Background: Preoperative identification of intramuscular hemangioma (IMH) subtypes (capillary hemangioma, cavernous hemangioma, and mixed hemangioma) is urgently necessary. Enhanced T2*-weighted angiography (ESWAN) is sensitive to vessels and metabolites and can be used to diagnose IMH subtypes.
Purpose: To compare the diagnostic performances of ESWAN and conventional magnetic resonance imaging (MRI) for qualitative and quantitative diagnosis of IMH subtypes.
Material and methods: In total, 23 patients with IMHs were examined using conventional MRI and ESWAN. The signal intensity ratios (SIRs) of conventional MRI and ESWAN were measured.
Results: There was no significant difference for volume among the three subtypes (P = 0.124, P = 0.145). Various shapes and MRI signals were shown in the three subtypes of IMH. There was no significant difference for SIRs of conventional MRI (P = 0.558, P = 0.259, P = 0.385, P = 0.347). However, there was a significant difference for SIRs of ESWAN parameters (P = 0.050, P < 0.001, P = 0.005, P = 0.002). Capillary hemangiomas can be diagnosed when R2* SIR is <0.912 and intratumoral susceptibility signal (ITSS) percentage is <29.085%. Cavernous hemangiomas should be considered when R2* SIR is >0.912, ITSS percentage >35.226%, and phase SIR >2.536. In addition, mixed hemangiomas should be considered when T2* SIR is >0.662 and R2* SIR <1.618.
Conclusion: Conventional MRI can only display the volume, shape, and signal of IMHs. 3D-MinIP imaging of ESWAN can show the veins and minor hemorrhage. SIRs of ESWAN parameters including T2* value, R2* value, phase value, and percentage of ITSS can be used to quantitatively diagnose capillary hemangiomas, cavernous hemangiomas, and mixed hemangiomas.
Keywords: Intramuscular hemangioma; enhanced T2*-weighted angiography; magnetic resonance imaging; subtypes.