Purpose: To compare the apparent diffusion coefficients (ADCs) of myxoid and nonmyxoid soft‐tissue tumors using line‐scan diffusion‐weighted imaging (LSDWI), and to investigate the myxoid matrix influence on ADCs of soft‐tissue tumors.Materials and Methods: This study enrolled 44 patients with soft tissue tumors. They were divided into two groups: one with myxoid‐containing soft‐tissue tumors (N = 23) and the other with nonmyxoid soft‐tissue tumors (N = 21). The 44 patients were also classified histologically into 26 with malignant soft‐tissue tumors and 18 with benign soft‐tissue tumors. LSDWI was performed using b values of 5 and 1000 second/mm². The ADCs of the tumors were calculated and compared for myxoid and nonmyxoid tumors and for benign and malignant tumors.Results: The ADC (mean ± SD) was 1.92 ± 0.41 × 10^–3 mm²/second in myxoid containing tumors, whereas the ADC was 0.97 ± 0.33 × 10^–3 mm²/second in nonmyxoid tumors. The ADCs of the myxoid and nonmyxoid tumors were significantly different (P < 0.01). The ADCs were 1.45 ± 0.59 × 10^–3 mm²/second in malignant tumors and 1.50 ± 0.64 × 10^–3 mm²/second in benign tumors. The ADCs of benign and malignant soft‐tissue tumors were not significantly different.Conclusion: The ADCs of myxoid‐containing soft‐tissue tumors were significantly higher than those of nonmyxoid soft‐tissue tumors. The myxoid matrix influences ADCs of both benign and malignant soft‐tissue tumors. J. Magn. Reson. Imaging 2007;25:1199–1204.

OBJECTIVE. Acute vertebral collapse is common, and it is sometimes difficult to determine whether the cause is benign or malignant. Recently, diffusion-weighted imaging has been reported to be useful for differentiating the two types. The purpose of this study was to evaluate diffusion abnormalities quantitatively in benign and malignant compression fractures using line scan diffusion-weighted imaging.SUBJECTS AND METHODS. Line scan diffusion-weighted imaging was prospectively performed in 17 patients with 20 acute vertebral compression fractures caused by osteoporosis or trauma, in 12 patients with 16 vertebral compression fractures caused by malignant tumors, and in 35 patients with 47 metastatic vertebrae without collapse. Images were obtained at b values of 5 and 1,000 sec/mm2. The apparent diffusion coefficient (ADC) was measured in vertebral compression fractures and metastatic vertebrae without collapse.RESULTS. The ADC (mean ± SD) was 1.21 ± 0.17 × 10–3 mm2/sec in benign compression fractures, 0.9...