 MR imaging in endometriosis. It itself is a quite a detailed topic and this is now one of the most upcoming indications for MRI because lot of surgical options are there for treating endometriosis and there are recurring endometriotic spectrum also now patients are having recurrent endometriosis, recurrent adhesions and accordingly they have to plan surgery. So if you see the spectrum it can have in multiple compartment wise you can divide the pelvis and also the abdomen and pick up these endometriotic deposits. So to begin with it can be uterus and ovaries themselves then it will be the deep pelvic endometriosis and the superficial pelvic endometriosis. So we will see them. Symptomatically you will definitely have the patient presenting with symptoms it is very unlikely that a symptomatic health checkup patient will present to you with an endometriotic spectrum of findings. Deep pelvic endometriosis can have chronic pelvic pain and why is it important to know this because sometime the symptoms may be unrelated to the menstrual cycle as well. So painful constipation, catamenial diarrhea, rectal bleeding, something like pneumothorax and epistaxis have also been described. But whatever the symptoms are they will be cyclical. So if you just ask your patient about these symptoms are they cyclical you will see that there is a correlation. Why is constipation and all important because the retroverted uterus is also ancillary finding in the endometriosis spectrum. So just by the shape of uterus and just because it is close to the rectal wall you may be missing macroscopic deposits, deep pelvic deposits but just because of those proximity the patient might have this kind of painful constipation. So the sites are intra-pelvic ovaries, uterosecral ligament, cirrhosis surface, fallopian tubes, recto-sigmatic colon, vagina, cervix, bladder and ureter so that is the intra-pelvic compartment and extra pelvic virtually any anatomic location. So people have presented and they have also given like publications are there for intra-spinal, intra-cranial endometriotic deposits so that is also there. So any site is possible but very very rare. But ideally at least abdomen you should do few sequences to just document there are no other deposits elsewhere apart from the pelvis. So abdominal wall, surgical scar sites, diaphragm so sub-diaphragmatic deposits are common, liver, kidney, pancreas, bones and brain and then coming to the spectrum. So now after all the modified criterias now they have come up with the nzian criterias for endometriosis. Again like the ACRORADS nzian is also available online and you can go through the stepwise approach to the endometriosis. It's like a combination of MRI and laparoscopic findings. So again we have to take out our part out of it and use it for our reporting templates. So superficial endometriosis is deposits which are very small and identifiable only at laparoscopy. They are located on the peritoneal surface of very close less than 5 millimeters from it. So you cannot see them on MRI. Endometriomas are those cystic structures with hemorrhagic content. So that is the endometriotic cyst and deep endometriosis they are the implants which are located at least 5 millimeters away from the peritoneal surface and they may invade the retroperitoneal space as well as the adjoining pelvic organs. So these two we have to identify and comment upon. So role of imaging will be to know the extent of the disease to describe where all endometriotic implants are present and also talk about additions as a complication of this spectrum. So two modalities which will be helpful are ultrasound and MR. Ultrasound will identify these but again sensitivity of MR will be much higher. To begin with the patient will have ultrasound done and also it will have the advantage of being dynamic. So all of us who do ultrasound also know that there is loss of sliding sign and while doing transfer general also we can elicit it and then we say that there are chances of additions between the ovaries and the uterus. So not going into the ultrasound appearance but now to the MR. So MRI the sensitivity and specificity ranges from 69 to 92 and 98. So very high sensitivity and specificity for these endometriotic deposits and this is the protocol which we are using for endometriosis. So we call it the endometriosis protocol and now also the referring physician they are writing endometriosis protocol. So somewhere they are coming across it during the conferences and they want a specific protocol for it. So you start with your antiparystallitic agent like Buscopan, MTE bladder or partially distended. MTE is good enough because MRI will anyways take 30 minutes and you will get some partial filling of the bladder. Starting with the sagittal T2 weighted sequence it will be very important and the axial and coronal T2, axial T1 non-fat set and axial T1 fat set because we are looking for blood products the main stage sequence will be T1 fat set because it will look bright. Then high resolution sagittal 3D T1 fat set. So that is another important thing which we do I will show you that sequence and that is for surface deposit. So on GE we call it Lava. So T1 fat suppress sequence in 3D which is taken in sagittal plane. Diffusion has a limited role in endometriosis per se you can just perform it and again contrast has also a limited role in it. Screening abdomen as we said to know the extent. So your typical appearance all of us know T1 bright because they are blood products and also bright on T1 fat set. So that is our typical description hyper on T1 and not getting suppressed on T1 fat set suggestive of blood products. T2 positive shading. This is important because these are blood products in different stages of degradation. Every cycle it is bleeding. So inside the blood products are at different stages and of different density. So they are kind of layering inside and giving this positive shading sign. So it is like a level which you see a gradual level on T2 weighted sequence which is called as a positive shading sign and that helps you to differentiate endometriotic cyst from a hemorrhage exist. Hemorrhage exist will not have a shading sign because it is just a one time hemorrhage within it. It will have just like a network or a mesh like appearance because those are like resolution of the hematoma and hemorrhage but this shading sign is typical for endometriotic cyst and we have seen it even for smaller cyst. It is not that only large cyst will show it. Even one centimetre sized cyst also show this shading sign. Then T2 dark spot sign. This is a sign of chronic hemorrhage. A very dark T2 bright spot eccentrically placed and diffusion and contrast they do not have much role. So this is another example of shading. You can see that there is a shaded appearance and a gradual fluid fluid levels as you can see on T2. This is the dark spot sign which is non enhancing dark spot we saw in ORADS. They were not giving any ORADS higher value to these dark areas. Absolutely T2 dark non enhancing. So that is seen with endometriotic cyst. So comparison endometriotic cyst, hemorrhage exist. Endometriotic cyst have smooth shading sign positive T1 bright. Hemorrhage exist have these mesh like appearance. They will not have shading and even if you may have doubt till end then you can just follow up. So hemorrhage exist should resolve and endometriotic cyst will not show that kind of resolution. So ultrasound is good enough to follow up. Again T1 also hemorrhage exist sometime may be hypo intense. It is not that it has blood and it will be hyper intense. So because it is slowly slowly the methymoglobin part is going down so it can come back to its normal T1 hypo intensity but endometriotic cyst will always be T1 bright. So that was about how they appear the typical endometriotic cyst and endometriomas. This is the high resolution 3D T1 sequence which we were talking about that is fat suppressed and the smaller surface deposits can be picked up easily on this sequence. So if you say two best sequence then it will be T2 that is sagittal T2 which you have taken and sagittal T1 fat suppressed sequence. So smaller endometriotic deposits on the surface which have caused additions and they can cause a problem during the surgery as symptoms also. So here you can see this is a hypo intense area in the torus uterinus which is the junction of the uterine body and the cervix. So that is the most common side where you get this deep pelvic endometriotic deposit. So when you are reporting these cases see the sagittal carefully and see if this area you can find out something which is ill-defined having some kind of speculations or if the rectum is quite flushed with the loss of fat plane between. So that is suggestive of some kind of deep pelvic deposit. So a lot of examples you will see if you even retrospective go and see your cases it may also go anteriorly invading the urinary bladder which is relatively uncommon but known. So again T1 fat set will show these kind of deposits on anterior wall of the urinary bladder then scar endometriosis. So scar endometriosis is very easy to find out if you take the patient's history. They will themselves give you the site of scar endometriosis because they have pain at that site. So if you put a vitamin E marker underline the marker only you will find this scar endometriosis. So during some previous surgery the path which was followed mostly the anterior abdominal wall get this kind of deposit which are typically hypo intense on T2 T1 may have those tiny hyper intensities like adenomyosis and speculations and cyclical pain will be a typical sign which your patient will point towards. Adenomyosis is also a part of the endometriosis spectrum. The mechanism here is different. So here the difference is that in adenomyosis these implants are travelling from the submucosal aspect to the sub-serusal aspect how they have described the pathophysiology. Whereas in endometriosis deep pelvic endometriosis what we call as the surface deposit the implants are starting from the surface and getting inside. So both of the phenomena are independent of each other. It's not that these adenomyosis will in future go out of the serosa and form the serosal deposits. So you can have serosal deposit even in a normal uterus because it's a separate pathophysiology. So that is why we should know that adenomyosis is from submucosal aspect outwards and these serosal deposits are from serosa inwards. So two separate independent entities. A typical appearance of what you call as a frozen pelvis it's a kind of little lamentum but here you can see that the ovaries are flushed with the uterine margins and that is suggestive of underlying additions and combination of smaller endometriotic deposits. So this is important to be put in your reports as well because during the planning of their surgeries they want to know this. So just one slide about this classification. This is the new thing which now 2021 Enzian classification has come up for comprehensive non-invasive and surgical description for endometriosis. So now there are Gainax who are working with this classification so they want us report like that only. Now again it has systematically divided the deposits into these compartments peritoneal, ovarian, tubal and the pelvic endometriosis. Everything has been described like the distance, how much is the spacing, the site whether it is as a torus, uterinus or not and then accordingly the bulk of the disease has been described. So now we can use because a part of it is laparoscopic also so that why we have to remove and use it as MRI purposes to give us the complete picture of pelvic endometriosis. So with this I would like to conclude this short session. So endometriosis is one of the most important indication nowadays for pelvic MRI and you should try and follow this kind of a reporting protocol. Thank you for your listening.