Evaluation of true diffusion, perfusion factor, and apparent diffusion coefficient in non-necrotic liver metastases and uncomplicated liver hemangiomas using black-blood echo planar imaging.

ABSTRACT

PURPOSE: To assess the added value of true diffusion (D), perfusion factor (f) and apparent diffusion coefficient at low b-values (ADC(low)) for differentiation between liver metastases and hemangiomas based on respiratory-triggered high-resolution Black-Blood Single-Shot SpinEcho Echo Planar Imaging (BB SS SE-EPI). MATERIALS AND METHODS: Twenty-five patients suspected for malignant colorectal liver lesions were included in this study. A total of 106 lesions were examined. Different b-value images were compared for lesion conspicuity, image quality and artifacts using rank order statistic (RIDIT) and Student's t-test. D, f, and ADC(low) values were calculated. Pearson correlation coefficient is used for comparison of interobserver variability. RESULTS: Best lesion conspicuity (p<0.05) was achieved with BB SS SE-EPI (b=0 and 10s/mm(2)); best image quality (p<0.05) with b=10s/mm(2). Image artifacts were lowest (p<0.05) with b=0s/mm(2). Over the whole sample, D in metastases (D(met)) was significantly (p<0.05) lower than D in hemangiomas (D(hem)); f and ADC(low) of metastases (f(met), respectively, ADC(lowmet)) were significantly (p<0.05) higher than f and ADC(low) of hemangiomas (f(hem), respectively, ADC(lowhem)). All Pearson correlations were statistically significant at a 0.01 level. CONCLUSIONS: This preliminary study shows the potential of BB SS SE-EPI as a useful technique to aid in differentiating between liver metastasis and hemangioma. The calculation of D, f and ADC(low) provides useful additional information for differentiating metastases from hemangiomas.