CT & MRI SCAN FINDINGS OF SOLITARY FIBROUS TUMOR ALIGN WITH THAT OF HISTOLOGICAL FINDINGS: AN EFFECTIVE NON INVASIVE DIAGNOSTIC TOOL

Purpose: To analyze the computed tomography (CT) and magnetic resonance imaging (MRI) features of histologically proven soft tissue solitary fibrous tumors to gain validity of imaging findings on final diagnosis. Materials and Methods: Twenty eight patients with confirmed SFTs by histopathology were retrospectively analyzed. 21 patients had undergone CT scan while 6 had undergone MRI and 1 patient had both CT and MRI scan. The Imaging characteristics before and after contrast enhancement were analyzed and correlated simultaneously with its patho-morphology. Results: Among 28 cases, 11 patients had no symptoms. These tumors were located mostly in the thoracic cavity (42%) and mediastinum (14%). The average size range was 8.2 X 6.8cm.2 These tumors in CT were predominantly heterogeneous with an average CT value of solid component being 41.5 HU. These were heterogeneously enhanced by contrast in the arterial phase. Most of these demonstrated a positive vessel sign (14/18). These tumors in MR scan were Iso-intense on T1WI and heterogeneous or hyper/iso-intense on T2WI. 85% of these tumors showed heterogeneous enhancement. Conclusion: SFTs usually are atypical tumors that are easily missed at diagnosis. The reliable diagnostic features in CT scan are - large well-defined hyper vascular tumor, variable degree of necrosis/cystic changes and enhanced serpentine vessels in arterial phase(CT) with flow void sign. Similarly, MR images that show homogenous iso- or hypo-intense signal on T1WI, and heterogeneous iso- or hypo-intense signal on T2WI with serpentine vessels enhanced in arterial phase and flow voids sign on T2WI are diagnostic of solitary fibrous tumors.