Non-invasive diagnosis of coronary artery disease with 16-slice computed tomography.

BACKGROUND: The gold standard for the diagnosis of coronary artery disease (CAD) is catheter angiography. However, catheter angiography is invasive and may not always be followed by interventional therapy. We report our results with the use of multislice computed tomography (MSCT) as a non-invasive diagnostic tool for CAD. METHODS: Thirty-one patients (26 with chronic stable angina, 5 with coronary anomalies) underwent 16-slice MSCT and catheter angiography. Vessels < 1.5 mm in diameter were excluded. The ability of MSCT to detect obstructive CAD (stenosis > or =50% of the diameter) was evaluated in pre-defined vessel segments. The association of calcium score with obstructive CAD, and the effect of heart rate on distal vessel visibility were also studied. RESULTS: There were 29 men and 2 women (age range: 36-80 years; mean [SD]: 53 [11] years). Of the 403 vessel segments, 391 were > 1.5 mm in diameter and 321 were interpretable on both modalities. The non-interpretability rates were 7% (26/391) for catheter angiography and 14% (54/ 391) for MSCT, with distal location (64%; 34), motion artifacts (29%; 16) and calcification (7%; 4) being chiefly responsible in case of the latter technique. The sensitivity, specificity, positive and negative predictive values of MSCT were 85% (95% confidence interval [CI]: 73-93), 94% (95% CI: 90-96), 76% (95% CI: 64-85) and 96% (95% CI: 93-98), respectively. MSCT correctly classified patients with no, single-, double- and triple-vessel disease in 87% of cases. One patient was incorrectly excluded on MSCT; catheter angiography showed 50%-70% stenosis in this case. Patients with obstructive CAD had a higher Agatston score equivalent (p=0.03). There was no significant effect of heart rate on distal segment visibility. MSCT correctly identified all coronary anomalies. CONCLUSION: MSCT has a good potential for the detection of coronary stenosis, and may be most useful for excluding CAD (due to its high negative predictive value). It accurately delineates coronary anomalies.

Colour Doppler flow imaging findings in portal biliopathy.

Biliary abnormalities in extrahepatic portal vein obstruction (EHPVO) have been described in detail on endoscopic retrograde cholangiopancreaticography (ERCP), but have never before been reported on colour Doppler flow imaging (CDFI). These changes occur either due to extrinsic compression of the bile ducts or due to ischaemic biliary stenosis. The aim of this study was to evaluate the role of CDFI in demonstrating the biliary changes in patients with EHPVO. Three out of 46 patients with EHPVO (7%), who presented clinically with obstructive jaundice, were subjected to a detailed CDFI study of the abdomen, followed by ERCP and splenoportovenography (SPV). One of the patients also underwent a repeat CDFI examination at 8 weeks following a lienorenal shunt. In all 3 cases, CDFI easily distinguished the anechoeic structures seen on ultrasound at the porta hepatis as periportal collaterals, the hepatic artery and dilated bile ducts. It revealed the actual indentation made on the common bile duct (CBD) by the collaterals besides showing the presence of biliary calculi. Gallbladder varices were also well demonstrated in all the cases. ERCP confirmed the presence of portal biliopathy besides showing other changes, such as angulation, displacement and stricture of the CBD. SPV confirmed the presence of EHPVO. One patient who underwent shunt surgery showed persistent dilatation of the CBD with calculi. CDFI is a rapid, non-invasive and widely available modality which can be used to demonstrate the biliary changes in patients with EHPVO with obstructive jaundice. It may thus help screen patients who require a further by ERCP examination for the planning of treatment.