Summary of MR imaging characteristics in diffuse peripheral nerve lesionsa
| Etiology | Enlargement | T2 Hyperintensity | Fascicular Pattern | Course | Enhancement |
|---|---|---|---|---|---|
| Trauma | ± | + | Minimally effaced/disrupted | May be altered due to hematoma/fracture | – |
| Acute inflammation | ± | ++ | Effaced/preserved | Not altered | + |
| CIDP | ++ | +++ | Effaced/enlarged | Not altered | ++ |
| Infectious | +/++ | ++ | Effaced/disrupted | May be altered by abscess/granulation tissue | ++ |
| CMT/HSMN | ++ | ++ | Preserved ↑ fatty infiltration around atrophic fascicles | Normal | ± |
| Radiation | ± (linear; geographic distribution of radiation field) | + | Preserved/effaced | Altered in subacute-chronic stages due to developing fibrosis | + |
| NL | ++ | ++ | Effaced/disrupted | Altered with focal masses | ++ |
| NF1 | ++ | ++ | Preserved | Altered with focal masses | +/++ |
| MPNST in NF1 | +++ | +, Necrotic areas | Disrupted | Altered due to mass-effect | ++ (heterogeneous) |
| Perineuroma | ++ | ++ | Preserved/effaced focally | Altered with focal masses | ++ |
| FLH | +++ | + (fat causing T1 hyperintensity) | Preserved (coaxial cable/spaghetti) | Altered with thick tortuous nerve | – |
| Amyloid | ++ | + Cutaneous induration with subcutaneus stranding | Preserved/disrupted focally | Altered with focal masses | ± |
a ± indicates variable; +, mild; ++, moderate; +++, marked; –. absent.