Correlation of magnetization transfer and diffusion magnetic resonance imaging in multiple sclerosis

Area of Science:

• Neuroimaging
• Radiology
• Biomedical Engineering

Background:

• Multiple Sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Magnetic Resonance Imaging (MRI) is crucial for MS diagnosis and monitoring.
• Diffusion MRI (dMRI) and Magnetization Transfer (MT) MRI are advanced techniques used to assess tissue microstructural changes.

Purpose of the Study:

• To correlate diffusion (Apparent Diffusion Coefficient - ADC) and Magnetization Transfer (Magnetization Transfer Ratio - MTR) MRI findings in MS patients.
• To determine if dMRI and MT MRI provide complementary information in characterizing MS lesions and normal-appearing white matter (NAWM).

Main Methods:

• ADC and MTR values were measured in 156 regions of interest (ROIs) across 14 MS patients.
• ROIs included T1 hypointense lesions (n=84), T1 isointense lesions (n=60), and NAWM (n=12).
• Statistical analysis, including Pearson correlation, was used to compare ADC and MTR values.

Main Results:

• MTR was lower in T1 hypointense lesions compared to T1 isointense lesions and NAWM.
• ADC was higher in T1 hypointense lesions compared to T1 isointense lesions and NAWM.
• A significant negative correlation between ADC and MTR was observed in T1 hypointense lesions (r = -0.758, P < 0.001), but weaker in T1 isointense lesions (r = -0.256, P = 0.049), and absent in NAWM.

Conclusions:

• The strong correlation between ADC and MTR in hypointense MS lesions suggests they reflect similar pathological processes when tissue integrity is compromised.
• In T1 isointense lesions and NAWM, where tissue integrity is less compromised, ADC and MTR may be sensitive to different underlying pathological changes.
• Combining dMRI and MT MRI may offer complementary insights into the complex pathophysiology of MS.