot b and this is proposed by re we don't do it in our usual practice but that's just a suggestion this makes a lot of sense so let's go on further that cranial now three which is an ocular motor now so cranial now three is a motor now to this almost all the super intra-orbital muscles it includes the superior rectus medial rectus inferior rectus inferior oblique and it also carries the parasympathetic innovation so whenever there is a lesion of the third cranial now the patient ends up having oculometer of telmoplegia so it's a very typical condition which every of telmologist is trained to diagnose clinically and there is that downward and abducted globe there is pupillary dilation that's because of the sympathetic fibers there is paralysis of accommodation, strabism, and ptosis now radiologically we all know that aneurysm of posterior communicating artery can actually cause a third now palsy and give rise to oculometer of telmoplegia and if you look at the anatomy that the posterior communicating artery actually arrives on top just superior to the third cranial now at the same time if there is uncull herniation there to increase intracranial pressure that also compresses upon the cranial now three from the side and that can give rise to oculometer of telmoplegia and also downward shift of brain stem can stretch of third cranial now so let's look at the third cranial now this is actually in all anatomy but this is for this is a fiesta sequence so fiesta sequence is excellent to look at the cisternal segment of the cranial nose and we actually make it a part of every cranial of protocol and if you look at the different parts here you can see that that is the third cranial now getting out from the cerebral peduncles and in the center is the basilar artery which is dividing into the the pca bilaterally within the intracranial system and the most common pathology of course and that up for this small guy is the sca so so the third cranial now is actually between the superior cerebral artery and posterior cerebral artery and that's where it comes susceptible to any processes of the of the posterior communicating artery now let's look at a lesion and i'm actually going to show you most of the lesion as schwannoma because in a because it outlines the cranial now and b because we do not have all the time in the world to show all the pathologies of different cranial nose but let's look at the schwannoma of the third cranial now and then this is a patient which presented with right of proximity weakness and mass effect on the cerebral peduncles the nose kind of origin is indeterminate but if you look at the position gets into the intracranial system and in the medial surface of the middle cranial fossa this actually is bound to be a third cranial now schwannoma so looking at the anatomy a little bit this is the ica that is the the pca the posterior cerebral artery that's a pcom and we are actually at the superior part of the intracranial system so as we go down on this fiesta sequences which is a heavily T2 weighted 3d sequence now we come to a p the pca and as we go downwards a little bit now we can see the origin of the third cranial now and this is the basilar artery this is the third cranial now on the other side again going down we can actually visualize both the third cranial nose and going further down we can now see superior cerebral artery taking off so in reality if you just look at that let's say this is the sagittal plane here within the sagittal plane this is let's say a 22 year old presenting with diplopia and what you can see here is this is the third cranial now and that was actually a third cranial you can trace it so right there you can see the third cranial now and let me show you the relationship so that's a third cranial now within the substance of the brainstem this is the cisternal portion of the cisternal portion is right underneath the pca and the right above the sca and that is why an aneurysm of posterior communicating artery right there will affect it very badly and this is the intra-cavernous segment and here through the super orbital fissure it enters the orbital cavity and divides the supply all the different muscles and if you look at it in different planes you can see the relationship in the coronal plane very well how it is in between the student nerves it's coming at you and now let me start from the beginning and this is the actual plane this is actually pathology to show you that actually is the schwannum of the third cranial now and here is the course of the normal third cranial now whichever which we have outlined this was one of our arsenic presentations so that's the nucleus of third cranial now right behind the interpericular system and then the cranial now third takes up the cisternal portion this is the cavernous portion and this is within the orbital cavity which is the the extra cranial portion and that shows the relationship beautifully going on to the fourth cranial of the trochlear now that is actually the smallest cranial now it's very difficult to image with mr and if it is normal sometimes you don't even see that it's a pure motor now the supere oblique muscle it supplies only one muscle and that's why there are very few fibers and that's why it's very small and this is what will be the clinical presentation but looking at the fourth cranial now the trochlear now that is the third which we see and this is the fourth now that arises from a nucleus on both the sides of the aqueduct of sylvia's within the midbrain and it is the only cranial now that arises from the posterior surface or dorsal surface of the brain stem now it comes through but it's only cranial now the cross is over so even though it is smaller some unique features about the fourth cranial now in that it's arises from the dorsal surface of the brain stem and crosses over all other cranial nows they actually supply the same side that it arises from but the trochlear now supplies the contralateral side which is so unique about it and then in the ambient system it courses around the perimidus and cephalic system again it courses just like the third cranial now in between the superior cerebellar artery and the posterior cerebellar artery and then enters into the cavernous portion on the side and from the cavernous portion for the supra-arbitral fissure it because this is the extra cranial portion which actually courses medially because it is supplying the superior oblique muscle so that is the trajectory of the fourth cranial now and now we looked at this is the supra-collicular this is intracollicular this is known as the supra-malary vellum and the fourth cranial now kind of arises and then comes out so let's look at the anatomy of the fourth cranial now so i i showed you the nucleus of third cranial now this is the nucleus of fourth but then the now that comes through is coming from the contralateral side so it kind of wraps around the midbrain and then it enters the cavernous sinus and in the axial plane it is very close to the nucleus of third cranial now this is how it looks like three and four and again it shows the different parts of the fourth cranial now going through into the brain and this is actually at the level of superior colliculus because supra-colliculus is associated with the orbit and the visual function intracolliculus is associated with the auditory function so you can see it going through the ambient system pre-pontine system into the orbital fissure in this actually shows the relationship of the third and fourth cranial now between the with the vascular structures uh looking at MRI and normal anatomy you can see the fourth cranial now the very wispy small thread like structures in the ambient system uh and that's the superior cerebellar artery right there uh and this tiny oblong structure which is intensely enhancing along the expected course of the fourth cranial now is a schwannoma of the fourth cranial now patient presenting with the plopia as you would expect in a supra oblique muscle palsy okay now we come to the big guy and this is the trigeminal now the fifth cranial now this is a whole topic in a chapter by itself so we'll try to cover it as much as we can but then it has three parts as we all know it that the it's divided into v1 v2 and v3 v1 is the ophthalmic now which actually hosts is the sensory narration of the skull the forehead the nose the globe the macerate now actually is responsible for the sensory iteration of the cheek and the upper teeth and uh it actually um has the other nose are the greater and lesser palatine now so it goes into the palate and heart and soft palate v3 is the mandibular now and you can see them actually this is the system of course of fifth cranial now uh within the mactal scale this is the trigeminal ganglion that's v1 v2 and v3 kind of drops down directly through for an ovale into the skull base to supply the muscles of massacation including pterigoids and masseter and then it goes down and then it gives out the now to the myelohyret muscle and anti-valium digestic muscle and then the sensory muscle, the sensory part of that now actually gets into the mandible and then it actually becomes the inferior alveolar now the lingual now and then it outside it becomes the auricula it communicates with the auricula temporal nerves so it's a big cranial now and that allows us very well to visualize the segment C and D of the cranial now which is the cisternal segment and the cisternal cave segment so it is surrounded by CSF and that's why we see it very well it's very visual very well visualized on thin section T2 where it is and this is a different vendor's name like Fiesta SSF 802 space but it means the same thing that we are able to see the fifth pinion now and you can see that in all its glory the cisternal portion arising from the side of the pawns not the ventral surface not the dorsal surface but from the side of the pawns and it enters the medical scale here where it forms it terminates into the trigeminal ganglion so if you look at the nucleus part of the fifth cranial now it has actually four nuclei it's a big now three of them are motor one is sensory next tends from mid rain to the upper cervical cord it's a long segment nucleus it's just not flat rounded nucleus the mesencephalic the main sensory nucleus which is huge and then there's a motor nucleus which is kind of a tiny compared to the sensory nucleus because the main motor now of the face maxillofacial structure is seventh cranial now and the main sensory now is the fifth cranial now so looking at some of the pathologies of the fifth cranial now when it emerges from the lateral pawns on the left side you can see there is a normal CSF and medical scale but on the right side you see a filling defect which is expand style which is mildly hyper intense through the brain current camera but not as bright as the as a CSF and it's fusiform dilation it actually starts from the cisternal portion gets into the mackerel's cave you know in post-contrast imaging there is very intense post-contrast enhancement it's also extends into the lateral surface of the K-1 assinus and this is the normal K-1 assinus on the left you can see the intra K-1 assinus ICA coursing up but in here the intra K-1 assinus ICA is pushed medially because of the huge mass arising from the lateral surface of the K-1 assinus and if you look at the normal anatomy this is the cisternal portion both the cranial five and that is in the this is a pre-pointed cistern that's a medical scale you're looking at and then on the right side it doesn't look quite the same as it doesn't look a chord like linear structure but a rounded structure on the right side and that is because you are actually looking at a schwannoma and on post-contrast imaging you can see intense enhancement of the same rounded soft tissue going down that schwannoma extends through the lateral border of the K-1 assinus and you can see a huge mass along the lateral border of the right K-1 assinus which is the schwannoma of the fifth plane of trijeminal and and then it can also have cystic degeneration as you go more lower down because larger the tumor more are the chances of tumor necrosis and then on T2 axial imaging one of the sequela of a trijeminal assinoma is seen very well you can see the nervation atrophy of the teri guard muscles here of the masticator muscles here just slaps out to the menibular ramus that's because the fifth cradle now is kind of drying up in some ways and most of the mastication are atrophied again another patient with left facial numbness and you can see a large mass which actually distorts and compresses the brain stem and then you can see a chord like structure extending into the magnol scale and this is very typical of K-15. Again we come to the next segment which is we can see very well which is actually the interneural segment and generally the interneural segment is associated with venous blood and which cradle now is better positioned to show you the relationship within the interneural segment and that's the fifth cradle now so if you look at it this is a heavily T2 weighted coronal image and we are at the level of the pituitary fossa you can see the cell atresica that's optic chiasm and here is the cavernous sinus on your right and within the lateral wall of the right cavernous sinus you can see various structures the one on the top that is the teraclinial now so this is the segment cranial now three dot e because this is segment e and then going down you have cranial now four so that is the cranial now four e and going down that's the cranial of six which is just lateral through the intra cavernous part of the ICA and this one is not within the wall of cavernous sinus it is a free floating cranial now within and surrounded on all the sides by venous blood which is flowing within the cavernous sinus and then going down you can see this huge segment of cranial now v1 and v2 and v3 is not seen because from from the trigeminal ganglia and it's actually definitely and straight down drops down into the foramen ovale and exits the skull so that actually is the the cranial now v3 that one and which is not part of the cavernous sinus and then sis with contrast again is a very good sequence to look at the cranial now because we can stand out let's look at the different divisions of the cranial now five we are still within the cranial now five which is v1 division or optical now that courses into the lateral part of the cavernous sinus here we see very well it is just below cranial now four just above v2 it exits the skull through the supra orbital fissure and then within the orbital cavity diverging through the lacrimal the frontal the nasal ciliary nose continues on as super orbital now on the superior margin of the orbit and then exits through the supra orbital foramen to supply the sensory part of the forehead so that is the sensory part and then we come to the next part of the cranial now that we would like to admire and see and analyze which is the foraminal part this is the this is a foramen through which the cranial now will exit the cranial cavity and become extra cranial and if you look at that that again can be surrounded by venous blood some catheteries and fat and of course bone it's not very well visualized on the traditional T2 weighted images because of the susceptibility but if you look at the contrast enhanced T2 weighted images then you can see them very well so look at let's look at the axial heavily T2 weighted imaging and the arrow points towards the foramen rotundum and that is the v2 segment going into the pterigopaladine fossa and that you can see very well in the coronal plane right there and that is when the second cranial the v2 or the second division of the cranial now drops down into the pterigopaladine fossa and from there actually it goes into so let's say if you look at its course it courses into the intercavernous portion underneath the v1 it exits the skull bister from the rotundum right there and then it actually drops into the pterigopaladine fossa and that you can see that these are the different segments of the orbital floor so this is the foramen rotundum this is the pterigopaladine fossa this is the infrared fissure and then it actually you can see that in the