The diagnostic precision of apparent diffusion coefficient (ADC) in grading of malignant endometrial lesions compared with histopathological findings

Objective: The present study aimed to extract apparent diffusion coefficient (ADC) values from the diffusion-weighted imaging (DWI) sequence of endometrial lesions and compare them with tissue specimen results in order to determine the precision of ADC values in grading of malignant endometrial lesions. Methods: The present prospective study was conducted on 22 patients complaining of abnormal vaginal bleeding or evidence for endometrial thickening or masses detected using the ultrasound. Sampling was performed for pathological examination. MRI T2W+DWI+T1W+Post Contrast T1W were performed for patients. The statistical analysis was performed in SPSS 20 and MedCalc. Results: In this study, although the mean ADC value was lower in patients with endometrial cancer than those with benign endometrial lesions, the difference was not significant (0.86 +/- 0.2 mm2/sec versus 1.33 +/- 0.53 mm2/sec; P = 0.13). Using the cutoff point of 0.53, the sensitivity and specificity of ADC value for differentiating benign and malignant lesions, respectively, equaled 90.91 and 9.09, with an equal positive and negative predictive value of 50%. In patients with endometrioid adenocarcinoma, mean ADC value was 0.93 +/- 0.15 in FIGO Grade I, and 0.76 +/- 0.165 in FIGO Grade II. Based on the statistical test, no significant difference existed between the two groups in terms of ADC values. Conclusion: Results indicate that the use of a DWI sequence (ADC values) can prevent invasive measures in the diagnosis of benign endometrial lesions and the identification of malignant lesions with a high precision in many patients having accompanying diseases or other cases for which invasive measures cannot be used. Also, there is no significant difference in the mean ADC values between G1 and G2 of endometrioid carcinoma.