Magnetisation Transfer 3D-Radial Zero Echo Time MR Imaging at 7T.

Area of Science:

• Medical Imaging
• Neuroscience
• Biophysics

Background:

• Magnetisation Transfer (MT) MRI aids in diagnosing neuro-degenerative disorders like Multiple Sclerosis (MS).
• Conventional MRI sequences struggle to detect short T2 MR signals due to long echo times.
• Investigating a 3D-radial Zero Time of Echo (ZTE) MT-weighted sequence for improved sensitivity.

Purpose of the Study:

• To evaluate a novel 3D-radial ZTE MT-weighted sequence for enhanced detection of short T2 MR signals.
• To assess the sequence's performance in visualizing Multiple Sclerosis (MS) pathology.
• To compare the sensitivity of the new sequence against conventional MRI techniques.

Main Methods:

• A 3D-radial ZTE MT-weighted sequence was implemented on a 7T MRI scanner.
• The sequence achieved whole-brain coverage with 0.8 mm isotropic resolution in 6.5 minutes.
• RF pulses were optimized for fat suppression, MT weighting, and mitigation of transmit field inhomogeneities.

Main Results:

• The SilentMT sequence successfully detected all MS lesions visible on 1.5T FLAIR in an MS patient.
• SilentMT identified lesions missed by both 1.5T and 7T FLAIR, including one not initially apparent.
• Increased Magnetisation Transfer Ratio (MTR) was observed in specific brain regions of the MS patient.

Conclusions:

• The MT-weighted ZTE sequence (SilentMT) demonstrates potential for increased sensitivity in MS imaging.
• This novel sequence may improve the detection of subtle or previously undetected MS lesions.
• SilentMT shows promise as an advanced tool for neuroimaging in Multiple Sclerosis.