Possibilities of Diffusion-Weighted MRI in the Differential Diagnosis of Early Recurrences of Retroperitoneal Liposarcomas and Postoperative Changes

Abstract

Purpose: To evaluate contrast-enhanced magnetic resonance imaging (CE‑MRI) and diffusion-weighted (DWI) in the detection and differential diagnosis of recurrent of retroperitoneal liposarcomas with postoperative changes.Material and methods: The retrospective study included of 23 patients previously operated on for retroperitoneal inorganic liposarcomas. All patients underwent MRI of the abdominal cavity and pelvis with intravenous contrast with further assessment of the size, shape, structure and characteristics of the accumulation of contrast agent in the detected formation.Results: Morphological verification were performed in 17 patients (74 %), in 6 cases (26 %) patients were left for dynamic control for 1–3 years. Local relapses were detected in 16 patients (67 %), postoperative changes — in 7 (33 %) patients, of which in 2 cases deformation of adipose tissue and fibrotic changes in the area of surgery was determined, in 3 patients granulomas were revealed, and in two patients — volvulus of the greater omentum and lymphocele. The sensitivity of MRI with intravenous contrast enhancement was 68.7 %, specificity 71.4 % and accuracy 69.6 %. The addition of DWI to the standard MRI protocol in patients with suspected recurrence of retroperitoneal liposarcoma to increase the sensitivity of the method in the differential diagnosis of recurrent drugs from postoperative changes to 93.7 % (15 out of 16), specificity up to 100 % (7 out of 7) and accuracy up to 95.6 % (22 out of 23).Conclusion: The joint use of MRI with intravenous contrast and DW‑MRI increases the information content in the detection and differential diagnosis of small-sized recurrent tumors in dedifferentiated and myxoid types of liposarcomas with postoperative changes.