orbital floor right there and that's because it's a schwannoma you can see it much better of course v3 is the third division of the fifth cranial now also known as mandibular now it does not pass through the cavernous sinus it actually drops directly down from the tragemental ganglion into an expanded foramen ovale you can compare the foramen ovale of the right and the left side and you can see that this one is expanded but very smoothly expanded and that's because it has a large intensely enhancing south tissue mass going through that and you can see that in different parts the motor route of course will bypass the tragemental ganglion the masculine now actually it starts up at skull base so this is the pterigoid muscle you can see that's the temporalis muscle so you can compare the left and right temporalis muscle and see the atrophy of the right temporalis muscle then you can look at the pterigoid muscle and that's the lateral pterigoid that's medial pterigoid and that's the masseter muscle and you can see that there's a relatively diminishing in size of all these muscles and that's because of the lesion of the fifth cranial now now this is because of the proximal lesion of the fifth cranial now on the right side is a case with an injury to the distal part of the fifth cranial now and then the muscles of masseter are of course affected but on top you can see that the antebelli of digestic is also thinned out as compared to the other side and this is due to the distal v3 injury and now let's look at the extra cranial portion of the fifth cranial now and you can see that very well and the fifth cranial now is the only now and especially v3 is the only cranial now but you can visualize on a normal routine MRI study even when it is normal when there is a tumor when there is a lesion when there is a normal enhancement you can always see it but even when it is normal v3 is the only cranial now that you can see and admire and trace very well these are the v3 segments myelotlates dropping down into the middle skull base through the from and off ovale and looking at the coronal plane you can see that it's kind of going down between the teregoid muscles like that through the from and off ovale you can trace it downwards and that's of course is a macron scale so let's look at a case of perineural spread and it is like everything is enhancing you can see that you can see the enhancement in the foramina rotundam it's v2 you can see it in the lateral wall of the cavernous sinus you can actually see the enhancement of even the the crust which is leading into the into the tentorium so you can see the neural margin of incisora even lighting up and that's again the third cranial now that is into orbital extension and you can see this is the v3 which is kind of lighting up and so you can see the perineural enhancement along the v2 sorry in the second cranial now you can see it around the third cranial now you can see along the fifth cranial now and skeosal carcinoma and adenocarcinoma are two passes which actually like the perineural spread we i had that whole talk on perineural spread and the Chandigarh conference last year and there you can see in detail how the perineural spread it kind of creeps along the different branches of the fifth and seventh cranial now and enters the cranial cavity in the retrograde fashion so now here you can see that there is involvement of bilateral trigeminal ganglion you can see that in the macroscale kind of lighting up you can see the intercavernous portion kind of lighting up you can see that here is the v1 segment and there is the v2 segment in the rotunda so a different cranial now is lighting up in the perineural spread so finally the fifth cranial now is over we can now start up with the abducent now the sixth cranial now that's a pure motor now that inner vertebrate lateral rectus muscle only and nothing else and this gives rise to a sixth now palsy which is known as quinn can give rise to complex neuropathy but let's trace its anatomic orientation so within the nucleus it is actually just in front of what is known as the facial colliculus in the floor of the fourth ventricle a facial colliculus is formed due to the fasciculi of the seventh cranial now it kind of wraps around this area but the nucleus of the cranial now is right in front of the facial colliculus but the course of the the B segment or the intraparent camel fasciculi day course anteriorly and then it of course emerges onto the ventral surface of the brain and when it emerges on the ventral surface of pawns the lower pawn it's the only cranial now that goes superiorly instead of going flat or inferiorly after it emerges so it courses superiorly within the pre-pontine system and enters a structure known as dorelos canal which is actually an unfolding of the dura and through that it enters the cavernous sinus and that makes it the interdural segment so within the cavernous sinus as I said earlier it is actually free floating within the cavernous sinus surrounded on all the sides by the venous blood of the sinus it is not along the wall and then it actually enters the orbital cavity through a through a ring it's a fibrous ring which is known as an annulus of zinc that to that ring are actually attached all the extra muscular musculature and then it crosses from medial to lateral to innervate all the different muscles of the orbit so you can see that it's kind of coursing through it it it comes straight on it ascends in the cisternal segment this is the this is very dental dorelos canal that's the cavernous segment and that is the intra-orbital segment and you can see in the axial plane that here is the nucleus of sixth venial now just in front of the facial colliculus and then it courses through the points ventrally emerges on the ventral surface courses superiorly within the pre-pontine system enters the dorelos canal which is a small dural unfolding enters the cavernous sinus within the cavernous sinus surrounded by on all the sides by the venous blood and through the annulus of zinc actually it passes into the orbital cavity and this actually in nutshell is the course of the sixth venial now so you have the cisternal portion the petro cloud portion the cavernous portion and the orbital portion of the sixth venial now and looking at and why I was actually emphasizing on the location of the nucleus is that whenever there is a palsy the lesion can be anywhere along the course of the cranial now so you have to look at the nucleus you have to look at the fascicular the cisternal segment the the dural cave the inter-dural segment the foraminal segment and the extra cranial segment so that you can analyze that particular cranial now and come to a conclusion as to the site of the lesion and many a times we are actually whenever whenever the patient is referred to us by the dural this and say sick venial palsy we have so much focused on looking at the cisternal part of the cranial now that we forget to look at the nucleus and this is exactly what is going on that there is actually an area of restricted diffusion we diminish the diffusion coefficient hyper intense flare signal and hyper intense T2 signal which corresponds to the location of the nucleus of the sixth cranial now so this is actually a brainstorm in fact which involves the cranial now six nucleus and this is a young female who actually had surgery for eighth cranial of swanoma then she had six now palsy again looking at this intensely enhancing mass lesion which is the swanoma of the cisternal segment of the sixth cranial now going on to the facial now the seventh now finally we are more than halfway through the facial now is again a big now it has three nuclei which out of which one is motor two are sensory it's predominantly a motor now which supplies the muscles of facial expression so whenever I'm speaking all the muscles on my face and grimacing all this is conveyed through the seventh cranial now it also carries the but a sympathetic supply to the electromal gland the submenibular gland and the sublingual gland and it's also responsible for the sense of taste in the anterior tooth of the tongue