Regional variation in paraspinal muscle composition using chemical shift encoding-based water-fat MRI

Area of Science:

• Anatomy
• Physiology
• Biomarkers

Background:

• Paraspinal musculature is extensive, yet regional composition variations and gender/BMI influences are poorly understood.
• Understanding these variations is crucial for interpreting muscle health and disease.

Purpose of the Study:

• To investigate regional differences in paraspinal muscle composition.
• To determine the influence of gender and BMI on muscle fat fraction across different spinal levels.

Main Methods:

• Six-echo chemical shift encoding-based water-fat MRI at 3 Tesla was used.
• Proton density fat fraction (PDFF) was measured in psoas and erector spinae muscles (segmented L3-L5, T12-L2, T9-T11) in 76 subjects.

Main Results:

• Significant gender differences in PDFF were observed for psoas and L3-L5 erector spinae muscles.
• The L3-L5 erector spinae muscle PDFF was higher than other segments and independent of BMI.
• Other segments and psoas muscles showed BMI dependency.

Conclusions:

• Regional variations in paraspinal muscle composition exist.
• The L3-L5 erector spinae muscle PDFF is a promising, BMI-independent biomarker for paraspinal muscle assessment.