2022/11 - Quantitative susceptibility mapping (QSM) of the cardiovascular system: challenges and perspectives [Journal Club]-Journal Club Webinar

Video Transcription

Video Summary

The JCMR Journal Club opened with housekeeping announcements about CME credit, chat participation, and recording availability, then introduced this month’s topic: quantitative susceptibility mapping (QSM) in the cardiovascular system. Andrew Tyler presented a review of QSM theory, explaining how susceptibility affects magnetic fields and how QSM reconstructs local tissue susceptibility from gradient echo phase data. He highlighted the main technical hurdles: removing overwhelming background fields, solving an ill-posed inverse problem, and avoiding streaking artifacts through regularized reconstruction methods such as MEDI.<br /><br />The discussion then focused on key cardiovascular applications. QSM may help measure left-right ventricular blood oxygen differences, detect intramyocardial hemorrhage after myocardial infarction, assess myofibril orientation, and characterize atherosclerotic plaque, especially to distinguish intraplaque hemorrhage from calcification. Speakers emphasized that QSM appears more sensitive than T2* in some hemorrhage settings and could provide non-contrast biomarkers.<br /><br />Major barriers to clinical translation include poor shimming, motion, epicardial fat, lack of an absolute reference standard in the heart, and susceptibility artifacts from implants. The panel agreed that future progress will depend on improved acquisition and reconstruction methods plus large clinical validation studies, with acute STEMI and plaque characterization seen as especially promising early applications.

Keywords

quantitative susceptibility mapping

cardiovascular MRI

gradient echo phase data

susceptibility reconstruction

MEDI regularization

myocardial hemorrhage

atherosclerotic plaque

T2* comparison

STEMI validation