Reduction of radiation dose with electrocardiogram-pulsing windows technique in dual-source CT coronary angiography

Abstract

Objective To evaluate the value of reducing radiation dose with decreased size of ECG-pulsing windows and influence on image quality in dual-source CT coronary angiography. Methods 120 patients with stable heart rate(HR) were divided into four groups according to HR and the rang of ECG-pulsing windows in dual-source CT coronary angiography: HR ＜ 70 bpm and 61% ～ 77% R-R interval of ECG-pulsing windows, HR ＜ 70 bpm and 25% ～ 80% R-R interval of ECG-pulsing windows,HR ＞ 80 bpm and 31% ～47% R-R interval of ECG-pulsing windows, and HR ＞ 80 bpm and 25% ～ 80%R-R interval of ECG-pulsing windows was employed, respectively. The radiation dose parameters were recorded and image quality scores were performed. The image quality and radiation dose between two slow HR groups and between two fast HR groups were compared respectively. Result The effective doses were (7.06 ± 2. 13 ), ( 11.34 ± 3.65 ), ( 6. 67 ± 1.97 ) and ( 9. 92 ± 3. 15 ) mSy for four groups, respectively.The effective dose was decreased by 37.74% for slow HR and by 32. 76% for fast HR using narrow ECG-pulsing windows. There was no difference on image quality between two slow HR groups and two fast HR grouvs. Concluslons The proper application of narrow ECG-pulsing windows can reduce radiation exposure significantly to stable slow or fast HR patients in dual-source CT coronary angiography withont sacrificing the image quality. Key words: Computed tomography; ECG-pulsing; Coronary; Radiation dose