ECG-gated coronary angiography enables submillisievert imaging in invasive cardiology.

BACKGROUND: The median dose area products (DAP) and effective doses (ED) of patients arising from coronary angiography (CA) are considerable: According the 2013 National German Registry, they amount to 19.8 Gy × cm(2) and 4.0 mSv, respectively.
METHODS: We investigated the feasibility of prospective electrocardiogram (ECG)-gated coronary angiography (CA)-a novel technique in invasive cardiology-with respect to possible reduction in irradiation effects. Instead of universally fix-rated radiographic acquisition within 7.5-15 frames/s, one single frame/heartbeat was triggered toward the diastolic moment immediately before atrial contraction (77 % of ECG-RR interval) most likely to provide motion-free and hence optimized resolution of the coronary tree. For 200 patients (body mass index 27.8 kg/m(2), age 67.5 years, male 55 %, 68 bpm) undergoing ECG-gated CA, we measured various median (interquartile range) parameters for radiation exposure.
RESULTS: The total DAP was 0.64 (0.46-1.00), radiographic fraction was 0.30 (0.19-0.43), and fluoroscopic fraction was 0.35 (0.21-0.57) Gy × cm(2). Radiographic imaging occurred within 21.7 s (17.1-26.3), with 25 frames (20-30) over the course of 7 runs (6-8). Fluoroscopy time was 119 s (94-141). Radiographic DAP was 12.6 mGy × cm(2)/frame and 13.8 mGy × cm(2)/s. Fluoroscopic DAP was 0.8 mGy × cm(2)/pulse and 3.1 mGy × cm(2)/s. Patient reference point air kerma was 17.0 mGy (11.1-28.1) and contrast volume was 70 ml (60-85).
CONCLUSION: In conclusion, invasive ECG-gated coronary imaging is feasible in clinical routine and enables patient EDs of approx. 3 % of typical values in invasive cardiology: 0.13 mSv (0.09-0.20).