so let's look at its anatomy so that we can go forward so this is you know we are again at the level of the fourth radical and then let's look at the nucleus of the seventh cranial now so this is kind of the facial colliculus that the sixth now nucleus and the seventh now nucleus is actually located just in front of the sixth now nucleus and then the the fiber tracks or the segment B that loops around the nucleus of sixth cranial now and then it comes out from the side of the so like the fifth cranial now again the fifth emerges from the side the sixth emerges from the front or the ventral surface seventh again emerges from the lateral surface of the brain stem and then it is actually you can all see it's the seventh cranial but at the same time because different part that's the facial now that is the nucleus this is the abducent nucleus that's the facial colliculus and these two are the nucleus of the tractors solitarious and the superior salivary nucleus so these two are the the parasympathetic fibers bit more this makes combined makes the now of risk work then it emerges into the system of segment so whenever it emerges into the system of segment you can see that that is actually the system of segment of the seventh cranial now this is the nervous intermediates and that is actually just anterior to the vestibular cochlear now in the system of portion so this is the cp angle system and the entemos part of the seventh cranial now and then from the cisternal portion it actually will lead you to the canalicular portion so this is the canalicular portion of the seventh cranial now which is anterior to the vestibular cochlear now and then let's look at some pathology of the canalicular segment this is an intensely enhancing mass entering the entering the iac and you can see that that goes all the way from the porous acousticus to the fundus of the iac but it does not enter the cochlear canal and because that is actually the seventh cranial now and then from the canalicular segment the next segment is the labyrinthine segment and this is through the facial now canal which you can see very well on ct but on mr you can actually hallucinate the labyrinthine segment of the seventh cranial now you can certainly see the genicular ganglion along the lateral margin and from there it gives up an anterior branch which is the superficial the greater superficial potential now and then bulk of it actually makes a herping band and transpose stereally to continue on as the telekinic segment of the seventh cranial now so looking at the anatomy the some of the pathology of the labyrinthine segment so this is again you can see that from the ct angle cisternal segment to the canalicular segment to the labyrinthine segment it again there is an enhancing mass at the genu of the the genicular fossa so this is the genu of the seventh cranial now and this is the anterior part the greatest superficial patrosal now which goes along actually it proceeds along the the carotid canal and then it combines with some of the sympathetic fibers to form the median now which actually communicates with the pterigopyridine ganglion and the pterigopyridine fossa it's a very interesting connection between the seventh and the fifth cranial now looking at this case on the left this is a coronal ct reconstructions and you can see there's a normal geniculate fossa but at the same time here is the expansion and erosion it's a kind of uniform expansion and asymmetrical enlargement of the labyrinthine segment of the seventh cranial now which is probably due to the schwannoma so now looking at the tympanic segment of the seventh cranial now as we saw previously that's a labyrinthine segment coming out and here is the geniculate ganglion and the bulk of the seventh cranial now will continue posteriorly as a tympanic segment and that tympanic segment when it courses posteriorly you go all the way down into the master canal and then it slides down into the stylo master foreman and that makes it the descending segment of the seventh cranial now so it emerges from it emerges actually right behind the stylo master process and in the stylo master foreman so just behind the stylo process and then it continues on into the into the parotid gland but before it does that it gives off branches to the stapedius muscle and if you can sometimes actually see the coratimpani branch very well and I see that much better on CT where I can see that little canal which actually emerges from the master canal and goes into the into the into the temporal bone into the medial tympanum. The coratimpani of course is responsible for the test sense of test in the anterior two third of the tongue. This is an MR image again and you can see very well this is actually the the the retromandibular vein but you can see that right there actually is the motor segment of the seventh cranial now and then what it does is that it it courses just behind the retromandibular vein and then it courses into the superficial lobe of the parotid gland and some of the motor parts will continue on to the facial parts and supply the muscles of the facial expression and now we come to the eighth cranial now the vestibular cochlear now the main function of course as we all know is about it's all about hearing and it's all about our relative position with relation to the gravitation force so that's the vestibular part and the hearing part is the cochlear part so let's look at the anatomy here and they again arise from the side of the brain stem so it emerges from the lateral surface again it courses to the force acoustics the anterior part is cranial of seven the posterior part is the vestibular cochlear now and then it actually supplies the cochlea and the vestibule but that's a very complex process and I have this little impact which we did for one of the presentations in the RSNA but if you look at the sense of hearing yeah let's look at the cochlear now and the vestibular now and how they play their part so I'm going to click on this and you should be able to see so this actually is the organum cordy that's modalis that's a cochlear now so when I'm actually talking to you when I'm speaking to you the whole thing is coursing through that so let me try to do that again oh it doesn't want to go back I think we can start all over that's organum cordy you're very well here from there the hearing goes through the modalis the cochlear now in goes the cochlear aperture this is the cochlear basal tone and then in for equilibrium the three semi-circular canal to the job this is channel seven this is the cochlear now superior vestibular segment in pure vestibular seven that's the crystal galley which is divided to our famous seven up coke down that's the crystal galley and here in that segment you can see the seven the cochlear the sv1 and the v2 the superior and inferior and there you can see the vestibular cochlear now in all its glory and that's of course the seventh cranial now the facial now and this is the vestibular cochlear now going forward let's look at some of the schwannomas of the eight cranial now intensely enhancing intracranallicular part and then this is a contrast you have inverted images of course and then you can see that as the feeling defect in the pair of sagittal t2 weighted images where you can see them very well within the isc as a feeling defect now as we all know that about 10% of the patients with acoustic tumor to present with acute hearing loss and these are the patient that we actually analyze and and and and we give them a pathology or not but if you look at the real incidence only one person of the patient which present with acute hearing loss will have acoustic tumor so 10% of the tumor will present with the acute hearing loss but if you go only by symptom only one person of the patient with acute hearing loss will have acoustic tumors but the only way for them to know is to get an MRI of brain and that's where we come into play so this again is a patient presenting with acute hearing loss and I hope I had somebody to ask whether you know what is going on here but this is a pre contrast t1 weighted image and you can see