Abstract:

Objective: The aim of our study is to investigate probable differences between the incidence of target sign detected by diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) values between metastases and hepatocellular carcinomas (HCC). Materials and Methods: A total of 155 lesions obtained from 57 (female/male: 18/39) patients were included in the study. Dimensions of lesions, the appearance of lesions detected by DWI, minimum ADC (ADCmin) values, and average ADC (ADCav) values were evaluated with 1.5 Tesla MRI using b= 0 and b = 1000 s/mm2 values. Differences between metastases and HCC were investigated in terms of defined parameters. Also, ROC (receiver operating curve) analysis was used to evaluate the performance of ADCmin and ADCav parameters in distinguishing metastases from HCC. Results: Of the lesions, 131 were metastases, while 24 were HCC. The image showing centrally hypointense, periphery hyperintense signal in DWI defined as target sign. Target sign detected in 72 metastatic lesions (55%) and 6 HCC lesions (25%) with DWI, and the rate of target sign detection was higher in the metastatic group compared with HCC (p<0.007). Also, ADCmin and ADCav values were found to be higher in the HCC group compared with the metastatic group (p<0.001). Based on ROC analysis optimal ADCmin and ADCav values were <758 x10-6 and <817x10-6 mm2/s, respectively, in distinguishing metastasis from HCC (Sensitivity: 0.412, 0.412; Specificity: 0.875, 0.917 respectively). Conclusion: Target sign detected by DWI and ADC values can be used as MRI markers that enhance diagnostic accuracy in distinguishing between metastases and HCC.

Keywords: