Efifcacy of A Multi-parametric MRI Protocol for BI-RADS Categorization of Breast Lesions / 中国医学影像学杂志

ABSTRACT

PurposeTo investigate a multi-parametric protocol for breast MRI examination and lesions assessment correlated to the American College of Radiology (ACR) breast imaging reporting and data system (BI-RADS) categorization, and to improve the management of the breast lesions.Materials and Methods 301 pathologically confirmed lesions on 278 patients were retrospectively included. The scan protocol used a dynamic contrast enhancement sequence (DCE) of 1 mm×1 mm×1 mm spatial resolution, 120 temporal resolution and a diffusion weighted imaging (DWI) of b=1000 s/mm2. The malignant morphological features on the early-enhanced images, type II or III time intensity curve and the apparent diffusion coefficient (ADC) value less than benign/malignant threshold was equally weighted. Each was given 1 point when present malignant features and treated different on mass and non-mass-like enhancement lesions. When the sum of score was ≥2 points, the lesion was categorized as BI-RADS 5. When the sum of score was 1 point, the lesion was categorized as BI-RADS 4. When the sum of score was <1 point, the lesion was categorized as BI-RADS 3. The other specific benign findings were categorized as BI-RADS 2. No abnormality on DWI, DCE, T2WI and T1WI was categorized as BI-RADS 1. The final categories were correlated to the pathological grades as benign (B), high risk (HR) and malignant (M).Results When grouped HR as malignant (M+HR), the area under curve (AUC) of the ROC was 0.860. When grouped HR as benign (B+HR), the AUC of the ROC was 0.876, and the optimized sensitivity, specificity and accuracy was 85.3%, 86.8% and 85.1%, respectively, which were better than the other grouping. If the management of HR lesions could be lumptoectomy or short-term follow-up, the positive predictive value (PPV) of BI-RADS 5 for excisable lesions (M+HR) was 93.2%, the PPV of BI-RADS 4 for excisable lesions (M+HR) was 46.9% and the biopsy was essential. The PPV of BI-RADS 3 and below for follow-up lesions (B+HR) was 90.4%.Conclusion A simple diagnosis algorithm was established, which equally weighted the DCE morphological feature, DCE-TIC and DWI-ADC. The diagnosis protocol was well consistent with BI-RADS categorization and could predict the benign, high risk and malignant lesions in pathology as well as the proper management.