Computer-aided detection in computed tomography colonography with full fecal tagging: comparison of standalone performance of 3 automated polyp detection systems.

PURPOSE: We sought to compare the performance of 3 computer-aided detection (CAD) polyp algorithms in computed tomography colonography (CTC) with fecal tagging. METHODS: CTC data sets of 33 patients were retrospectively analysed by 3 different CAD systems: system 1, MedicSight; system 2, Colon CAD; and system 3, Polyp Enhanced View. The polyp database comprised 53 lesions, including 6 cases of colorectal cancer, and was established by consensus reading and comparison with colonoscopy. Lesions ranged from 6-40 mm, with 25 lesions larger than 10 mm in size. Detection and false-positive (FP) rates were calculated. RESULTS: CAD systems 1 and 2 could be set to have varying sensitivities with higher FP rates for higher sensitivity levels. Sensitivities for system 1 ranged from 73%-94% for all lesions (78%-100% for lesions > or =10 mm) and, for system 2, from 64%-94% (78%-100% for lesions > or =10 mm). System 3 reached an overall sensitivity of 76% (100% for lesions > or =10 mm). The mean FP rate per patient ranged from 8-32 for system 1, from 1-8 for system 2, and was 5 for system 3. At the highest sensitivity level for all polyps (94%), system 2 showed a statistically significant lower FP rate compared with system 1 (P = .001). When analysing lesions > or =10 mm, system 3 had significantly fewer FPs than systems 1 and 2 (P < .012). CONCLUSIONS: Standalone CTC-CAD analysis in the selected patient collective showed the 3 systems tested to have a variable but overall promising performance with respect to sensitivity and the FP rate.

Evaluation of left and right ventricular diastolic function by electron-beam computed tomography in patients with passive epicardial constraint.

OBJECTIVE: Previous investigations have shown the usefulness of electron-beam computed tomography (EBCT) to describe ventricular diastolic function and to detect constrictive filling pattern. We used EBCT to analyze diastolic function in patients who underwent passive epicardial constraint because data describing ventricular filling in these patients are still incomplete. METHODS: Ten patients with dilated cardiomyopathy (group 1) underwent EBCT examination before and again 6 months after surgery. Ten patients with normal diastolic function (group 2) and 5 male patients with constrictive pericarditis (group 3) served for comparison. Volume-time curves throughout the entire diastole were generated, and the rapidity of diastolic filling was assessed by calculating the percent filling fraction at consecutive EBCT frames throughout the diastole. Pericardial thickness was measured in a standardized fashion at different locations around both ventricles. RESULTS: Early left ventricular filling pattern in group 1 did not change postoperatively (filling fraction at third diastolic frame was 50.0 +/- 15.4% and 53.8 +/- 14.4% before and after surgery, respectively) and was not significantly different from group 2 (48.7 +/- 8.5%). In contrast, in group 3, early left ventricular filling was significantly accelerated (71.4 +/- 9.3%) when compared with groups 1 and 2. A similar pattern was observed for the right ventricle. Pericardial thickness between groups 1 (1.22 +/- 4.22 and 1.43 +/- 0.39 mm before and after surgery, respectively) and 2 (1.38 +/- 0.43 mm) did not differ significantly. In contrast, pericardium in group 3 was significantly thickened (4.93 +/- 1.11 mm) when compared with both groups 1 and 2. CONCLUSIONS: The EBCT identified an abnormal accelerated diastolic filling and thickened pericardium in patients with constrictive pericarditis. Conversely, a normal diastolic filling pattern and pericardial thickness seem to be preserved in patients after passive epicardial constraint, when compared with baseline values and with normal subjects.

Electrocardiographic-gated multislice computed tomography for visualization of cardiac morphology in congenitally corrected transposition of the great arteries.

A case of congenitally corrected transposition of the great arteries in a 64-old-woman is presented. Diagnosis was missed by invasive angiocardiography. Electrocardiographic-gated multislice computed tomography not only demonstrated switching of the aortic root and pulmonary trunk but clearly identified fine morphologic details of the cardiac chambers, including the atypical coronary artery pattern.