MRI manifestations and literature review of alveolar soft part sarcoma
Objective To investigate the MRI manifestations of alveolar soft part sarcoma(ASPS)and to improve the diagnostic accuracy of ASPS.Methods The clinical and MRI data of 9 patients with ASPS confirmed by surgical pathology were analyzed ret-rospectively,and the MRI features were summarized and analyzed.Results Four cases were located in the thigh,three cases in the pelvis,one case in the calf,and one case under the chin.Seven cases were spindle shaped,one case was irregular,and one case was quasi-circular.All nine cases had clear boundaries.Seven cases of ASPS had lung metastases,and two of these also had brain metasta-ses.On T1WI,three cases showed isointense signals,and six cases showed slightly hyperintense signals.On T2WI,seven cases showed mixed hyperintense signals and two cases showed homogeneous hyperintense signals.On diffusion weighted imaging(DWI),six cases showed mixed hyperintense signals,one case showed homogeneous hyperintense signals,and one case showed isointense sig-nal;the average apparent diffusion coefficient(ADC)value was(1.14±0.10)×10-3 mm2/s.Six cases showed inhomogeneous obvious enhancement,and one case showed homogeneous enhancement;three cases showed relatively obvious enhancement in small strip-like fat suppression(FS)-T2WI hyperintense areas of ASPS.All nine cases of ASPS showed"flow void vessels sign",with seven cases showed"flow void vessels"both intratumor and peritumor,while the other two cases showed"flow void vessels"only peritumor.Six cases of ASPS showed cystic changes and necrosis.Three cases showed"pseudocapsule".Two cases showed T2WI hypointense septa-tion.Conclusion Hyperintense signals on T1WI,"flow void vessels sign"on T2WI,and inhomogeneous obvious enhancement in ASPS are helpful for diagnosis,with final confirmation relying on pathology.
alveolar soft part sarcomamagnetic resonance imagingdiffusion weighted imagingapparent diffusion coefficient