Diagnostic accuracy of diffusion‐weighted imaging in differentiating benign from malignant ovarian lesions

Abstract

Purpose: To clarify the diagnostic accuracy of diffusionweighted imaging (DWI) in differentiating benign from malignant ovarian lesions. Materials and Methods:We retrospectively analyzed magnetic resonance images of 123 ovarian lesions in 119 patients. We defined lesions with abnormal signal intensity as malignancy and assessed the location of abnormal intensity within the lesions on DWI. We also assessed the mean and lowest apparent diffusion coefficient (ADC) values of the solid portion for each ovarian lesion. Results:The majority of malignant ovarian tumors and mature cystic teratomas, and almost half of the endometriomas, showed abnormal signal intensity on DWI, whereas most fibromas and other benign lesions did not. The main locations of abnormal signal intensity were solid portions in malignant ovarian tumors, cystic components suggestive of keratinoid substances and Rokitansky protuberance in mature cystic teratomas, and intracystic clots in endometriomas. On DW imaging, receiver-operating characteristic analysis yielded mean Az values of 0.703. There was no significant difference in mean and lowest ADC values between malignant and benign lesions.Conclusion: DWI of ovarian lesions and ADC values of the solid component are not useful for differentiating benign from malignant ovarian lesions. This knowledge is essential in avoiding misinterpretation in the diagnosis of ovarian lesions.

Diffusion-weighted Imaging of a Malignant Brenner Tumor

“…We believe no report has demonstrated the usefulness of DWI and ADC value in diagnosing a malignant Brenner tumor, and their clinical usefulness in discriminating benign from malignant ovarian tumors has been controversial. [10][11][12] Takeuchi's team 10 reported a tendency of the ADC of the solid component of malignant/borderline malignant ovarian tumors to be lower than that of benign ovarian tumors, probably because of the higher cellularity and more enlarged nuclei in the malignant/borderline tumor.…”

“…Thomassin-Naggara 11 and Fujii 12 and their associates demonstrated that ADC measurement did not contribute to the diŠerentiation of benign from malignant ovarian mass because of the frequently low ADC value of benign ovarian tumors, such aŝ broma,ˆbrothecoma, cystadenoˆbroma, teratoma, and endometrial cyst, and the usually high ADC value of malignant ovarian tumors, such as serous or mucinous borderline malignant tumor and metastatic tumor.…”

Differentiation of Benign from Malignant Adnexal Masses by Functional 3 Tesla MRI Techniques: Diffusion-Weighted Imaging and Time-Intensity Curves of Dynamic Contrast-Enhanced MRI

“…that ADC values are not useful for differentiating benign from malignant adnexal masses (Katayama et al, 2002;Fujii et al, 2008). Thomassin-Naggara et al (2009) demonstrated that DWI signal intensity is an accurate tool for predicting benignity of complex adnexal masses, but ADC measurements did not contribute to differentiating benign from malignant adnexal masses.…”

“…Some studies showed that ADC value is useful in discriminating benign from malignant masses (Takeuchi et al, 2010;Li et al, 2012;Zhang et al, 2012). But on the contrary, the results of the studies by Thomassin-Naggara et al (2009), Katayama et al (2002), and Fujii et al (2008) demonstrated that ADC measurements did not contribute to differentiating benign from malignant adnexal masses.…”

Extragonadal teratomas of the adult abdomen and pelvis: a pictorial review

“…8 This is thought to be due to keratin and solid RP, making them unreliable in distinguishing benign from malignant teratomas. 9 The plain film appearance of MT can be a non-calcified mass. With ultrasonography, they frequently appear as a hypoechogenic mass with slight posterior enhancement.…”