Document Type : Research Article
Background: Diffusion weighted MR is an attractive technique which uses both quantitative and qualitative data to differentiate benign and malignant lesions. The purpose of this study was to evaluate the sensitivity and specificity of Diffusion weighted imaging (DWI) and Apparent Diffusion Coefficient (ADC) in diagnosing hepatic lesions and to evaluate the efficacy of DWI and ADC mapping to differentiate benign lesion from malignant hepatic lesions.
Aims: To evaluate the sensitivity and specificity of diffusion weighted imaging in diagnosing benign and malignant hepatic lesions.
Settings and design: The diagnostic accuracy study was conducted for one year duration starting from July 2019 to July 2021 after the date of approval from the thesis protocol review committee (Scientific, Ethical & Financial), Amrita institute of medical sciences and research Centre, Kochi, Kerala.
Method: In this observational study, a total of 59 patients with liver lesions were enrolled. All detected liver lesions in USG/CT were imaged with DWI and their corresponding ADC values were calculated and recorded. Sensitivity and specificity of ADC mapping and DWI in differentiating benign lesions from malignant lesions were evaluated.
Result: 59 hepatic lesions were imaged with DWI which was performed at three different b values of ‘b’ 50, ‘b’ 500 and ‘b’ 1000 sec/mm2. By performing DWI, ADC values were also calculated for each lesion. For differentiating benign lesions from malignant lesions, we used the ADC cutoff value of 1.45x10-3 mm2/s. As per the study result,19 lesions were benign and 40 lesions were malignant. ADC value had a sensitivity of 97.5% and specificity of 84.2%, whereas DWI MRI had a sensitivity of 97.5 % and specificity of 78.9 %.
Conclusion: This study showed that malignant and benign liver lesions can be differentiated by using DWI and ADC mapping technique. ADC value had a sensitivity of 97.5% and specificity of 84.2%, whereas DWI MRI had a sensitivity of 97.5 % and specificity of 78.9 %. It is difficult to trace and target the small or deeply situated lesions for FNAC/biopsies and it stands a risk of bleeding. Using DWI and ADC mapping technique, these lesions can easily be traced and characterized into benign and malignant. This study demonstrated that with the help of DWI, dependency on FNAC/biopsy for differentiating malignant lesion from benign can be reduced and biopsies may be further restricted to a subset of those suspected to be malignant.