that the kind of hyper intense t1 structure which is probably hemorrhage and you can see that both these images are without contrast but they're still bright and that's because of the hemorrhage in the in in the cystic chronoma due to degeneration so that's not uncommon and if it is acute presentation and not calling then the possibility of hemorrhage is quite likely and that hemorrhage can be within a cystic mass or it could be a inter labyrinthine hemorrhage so looking at an acoustic chronoma you can see that laterally going through the cp angle system into the chronocular segment but there is also a cystic part a cystic component of the mass very well and the bigger the tumor the more likely it is bound to the cystic um and you can see that the little graphic here there's a cochlear there's a cochlear now and this is a vestibular one and two here is a middle ear cavity with the stapedius and the inter labyrinthine chronoma again can be within the cochlear within the vestibule it could be transortic it could be transmodular it could be transmecular um again uh whenever you see something like a bright structure within a uh within cochlear vestibule you have to rule out labyrinthitis and uh and hemorrhage now let's look at some of the case this is a post contrast imaging you can see them lighting up on post contrast images and that again is a a case of labyrinthine chronoma now labyrinthine chronoma again are treated conservatively so the surgical treatment is actually reserved only for people with infractable business or you have transmecular or transmodular or transortic tumor but if it is isolated the cochlear or vestibular mass it is left alone moving on to the ninth cranial now the glossopharyngeal now now glossopharyngeal now is um this kind of lower down uh it is responsible for the sensational test in the posterior one third of the tongue uh it carries the afferent sensory fibers from the middle ear and fairings also the parasympathetic fibers of the parodic gland and a motor fiber to the style of pharyngeosis muscle uh so whenever there is a policy of the glossopharyngeal now you have a typical presentation but anatomically for the radiologist we can actually see that this is a jaguar ferment that's a jaguar ridge and you can see that it divides the daguar ferment into the parse uh nervosa which is anterior and parsovascularis which is more posterior and in this cardin you can see very well that the ninth cranial now resides in the parse nervosa so the only structure of any importance which is actually in the parse nervosa which you see here is the ninth cranial now because the jaguar vein in all the other cranial now which is the tenth and eleventh are within the parsevascularis if you look at the coronal plane and you can see this eagle beak here is a hypoglossal canal underneath that but superior and lateral to it is a jaguar spine and you can see a parse nervosa sitting right on top parsevascularis is much more lateral much more expanded and on the right side on post carotid smithing you can see this internal jaguar vein and in the anterior part you can see the intrapitrozole vein you can also see the carotid vein sorry the carotid artery so if you look at that anatomically and this heavily T2 weighted image which is part of my cranial or protocol for all the different cranial nows you can see that from the lateral surface and this is in the post olivary circles and this is the medullary olive in the post olivary circles you have the ninth, tenth, eleventh cranial nows taking up and they actually ninth is a little higher than the tenth but it's kind of pretty close by so it's very difficult to separate it out from the tenth and eleventh but that complex you can see taking up from the lateral surface of the medulla and going towards the jaguar foramen on the right side I have outlined this is a jaguar bulb that's a jaguar spine here that is the carotid artery and then you can see that is the ninth cranial now passing through the jaguar foramen so if you look at again the post contra CT scan then here is a jaguar vein and this is the extra foraminal component and we can see that position relatively so this is actually the ninth which is more anterior arising from the pars nervosa so the ninth cranial now will lie actually on the enthral medial surface of the internal jaguar vein the tenth and eleventh will lie actually at the posterior part of the medial surface of the internal jaguar vein and then the twelfth of course is much anterior and that's actually seen with relation to the the carotid artery and not the internal jaguar vein um tenth cranial now is the vagus now again a very important and huge nerve and if you look at it again it's very difficult to separate it out from the ninth or tenth or eleventh so you can see the rising in the post olivary surface from the lateral surface of the medulla and then again i have the same slide to show you for the anatomic positioning but within the within the skull base it actually goes to the carotid space now so if you run in the carotid sheet it courses inferiorly between the internal jaguar vein and the carotid artery and that's why we know that whenever there is a glomus free galley it's going to cleave the regular vein and internal carotid artery so whenever there is actually in the hexacranial segment this is the the white arrow points towards the vagus now situated posterior but in between the internal carotid artery and the internal jaguar vein and that gives rise whenever there's a tumor then the artery and vein will be separated out and that is very characteristic of a vagal lesion uh in the hexacranial segment again so and then the vocal cord palsy so that happens because of the recurrent laryngeal now which is again a branch of the vagus now and on uh MRI a brain or CT scan of brain there is medialization there is thickening of the area pigletic core that is a symmetric prominence of the um periform sinus and then there is medialization of the vocal cord that's how you diagnose that and that happens separately from the right in the left now so you can see here the position of the vagus now with relation to the arch of aorta and then you can see the intravena keva going more posteriorly you can see that the right vagus now comes only up to the level of the recurrent laryngeal now basically takes off midway through so the right vagal now of course comes down but the recurrent laryngeal now actually takes off a little higher on so it takes off just at the level of the right subclavin artery that's why it is higher but on the left side again it takes off all the way at the level of the left main bronchus so this is very important in diagnosis of the vocal cord paralysis so you can see here this graphic and this is again a 66 year old male which had dissecting aneurysm it is an left vocal cord palsy now what's going on here is that the dissecting aneurysm is at this level basically and that that is why what is going on is that it is actually taking along the left it it's compressing upon the left recurrent laryngeal now and that is why the patient has ended up with the left vocal cord palsy again another case there is a vagal schwannoma in the intrahiocardic space you can see that it cleaves the intergecular vein and the carotid artery huge one going longitudinally because this is along the course of the vagus now within the carotid space and this is the surgical image and you can see how the fusiform dilation of the vagus now it's showing up there again looking at a vagal now schwannoma intracranially it's in the lower part of the cp-angle system and that continues on towards the regular from and not iac so you have to be very careful when looking at an iac mass sometimes we confuse between a vestibular schwannoma and the vagal now schwannoma but with cathode consideration you would be much better coming on to the accessory now or 11th cranial now again it's a motor now and that supplies only two muscle the sternocleidomastrum right there and the trapezius right in the back um and if you look at its course again it arises from the same place that we saw previously but it