Intravoxel Incoherent Motion MR Imaging: Comparison of Diffusion and Perfusion Characteristics for Differential Diagnosis of Soft Tissue Tumors.

Abstract

We used intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) to explore the possibility of preoperative diagnosis of soft tissue tumors (STTs). This prospective study enrolled 23 patients. Conventional MRI and IVIM examinations were performed on a 3.0T MR imager. Eight (35%) hemangiomas, 11 (47%) benign soft tissue tumors excluding hemangiomas (BSTTEHs) and 4 soft tissue sarcomas (STSs) were assessed. The mean tumor size was about 1652.36 ± 233.66 mm2. Ten b values (0–800 s/mm2) were used to evaluate diffusion and perfusion characteristics of IVIM. IVIM parameters (ADCstandard, ADCslow, ADCfast, and f) of STTs were measured and evaluated for differentiating hemangiomas, BSTTEHs, and STSs. ADCslow and ADCfast value were different for hemangiomas, BSTTEHs, and STSs separately (P < 0.001, P < 0.001, and P = 0.001). ADCslow, cut-off value smaller than 0.93 × 10–3 mm2/s, was the best parameter to differ STSs (0.689 ± 0.173 × 10−3 mm2/s) from hemangiomas (0.933 ± 0.237 × 10−3 mm2/s) and BSTTEHs (1.156 ± 0.120 × 10−3 mm2/s) (P = 0.001). ADCslow (0.93 × 10−3 mm2/s <cut-off value <0.96 × 10−3 mm2/s) was used to distinguish hemangiomas from BSTTs. There were significant difference among hemangiomas, BSTTEHs, and STSs (P = 0.014, P = 0.036, P < 0.001). The ADCstandard, ADCfast, and f value were different (P < 0.05) for STSs (1.009 ± 0.177 × 10−3 mm2/s, 15.700 ± 1.992 × 10−3 mm2/s, 0.503 ± 0.068), hemangiomas (1.505 ± 0.226 × 10−3 mm2/s, 11.675 ± 0.456 × 10−3 mm2/s, 0.682 ± 0.060), and BSTTEHs (1.555 ± 0.176 × 10−3 mm2/s, 11.727 ± 0.686 × 10−3 mm2/s, 0.675 ± 0.054). And there was no significant difference for these 3 parameters between hemangiomas and BSTTEHs (P = 0.584, 0.907, and 0.798). IVIM may be of significant value for differential diagnosing hemangiomas, BSTTEHs, and STSs.