Table 3:

Summary of MR imaging characteristics in diffuse peripheral nerve lesions^a

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.