2020/05 - Respiratory motion-compensated high-resolution 3D whole-heart T1p mapping [ Journal Club ]-Respiratory motion-compensated high-resolution 3D whole-heart T1p mapping [ Journal Club ]

Respiratory motion-compensated high-resolution 3D whole-heart T1p mapping [ Journal Club ]

Video Transcription

Video Summary

The JCMR Journal Club opened with announcements about recording availability, free CME for members, and a schedule change moving future sessions from 10:00 to 11:00 AM on the second Wednesday of the month. Dr. Raymond Kwong introduced a presentation from Dr. Haikun Qi on whole-heart 3D T1rho mapping.<br /><br />Dr. Qi explained that T1rho MRI measures low-frequency spin-lock interactions and may offer an endogenous contrast mechanism for cardiac tissue characterization without gadolinium. He reviewed prior applications in myocardial infarction and diffuse fibrosis, then described limitations of conventional 2D and 3D methods, including motion artifacts, low SNR, heart-rate sensitivity, and long scan times.<br /><br />The proposed sequence uses a saturation pulse at each heartbeat, segmented spin-lock preparation, navigators for respiratory motion tracking, variable-density spiral sampling, and a low-rank reconstruction algorithm. In phantom and human studies, the technique produced near-isotropic whole-heart maps in about 6 minutes, with accuracy similar to a 2D reference, though precision decreased at higher heart rates and near the apex due to motion correction challenges. Early patient examples showed elevated T1rho in infarcted myocardium.<br /><br />The discussion focused on heart-rate robustness, spin-lock amplitude limits, feasibility at 3T, comparison with LGE and native T1, potential for fibrosis/scar assessment, and future multicenter translation.

Keywords

JCMR Journal Club

whole-heart 3D T1rho mapping

cardiac MRI

gadolinium-free imaging

myocardial fibrosis

spin-lock MRI

respiratory motion correction

low-rank reconstruction

myocardial infarction