actually tiles along with the cranial of 9 and 10 and then it goes through the past vascularis of the of the jugular foramen and then it supplies actually the sternocleidomastrum and trapezius and a pathology of 11th cranial now will result into you can see that atrophy of the sternocleidomastrum on the left side and also the trapezius muscle on the left side as compared to the right side so if you want to look at a schwannoma of the accessory now then you can see that as an enhancing mass which actually is adjacent to the posterior of the liver's scapula and liver's scapula is deep to sternocleidomastrum it's right there that's the liver's scapula and you compared both the sides and you realize that that huge mass is the traunoma of the 11th cranial now and why I'm saying that is that look at the trapezius muscle on the left as compared to the trapezius on the right there is a deneration atrophy of the trapezius muscle on the right side because of this huge mass and now we can actually diagnose that on CT that this is the schwannoma of the 11th cranial now because of the location that it is located just lateral to this the liver's scapula and also because of the atrophy of the trapezius muscle and then again another case of deneration atrophy you can see how the sternocleidomastrum and the trapezius muscles show atrophy that's actually the normal size liver's scapula muscle coming to the last now just hypoglossal now the 12th cranial now very important now and that is the one which arises from the ventral surface of the brain stem so it arises from the ventral surface this is the 9, 10, 11 arising from the sides and then the nucleus is of course around the act for that and then it the fascicula course through the medulla and then emerge in the pre-olivarous of course not the post-olivarous so that's how you can differentiate them and if you look at the axial imaging you can see this is the fascicula part here are the two 12th cranial now or the hypoglossal now this is the cisternal segment and at mass of that you can see there is actually enlargement of the hypoglossal canal and you can see this lobidated mass which is kind of entrolateral so do not confuse this with a mass of the 9, 10, 11 now or Jaguar fossa because compared to the other side this is the Jaguar fossa which would be right here on the left side it would be much more posterior because on the right side you can see that's the flow void of the internal carotid artery and just next to it is the internal Jaguar vein posteriorly and then the Jaguar ferramen is little anterior so hypoglossal canal again if you look at the CT the center is clivus and just lateral to clivus you see this very well-cordicated bony canal that's the hypoglossal canal which is actually medial to the Jaguar ferramen and in the coronal plane this is the eagle beak sign and this is the Jaguar tubercle and below that is the hypoglossal canal while the Jaguar ferramen is superior and lateral to it again if you look at the hexacranial segment of the hypoglossal now and this is a post-contrast T1 coronal I'm sorry this is a pre-contrast T1 coronal and you can see the fatty atrophy fatty atrophy of the right side of the tongue and that is because of the lesion of the hypoglossal canal so there's a haemia atrophy of the tongue on the right with fatty deposition and that is because of a lesion of the hypoglossal canal on that side again you can see this a huge mass at the skull base but at the same time you can see fatty atrophy of the tongue and you can say ah this is because of the hypoglossal canal right there so we have seen basically all the six or seven all the seven segments of the cranial valves we have seen the nucleus we have seen the fasciculi we have seen the cisternal portion we have seen the dural cave of every cranial now we have seen the inter dural segment we have seen the foraminal segment and then we have seen the hexacranial segment of all the 12 cranial valves today and this is you know what I would advise that to analyze the cranial now by this different segment and whenever there is a patient with a pulse of any of the cranial now analyze everything from the nucleus to the end organ and then you'll find the lesion somewhere if you look at the cranial neuropathies they are either reversible or irreversible if they are irreversible then they're likely to be neoplastic or congenital or sometimes miscellaneous but if it is reversible then they're probably all immune there's infectious etiology there's some metabolic etiology some vascular compression is responsible or neoplasm in the adjacent tissue which will causing just causing mass effect on the cranial now then of course there are of course idiopathic variations so so analyze the cranial now based on pathology the history the anatomy the imaging techniques of course I don't need to advise you for that but as I said earlier CT is better than CT is better for skull base because you can look at the foraminal much better so if you're suspecting the foraminal location for some reason go for CT in almost all the cases you're going to have both the CT and MRI ordered by the physician and you'll get a good diagnosis but CT is very good to look at the the foraminal so in conclusion the understanding of the anatomical course and end organs of the throat region now knowledge of variable appearance of pathologies which I did not go over exquisitely we can do it some other time and the knowledge of the treatment option and the sequela will lead to accurate diagnosis treatment planning and evaluation of treatment response so that's all I have some my two boys and they are actually standing near the Wright brother memorial this is says the brother Wilbur and Orville the other two boys who are very close to each other so thank you very much I thank you for the opportunity and I hope somebody's listening because I have no way of knowing that somebody's on line or not yeah thanks a lot everybody so that was Dr. Gaurang Shah who took MRI of Kinial knows for us an excellent talk in an early exhaustive talk so I'm extremely thankful to Dr. Gaurang Shah and Dr. Bishik Mahajan sir as well for those wonderful lectures for today's brilliant so we've shared the link for the registration for the international edition online edition of the MRI teaching course in the chat box also the sonobas 2024 is to be held in January at Sahara star Mumbai we'll be sharing the link for this as well so now let's move on to our quiz which will be taken by Dr. Mitusha Verma she's a consultant radiologist in pet city CTMR at Nanavati max super speciality hospital her special interest in body imaging and radiology advances she is a co-guide for the postgraduate dnv radiology and bio-med engineering students has presented in various national international conferences received many awards including the times applaud young achiever award in health care 2022 and the leading young radiologist and at the radiology and imaging excellence awards by elix 2021 a very young dynamic radiologist we all know her very well so Mitusha over to you the last there are two there are two winners for the quiz which Mitusha will explain in detail and they'll be receiving free registration for the online conference so with this now at 40 explain we'll have a short quiz with 10 questions you have to answer them in the chat box so just put your diagnosis in the chat box the last two are the prize winning questions and the person who gives the correct answer first will get the prize and the prize is a free registration to the upcoming complete international edition of MRI teaching course which is spread over five days because of the exhaustive program which we could cure it so 28 29th October 3rd 4th and 5th of November the registration links as Gauri mentioned are there in the chat box we request you to register for the same as well because it's going to be really helpful especially for those who are practicing MRI because we are going to cover everything in MRI and specifically pertaining to advances and recent techniques we do have papers and posters options and case of the day prize winning case of the day