Accuracy of MDCT in the determination of supraaortic artery stenosis using DSA as the reference standard.

PURPOSE: Accurate stenosis quantification in the carotid arteries is of great clinical importance. We aimed to compare the diagnostic accuracy of multi-slice computed tomography angiography (CTA) to digital subtraction angiography (DSA) for the detection and grading of atherosclerotic lesions involving the supraaortic arteries. MATERIALS AND METHODS: We retrospectively analyzed 30 patients (10 women; mean age, 67 years). CTA was performed after administration of 100 ml Ultravist 370 (Bayer Schering, Germany), at a flow of 5 ml/s, using a Philips Brilliance 16MDCT scanner (Philips, Best, Netherland) at a collimation of 16 mm×0.75 mm prior to DSA. The supraaortic arteries were divided into 17 segments, and, within each segment, the presence and severity of stenotic or occlusive lesions was determined, based on a four-point scale (0-49%, 50-69%, 70-99%, occlusion), by four independent readers using the NASCET criteria. Sensitivity and specificity of MDCT was calculated for the detection of moderate (50-69%) versus significant stenoses (70-99%) and occlusion. RESULTS: There were 291 segments assessed with both methods. Thirteen lesions were "not assessable" on CTA. DSA identified 53 significant lesions, and CTA 56 significant lesions. With regard to significant lesions, CTA overrated six lesions and underestimated six lesions, resulting in a sensitivity, specificity, and accuracy of 86.4%, 97.6%, and 95.9%, respectively. For the detection of stenoses greater than 50%, sensitivity, specificity, and accuracy were 90.2%, 95.8%, and 94.8%, respectively. CONCLUSIONS: Compared to DSA, CTA shows high accuracy in the detection and grading of lesions involving the supraaortic arteries enabling its use in the detection and treatment planning for stenoses of the supraaortic vessels.

[Practical usage of a quality management system according to ISO 9001 : 2000 focusing on the double contrast (barium) enema]. / Praktische Anwendung eines Qualitätsmanagementsystems nach ISO 9001:2000 am Beispiel von Qualitätsverbesserungsmassnahmen beim Kolon-Kontrastmitteleinlauf, Germany.

PURPOSE: We describe the implementation of quality improvement measures in a quality management system. METHODS: With questionnaires for radiologists and patients, we investigated the relations between patient preparation and diagnostic quality serving the main purpose, to improve diagnostic quality with the help of more detailed patient information (e.g., changing preparation sheets and handling out "peri-med" information sheets to the patients). Furthermore, a comparative data ascertainment at other institutes was integrated. RESULTS: For the group of outpatients, increasing process quality (patient information) and outcome (diagnostic quality) could be achieved. Taking aspects of quality costs into consideration, a decrease in costs due to failures was achieved. CONCLUSION: More detailed patient information has positive effects on diagnostic quality of the double contrast (barium) enema.