 Hello, this is Dr. Bansi Sawzani and my topic is diagnostic efficacy of MRI in cerebellum pontine-angle lesion. Now, what is a CP angle? It is a system of subarachnoid space which containing cranial nerves and vessels within the CSF. CP angle is bounded anteriorly by the bones, posterior by the anterior aspect of the cerebellum and the pitrus temporal bone covered by the deuterometer. It is centered by internal auditory canal, extended cordially from the 5th cranial nerve to the 9th, 10th and 11th cranial nerve complexes. Three most common lesions of CP angles are swanoma, meningioma and epidermoid cyst, in which the swanoma is accounted for 70 to 80 percent. Most common tumor of CP angle. The tumor of CP angle may be arising from the various anatomical structures, primarily originating from the internal auditory mediators, counter-ceribular system, lateral recesses of fourth ventricle, brain stem, cerebellum nervous tissue and the clinical symptoms of all the CP angle tumors are mainly headache, vomiting, what I call. So we cannot differentiate the pathology or extent of CP angle by this. So we need some neurological imaging modality to assess the extent and the type of lesion allowed for the proper treatment. MRI is considered as a superior in differentiating the different types of CP and masses. So the typical characteristic features, more specific features like ice cream cone obedience in case of swanoma, adjacent hyprostasis, dural dales and in case of meningioma, enlargement of internal auditory canal, this helps in limiting the differentiation. Recent reports of MRI in normal anatomy of lesions of the CP angle and internal auditory canal is most important. Why MRI? Because of absence of beam hardening artifact, multi-planar imaging capability and greater intrinsic soft tissue contrast have a significant advantages of MRI in compared to the city. The aim of my study is to evaluate the current role of MRI in the diagnosis of CP angle lesions as is the effectiveness and accuracy of the MRI in case of CP angle lesions and evaluate the role of MRI and the contrast enhance MRI as imaging modality in the diagnosis of CP angle lesions. In my study, I carried out 25 patients into period of one and a half year. I include the patients who are willing to participate in the study with the CP angle lesion detected on contrast MRI in all age group. Patients who are not willing to participate are excluded from the study with having a history of claustrophobia and the contraindications to MRI. MRI performed with the 1.5 Tesla MR Phillips Achiva using a dedicated head coil. Study is carried out with the patient in lying down supine position. We use a D1-P2 sequences, flare sequences, post-contrast images, diffusion weighted and FFP. Contrast imaging is performed by using a getyrinium DTPA contrast agent. Now the distribution of patients according to the age. So most common age group involved is 45 to 55 year of age. Young adults like 15 to 35 years of age are less commonly involved. Distribution of patient according to sex. The female are most predominant than the male. Distribution according to the clinical symptoms out of 25, 16 patients shows a headache. So headache is the most common clinical symptoms followed by vomiting. Distribution of patient according to the type of lesion. As I say, the swanoma is the most common type of lesion of safety angle. So out of 25, 11 patients shows a swanoma. While adiconoid cyst and peregrinoma is very less common. In my study, the commonest lesion found is a swanoma in 44% cases. Most common age group involved is 45 to 55 years with women predominance. Most common symptom is headache followed by vomiting. The first pathology is meningioma. Meningioma is the benign lesion arising from the meningis. So it is on the flared image. As you can see in A image, there is a well-defined broad-based hyperinduced lesion in left Cp angle. On B image, you can see it obliterate the course of 7th and 8th node. On post contrast image, there is a homogeneous post contrast enhancement and butyl tail sign, which is a pathognomy for meningioma. Adiconoid cyst. Adiconoid cyst is the benign cystic lesion present in the sub-adiconoid space, which contain a CSF. So it follows a CSF signaling all the sequences. So on T1, it is the hyperintense. T2 is hyperintense. On flare, there is a suppress completely on the flare images and there is a no diffusion restriction. Epidermoid cyst. It is a very rare congenital cystic lesion. It shows a CSF intensity in both T1 and T2, which flare image shows a heterogeneously hyper-intense lesion with no post contrast enhancement and there is a diffusion restriction. This point is very helpful to differentiating between the adiconoid cyst and epidermoid cyst. There is a diffusion restriction is seen in epidermoid cyst. Now, swanoma is the most common lesion of Cp angle and it is a nerve-sit tumor which is arising from the cranial dose. So on T1 images, as you can see in A image, there is a hypo-intense lesion. On T2 and flare, there is a heterogeneously hyper-intense lesion with post contrast heterogeneous enhancement and it is extending to the internal auditory canal which gives it a ice cream cone appeal. This is a pathogromic feature for the swanoma. Now, glomus jubilare or para gengioma, it is mainly seen in the jubilar fossa. So it shows a heterogeneously hypo-intense on T2, heterogeneously hyper-intense on T1, heterogeneously hyper-intense on T2 and on GRE, there is an area of blooming of micro-hemorrhages and post-contrast intensive enhancement. Salt and pepper appearance is the pathogromic for the para gengioma. So these are the characteristic and suggestive features of Cp angle lesions to differentiate the various types of Cp angle lesions. Like in swanoma, there is an ice cream cone appearance. In meningoma, there is a dual date sign. We can differentiate epidermal cysts and adecanoids by the diffusion-rated images as diffusion restriction in epidermal. And there is no diffusion restriction in adecanoid. And para gengioma, there is a salt and pepper appearance, which is a pathogromic feature for the para gengioma. There is an heterogeneously hypo-intense on T1 and heterogeneously hyper-intense. It gives a salt and pepper appearance. So the MRI is very useful method to improve the sensitivity of Cp angle lesion detection. And it is very cold standard method to differentiating the lesion by its site of origin, its shape, its signal intensity, behavior after the injection of contrast media. So in some cases, a complementary MRI technique like diffusion. As I say that epidermoid and adecanoid differentiate it only by diffusion-rated images. So diffusion-rated images is complementary useful in some lesions. MRI has excellent diagnostic accuracy and sensitivity in specificity in Cp angle lesion diagnosis. And also extent and surround of adjacent structures for the pre-operative planning. So MRI is the best. Contrast MRI is the modality of choice in case of Cp angle tumors and differentiating the Cp angle tumors. Thank you so much. And special thanks to my co-author. Thank you so much.