title: Diffusion-weighted imaging of tumor recurrencies and posttherapeutical soft-tissue changes in humans.
abstract: The aim of this study was to examine soft tissue tumor recurrences and posttherapeutic soft tissue changes in humans with a diffusion-weighted steady-state free precession (SSFP) sequence. Twenty-four patients with 29 pathologies of the pelvis or the extremities were examined. The lesions were classified as follows: group 1, recurrent viable tumors (n = 10); group 2, postoperative hygromas (n = 7); and group 3, posttherapeutic reactive inflammatory muscle changes (n = 12). The sequence protocol in these patients consisted of short tau inversion recovery images, T2-weighted spin-echo (SE), pre- and postcontrast T1-weighted SE images and the diffusion-weighted SSFP sequence. The signal loss on diffusion-weighting was evaluated visually on a four-grade scale and quantitatively. The signal intensities were measured in regions of interest and a regression analysis was performed. Statistical analyses was performed utilizing the Student's t-test. The signal loss was significantly higher for hygromas and edematous muscle changes than for recurrent tumors (p < 0.001) indicating higher diffusion of water protons. The regression coefficient was -0.11 (mean) for tumors. Hygromas had a significantly higher signal loss than inflammatory edematous muscle changes (p < 0.01). The regression coefficients were -0.29 (mean) for hygromas and -0.22 (mean) for edematous muscle changes. The SSFP sequence seems to be a suitable method for diffusion-weighted imaging of the musculoskeletal system in humans. These preliminary results suggest that the signal loss and the regression coefficients can be used to characterize different types of tissue.
authors.affiliation: Department of Diagnostic Radiology, University of Munich, Marchioninistrasse 15, 81377 Munich, Germany. andrea.baur@ikra.med.uni-muenchen.de
authors.forename: A
authors.initials: A
authors.lastname: Baur
authors.forename: A
authors.initials: A
authors.lastname: Huber
authors.forename: S
authors.initials: S
authors.lastname: Arbogast
authors.forename: H R
authors.initials: HR
authors.lastname: Dürr
authors.forename: S
authors.initials: S
authors.lastname: Zysk
authors.forename: C
authors.initials: C
authors.lastname: Wendtner
authors.forename: M
authors.initials: M
authors.lastname: Deimling
authors.forename: M
authors.initials: M
authors.lastname: Reiser
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000473:pathology* / Q000628:therapy