Role of Diffusion Weighted Imaging with Background Body Signal Suppression (DWIBS) in Evaluation of Breast Masses and Correlation with Histopathological Findings

Abstract

Abstract Background Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is an important tool in breast imaging. Yet, it has two major limitations which are represented by its specificity and the use of contrast material. Diffusion weighted imaging (DWI) provides important functional information without the need for contrast material. A newly introduced Diffusion weighted imaging with back-ground suppression (DWIBS) sequence is an accurate and rapid tool for the identification and characterization of breast lesions, with its short examination time, high lesion-to-background contrast, and lack of need for intravenous contrast agents. Objective To assess the role of DWIBS sequence for evaluating breast masses and to compare DWIBS results with DCE-MRI in correlation with histopathological findings for intermediate, suspicious and malignant imaging results. Methods The study was conducted during the period from December 2020 t& January 2023. Thirty five patients were included in the study, referred from Ain Shams university hospitals sonomammography clinic to Ain Shams university hospitals MRI unit for further MRI assessment of breast masses (BIRADS 3, BIRADS 4& BIRADS 5), probably benign, suspicious and malignant- lesions on sonomammography imaging results. MRI breast protocol which included DCE-MRI and DWIBS sequences were obtained for characterization and were verified by core needle biopsy or excisional biopsy. The results were statistically analyzed. Sensitivity, specificity, diagnostic accuracy (DA), positive predictive value (PPV) and negative predictive value (NPV) were calculated for DCE-MRI and DWIBS. Apparent diffusion co-efficient (ADC) values were calculated with ADC <1.2 x 10-3 mm2/s were considered suspicious for malignancy. The results were then compared with the histological findings. Results 35 female patients had 39 breast masses included in our study. By DCE-MRI, 8 (20.5%) of masses were categorized as benign and 31(79.5%) of masses were categorized as malignant. By DWIBS sequence, 7 (17.9%) of masses were categorized as benign and 32 (82.1%) of masses were categorized as malignant. By histopathology, 14 (35.9%) of masses were benign and 25 (64.1%) were malignant. DCE-MRI obtained accuracy, sensitivity, specificity, PPV and NPV values of 84.6, 100, 57.1, 80.6, 100 %, respectively. DWIBS sequences obtained accuracy, sensitivity, specificity, PPV and NPV values of 82.1, 100, 50, 78.1, 100 %, respectively. Conclusions DWIBS can be added to DCE breast MRI, to improve DCE-MRI sensitivity and specificity. It can as well be used instead of DCE -MRI sequences in certain circumstances as in cases of renal impairment, but with some limitations as DWIBS cannot assess the extent of the malignant process.