Description

Determine coronary rest period Acquire HLA with high temporal resolution (50 phases) Navigator-gated, free-breathing 3D pulse sequence: Trans-axial slices (from the proximal main pulmonary artery to the middle of the right atrium; entire cardiac coverage if desired). Slice thickness: 1-1.5 mm Spatial resolution in-plane: 1.0 mm or less Slices: typically 50 – 80 Adjust trigger delay and acquisition window according to observed coronary artery rest period Parallel acquisition preferred Navigator placed over the right hemi-diaphragm Optional: Consider contrast to increase vessel conspicuity Breath-hold techniques if poor image quality or if navigators are unavailable or are of poor quality T2-prepared sequence may be useful

Tips and Tricks

Problems identifying coronary rest period: Repeat high temporal resolution 4-ch scan at the correct HR Consider cine scan during free-breathing if HR changes significantly during breath-hold Check during systole with a tight window (<50 ms) As a compromise, scan with longest trigger delay and a tight window (<50 ms) Coronary rest period may differ between LCA and RCA High HR (≥ 90bpm): Use shortest scan window possible to minimize blurring Keep scan times to a sensible limit Higher spatial resolution equals longer scan times

4-ch view showing the RCA in diastole