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Updated: Dec 23, 2025
Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
Published on: December 18, 2016
A quantitative method to assess muscle edema using short TI inversion recovery MRI
Julia R Dahlqvist1, Ruth Salim2, Carsten Thomsen3
1Copenhagen Neuromuscular Center, Section 3342, Department of Neurology, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen, Denmark. julia.rebecka.dahlqvist@regionh.dk.
Abstract:
Muscle inflammation is an important component of disease pathophysiology in several muscular dystrophies. Hyperintensities on MRI sequences with short TI inversion recovery (STIR) reflect edema, or inflammation (STIR+). Conventionally, STIR evaluation has been done by visual inspection. In this study, we developed a quantitative STIR method, and tested its ability to identify STIR+ lesions in healthy controls and patients with Facioscapulohumeral muscular dystrophy and compared the results with visual STIR evaluation and quantitative T2 relaxation time mapping. The method was based on pixel-by-pixel histograms of the distribution of signal intensities from muscles. Signal intensities from healthy control muscles were averaged and used to define an upper reference limit. Muscles with >2.5% pixels above the limit were defined as being STIR+. The new method showed agreement with T2 relaxation time mapping in 95% of muscles. The visual STIR method only showed agreement with the quantitative STIR method and T2 relaxation time mapping in 88 and 84%, respectively. STIR sequences are available on most MR scanners and the post-processing used in the new quantitative method can be performed using free software. We therefore believe that the new method can play an important role in identifying STIR+ lesions in patients with neuromuscular diseases.
Insights
A new quantitative MRI method accurately detects muscle inflammation (STIR+) in muscular dystrophy patients. This technique offers improved objectivity over visual assessment for diagnosing neuromuscular diseases.
Area of Science:
- Medical Imaging
- Neuromuscular Diseases
- Quantitative MRI
Background:
- Muscle inflammation is a key factor in muscular dystrophy.
- Short TI inversion recovery (STIR) MRI hyperintensities indicate edema/inflammation (STIR+).
- Current STIR evaluation relies on subjective visual inspection.
Purpose of the Study:
- To develop and validate a quantitative STIR MRI method.
- To assess its accuracy in identifying STIR+ lesions in Facioscapulohumeral muscular dystrophy (FSHD).
- To compare quantitative STIR with visual STIR and quantitative T2 mapping.
Main Methods:
- Developed a pixel-by-pixel histogram-based quantitative STIR method.
- Defined STIR+ lesions based on signal intensity thresholds from healthy controls.
- Compared results with visual STIR and quantitative T2 relaxation time mapping.
Main Results:
- The quantitative STIR method achieved 95% agreement with T2 mapping.
- Visual STIR showed lower agreement (88% with quantitative STIR, 84% with T2 mapping).
- The method is applicable to standard MRI scanners and uses free software.
Conclusions:
- Quantitative STIR MRI provides an objective and accurate method for detecting muscle inflammation.
- This technique can significantly aid in the diagnosis and management of neuromuscular diseases.
- It offers a more reliable alternative to subjective visual STIR assessment.
