Body weight-tailored contrast material injection protocol for 64-detector row computed tomography coronary angiography

The aim of this study was to assess the body weight-tailored contrast material injection protocol for 64-detector computed tomography (CT) to maintain optimal coronary CT attenuation. A total of 60 patients who underwent CT coronary angiography were assigned to one of three groups: protocol A, total of 0.7 ml kg(-1) with 300 mg I/ml iodine concentration; protocol B, total of 0.6 ml kg(-1) with 350 mg I/ml; protocol C, total of 0.7 ml kg(-1) with 350 mg I/ml. The injection duration was 10 s in all patients. The proportion of intracoronary attenuation values > 325 HU was compared on a pervessel and per-patient basis. The attenuation value was significantly more likely to exceed 325 HU with protocol C (95% for reader 1 and 90% for reader 2) than with protocol A or B on the per-vessel analysis (P < 0.05). The attenuation value also signifi cantly exceeded 325 HU with protocol C (95% and 90%, respectively) more often than with protocol A or B on the per-patient analysis (P < 0.05). A total of at least 0.7 ml kg(-1) contrast material with 350 mg/ml iodine concentration is required to achieve optimal coronary CT attenuation (> 325 HU) with 64-detector CT when using an injection duration of 10 s.