Abstract 16796: Sub-millisievert Radiation Dose with Retained Image Quality in Patients Undergoing Coronary Computed Tomographic Angiography using 80 kV Tube Voltage: A Prospective Multicenter Multivendor Randomized Trial
Introduction: Coronary computed tomographic angiography (CCTA) is associated with non-negligible radiation doses; current
Methods: to lower radiation dose include the use of decreased 100 kV tube voltage.
Hypothesis: CCTA using further reduced 80 kV tube voltage will Results in an incremental reduction in radiation dose with preserved image quality in patients with normal body habitus.
Methods: We performed a prospective multicenter multivendor randomized trial evaluating 142 consecutive patients without prior coronary revascularization and normal body mass index (<25 kg/m2) referred for CCTA; patients were randomized to 80 kV (n=71) or 100 kV imaging (n=71) at 4 sites using 3 vendor platforms. Blinded CCTA core lab analysis by 2 experienced readers assessed image quality (scale 1–4); signal and noise (mean of aortic root, left main artery, right coronary artery); contrast (mean signal - subcutaneous adipose tissue signal); and presence or absence of obstructive (>=50%) coronary artery stenosis.
Results: Data are presented in the table below. In multivariable analysis, 80 kV tube voltage imaging was independently associated with a 44% (95% confidence interval 39–49%) reduction in radiation dose (p<0.001). Interobserver agreement for obstructive stenosis on a per-vessel basis was high and comparable in both groups [283/284 (99.6%, k=0.91) for 80 kV vs. 281/284 (98.9%, k=0.82) for 100 kV, p=0.32].
Conclusion: The use of reduced 80 kV voltage for CCTA in patients with a normal body size reduced radiation dose by almost 50%. Despite differences in signal to noise and contrast to noise ratios, image quality and reader agreement were comparable.
- © 2010 by American Heart Association, Inc.