The effect of adaptive iterative dose reduction on image quality in 320-detector row CT coronary angiography

Objective: To evaluate the effect of adaptive iterative dose reduction (AIDR) on image noiseand image quality as compared with standard filtered back projection (FBP) in 320-detector row CT coronary angiography (CTCA). Methods: 50 patients (14 females, mean age 68±9 years) who underwent CTCA (100 kV or 120 kV, 400–580 mA) within a single heartbeatwere enrolled. Studies were reconstructed with FBP and subsequently AIDR. Image noise, vessel contrast and contrast-to- noise ratio(CNR) in the coronary arteries were evaluated. Overall image quality for coronary arteries was assessed using a five-point scale (1, non-diagnostic; 5, excellent). Results: All the examinations were performed in a single heartbeat. Image noisein the aorta was significantly lower in data sets reconstructed with AIDR than in those reconstructed with FBP (21.4±3.1 HU vs 36.9±4.5 HU; p<0.001). No significant differences were observed between FBP and AIDR for the mean vessel contrast (HU) in the proximal coronary arteries. Consequently,...