Ultra-Low Radiation Dose and Contrast Medium of Coronary CT Angiography Using Prospectively ECG-Triggered Without Heart Rate Control: A New Strategy

摘要

The high pitch sprial (HPS) mode of Coronary CT angiography (CCTA) allows the radiation dose and contrast medium to be very low. However, the unsuccessful rate was to be considered, especially on high heart rate. The purpose of this study was to evaluate a new strategy without heart rate control by HPS and/ or Sequence mode in patients. A total of 46 patients were included (median age: 62.00 years old). At low heart rate (= 70 bpm), HPS mode with tube voltage 70-80 kVp and 30-40 mL contrast medium (270 mgI/ mL) for patients; Sequence mode with acquisition window (35%-45% of the R-R interval), tube voltage 70-80 kVp and 40-50 mL contrast medium for patients at high heart rate. A routine Sequence mode with wide acquisition window (30%-80% of the R-R interval) would be repeated when the coronary artery could not be assessed adequately. The image quality, radiation dose and contrast medium would be evaluated. In result, there were 3 patients with a repeated scanning. The effective dose (ED) was 0.51 +/- 0.41 mSv. The mean contrast medium and total iodine content were 39.78 +/- 12.91 mL and 10741.30 +/- 3485.18 mg. The assessment rate of coronary artery segments was 100%. In conclusion, different combinations of HPS and/or Sequence mode could provide satisfactory image assessment and minimize the radiation dose and contrast medium without heart rate control.