Magnetic Resonance Imaging Modified Dixon Fat Quantification Analysis Is a Quantitative and Reliable Method for...

Area of Science:

• Orthopedics and Sports Medicine
• Radiology and Medical Imaging

Background:

• Proximal hamstring avulsion injuries can lead to fatty degeneration and muscle atrophy.
• Accurate assessment of fatty degeneration is crucial for treatment planning and prognosis.
• Current methods for quantifying fatty degeneration may lack objectivity and reproducibility.

Purpose of the Study:

• To evaluate the reliability and validity of objective fat quantification using the modified Dixon magnetic resonance imaging (MRI) sequence.
• To assess fatty degeneration in patients with proximal hamstring avulsion injuries treated conservatively.
• To determine the suitability of the modified Dixon sequence as a measurement tool for fatty atrophy.

Main Methods:

• MRI with a modified Dixon sequence was performed on 16 patients with proximal hamstring avulsion injuries.
• Fat percentage was measured using the modified Dixon FatFraction Map with three region-of-interest (ROI) methods.
• Ischiocrural muscle cross-sectional area and Goutallier-like classification were determined to assess atrophy.

Main Results:

• Inter- and intraobserver reliability for modified Dixon fat content and muscle cross-sectional area were good (≥0.933).
• Fat content determined by the entire bundle and muscle belly ROI methods showed comparable results, indicating suitability for fat quantification.
• Fat content correlated significantly with Goutallier-like classification stages (r=0.823) and muscle cross-sectional area (r=0.363).

Conclusions:

• The modified Dixon sequence provides a quantitative and objective measure for fatty atrophy after proximal hamstring tendon injuries.
• A simplified ROI placement approach demonstrates good validity and reproducibility for fat quantification.
• Modified Dixon MRI is a suitable measurement tool for assessing fatty degeneration in these injuries.