Comparison of systolic and diastolic 3D SSFP for arterial dimensions and coronary artery origins in patients with congenital heart disease

Background 3D steady-state free precession (SSFP) sequences allow for acquisition of isotropic datasets without the need for IV placement and contrast administration. Similar to MR angiography, they can be post-processed using multiplanar reconstruction, allowing for cross-sectional vessel measurements. They are also ECG-gated, allowing for visualization of coronary artery origins, which cannot be reliably evaluated by MRA. Arteries are preferentially measured in systole to obtain maximal diameter. However, because of motion blurring, this may be a suboptimal phase for diagnosis of coronary origins. We hypothesized that systolic SSFP (sSSFP) would provide larger measurements of arterial vessel diameter than either diastolic SSFP (dSSFP) or MRA sequences, yet provide adequate image quality for diagnosis of coronary artery origins.