Table 2.
Score | Lamminen [79] | Mercuri et al. [59, 78] | Jungbluth et al. [62, 64] |
---|---|---|---|
0 | Normal | Normal | |
1 | Normal muscle signal intensity | Early moth-eaten appearance, with scattered small areas of increased density on T1 MRI | Mild with only traces of increased signal intensity |
2 | Slightly hyperintense, patchy intramuscular signal changes | A: Late moth-eaten appearance, with numerous discrete areas of increased density with beginning confluence, comprising less than 30% of the volume of the individual muscle B: Late moth-eaten appearance, with numerous discrete areas of increased density with beginning confluence, comprising 30–60% of the volume of the individual muscle |
Moderate with increased signal in less than 50% of affected muscle |
3 | Markedly hyperintense, patchy but widespread intramuscular changes | Washed-out appearance, fuzzy appearance due to confluent areas of increased density with muscle still present at the periphery | Severe with increased signal intensity in more than 50% of affected muscle |
4 | Total, homogeneous hyperintense signal change in whole muscle, equaling the signal intensity of adjacent subcutaneous or paramuscular fat | End-stage appearance, muscle replaced by increased density connective tissue and fat with only rim of fascia and neurovascular structures distinguishable | Entire muscle replaced by abnormal signal |