Diffusion MRI with quantification of ADC value in characterization of benign and malignant hepatic lesions and their correlation with cyto-histopathology

Abstract

Background: Diffusion weighted Imaging (DWI) is a useful noninvasive tool in MRI as it can be performed quickly and does not require contrast injection. In addition to it, DWI imaging and apparent diffusion coefficient (ADC) quantification not only can add additional anatomical data about the lesion but can also help in characterization of focal liver lesions into malignant or benign. The study attempts to establish a cut off value of ADC differentiating a benign from malignant lesion. Materials and Methods : 32 patients with age group of 40-85 years with 46 diagnosed focal liver lesions on CT and MRI were included in the study. MRI was performed using 1.5 Tesla GE Healthcare HDxT machine. Conventional sequences followed by diffusion weighted sequences were acquired. Quantitative analysis was derived from ADC maps with calculation of ADC values. ADC values of the hepatic lesions were compared with histopathology as reference standard and analyzed statistically. Results: In this study, 25 focal lesions in 18 patients had histopathological diagnosis of malignant pathology and had mean ADC value 1.13(x10 (−3) mm 2 /s) and 21 lesions in 14 patients with histopathological diagnosis of benign pathology had ADC value of 1.63(x10 (−3) mm 2 /s). Statistically significant difference between ADC value of benign and malignant lesions was found. Conclusion: The study proclaimed that DWI with ADC quantification be used as an additional non invasive MRI tool to differentiate benign and malignant hepatic lesions with a sensitivity of 85.7%, specificity of 88%, PPV of 88% and NPV of 85.7%