Assessment of image quality and radiation dose in prospective ECG-triggered coronary CT angiography compared with retrospective ECG-gated coronary CT angiography.
We sought to determine the cut-off point of the average heart rate (HR) and HR differences in obtaining diagnostic image quality using prospective electrocardiographically-triggered (PT) coronary computed tomographic angiography (CCTA) and to compare image quality and radiation dose for CCTA obtained with PT CCTA and retrospective electrocardiographically-gated (RG) CCTA. A total of 178 patients who were referred for CCTA were enrolled in the study. Two independent radiologists evaluated subjective image quality. The non-diagnostic coronary segments were 32 of 1,226 segments (2.6%) for PT CCTA and 12 of 1,346 segments (0.9%) for RG CCTA (P < 0.001). The mean image quality scores for PT CCTA and RG CCTA were 3.82 +/- 0.29 and 3.93 +/- 0.14, respectively. The mean radiation dose of patients that underwent PT CCTA was 3.83 +/- 0.84 mSv and RG CCTA 10.7 +/- 2.70 mSv. For patients who underwent PT CCTA, image quality was inversely related to HR (56.5 +/- 4.3 bpm; r = 0.38; P < 0.001) and HR differences (2.8 +/- 2.7 bpm; r = 0.49; P < 0.001). With the use of receiver operator characteristic analysis, a cut-off HR of 57 bpm (58% sensitivity, 67% specificity) and HR difference of 6 bpm (93% sensitivity, 46% specificity) were the best threshold for the prediction of diagnostic image quality. In patients with a regular, low HR, PT CCTA offers diagnostic image quality and substantially reduces effective radiation compared with the use of RG CCTA with dose modulation.
Ko
Sung Min
SM
Department of Radiology, Konkuk University Hospital, Konkuk University School of Medicine, 4-12 Hwayang-dong, Gwangjin-gu, Seoul, 143-729, South Korea.
Kim
Na Ra
NR
Kim
Dong Hun
DH
Song
Meong Gun
MG
Kim
Jin Hwan
JH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D055815:Young Adult