Evaluation of Magnetization Transfer Contrast Sequences: Application to Monitor Age-Related Differences in Muscle...

Area of Science:

• Biomedical Imaging
• Musculoskeletal Radiology
• Aging Research

Background:

• Aging muscle exhibits increased fibrosis, adipose tissue, and fiber atrophy.
• Magnetization transfer contrast (MTC) imaging offers various sequences to assess tissue composition.
• Quantitative MTC (qMT) provides macromolecular fraction, while other methods use signal intensity ratios.

Purpose of the Study:

• To evaluate five MTC sequences for their ability to detect age-related muscle tissue differences.
• To compare the efficacy of different MTC techniques in characterizing muscle aging.

Main Methods:

• Fifteen young and nine senior adults underwent lower leg MRI using multi-offset qMT, single-offset qMT, MTsat, MTR, and MTRcorr sequences.
• T1 mapping was also performed.
• Statistical analysis identified age-related and regional differences.

Main Results:

• Significant age-related decreases were observed in macromolecular fraction, MTsat, MTR, and MTRcorr (p < 0.001).
• A significant age-related increase in T1 was also noted (p < 0.001).
• Weak to moderate, but significant, correlations were found between T1 and MTC indices.

Conclusions:

• Age-related MTC decreases likely reflect myofibrillar protein loss outweighing collagen increase.
• The modest T1-MTC correlation suggests inflammation does not fully explain age-related MTC changes.
• The MTsat sequence is clinically relevant due to speed, simplicity, and effectiveness in detecting age-related macromolecular changes.