Simultaneous computed tomographic angiography of the coronary and radial arteries.

Our aim was to assess a method of simultaneous computed tomographic (CT) angiography of the coronary and radial arteries without increasing contrast medium usage. Radial access is a standard approach in coronary interventions. However, radial artery puncture is difficult due to the small size of the radial artery and potential unexpected anomaly. If we can obtain anatomical information on the radial artery beforehand, the success rate of radial artery puncture may increase. Simultaneous CT angiography of the coronary and radial arteries without increasing contrast medium usage was planned. Contrast medium was injected in the right elbow vein. Time to peak concentration of contrast medium in the aorta (TPA) and time to peak concentration of contrast medium in the radial artery (TPR) were obtained by the test scan in each patient based on the time-density curve. The main scan was performed using 265 mg iodine/kg of contrast medium. The start time was decided according to TPA and TPR, respectively. This study included 192 cases [age, mean ± standard deviation (SD),72.0 ± 9.9 years]. Mean TPA and TPR were 19.0 ± 2.3(SD) seconds and 34.0 ± 10.0 s, respectively. Clear images of radial arteries were obtained in 89.6% (right) and 84.9% (left). Radiation exposure during cardiac CT angiography (CCTA) and radial artery CT angiography (RCTA) was 269.9 ± 155.6 mGy cm and 31.1 ± 12.3 mGy cm as dose length product, respectively. RCTA immediately following CCTA was safely performed with minimal increase in radiation exposure and no additional contrast medium. These images can help in radial access as well as distal radial access in coronary interventions.