Modified PROPELLER approach for T₂-mapping of the abdomen

Quantitative abdominal T₂ measurements may be useful for lesion differentiation and functional tissue characterization. However, T₂ mapping of the abdomen with conventional spin-echo (SE) and turbo-spin-echo (TSE) approaches can be challenging due to physiologic motion artifacts. Multishot TSE-based PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) can provide superior image quality due to reduced sensitivity to motion artifacts. With echo-reordering to accurately estimate effective echo times and an extended slice thickness ratio to reduce stimulated echo effects, a modified PROPELLER approach may permit accurate, robust abdominal T₂ measurements. We validated the accuracy of our modified PROPELLER T₂-mapping approach by comparison to conventional SE measurements in a phantom model and demonstrated the feasibility of acquiring accurate, high-quality abdominal T₂ maps in normal volunteers.