 Dr. Astha Garba, I'll be presenting my paper on the evaluation of MRCP in biliary obstruction with ERCP and histopathological correlation. I'll be doing it under the guidance of Dr. Varsha Ma'am, who's a professor of radiology and Dr. Krishnath Eja, assistant professor of radiology. The aims and objectives include to evaluate the efficacy of MRCP as a diagnostic tool as compared to ERCP in diagnosing extra-hypatic biliary abnormalities like colodicolithiasis structures and malignancies, to evaluate the efficacy of MRCP in diagnosing ancillary findings like gallstone disease, biliary ductal lalitation and abnormalities of the pancreatic duct, and to correlate the findings with histopath if available. Obstructive jaundice is caused by biliary obstruction, which is due to blockage in any of the ducts that carry bile from liver to gallbladder and then to the small intestine. The causes of obstructive jaundice can be divided into intra-hypatic and extra-hypatic. Intra-hypatic, the most common causes are hepatitis, cirrhosis and HCC. Extra-hypatic can again be divided into intraductal and extraductal. Intraductal includes neoplasm, colidopolithiasis, biliary strictures, and primedysclerosine colongitis. Extraductal include neoplasms, pancreatitis, and cystic ductstones, which is also known as mirage syndrome. So the commonest cause of obstructive jaundice is stones. Obstruction of the biliary tract is a common clinical problem which requires accurate localization and discrimination of the pathology. In the evaluation of a suspected biliary obstruction, the initial choice of investigation remains as trans-abdominal ultrasound due to its ready availability, non-invasiveness and inexpensiveness. The excellent clue in finding biliary obstruction in ultrasound has been ductile dilatation. However, USG cannot identify the cause and level of the obstruction accurately. It is operated-dependent procedure and there might be suboptimal imaging of the retroperitoneal structures due to the overlying bobble gases. Now Magnetic Resonance Colangia Pancreatography, MRCP, was initially introduced in the year 1991 and has been improved since then, to the point where it is considered at part with endoscopic retrograde colangia pancreatography, which is ERCP. It can help not only to identify the obstruction, but also demonstrate the nature of the pathology. So MRCP refers to the selective fluid-sensitive magnetic resonance imaging of pancreatic and biliary ducts. Also, when conventional T1 and T2 weighted sequences are combined together, the detection of the extra ductile diseases by MRCP is possible. So if we compare MRCP and ERCP, however ERCP is considered as the gold standard, it is still an invasive procedure. It requires endoscopic cannulation, sedation and the use of ionizing radiation. It is filled with complications such as haemorrhage, sepsis, pancreatitis, bilek and mortality. Whereas MRCP is non-invasive, radiation-free, non-operative-dependent, multi-planar imaging modality. So in our prospective study, we wish to determine the diagnostic efficacy of MRCP considering ERCP as a gold standard and whether MRCP can replace ERCP for diagnosis, while ERCP can solely be reserved for therapeutic applications. So materials and methods, a prospective study of 50 consecutive patients with biliary obstruction referred for MRCP with subsequent assessment by ERCP and histopathology were included. The study was conducted at MR and ERCP units in our tertiary care center. MRCP scanner used was 1.5T scanner using an in-house 16-channel body coil. Pre-procedure preparation included 6R duration of fasting, which helps in promoting the filling of gallbladder, usually takes about 20 minutes to complete the full examination. The sequences which were taken were localizer in three planes, AXL T1 in phase, Trufi, AXL T2 haze, Fatsat, Coronal T2 haze, Fatsat, Thick slab haze, and 3D volume respirator triggered MRCP, which was taken in two planes, Coronal section in plane with CBD and AXL section in plane with pancreatic duct. MRCP was performed prior to ERCP, which was then performed by a well-trained and experienced endoscopist. Colangiographs were obtained and compared with the MRCP findings. Considering ERCP as whole standard, the sensitivity, specificity, positive and negative predictive values MRCP was evaluated, if available, correlation with the histopathology was also made. So coming to the results, this is the pie chart which shows the percentage of the population according to the age group and the highest patients were noted in the age group of 46 to 55 years of age. In sex distribution, we found that females were more predominantly the patients with the biliary obstruction. This histogram shows the number of patients in which the pathologies were detected in the in our study population. So the commonest pathologies were bile