Accuracy of Magnetic Resonance Cholangiopancreatography in Case of Biliary Obstruction Comparing Post-operative Findings: A Study of 50 Cases

Complete assessment of obstructive jaundice requires the use of various imaging modalities that are required to detect the cause and level of obstruction thus helping in treatment planning. Magnetic Resonance Cholangio Pancreatography (MRCP) is a current available technology which is a non-invasive technique that visualizes the gallbladder, biliary tree and pancreatic duct and also provides information about surrounding structures. This study was done to correlate the MRCP findings with post-operative result and thereby demonstrate the specificity, sensitivity and efficacy of MRCP as an accurate investigatory tool for biliary obstruction. Total of fifty (50) patients of clinically diagnosed obstructive jaundice were studied from March 2017 to August 2017 in the Department of Radiology and Imaging, Combined Military Hospital, Dhaka, Bangladesh. In all these cases, USG was the initial screening investigation followed by MRCP. Cause and level of obstruction were evaluated using MRCP findings. MRCP results were correlated with surgical findings and few cases also with direct ERCP findings. Statistical analysis was done to see the sensitivity, specificity, accuracy, positive and negative predictive values of MRCP in diagnosis of biliary obstruction. In this study, USG detected level of obstruction in 56% (28 out of 50) cases. USG could detect causes of obstruction in 100% (02 out of 02) cases of choledocal cyst and 66.67% (02 out of 03) benign stricture, 60% (03 out of 05) cases of periampullary carcinoma, 57.70% (06 out of 14) cases of choledocholithiasis, and 42.86% (15 out of 26) cases of cholangiocarcinoma. On the other hand, MRCP detected level of obstruction in 98% (49 out of 50) cases. MRCP could detect causes of obstruction in 100% cases of cholangiocarcinoma, choledocholithiasis, benign stricture and choledocal cyst and 80% (04 out of 05) cases of periampullary carcinoma. In this study, ERCP could detect causes of obstruction in 32 cases of choledocholithiasis and benign stricture, but in case of cholangiocarcinoma ERCP was failed in 3 cases. In this study, for detection of cause of obstruction, ERCP had the highest sensitivity (97.79%); followed by MRCP (96.65%) and USG (60.25%). The overall diagnostic accuracy for detection of cause of obstruction was the highest for ERCP (95.50%); followed by MRCP (94.50%) and USG (64.50%). MRCP can be done in a short duration and is a noninvasive diagnostic modality compared to ERCP. MRCP needs to be advocated as a viable and non-invasive alternative with compararable sensitivity and specificity to ERCP.

Delayed post-hypoxic leukoencephalopathy following alcohol consumption and cardiopulmonary arrest

Delayed post hypoxic leukoencephalopathy (DPHL) is a rare consequence of hypoxic brain injury that occurs several days to weeks following an initial hypoxic insult. Most of the previously published cases occur in the setting of drug overdoses or carbon monoxide poisoning, where the incidence of DPHL is as high as 3%. Our case depicts a patient with delayed hypoxic brain injury following cardiac arrest with cardiopulmonary resuscitation. Initial neuroimaging was normal, and a repeat MRI scan six days later revealed DWI changes consistent with DPHL. Our patient remained comatose throughout his clinical course until his eventual death nine days after the initial incident. The autopsy confirmed hypoxic-ischemic brain injury with co-existent Wernicke's encephalopathy, a known consequence of alcohol use disorder. This case outlines the clinical course of DPHL accompanied by the unique neuroimaging features that distinguish it from conventional hypoxic-ischemic brain injury.

Optical Properties Of Tantalum Oxide Films Deposited On BK7 Substrates By Excimer Laser Ablation

Thin amorphous films of tantalum oxide were grown on borosilicate crown glass substrates by KrF excimer pulsed laser ablation of a Ta2O5 target, in an oxygen environment. The deposition was performed at a temperature of 250 or 400 °C, while the oxygen pressure was set in the range 5 to 30 mTorr. The optical properties of the tantalum oxide coatings, as evaluated by reflectance/transmittance spectrophotometry, were found to be dependent on the oxygen gas pressure. At a pressure of 5 mTorr, absorbing films were obtained, with extinction coefficients above 10−2 (at λ=633 nm), along with an optical energy band-gap as low as 0.7 eV. At a pressure of 10 mTorr and above, the coatings had refractive indices up to 2.25 (at λ=633 nm), extinction coefficients below 10−4 (for λ>390 nm), and an optical energy band-gap in the range 3.9 to 4.0 eV.