This study demonstrates that, in the case of diagnostic image quality, contrast-enhanced MDCT permits an accurate identification of coronary plaques and that computed tomography density values measured within plaques reflect echogenity and plaque composition.

Dual Energy CT with specific postprocessing can reduce metal artefacts and may significantly enhance diagnostic value in the evaluation of metallic implants.

Our objective was to evaluate the association of arterial 18 F-FDG uptake and calcifications in large arteries as detected by 18 F-FDG PET/CT with the subsequent occurrence of vascular events in otherwise asymptomatic cancer patients. Methods: Clinical follow-up information was obtained for 932 cancer patients examined with whole-body 18 F-FDG PET/CT (median follow-up time, 29 mo). Among this cohort, 279 patients had died from their oncologic disease. In 15 of 932 patients (1.6%), a vascular event, defined as ischemic stroke, myocardial infarction, or revascularization, was registered. The maximal standardized uptake value (SUV) was divided by the blood-pool SUV, yielding a target-to-background ratio (TBR) for each arterial segment. The mean TBR as well as a calcified plaque sum score per patient were calculated in the major vessels: ascending, descending, and abdominal aorta, aortic arch, as well as iliac and carotid arteries. Results: A significant correlation was observed between mean TBR and calcified plaque sum (P , 0.001). Although calcified plaque sum significantly correlated with all conventional risk factors for vascular events, mean TBR correlated only with age, the male sex, and hypertension. The Cox regression hazard model identified a mean TBR $ 1.7 and a calcified plaque sum $ 15 as independent predictors for the occurrence of a vascular event. Patients with both mean TBR and calcified plaque sum above these thresholds were identified as having the highest risk for a future vascular event. However, a mean TBR $ 1.7 had greater prognostic value than did a calcified plaque sum $ 15. Conclusion: In a large cohort of cancer patients, increased 18 F-FDG uptake in major arteries emerged as the strongest predictor of a subsequent vascular event. Concomitant severe vascular calcifications seemed to impart a particularly high risk. Given the small event rate in the present study, larger, prospective trials of patients without cancer are required to substantiate these promising results.

We conclude that 64-slice CT reveals encouraging results to noninvasively detect different types of coronary plaques located in the proximal coronary system. The ability to determine plaque burden currently is hampered by mainly an insufficient reproducibility.

Background and aims: This prospective trial was designed to compare the performance characteristics of five different screening tests in parallel for the detection of advanced colonic neoplasia: CT colonography (CTC), colonoscopy (OC), flexible sigmoidoscopy (FS), faecal immunochemical stool testing (FIT) and faecal occult blood testing (FOBT). Methods: Average risk adults provided stool specimens for FOBT and FIT, and underwent same-day low-dose 64-multidetector row CTC and OC using segmentally unblinded OC as the standard of reference. Sensitivities and specificities were calculated for each single test, and for combinations of FS and stool tests. CTC radiation exposure was measured, and patient comfort levels and preferences were assessed by questionnaire. Results: 221 adenomas were detected in 307 subjects who completed CTC (mean radiation dose, 4.5 mSv) and OC; 269 patients provided stool samples for both FOBT and FIT. Sensitivities of OC, CTC, FS, FIT and FOBT for advanced colonic neoplasia were 100% (95% CI 88.4% to 100%), 96.7% (82.8% to 99.9%), 83.3% (95% CI 65.3% to 94.4%), 32% (95% CI 14.9% to 53.5) and 20% (95% CI 6.8% to 40.7%), respectively. Combination of FS with FOBT or FIT led to no relevant increase in sensitivity. 12 of 45 advanced adenomas were smaller than 10 mm. 46% of patients preferred CTC and 37% preferred OC (p,0.001). Conclusions: High-resolution and low-dose CTC is feasible for colorectal cancer screening and reaches sensitivities comparable with OC for polyps .5 mm. For patients who refuse full bowel preparation and OC or CTC, FS should be preferred over stool tests. However, in cases where stool tests are performed, FIT should be recommended rather than FOBT.Colorectal cancer is one of the major public health issues in industrialised countries. Most colorectal cancers are thought to originate from benign adenomatous polyps that develop over a period of many years.1 Early detection followed by removal of adenomas has been shown to reduce incidence and colorectal cancer-related mortality.2 3Therefore, screening of the asymptomatic and average risk population is recommended by many organisations and expert panels, and is reimbursed by insurance companies in several countries. 4-7Next to colonoscopy, flexible sigmoidoscopy (FS) and guaiac-based faecal occult blood test (FOBT) are widely applied screening procedures which have been compared prospectively with each other. Colonoscopy has been found to be the screening test with the highest sensitivity and outperforms FS and FOBT which miss a significant number of relevant adenomas. 8 Colonoscopy, however, is not a perfect test in itself, and misses 6-12% of large adenomas. 9-11CT colonography (CTC), also known as virtual colonoscopy, and faecal immunochemical tests (FITs) have been proposed as screening tests for colonic neoplasia.12-14 They have at present not been integrated into screening programmes. Based on recent research, CTC shows heterogeneous results in the detection of colonic polyps: some studies demonstrated high sen...