Abstract 17838: High-Pitch Spiral Coronary Angiography by 128-Slice Dual-Source Computed Tomography (CT) Realizes a Sensational Low Radiation Exposure Without Reduced Image Quality
Background: Coronary CT angiography (CTA) is well-accepted for the noninvasive evaluation of the patients with known or suspected coronary artery disease. However, the problem of the radioactive exposure is remaining. Purpose: The aim of this study was to evaluate image quality and radiation dose of coronary CTA using a 128-slice dual source CT in prospectively ECG triggered and high-pitch spiral (high-pitch DSCT).
Methods: A total of 2023 consecutive patients underwent coronary CTA. We used Siemens' Definition flash which is latest high-end scanner in all patients.Coronary CTA with high-pitch DSCT were performed in the patients with stable heart rate (lower than 65 bpm). The patients with tachycardia, severe calcification and received coronary revasculization were excluded. Data acquisition was prospectively ECG-triggered using a pitch of 3.2. Images were reconstructed with 75ms temporal resolution, 0.6mm slice thickness and 0.3mm increment. Tube voltage (100kV or 120kV) was selected according to body surface area of the patients. We made MPR images, and image quality of coronary arteries was graded on a 4-point scale (1=excellent, 2=good, 3=fair, 4=poor/nondiagnostic) by 2 independent readers. Radiation dose was compared with two other DSCT scan modes (prospectively step and shoot, and retrospectively ECG gated).
Results: Coronary CTA with high-pitch DSCT were performed in the 323 patients. Mean HR of them was 56 bpm. Among 323 patients, 318 (98.2%) were in stable sinus rhythm and the other patients had arrhythmia (complete atrioventricular block). Diagnostic Image quality (score 1,2 and 3) was found for 4386/4515 segments (96.2%) and especially image quality score 1 was found in 3477/4515 segments (77%). Interobserver agreement in grading image quality of coronary artery segments was good (kappa = 0.77). The mean radiation dose (effective dose) of high-pitch DSCT was 1.76+/−0.86mSv and was lower than that of other scan modes (prospectively step and shoot; 7.73+/−4.07mSv, retrospectively ECG gated ; 19.89+/−9.76mSv).
Conclusion: Prospectively 128-slice dual source CT in high-pitch spiral mode is feasible for evaluation of coronary arteries in patients with stable and low HR, and provides high image quality at sensational low radiation exposure.
- © 2010 by American Heart Association, Inc.