quizzes as well as contests will be there during the course so with this now let us start with the quiz and I will get back with the details of the upcoming course in between so this is going to be the first question on your screen and you have to identify the diagnosis and put it in the chat box so you have to identify the type of kinetics curve which we also call as schools kinetics curve so just put your answers in the chat box so when we know this dynamic imaging we get these kind of curves based on the signal intensity after contrast injection and depending on whether the contrast uptake is early or late we can get three types of curve we also follow it up with what happens next whether there is a washout or not so I can see people coming up with type 2 and type 1 curve so basically we see that it is quite quick in uptake so it's a rapid initial update and followed by like a dip in the way it is enhancing so basically this is type 3 curve so why I have kept like this because just to mention like a point that they are not very ideal curve most of the time so in your practical day-to-day practice if you use these your curves you will see that when we are putting the ROIs the curves are not typically down falling which we call it as washout it will be just a small dip but when we see actual plateauing or persistent contrast enhancement there will be no downfall in the contrast enhancement kinetics once the contrast pickup is there so basically you have to see the morphologic features also but this type of curve is type 3 curve kinetics so rapid fill-in will be there followed by persistent rise that is type 1 plateauing is type 2 and washout is type 3 now the next question on your screen so 50-year-old female who presented with increasing fatigue and speech difficulty and these are the images axial t2 t1 post contrast and few more images diffusion so on and flare also we have given you spectroscopy so by the location and by seeing the characteristics on flare and so on on contrast if you can come up with a diagnosis so I can see yes so Dr. Shalini has given the correct answer specifically which is oligodendrogliomas so third most common gliomas for 2 to 5 percent of primary brain tumors and tumors are mainly seen for middle age group adults location are mostly cortical therefore they present with seizures and by definition now as we know it is all molecular biology ideas mutation either ideas 1 or 2 should be there and 1p19 q correlation that has to be there the typical appearance which we saw on gradient or swan was because of the calcium creating blooming and also the enhancement is not a very reliable tumor marker or grade marker but it would be heterogeneous enhancement diffusion restriction is a marker of high cellularity and in these tumors they will not be the significant restricted diffusion one sign which we should know and should revise as t2 flare mismatch it's a highly specific radiogenomics signature for diffuse astrocytomas which are idh mutant and 1p19 q non-core deleted as opposed to the other lower grade gliomas and this has a specificity of almost 100 percent for identifying these higher grade astrocytomas so that is one thing now coming to the next case which is on your screen this is a 60 year old female with pr bleeding and you see something which is involving the rectum and the anal canal so somebody has come up with a diagnosis of melanoma I think looking on the bright intensity on these images but if you look carefully it is still t2 weighted sequence and not even and I think Dr. Seema is correctly mentioning it as carcinoma of rectum which has mucinous component so the same patient came after surgery and in 2023 that is a gap of two years post op and she had something like this where you could see that there is obstruction into the vagina vaginal tract and therefore there is upstream all distention in the vaginal cavity so this is a ca rectum with mucinous component and this is the recurrence of the same with same signal intensity so these are the tumors which are quite aggressive they are bright on t2 weighted images and they may create even after short interval recurrence is a known phenomena here there is a recurrent mass lesion causing all obstructive features in the vaginal cavity so mucinous adenocarcinoma of the rectum with vaginal metastasis now coming to the next case on your screen this is something from prostate if you can identify and put it some pirates category to this lesion so cases are little basic types it's for discussion it's just for revision and for fun activity because last two cases we'll have prices as well so pirates 3 4 5 I can see in the chat box so this is something which is involving the inner zone of the prostate gland hypo intense on t2 with restricted diffusion and some enhancement so based on the size of this lesion which is more than 1.5 centimeters I have not given the size but roughly so this is definitely neoplastic so if you are not taking size consideration pirates 4 is also correct pirates 5 is also correct so basically we understand that the neoplastic process in the prostate is commonly seen in the peripheral zone rather than the inner zone but if it is there in the inner zone what are the characteristics we should which we should look for and which we should utilize to characterize them into pirates 4 and 5 categories so one of the most important marker is non circumscribed this term which we should take care of so it has to be a t2 hypo intensity which is non circumscribed so the margins of this lesion or this area are going to be very fuzzy they are going to be blurry so it's like an erase charcoal that also is a term which has been utilized so for transition zone the first sequence which we look is t2 on t2 weighted images we are looking for hypo intensity like in this example we had a hypo intense area but there are few other hypo intense areas as well these have a little bit of a circumscription to their margins but this one is relatively ill defined with some kind of non circumscribed margins and then we go for straight away they ask us to go for diffusion and post contrast dynamic evaluation with early post contrast enhancement and restricted diffusion we can put it as pirates 4 or 5 categories based on the size of lesion so that was about this case and now let's come on to the fifth quiz case which is this one from breast and we have one usc picture mr pictures something which is quite well defined but at the same time quite vascular any diagnosis to this case which you think of most of you think that it is phyloids it was quite a vascular the shape if you see it looks like more like something oval like how we see the usual fibroid enomas and this is not phyloids but bash which is pseudo angiometer stromal hyperplasia it's a benign and relatively uncommon mesenchymal overdose so even the patient might not feel it for a while because these are soft lesions and they are going to be highly vascular these are diagnoses of exclusion but definitely the MRI feature of being highly vascular helps in the diagnosis now coming to the sixth case on your screen here it is 57 year old gentleman with progressive bilateral facial nerve policies over past few months so what we are seeing here is that there is definite enhancement along the nerve roots multiple nerve root so on the right the trigeminal nerve root is enhancing on the left here the seventh in nerve complex is enhancing so premium love thickening premium love enhancement in a 57 year old gentleman what do you think it can be if any differentials you could put to it so one is sarcoid other one yeah dr. Seema mentions perineural spread what else can that be so I have few other now CIDP is also one of the differentials for multiple cranial nerve enhancement we have few more images now I think most of you will get the correct diagnosis so this was the same patient who came after few months now with this lesion now what do you think multiple cranial nerves and then a focal lesion yeah so here I think dr. Pragya Ghosh has answered lymphoma so this is the case so lymphoma is one of the differentials for multiple cranial nerves