Tubo-Ovarian Abscess (with/without Pseudotumor Area) Mimicking Ovarian Malignancy: Role of Diffusion-Weighted MR Imaging with Apparent Diffusion Coefficient Values.

Tingting Wang,Bing Yin,Xiangru Wu,Caiting Chu,Ming Ding,Yanfen Cui,Wenhua Li,Xiaobing Fan

doi:10.1371/journal.pone.0149318

Tingting Wang, Bing Yin + Show 6 more

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https://doi.org/10.1371/journal.pone.0149318

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Journal: PloS one	Publication Date: Feb 19, 2016
Citations: 15	License type: CC BY 4.0

Affiliation: XinHua Hospital, Shanghai Jiao Tong University

Abstract

ObjectiveTo assess the added value of diffusion-weighted magnetic resonance imaging (DWI) with apparent diffusion coefficient (ADC) values compared to MRI, for characterizing the tubo-ovarian abscesses (TOA) mimicking ovarian malignancy.Materials and MethodsPatients with TOA (or ovarian abscess alone; n = 34) or ovarian malignancy (n = 35) who underwent DWI and MRI were retrospectively reviewed. The signal intensity of cystic and solid component of TOAs and ovarian malignant tumors on DWI and the corresponding ADC values were evaluated, as well as clinical characteristics, morphological features, MRI findings were comparatively analyzed. Receiver operating characteristic (ROC) curve analysis based on logistic regression was applied to identify different imaging characteristics between the two patient groups and assess the predictive value of combination diagnosis with area under the curve (AUC) analysis.ResultsThe mean ADC value of the cystic component in TOA was significantly lower than in malignant tumors (1.04 ± 0 .41 × 10−3 mm2/s vs. 2.42 ± 0.38 × 10−3 mm2/s; p < 0.001). The mean ADC value of the enhanced solid component in 26 TOAs was 1.43 ± 0.16×10−3mm2/s, and 46.2% (12 TOAs; pseudotumor areas) showed significantly higher signal intensity on DW-MRI than in ovarian malignancy (mean ADC value 1.44 ± 0.20×10−3 mm2/s vs.1.18 ± 0.36 × 10−3 mm2/s; p = 0.043). The combination diagnosis of ADC value and dilated tubal structure achieved the best AUC of 0.996. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MRI vs. DWI with ADC values for predicting TOA were 47.1%, 91.4%, 84.2%, 64%, and 69.6% vs. 100%, 97.1%, 97.1%, 100%, and 98.6%, respectively.ConclusionsDW-MRI is superior to MRI in the assessment of TOA mimicking ovarian malignancy, and the ADC values aid in discriminating the pseudotumor area of TOA from the solid portion of ovarian malignancy.

Highlights

Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of magnetic resonance imaging (MRI) vs. diffusion-weighted magnetic resonance imaging (DWI) with apparent diffusion coefficient (ADC) values for predicting tuboovarian abscesses (TOA) were 47.1%, 91.4%, 84.2%, 64%, and 69.6% vs. 100%, 97.1%, 97.1%, 100%, and 98.6%, respectively
DW-MRI is superior to MRI in the assessment of TOA mimicking ovarian malignancy, and the ADC values aid in discriminating the pseudotumor area of TOA from the solid portion of ovarian malignancy
A patient with acute pelvic infection typically presents with fever, chills, leukocytosis and/or increased blood C-reactive protein (CRP), which is distinct from adnexal malignant tumor

Summary

Introduction

A patient with acute pelvic infection typically presents with fever, chills, leukocytosis and/or increased blood C-reactive protein (CRP), which is distinct from adnexal malignant tumor. MRI findings of thickened wall or septa (> 3 mm) or various degrees of solid portions are strongly suggestive of ovarian malignancy [4,5,6]. Inflammation can often cause damage to the rectosigmoid colon and ureter, leading to reactive lymph node swelling and the production of moderate to considerable free fluid in the pelvis. These MRI findings associated with vague clinical symptoms of infection can further contribute to errors in diagnosis, and suspicion of ovarian malignancy [1]

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