Diagnostic Accuracy of Magnetic Resonance Cholangiopancreatography (MRCP) In-Patients Undergoing Endoscopic Retrograde Cholangiopancreatography (ERCP) for Pancreaticobiliary Disorders

This is a prospective study done to compare the diagnostic accuracy of Magnetic Resonance Cholangiopancreatography (MRCP) in patients undergoing Endoscopic Retrograde Cholangiopancreatography (ERCP) for pancreaticobiliary disorders.Majority of the study participants were males (63.3%), while the rest 36.78% of them were females and periampullary carcinoma (11.7%) and common bile duct calculus (11.7%) are the common cause of obstruction found on MRCP followed by malignant stricture (10%). The extent of obstruction was determined in most of the study participants (91.7%) by MRCP while the rest 8.3% were not determined by MRCP. The Common bile duct calculus (11.7%) is the common cause of obstruction on ERCP followed by malignant stricture (10%) and Periampullary carcinoma (10%) and 20% of the patients were found to be normal in ERCP. Among them, 71.4 % did not show MRCP and the association was found to be significant. (p- Value < 0.00).


INTRODUCTION
Northern India has one of the highest reported incidences of gallbladder cancer (GBC) in the World [1]. Magnetic resonance cholangiopancreatography (MRCP) is an abdominal MR imaging method that allows noninvasive visualization of the pancreatobiliary tree and requires no contrast administration [2,3]. The specific reason behind this is MRCP results are more sensitive and specific than ERCP in the setting of common bile duct stones. Also MRCP is entirely non-invasive and avoids the risks of ERCP and thus MRCP has emerged as a diagnostic alternative to ERCP for the detection and exclusion of common bile duct stones [4]. Comparing the diagnostic accuracy of Magnetic Resonance Cholangiopancreatography (MRCP) in-patients undergoing Endoscopic Retrograde Cholangiopancreatography (ERCP) for pancreatic biliary disorders.
The major limitation of MRCP is that it is not a therapeutic procedure. In contrast, ERCP provides diagnostic information as well acts as a therapeutic tool in the same setting. Like ERCP, MRCP is operator dependent. This study aristo compare the diagnostic accuracy of Magnetic Resonance Cholangiopancreatography (MRCP) in-patients undergoing Endoscopic Retrograde Cholangiopancreatography (ERCP) for pancreatic biliary disorders.

Study Setting
The study was conducted in the Department of Radio Diagnosis and Imaging and collaboration with Department of Gastroenterology, Sree Balaji Medical College and Hospital, Chennai. Study Population: This study was done among patients referred to Department of Radiodiagnosis from evaluation of pain abdomen/ Jaundice/ fever.  (right upper quadrant pain), fever, vomiting, cachexic patient, yellow coloured urine (dark urine), pale coloured stools, pruritus, abnormal liver profile who are suitable to undergo ERCP as a gold standard investigation, would be included in this study. Such patients would normally be required to undergo MRCP as a pre ERCP. Work up. The study is to compare the results of both procedures and to determine the diagnostic accuracy of MRCP. 60 patients presented with the above symptoms undergone MRCP (3 TESLA MRI) and the same patients were exposed to ERCP by Gastroenterologist and their results were compared. The results were compared based on Pearson Chi Square method.
Results: Higher proportion of male (34.2%) and females (27.3%) were found in the age group above 60 years. The association was not found to be significant. (p-value-0.908). Among the study participants, pain abdomen is the common compliant among male (44.7%) and female (45.5%). The association was not found to be significant. (pvalue-0.744). Peri ampullary carcinoma (13.2%) in males and GBC+ CC and primary sclerosing cholangitis (13.6%) in females were the common ERCP findings. The association was not found to be significant. (pvalue-0.867) Among the study participants, the extent of obstruction was determined in 95.5% of females and 89.5% of males. The association was not found to be significant (pvalue-0.419).
There is 88.3% agreement between MRCP findings and per-operative findings i.e. 88% of the findings in MRCP is same as in per-operative findings and there is 11.7% disagreement between MRCP and per-operative findings. There is 78% agreement between ERCP findings and per-operative findings i.e. 78% of the findings in ERCP is same as in peroperative findings and there is 21.7% disagreement between ERCP and per-operative findings. Among the study participants, 96% findings of females and 85% of findings of males agree with that of per operative findings. The association was not found to be significant (pvalue-0.191).

DISCUSSION
Majority of the study participants were males (63.3%), while the rest 36.78% of them were females. Similar results were seen in a study done by A Mahaboobkhan et al. where among the study participants majority [5] were male and rest were female [6]. In contrast to these studies in a study done by J. Kats et al majority were female patients (127 out of 200). Dwerryhouse et alregarded the clinical findings of jaundice, cholangitis, and acute gallstone pancreatitis as high-risk factors, and patients with these symptoms underwent ERCP without undergoing MRCP likewise in our study pain abdomen (45%) was the common complaint among the study participants followed by jaundice (36.7%) and Fever with pain abdomen (18.3%). In their study J. Kats et al. [7] described that the indications for MRCP are bile duct lesions, primary sclerosing cholangitis, common bile duct cysts, congenital bile duct atresia and pancreatic duct evaluation in chronic pancreatitis.
In the present study periampullary carcinoma (11.7%) and common bile duct calculus (11.7%) are the common cause of obstruction found on MRCP. In their study, H E Adamek et al observed that majority (38%) [8] of the patients undergoing MRCP were having malignant stricture followed by benign stricture and normal pancreatobiliary system. Cholangiocarcinoma and Choledochal cyst were rare findings.
In our study, we observed that the extent of obstruction was determined in most of the study participants (91.7%) by MRCP while the rest 8.3% were not determined. In the present study, Common bile duct calculus (11.7%) is the common cause of obstruction on ERCP followed by malignant stricture (10%) and Periampullary carcinoma (10%) and 20 % of the patients were found to be normal in ERCP.

CONCLUSION
In summary, since the first clinical application of MRCP, it has emerged as a viable alternative to diagnostic ERCP, in patients in whom an interventional endoscopic procedure is unlikely, MRCP can replace ERCP as a diagnostic tool, as it is non-invasive and well tolerated by patients. MRCP is a non-invasive important tool in the diagnosis of billion-pancreatic diseases and has a comparable accuracy to ERCP. Despite relatively low spatial resolution when compared with ERCP the early assessments of diagnostic performance suggest that MRCP can reliably demonstrate normal and abnormal pancreatic and biliary ducts, accurately diagnose the cause and site of obstruction, be of diagnostic value when ERCP is unsuccessful.

CONSENT AND ETHICAL APPROVAL
As per international standard or university standard guideline Patient's consent and ethical approval has been collected and preserved by the authors.