The applied research of prospective ECG-gated 256 slice spiral CT with low radiation dose in high heart rate patients

Objective To approach the feasibility of prospective ECG-gated 256 slice spiral CT in high heart rate( HR) patients,and evaluate the image quality. Methods All patients scanned with prospective ECG-gated coronary CT angiography( CCTA) in our hospital from December 2010 to March 2013 were collected and divided into four groups according to HR before scan. Group a,HR 70 beat per minute( bpm); group b,70 bpm ≤ HR 80 bpm; group c,80 bpm≤HR 90 bpm; and group d,HR≥90 bpm. Thirty consecutive patients of each group were chosen and the image quality of them was evaluated by 4-score scale. The segments which were scored higher than 2 could satisfy the diagnosis. The radiation dose was recorded. Results The image quality and diagnostic rate( 98. 5%) of group b were not significantly different from group a. The image quality of group c and d descended obviously and the diagnostic rate were 90. 8% and 79. 5%,respectively,which was significantly different from group a. There was no significant difference of the radiation dose between groups. Conclusion In prospective ECG-gated CCTA by 256 slice spiral CT,the suitable HR can be raised to 80 bpm. Besides,the radiation dose can be controlled effectively.