Prospectively gated low-dose CCTA: 24 months experience in more than 2,000 clinical cases

Cardiac CT exams have recently come under increased scrutiny because of their relatively high radiation dose. The most effective way to lower the dose of coronary computed tomography angiography (CCTA) exams is with the use of prospective gating. This allows for a significant reduction in effective radiation dose when compared to retrospective ECG gating while image quality is maintained or improved. We reviewed data from 2,124 consecutive cardiac CT exams, including 1,978 CCTA's and 146 CCTA's post CABG. With effective heart rate control, prospective gating was used for 92.1% of the CCTAs and 83.2% of CCTAs following CABG. The prospectively gated CCTAs had a mean effective dose of 3.1 +/- A 1.5 mSv, CCTAs following CABG had a mean dose of 6.4 +/- A 2.3 mSv. We review our experience using prospective gating in specific areas to include patient selection, patient preparation, use of beta- and calcium-channel-blockers for heart rate control, selection of gating technique and scan parameters, radiation dose, and post-processing techniques.