Fat-Fraction Quantification Using Three-Point Dixon Technique in Duchenne Muscular Dystrophy and Its Correlation With...

Area of Science:

• Biomedical Imaging
• Musculoskeletal Research
• Neuromuscular Disorders

Background:

• Muscle fat fraction (MFF) quantification via Dixon MRI is an emerging, non-invasive biomarker for Duchenne muscular dystrophy (DMD).
• Understanding MFF's relationship with disease progression is crucial for monitoring DMD.
• This study investigates MFF's correlation with functional decline and genetic characteristics in DMD.

Purpose of the Study:

• To evaluate the relationship between muscle fat fraction (MFF) and disease progression in Duchenne muscular dystrophy (DMD).
• To assess the correlation of MFF with functional decline and genotypic characteristics in DMD patients.

Main Methods:

• A single-center prospective observational study included ambulatory boys with genetically confirmed DMD.
• Muscle fat fraction (MFF) of pelvic and thigh muscles was quantified using Dixon MRI.
• Functional measures (MRC sum score, NSAA, 6MWT) were assessed at baseline, 6, and 12 months.

Main Results:

• Forty boys (median age 8 years) participated. Gluteal muscles showed the highest MFF, hamstrings the lowest.
• MFF strongly inversely correlated with all functional measures across most muscle groups.
• Baseline quadriceps MFF showed the strongest correlation with the rate of 6MWT decline over one year.

Conclusions:

• Baseline MFF, particularly in the quadriceps, predicts functional decline in ambulatory DMD patients.
• Genotype-specific adductor muscle involvement suggests variant-specific spatial differences in DMD.
• Longitudinal studies with genotype-phenotype analysis are needed to validate MFF as a biomarker for DMD clinical trials.