OBJECTIVES:  To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECG_{dual_step}) for evaluation of coronary arteries and cardiac function.

 METHODS: Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECG_dual-step) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65 bpm/70% RR interval <65 bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated.

 RESULTS: Mean HR was 68 bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p = 0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p < 0.001) and more segments with impaired image quality (p < 0.001 and p = 0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6 mAs (p < 0.001). The average radiation dose was 3.8 mSv (range, 1.7–7.9) in patients in SR.

 CONCLUSIONS: pECG_dual-step128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dose.

One Response

1. 

   Paul Schoenhagen  on July 6th, 2010

   There are several new protocols that blur the lines between prospective triggering and retrospective gating.
   Based on the clinical indication and patient specific characteristics these protocols allow CT imaging with reduced radiation exposure.

Leave a Reply