Analysis of fatty infiltration and inflammation of the pelvic and thigh muscles in boys with Duchenne muscular dystrophy (DMD): Grading of disease involvement on MR imaging and correlation with clinical assessments

Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH, 45229-3039, USA, .
Pediatric Radiology (Impact Factor: 1.57). 05/2013; 43(10). DOI: 10.1007/s00247-013-2696-z
Source: PubMed


BACKGROUND: Prior reports focus primarily on muscle fatty infiltration in Duchenne muscular dystrophy (DMD). However, the significance of muscle edema is uncertain. OBJECTIVE: To evaluate the frequency and degree of muscle fat and edema, and correlate these with clinical function. MATERIALS AND METHODS: Forty-two boys (ages 5-19 years) with DMD underwent pelvic MRI. Axial T1- and fat-suppressed T2-weighted images were evaluated to grade muscle fatty infiltration (0-4) and edema (0-3), respectively. Degree and frequency of disease involvement were compared to clinical evaluations. RESULTS: Gluteus maximus had the greatest mean fatty infiltration score, followed by adductor magnus and gluteus medius muscles, and had the most frequent and greatest degree of fatty infiltration. Gluteus maximus also had the greatest mean edema score, followed by vastus lateralis and gluteus medius muscles. These muscles had the most frequent edema, although the greatest degree of edema was seen in other muscles. There was correlation between cumulative scores of fatty infiltration and all clinical evaluations (P < 0.05). CONCLUSION: In DMD, the muscles with the most frequent fatty infiltration had the greatest degree of fatty infiltration and correlated with patient function. However, the muscles with the most frequent edema were different from those with the greatest degree of edema. Thus, edema may not predict patient functional status.

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    • "The impressive objective finding was MRI-msk with no increase in the fatty infiltration (Figure 2A, 2B). Analysis of serial MRI scans of children with DMD suggests a 5% increase of fatty infiltration every year [27]. No significant increase in the fatty infiltration in 36 months suggests altered disease progression. "
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    ABSTRACT: Patient: Male, 9 Final Diagnosis: Duchenne muscular dystrophy Symptoms: Hyporeflexia • hypotonia • weaknes of lower limbs Medication: - Clinical Procedure: - Specialty: Neurology. Congenital defects/diseases. Duchenne muscular dystrophy (DMD) is a fatal, genetic, progressive, degenerating muscle disorder. Current treatment options are palliative. Newer options of cellular therapy promise to alter the disease process. Preclinical studies have successfully tested myogenic, neurogenic potential and dystrophin expression of bone marrow mononuclear cells. We treated a 9-year-old boy suffering from DMD with serial autologous bone marrow mononuclear cell transplantations followed by multidisciplinary rehabilitation. Brooke-Vignos score was 10 and he was wheelchair-bound. Over 36 months, gradual progressive improvement was noticed in muscle strength, ambulation with assistive devices, fine motor movements, Brooke-Vignos score, and functional independence measure score. Nine months after the transplantation, electromyography findings showed development of new normal motor unit potentials of the vastus medialis muscle. Magnetic resonance imaging scan of musculoskeletal systems showed no increase in fatty infiltration. This case report provides early investigative findings or the restorative effects of cellular therapy in DMD.
    American Journal of Case Reports 03/2014; 15:128-34. DOI:10.12659/AJCR.890078
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    ABSTRACT: Various skeletal muscle diseases result in fatty infiltration, making it important to develop noninvasive biomarkers to objectively measure muscular fat. We compared T2 relaxation time mapping (T2 maps) and magnetic resonance spectroscopy (MRS) with physical characteristics previously correlated with intramuscular fat to validate T2 maps and MRS as objective measures of skeletal muscle fat. We evaluated gluteus maximus muscles in 30 healthy boys (ages 5-19 years) at 3 T with T1-weighted images, T2-W images with fat saturation, T2 maps with and without fat saturation, and MR spectroscopy. We calculated body surface area (BSA), body mass index (BMI) and BMI percentile (BMI %). We performed fat and inflammation grading on T1-W imaging and fat-saturated T2-W imaging, respectively. Mean T2 values from T2 maps with fat saturation were subtracted from T2 maps without fat saturation to determine T2 fat values. We obtained lipid-to-water ratios by MR spectroscopy. Pearson correlation was used to assess relationships between BSA, BMI, BMI %, T2 fat values, and lipid-to-water ratios for each boy. Twenty-four boys completed all exams; 21 showed minimal and 3 showed no fatty infiltration. None showed muscle inflammation. There was correlation between BSA, BMI, and BMI %, and T2 fat values (P < 0.05), and between BMI and BMI %, and lipid-to-water ratios (P < 0.05). There was strong correlation between T2 fat values and lipid-to-water ratios (P < 0.0001, r = 0.83). T2 maps and MR spectroscopy correlate with physical characteristics associated with fatty infiltration of skeletal muscles, even in microscopic amounts, and validate each other. Both techniques might enable detection of minimal pathological fatty infiltration in children with skeletal muscle disorders.
    Pediatric Radiology 11/2013; 44(2). DOI:10.1007/s00247-013-2791-1 · 1.57 Impact Factor
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