Table 2:

Imaging findings of IOVM and common lesions in the differential diagnosis

DiagnosisCT FindingsMR Imaging Findings
IOVMExpansile and well-circumscribedCortex intact, but thin/scallopedStippled internal trabeculae, or,Honeycomb/spoke wheel ossificationT2-very hyperintense, with internal stippled or striated signal voidT1 signal varies, thrombus may be brightT1 + gadolinium–avid enhancement
Intraosseous meningiomaDense marrow sclerosis and shaggy cortical hyperostosisExtraosseous soft tissueT2 intermediateT1 + gadoliniumIntraosseous: ± enhancementExtraosseous: avid plaquelike enhancement
Fibrous dysplasiaGround-glass matrix, ± cystic or more sclerotic elementsT2 low-intermediate signal, though varies depending on cystic changeT1 + gadolinium: avid enhancement
Metastasis, myelomaNo matrixCortical lysisMultiplicityVariable, depending on primary tumor
LymphomaNo matrixHyperdense soft tissueT2 intermediate, T1 + gadolinium: bland enhancementDiffusion-restriction, hypercellularity
ChondrosarcomaRings/whorls of calcified matrixClassic location, petroclivalT2 marked hyperintensityEnhancement, variable but often mild
Epidermoid cystLow densityNo internal matrixT1-hypointense, T2-hyperintenseDiffusion restrictionNo internal enhancement