Longitudinal Evaluation of Muscle Composition Using Magnetic Resonance in 4 Boys With Duchenne Muscular Dystrophy: Case Series
Bibliographic record
Abstract
BACKGROUND: Duchenne muscular dystrophy (DMD), an inherited recessive X chromosome-linked disease, is the most severe childhood form of muscular dystrophy. Boys with DMD experience muscle loss, with infiltration of intramuscular fat into muscles. OBJECTIVES: This case series describes the progression of DMD in boys using magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Magnetic resonance results are then compared with an established functional timed test. METHODS: Four boys with DMD and 4 healthy age-matched controls were chosen from a larger cohort. Boys with DMD were assessed at 4 time points over 2 years, with controls assessed at baseline only. Progression of the disease was documented by assessing the plantar flexors using MRI and MRS techniques and by assessing ambulation using the 30-Foot Fast Walk Test. RESULTS: Transverse relaxation time (T2) values were elevated in all boys with DMD at baseline. The lipid ratio increased rapidly as the disease progressed in 2 boys. Discrete changes in T2 in the other 2 boys with DMD indicated a slower disease progression. Magnetic resonance imaging and MRS allowed monitoring of the disease over all time periods regardless of ambulation status. LIMITATIONS: The magnetic resonance data were collected with 2 different magnets at 2 different field strengths (1.5 and 3.0 T). Although we corrected for this difference, care must be taken in interpreting data when different image collection systems are used. This was a case series of 4 boys with DMD taken from a larger cohort study. CONCLUSIONS: Magnetic resonance imaging and MRS are objective, noninvasive techniques for measuring muscle pathology and can be used to detect discrete changes in both people who are ambulatory and those who are nonambulatory. These techniques should be considered when monitoring DMD progression and assessing efficacy of therapeutic interventions.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".