Validation of cardiac diffusion tensor imaging sequences: A multicentre test-retest phantom study.

Area of Science:

• Medical Imaging
• Biophysics
• Cardiovascular Research

Background:

• Cardiac diffusion tensor imaging (DTI) is an emerging in vivo technique for characterizing myocardial microstructure.
• There is a significant need for validation and standardization of cardiac DTI techniques.

Purpose of the Study:

• To establish the accuracy, precision, repeatability, and reproducibility of state-of-the-art cardiac DTI pulse sequences.
• To assess these parameters across 10 international centers using standardized phantoms.

Main Methods:

• Utilized polyvinylpyrrolidone (PVP) phantoms (0%-20%) scanned with product pulsed gradient spin echo (PGSE) and custom motion-compensated spin echo (SE) or stimulated echo acquisition mode (STEAM) sequences.
• Performed identical repeat scans 1-9 days later and conducted central data analysis.

Main Results:

• Mean diffusivities (MDs) in 0% PVP were highly accurate (within 1.5% of literature data) for all sequences (PGSE, SE, STEAM).
• Inter-center coefficients of variation for MDs were low (2.1%-3.1%), comparable to previous PGSE-only studies.
• Excellent reproducibility in MD was demonstrated, with minimal mean differences across sites for all tested sequences.

Conclusions:

• Custom sequences for cardiac DTI provide accurate, precise, repeatable, and reproducible measurements of myocardial microstructure.
• These findings support the standardization and clinical application of advanced cardiac DTI techniques.
• Further investigation with anisotropic and/or deforming phantoms is recommended.