Diagnostic image quality of a comprehensive high-pitch dual-spiral cardiothoracic CT protocol in XXXX with undifferentiated acute @entity662 .

@entity1 @entity662 @entity1151 @entity3979 @entity358 @entity2073 @entity1580
OBJECTIVE: To evaluate diagnostic image quality of high-pitch dual source comprehensive cardiothoracic CT protocol in @entity1 presenting with acute undifferentiated @entity662 . MATERIALS AND METHODS: Consecutive symptomatic subjects (n=51) with undifferentiated acute @entity662 underwent ECG-synchronized high-pitch dual-spiral chest CT angiography (Definition Flash, Siemens Medical Solutions, 2   100 kVp or 2   120 kV if BMI>30, collimation: 128   0.6mm, pitch: 3.2). Independent investigators determined the image quality of each cardiac and pulmonary vessel segment, measured contrast-to-noise-ratio (CNR), and determined radiation exposure. In addition, the prevalence of CT findings ( @entity1151 ( @entity1151 ), @entity1580 ( @entity1580 ) and significant @entity3979 (>=  50%)) was determined. Univariate and multivariate analysis were performed to determine the subpopulation with highest diagnostic quality. RESULTS: Among 51 subjects (66% male, average age: 63    15.8), the prevalence of positive CT findings was moderate (overall: 11.7%). Overall, image quality of the pulmonary, aortic and coronary vasculature was good (1.26    0.43 and CNR: 2.52) with an average radiation dose of 3.82 @entity2073 and 3.2% of segments rated non-evaluable. The image quality was lowest in the coronary arteries (p=0.02), depending on the heart rate (r=0.52, p<0.001). In subjects with a heart rate of  <= 65 bpm (n=30) subjective image quality and CNR of the coronary arteries were higher (1.6    0.5 vs. 2.1    0.5, p=0.03 and 1.21    0.3 vs. 1.02    0.3, p=0.05) with only 1.5% segments classified as non-evaluable. CONCLUSION: High-pitch dual-spiral comprehensive cardiothoracic CT provides low radiation exposure with excellent image quality at heart rates  <= 65 bpm. In subjects with higher heart rates, image quality of the aortic and @entity358 remains excellent, while the assessment of the coronary arteries degrades substantially.
