Related Experiment Video
Updated: May 7, 2026
09:17
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Published on: July 29, 2011
14.9K
Rotating Frame Relaxation Time Mapping for the Visualization of the Sinoatrial Node Without Contrast Agent
Yi Li1, Victor Casula1, Tarja Huhta2
1Research Unit of Health Sciences and Technology, University of Oulu, Oulu, Finland.
NMR in Biomedicine
|June 30, 2025
Summary
This study introduces rotating frame relaxation (RAFF2 and T1ρ) MRI to visualize the sinoatrial node (SAN) in swine hearts without contrast agents. These methods offer a promising non-invasive alternative for SAN imaging and characterization.
Area of Science:
- Cardiovascular Magnetic Resonance Imaging
- Medical Imaging Physics
- Cardiac Electrophysiology
Background:
- Late gadolinium-enhanced cardiovascular magnetic resonance (LGE-CMR) is used for sinoatrial node (SAN) visualization.
- Contrast agents pose limitations for repeated or long-term imaging.
Purpose of the Study:
- To investigate rotating frame relaxation (RAFF2 and T1ρ) time mapping for characterizing swine heart SAN structure ex vivo.
- To assess the feasibility of non-contrast MRI techniques for SAN imaging.
Main Methods:
- Ex vivo swine hearts scanned using 7T and 3T MRI systems.
- Comparison of TRAFF2, T1ρ, T1, T2 relaxation time mappings, and magnetization transfer (MT) imaging.
- Histological validation using Masson's trichrome staining.
Main Results:
- Significant differences in endogenous MRI contrasts observed between SAN and myocardium.
- TRAFF2 and T1ρ demonstrated the highest contrast between SAN and myocardium.
- SAN sizes from TRAFF2 and T1ρ maps correlated well with histological fibrous structures.
Conclusions:
- TRAFF2 and T1ρ mapping show potential for non-contrast visualization of the SAN in swine hearts.
- These techniques could provide a non-invasive alternative to LGE-CMR for SAN detection and characterization.
