Background: Dual-phase 3-dimensional whole-heart acquisition allows simultaneous imaging during systole and diastole. Respiratory navigator gating and tracking of the diaphragm is used with limited accuracy. Prolonged scan time is common, and navigation often fails in patients with erratic breathing. Image-navigation (iNAV) tracks movement of the heart itself and is feasible in single phase whole heart imaging. To evaluate its diagnostic ability in congenital heart disease, we sought to apply iNAV to dual-phase sequencing. Methods: Healthy volunteers and patients with congenital heart disease underwent dual-phase imaging using the conventional diaphragmatic-navigation (dNAV) and iNAV. Acquisition time was recorded and image quality assessed. Sharpness and length of the right coronary (RCA), left anterior descending (LAD), and circumflex (LCx) arteries were measured in both cardiac phases for both approaches. Qualitative and quantitative analyses were performed in a blinded and randomized fashion. Results: In volunteers, there was no significant difference in vessel sharpness between approaches (p>0.05). In patients, analysis showed equal vessel sharpness for LAD and RCA (p>0.05). LCx sharpness was greater with dNAV (p<0.05). Visualized length with iNAV was 0.5±0.4cm greater than that with dNAV for LCx in diastole (p<0.05), 1.0±0.3cm greater than dNAV for LAD in diastole (p<0.05), and 0.8±0.7cm greater than dNAV for RCA in systole (p<0.05). Qualitative scores were similar between modalities (p=0.71). Mean iNAV scan time was 5:18±2:12min shorter than mean dNAV scan time in volunteers (p=0.0001) and 3:16±1:12min shorter in patients (p=0.0001). Conclusions: Image quality of iNAV and dNAV was similar with better distal vessel visualization with iNAV. iNAV acquisition time was significantly shorter. Complete cardiac diagnosis was achieved. Shortened acquisition time will improve clinical applicability and patient comfort.
- Congenital heart disease
- Dual phase imaging
- Respiratory motion correction
- Steady-state free precession MRI
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging