Enhanced and unenhanced MR with magnetization transfer in multiple sclerosis

Area of Science:

• Radiology
• Neurology
• Medical Imaging

Background:

• Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system.
• Accurate identification of active lesions is crucial for monitoring disease progression and treatment efficacy in MS.

Purpose of the Study:

• To evaluate the utility of magnetization transfer (MT) imaging in conjunction with contrast-enhanced MRI for detecting enhancing lesions in multiple sclerosis.
• To assess whether MT imaging improves the detection or characterization of active MS lesions compared to standard contrast-enhanced MRI.

Main Methods:

• Contrast-enhanced T1-weighted spin-echo MR images were acquired in 20 relapsing-remitting MS patients, with and without MT sequences.
• Enhancing plaques were identified and compared between enhanced and unenhanced T1-weighted MT images.
• Contrast-to-noise ratios (CNRs) were calculated for lesions on both enhanced and unenhanced MT T1-weighted images.

Main Results:

• Ten plaques were identified as enhancing only when using enhanced MT T1-weighted images (≥11% increase).
• These plaques were also hyperintense on unenhanced T1-weighted MT images.
• The CNRs for these lesions were not statistically different between enhanced (16.52) and unenhanced (15.65) MT images.

Conclusions:

• Using contrast-enhanced magnetization transfer MR images alone may lead to an overestimation of the number of enhancing plaques in MS patients.
• Careful interpretation is needed when evaluating lesion enhancement in MS, considering both enhanced and unenhanced sequences.