2024/06 - Characterization of Quantitative Susceptibility Mapping in the Left Ventricle of the Myocardium [Journal Club]-June JCMR Journal Club 2024

Video Transcription

Video Summary

The JCMR Journal Club episode featured Dr. Andrew Tyler and Dr. Pier Giorgio Moschke presenting their paper on quantitative susceptibility mapping (QSM) of the left ventricular myocardium. They explained the physics behind QSM, including how susceptibility relates to magnetic field perturbations, and why cardiac imaging is challenging because of background field inhomogeneity, motion, and the need to solve an ill-posed deconvolution problem.<br /><br />The study included phantom testing, healthy volunteer test-retest scans, patients without myocardial infarction, and patients with acute STEMI. Using a 1.5T Siemens scanner and a multi-echo 3D GRE sequence, the team showed that QSM was accurate in the phantom, reproducible in healthy volunteers, and able to detect intramyocardial hemorrhage (IMH) in acute infarction. In several cases, QSM appeared more specific than T2* by avoiding false positives caused by B0 inhomogeneity or edema.<br /><br />The discussion highlighted practical issues such as motion sensitivity, regularization choices, fat suppression, and the potential for future quantitative iron assessment. The presenters and moderator agreed that QSM is promising for quantitative IMH evaluation, but larger clinical validation studies are still needed.

Keywords

quantitative susceptibility mapping

left ventricular myocardium

intramyocardial hemorrhage

cardiac MRI

magnetic susceptibility

acute STEMI

B0 inhomogeneity

T2* imaging