Coronary computed tomography angiography at 140 kV versus 120 kV: assessment of image quality and radiation exposure in overweight and moderately obese patients

BackgroundAlthough a tube potential of 140 kV is available on most computed tomography (CT) scanners, its incremental diagnostic value versus 120 kV has been controversial.PurposeTo retrospectively evaluate the image quality and radiation exposure of cardiac computed tomography angiography (CCTA) performed at 140 kV in comparison to CCTA at 120 kV in overweight and moderately obese patients.Material and MethodsEighty-eight patients who were referred for CCTA between January 2010 and May 2012 were included. Forty-four patients who were overweight or moderately obese (body mass index [BMI], 25–35 kg/m2) underwent CCTA with dual-source CT (DSCT) scanner at 140 kV. Forty-four match controls who underwent CCTA with DSCT at 120 kV were identified per BMI, average heart rate, scan indication, and scan acquisition mode. All scans were performed per routine protocols with direct physician supervision. Quantitative image metrics (CT attenuation, image noise, contrast-to-noise ratio [CNR], and signal-to-noise ratio ...