MRI Findings and Diagnostic Significance of Soft Tissue Schwannomas in the Extremities

Objective:To analyze the MRI features and rare manifestations of schwannomas of the extremities to improve diagnosis.Methods:Retrospective analysis of 23 cases of schwannomas in the extremities confirmed by surgical pathology,summarizing its signs,signal characteristics and MRI enhancement.Results:Among the 23 cases,20 were single lesions,and 3 were multiple lesions,resulting in a total of 28 lesions.The distribution of these lesions included 7 in the thigh,9 in the calves,4 in the armpits,3 in the hips,and 4 each in the upper arms and forearms.Additionally,there was one lesion located in the groin.On T1-weighted imaging(T1WI),the lesions showed iso-intensity or hypo-intensity.On T2-weighted imaging(T2WI),they appeared slightly hyperintense or hyper-intense.Some lesions exhibited multiple small vesicle-like higher signals,cystic changes,and fiber spacing on T2WI.Furthermore,one lesion showed a liquid-liquid plane.The“target sign”was observed in 18 lesions(64.3%)and“neuropathic signs”were present in six lesions(21.4%).Finally,it was noted that on MRI enhancement,the lesions demonstrated uniform or uneven enhancement.The lesions were uniformly or unevenly enhanced on MRI enhancement.Conclusions:The MRI findings of schwannoma in the extremities exhibit specific characteristics.The cystic changes on T2WI also display distinct features.Recognition of rare MRI findings,such as cystic changes,liquid-liquid plane and septum,should be emphasized to enhance the accuracy of pre-diagnosing schwannomas.

CT and MRI Findings of Intracranial Cavernous Hemangioma Malformation

Objective:To investigate the computed tomography(CT)and magnetic resonance imaging(MRI)features of cavernous hemangioma malformation(CHM)to enhance diagnostic accuracy.Methods:The CT and MRI findings and clinical information of 23 patients with CHM were retrospectively analyzed.Results:CT examinations were conducted in 7 cases,while MRI was utilized in 23 cases.Additionally,SWI was employed in 5 cases and enhanced imaging techniques were applied in 14 cases.Among the observed lesions,20 cases presented with a singular lesion,whereas 3 cases exhibited multiple lesions.The lesions were located in 8 frontal lobes,6 cerebellums,2 brainstems,6 temporal lobes,1 basal ganglia,3 parieto-occipital lobes,and 2 thalamus regions.The nodules appeared as quasi-circular lesions with clear or well-defined boundaries.They presented as isodense lesions on CT scans,with one lesion showing peritumoral edema.On MRI,T1-weighted imaging(T1WI)demonstrated isointense signals,while T2-weighted imaging(T2WI)showed isointense and hyperintense signals.Additionally,10 lesions exhibited a low signal ring on T2WI.Diffusion-weighted imaging(DWI)revealed nodular or isointense low signals,while susceptibility-weighted imaging(SWI)displayed enlarged areas of low signal.Fourteen lesions underwent contrast-enhanced scanning,with 2 lesions showing no obvious enhancement,1 lesion demonstrating mild to moderate enhancement,and 11 lesions exhibiting significant enhancement.Notably,6 of these enhanced lesions were surrounded by small blood vessels.Conclusion:Cavernous hemangioma malformation is more commonly found in individual cases.CT alone lacks specificity,making it prone to misdiagnosis.A more comprehensive evaluation of cavernous hemangioma malformation can be achieved through a combination of MRI,DWI,SWI,and enhanced examination,providing valuable references for clinical assessment.