enhancement and thickening at the same time we have seen almost five to seven cases by now over a period of two to three years and also we have published one case series like that now this focal lesion had a good spectrum also which resemble what we are expecting for lymphoma with a choline peak and a lipid lactate peak so twin peak sign of lymphoma lymphomas are tumors which are by incidence relatively uncommon by but in your practice I'm sure if you're getting brain tumors and focal lesions we see them often these are highly cellular masses and primary as well as secondary CNS lymphomas are known primary lymphomas they may be solitary or they may be multiple by location they are pericalosal that location is very common they are usually solid therefore they are known to have homogeneous enhancement but if the patient is immunocompromised or if somebody has given steroid thinking that this is demyelination or something the tumor morphology might change and you may get central areas of non enhancement therefore even the surgeons they try to avoid or even the physicians they will try to avoid giving steroid to these patients if lymphoma is one of the differentials because not only in radiology but even the histopath images and the characteristic change when the patient has received steroid in cases of lymphoma and therefore the patient might get a delayed diagnosis because of this steroid many injections in between or steroid injections so this is the case which we had the case series which we had published multiple cranial nerves involvement as a presentation of primary CNS lymphoma so now coming to the seventh case and this is the case on your screen set of images MRI and something going around the kidneys so if you see carefully on the signal characteristics you can get into the diagnosis also both the kidneys are having similar kind of changes by any differential to this case yes so one we got is liposarcoma adiposeema with perirenal lipomatosis so definitely the correct part of it is there is fat component along the perinephric area perinephric fat is abnormal and geomyolipoma is one of the differentials so here this is bilateral liposarcoma perirenal liposarcoma so dirty fat heterogeneous appearance it's not only lipomatosis but there is something else going on and this is perinephric liposarcoma so they are again rare tumors but they are known and also they may be bilateral so in this case the kidney was the one of the kidneys right kidney was ectopically impelvis but still it had that liposarcoma with it and a smaller area of similar signal intensity along the left kidney now coming to the case number eight and just to remind you case number nine case number ten be quick to answer the correct answers as they are the price winning questions case number eight on your screen easy diagnosis kind of a spotter only so what do you think this is dermoid but all of these are T2 weighted sequences I don't think we can see fat confidently here see the appearance and I know all of you who are tuned in they know the answers if you just see the kind of morphology what is the descriptive term which you are going to use for it something like small small cystic areas bunch of we call it bunch of grapes I'm giving you hints also so a lot of differentials coming in so this is that typical bunch of grape appearance which we see with the hydratiform mule or gestational trophoblastic disease that appearance and this was within the uterine cavity okay so now I move to the case number nine which is the price winning case and I know all of you are very good because I'm seeing the correct answers for the last eight cases so I hope that you get the correct answers to these two and be quick in putting in the chat box so case number nine here on the screen what do you think just you can give try to give the complete diagnosis in one sentence or if you want to put it in few words that's also fine so again set of MRI images and I think Dr. Shalini came up with liposarcoma of uterus so post-contrast images specifically ADC has been given and this organ which we are pertaining to is uterus yes that's correct anything else neomyosarcoma Dr. Harsha okay I think we can give it to Dr. Harsha as she answered it first but Dr. M. Chandramolli is also correct with fibroids and sarcoma Gauri we can just consider Dr. Harsha K as the winner for this one and this is uterus which is bulky and has multiple fibroids but one of them is showing sarcoma as features in the form of large area of necrosis and districted diffusion so multiple fibroids and with one leomyosarcoma and Dr. Harsha I would request if you could please share your email id in the chat box now the last question for today and again this is a prize winning question easy one so just relax and answer it quickly yeah here on your screen so what do you think this is so MRI images from Pelvis and we have seen something abnormal in the prostate gland what do you think this is just come up with the differentials and same person can attempt it multiple times so that's not an issue so what do you think this large nodule which is there it is arising from where in our zone where it is and what it is exactly so I think we have got the answer then this time we can give it to Dr. M. Chandramolli for exophytic hyperplasia so this is a benign prosthetic nodule only but this is exophytic nodule which has kind of come up and is around the peripheral zone now it has all the features with no restricted diffusion well circumscribed margins not T2 hypo intense to a greater extent correctly mentioned ectopic or exophytic BPS nodule so thank you all for being there with us today for this prelude session and it was really nice to see all of you participating in the quiz congratulations to Dr. Harsha and Dr. M. Chandramolli Dr. Harsha has already shared the email ID and I request Dr. Chandramolli also to please share the email IDs and phone numbers and both of you get free registration to the upcoming MRI teaching course international edition five day conference we have two more prelude sessions on one is on 17th one is on 22nd October we are going to share the links the links are the same actually but again we'll post on various social media platforms and again we'll have quiz sessions at the end of these two day prelude as well and prizes to be won please do participate in prelude they are just registration is compulsory but it is not charged and we have speakers like Dr. Manjiri D. G. Dr. Alok Jaju Dr. Raj Keenal they'll be talking about MRI and renal masses MRI and pediatric brain tumors and MRI and evaluation of glacial pathologies do register for the complete course which is five day thing 28 29th October 3rd 4th 5th November already shared the links in the chat box for registration or else you can also visit Indian radiologist webpage and you get links for all these courses coming up so all these are going to be great speakers with huge amount of experience and they have agreed to be a part of this course most of them are going to be live or even if they are sharing recorded session your two differences in time zone they are going to be live for Q&A sessions we have Dr. Scott Flam which who is going to take a lot about cardiac MRIs at least three to four topics he's going to cover Dr. Manohar Sharoff sir and then we have all these speakers from Mayo Clinic team who are going to take us through all advances in MRI one day will be completely from Mayo Clinic one day we have complete program under Dr. Dushan Sahani sir and that will be from University of Washington so it's going to be a good experience for all of us please do participate and register upcoming prelude sessions on 17th and 22nd of October also please do join us for the same congratulations Dr. Harsha and Dr. Chandramolli and also this is about Sonobhas 2024 registrations are on and you can visit Indian radiologist webpage and register for the same this is going to be on site it's already a popular event and this is going to be in Mumbai January other dates are 5th to 7th Jan and registrations are on thank you all and with this I think we can end today's prelude session