Improved differentiation between hepatic hemangioma and metastases on diffusion-weighted MRI by measurement of standard deviation of apparent diffusion coefficient

Abstract Background Diffusion-weighted magnetic resonance imaging (DW-MR) can be useful in the differentiation of hemangiomata from liver metastasis, but improved methods other than by mean apparent diffusion coefficient (mADC) are needed. Methods A retrospective review identified 109 metastatic liver lesions and 86 hemangiomata in 128 patients who had undergone DW-MR. For each lesion, mADC and the standard deviation of the mean ADC (sdADC) were recorded and compared by receiver operating characteristic analysis. Results Mean mADC was higher in benign hemangiomata (1.52±0.12 mm2 /s) than in liver metastases (1.33±0.18 mm2 /s), but there was significant overlap in values. The mean sdADC was lower in hemangiomata (101±17 mm2 /s) than metastases (245±25 mm2 /s) and demonstrated no overlap in values, which was significantly different ( P < .0001). Conclusions Hemangiomata may be better able to be differentiated from liver metastases on the basis of sdADC than by mADC, although further studies are needed.