Fedel Machado-Rivas1,2, Daniel J Park3, John Conklin1,2, John E Kirsch2,3, and Michael S Gee1,2
1Radiology, Massachusetts General Hospital, Boston, MA, United States, 2Radiology, Harvard Medical School, Boston, MA, United States, 3MGH Martinos Center for Biomedical Imaging, Boston, MA, United States
1Radiology, Massachusetts General Hospital, Boston, MA, United States, 2Radiology, Harvard Medical School, Boston, MA, United States, 3MGH Martinos Center for Biomedical Imaging, Boston, MA, United States
Widening of the refocusing pulse of T2-weighted multi-shot TSE can mitigate signal loss associated with through-plane respiratory motion. 2x refocusing pulse modified free breathing sequence provides comparable image quality and contrast to a triggered acquisition.
Schematic representation of through plane motion and refocusing pulse modifications. (A) shows a coronal acquisition during expiration and inspiration, where abdominal contents are displaced by the diaphragm. (B) illustrates the proposed refocusing pulse modification by doubling its thickness to mitigate long T2 signal loss.
Comparison of respiratory triggered, free-breathing, and modified 2x refocusing pulse free breathing T2-weighted fat suppressed multi-shot TSE (BLADE). Arrow shows severe signal loss for the standard free breathing sequence that is mitigated in the modified 2x refocusing pulse sequence. Acquisition times (AT) for each sequence are displayed in mm:ss.