ductalitation, polydocolithiasis, which was 56%, strictures and malignancies. Here we are showing the sensitivity and specificity of both MRCP and ERCP where this histogram shows the comparison between them. So we found that the sensitivity of MRCP was 87.5% for polydocolithiasis, it was 100% for CBD malignancy and IHPR strictures, 84.6% for CBD strictures and it was 100% for biliary ductalitation. Coming to the specificity, we found that MRCP was 100% specific for polydocolithiasis, IHPR strictures and CBD malignancies. However, it was 92% specific in detecting CBD strictures and 98% in detecting polylithiasis. So the aim of our study was to assess the diagnostic efficacy of MRCP as a diagnostic imaging modality compared to invasive ERCP in the diagnosis of bile duct abnormalities using specificities, sensitivity and positive and negative predictive values. If our results favor MRCP, then diagnostic ERCP could be completely avoided and MRCP can be used as investigation of choice for diagnosing biliary abnormalities, while ERCP is reserved only for therapeutic purpose solely. So in case of CBD strictures, CBD stones and amplary stones, MRCP was comparable to ERCP. The study conducted by Nairi Griffin at all reported sensitivity of 91 to 100% in detecting CBD strictures, whereas the sensitivity attained in our study was slightly lower, which was 84%. However, it was comparable to other studies and it falls within the overall sensitivity range of studies carried out worldwide. For Amplary Tumor sensitivity of MRCP and ERCP was equivalent, which may be fallacious considering the small sample size. It was higher than the study conducted by Parmos at all, where the sensitivity and specificity was 183% respectively. Therefore, they recommended that ERCP in detecting Amplary Casinoma, whereas our study is more in the favor of MRCP. Additionally, MRCP was found to have to be better in delineating the extent of the tumor and extra hip, extra biliary extension. ERCP may just show the level of the block, however, the proximal extent and the involvement of the adjacent structures could not be evaluated. Note for that MRCP has high diagnostic accuracy and is equivalent to ERCP in diagnostic abnormalities like IHBS strictures and CBD tumors. For the lower biliary tract abnormalities like Amplary Strictures and pancreatic ductile abnormalities, MRCP was found to have lower sensitivity. Ancillary findings like intrapartic biliary radical dilatation and gallstone diseases are well demonstrated on MRCP. So, we concluded that MRCP is the method of choice for diagnostic imaging of biliary tree and ERCP reserve for therapeutic intervention in the setting. As common pathologies such as stones, strictures, malignancies in upper biliary tract can be easily identified with high specificity on MRCP. In cases where a histopathology were available, that is in case of tumors, MRCP showed high specificity as well as sensitivity. The results we obtained in our study were comparable to pioneer studies conducted worldwide. Coming to the images, this is an anatomy, an image showing the normal anatomy of the biliary tree in which we can see the intrapartic biliary radicals forming right and left hepatic duct which joined together to form the common hepatic duct. This common hepatic duct is joined by the cystic duct to form the common bile duct. We can see that this thin line is the main pancreatic duct which joins with CBD and they both open into the second part of the deodorant. Here is the image showing ERCP of the same anatomy where we can see that these are the intrapartic biliary radicals. Common hepatic duct, this is cystic duct and then our CBD is formed and this thin line is the pancreatic duct. So coming to the pathologies, these are coronal images of MRCP in which we can see that there are filling defects within the common bile duct which are these CBD stones and here these are confirmed on the ERCP. Again, here they are shown as filling defects within the CBD. Here we can see that there is a CBD stricter which is seen as narrowing of the duct. Here also we can see that the CBD is narrowed and which is a CBD stricter. Here we can see that there is moderate dilation of the intrapartic biliary radicals and there is abrupt cut-off of the biliary channels at the site of formation of the common hepatic duct. So these are MRCP and ERCP images showing features of a CBD tumor. Here we can see that there is upstream dilation of the CBD and this is being caused due to amplinary mass lesion because of which there is proximal dilation of the whole biliary treatment. One limitation which of our study was that we had a small study of population owing to the difficulty in collecting patients who underwent both ERCP and MRCP as most of the patients after ultrasound are directly subjected to ERCP. These are the references which I have used for my paper.