Magnetic Resonance Features and Characteristic Vascular Pattern of Alveolar Soft-Part Sarcoma

The aim of this study was to investigate the magnetic resonance (MR) features of alveolar soft-part sarcoma (ASPS).

We studied 12 patients with ASPS confirmed by pathology in this retrospective study. MR features were analyzed, especially for the location, morphology, signals, and related enhanced features of the tumor vessels.

Flow voids were shown in the central part of the tumor on T2-weighted imaging (T2WI) in all patients; they were arrayed in a radiating mode gathered toward the center (8 cases), designated by us as vascular center-gathered syndrome (VCGS), or scattered like twigs (4 cases). The flow voids were accompanied by high signals in all patients, including tubular (6 cases) and platy (6 cases) signals. Slightly higher signals were shown in the peripheral part of the tumor in all patients. Flow voids in the peripheral part were shown in all patients, and the majority of the flow voids surrounded the tumor (8 cases). The vessels around the tumor in 9 patients showed high signals, and the majority of the vessels were located at the superior and inferior poles (8 cases). 6 patients underwent enhanced scanning, including moderate (5 cases) and significant enhancement (1 case).

Low signals of radiating flow voids accompanied by high signals of slow blood flow or blood sinuses in the center part have high significance for the diagnosis of ASPS.