Coronary Artery Visualization by Using the 64-row MDCT in Pediatric Patients

Abstract

We retrospectively evaluated the visualization of pediatric coronary computed tomography angiography (CCTA) images by using the 64-detector row CT scanner between the electrocardiogram-gated helical scan and non-electrocardiogram-gated helical scan. From January 2015 to March 2019, 100 children who underwent CT angiography examination were retrospectively enrolled. Group A consisted of 50 patients with electrocardiogram-gated helical scan. Group B consisted of 50 patients with non-electrocardiogram-gated helical scan. All patients were scanned using a 64-detector row CT scanner (LightSpeed VCT), and helical scans were acquired. The CT scanning parameters were 0.4-s rotation, 0.625-mm slice thickness, 0.24 (group A) helical pitch (beam pitch), 1.375 (group B) helical pitch (beam pitch), 80 kVp, and 50-300 mA (noise index 40). A retrospective method was used for electrocardiogram gated. To compare the radiation dose, CT volume dose index (CTDIvol) and dose length product (DLP) displayed on the console were recorded. The visualization scores of the coronary artery images were compared between each group. In group A, CTDIvol and DLP values were 6.74 (1.05-11.97) mGy and 79.87 (15.90-146.65) mGy·cm, respectively. In group B, CTDIvol and DLP values were 0.51 (0.39-0.95) mGy and 8.15 (6.30-17.50) mGy·cm, respectively. There were significant differences in CTDIvol and DLP values between both groups (p<0.05). The visualization rates for the proximal and distal coronary arteries were 88% and 54% for the right coronary artery, 84% and 58% for the left anterior descending artery, and 66% and 30% for the left circumflex branch in group A, respectively. The visualization rates for the proximal and distal coronary arteries were 52% and 0% for the right coronary artery, 56% and 0% for the left anterior descending artery, and 32% and 0% for the left circumflex branch in group B. In 64-row multidetector computed tomography (MDCT), the visualization rates for the proximal and distal coronary arteries were significantly higher in the electrocardiogram-gated scan, but the exposure dose was several times higher in the pediatric CCTA. For accurate diagnosis in pediatric coronary arteries, electrocardiogram-gated helical scan should be performed.