- Meeting abstract
- Open Access
1027 Rapid and accurate free-breathing 3D delayed enhancement imaging for myocardial viability assessment: comparison with breath-hold 2D imaging
© Nguyen et al; licensee BioMed Central Ltd. 2008
- Published: 22 October 2008
- Average Image Quality
- Myocardial Viability Assessment
- Routine Clinical Imaging
- Current Reference Standard
- Similar Infarct
Delayed enhancement MRI (DE-MRI) has been established as a diagnostic imaging standard for myocardial viability assessment. The current reference standard for DE-MRI uses an inversion-recovery 2D gradient echo sequence to acquire images during repetitive breath-holds. This breath-hold 2D (2DBH) technique requires significant patient cooperation and suffers from potential slice misregistration due to diaphragmatic excursions in different breath-holds. To overcome these limitations, navigator-gated 3D (3DNAV) DE-MRI has been developed using a diaphragmatic navigator to monitor respiratory motion and adjust data acquisition accordingly. Previous 3DNAV sequences employed the accept/reject gating algorithm with a fixed gating window which can lead to long imaging time in the case of a steady diaphragmatic drift.
The objective of this study was to develop a rapid and accurate free-breathing 3DNAV DE-MRI sequence using the drift-resistant phase ordering with automatic window selection (PAWS) gating algorithm and to evaluate its feasibility in routine clinical imaging with 2DBH DE-MRI as the reference standard.
The developed 3DNAV sequence combined 3D partial k-space acquisition with an efficient 2-bin PAWS real-time navigator gating algorithm to reduce scan time. PAWS automatically selects a gating window at the most likely diaphragmatic position even in the case of respiratory drift and reduces residual motion artifacts within the gating window through view ordering. The 3DNAV sequence was incorporated into a routine cardiac MRI protocol on a 1.5 T GE clinical scanner and imaging was performed in 22 patients (10 men, mean age of 50 ± 19 years). 2DBH DE-MRI was initiated 10 min after contrast administration (0.2 mmol/kg) and followed by free-breathing 3DNAV DE-MRI. The typical imaging parameters were: 1) 2DBH: TR/TE/FA/rBW = 7.0 ms/3.4 ms/20°/± 31.25 kHz, 256 × 192 matrix, slice = 6 mm/4 mm skip, 24 views per segment, 2RR; 2) 3DNAV: TR/TE/FA/rBW = 4.8 ms/1.5 ms/20°/± 62.5 kHz, 256 × 256 matrix, slice = 5 mm, partial NEX = 0.75, partial kz factor = 0.75, 36 views per segment, 1RR, 4 mm gating window. A subject-specific inversion time was used to null the viable myocardium.
Quantitative comparison of 2DBH and 3DNAV DE-MRI techniques
SNRinf (N = 8)
CNRinf-myo (N = 8)
Number of acquired slices (N = 22)
Scan time (N = 22)
26 ± 9
18 ± 10
11 ± 1
414 ± 118 s
46 ± 19
35 ± 19
22 ± 4
251 ± 93 s
Free-breathing navigator-gated 3D DE-MRI viability assessment is feasible and provides a similar infarct detection rate with better diagnostic confidence in shorter scan time compared to the standard breath-hold 2D DE-MRI.
This article is published under license to BioMed Central Ltd.