Shear Wave Elastography of Invasive Ductal Carcinoma: Correlations between Shear Wave Velocity and Histological Prognostic Factors.

The correlations between shear wave velocity (SWV) calculated from virtual touch tissue imaging quantification (VTIQ) technique and histological prognostic factors of invasive ductal carcinoma was investigated. A total of 76 breast tumors histologically confirmed as invasive ductal carcinomas were included in this study. SWV values were measured by VTIQ for each lesion preoperatively or prior to breast biopsy. The maximum values were recorded for statistical analysis. Medical records were reviewed to determine tumor size, histological grade, lymph node status and immunohistochemical results. Tumor subtypes were categorized as luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) positive and triple negative. The correlations between SWV and histological prognostic factors were analyzed. It was found that tumor size showed positive association with SWV (r=0.465, P<0.001). Larger tumors had significantly higher SWV than smaller ones (P=0.001). Histological grade 1 tumors had significantly lower SWV values than those with higher histological grade (P=0.015). The Ki67 expression, tumor subtypes and lymph node status showed no statistically significant correlations with SWV, although triple negative tumors and lymph node-positive tumors showed higher SWV values. It was concluded that tumor size was significantly associated with SWV. Higher histological grade was associated with increased SWV. There was no statistically significant correlations between SWV and other histological prognostic factors.

Rim sign in breast lesions on diffusion-weighted magnetic resonance imaging: diagnostic accuracy and clinical usefulness.

PURPOSE: To investigate the diagnostic accuracy and clinical usefulness of the rim sign in breast lesions observed in diffusion-weighted magnetic resonance imaging (DWI). MATERIALS AND METHODS: The magnetic resonance imaging (MRI) findings of 98 pathologically confirmed lesions (62 malignant and 36 benign) in 84 patients were included. Five breast radiologists were asked to independently review the breast MRI results, to grade the degree of high peripheral signal, the "rim sign," in the DWI, and to confirm the mean apparent diffusion coefficient (ADCmean ) values. We analyzed the diagnostic accuracy and compared the consensus (when ≥ 4 of 5 independent reviewers agreed) results of the rim sign with the ADCmean values. Additionally, we evaluated the correlation between the dynamic contrast-enhanced (DCE)-MRI morphologic appearance and DWI rim sign. RESULTS: According to the consensus results, the rim sign in DWI was observed on 59.7% of malignant lesions and 19.4% of benign lesions. The sensitivity, specificity, and area under the curve (AUC) value for the rim sign in DWI were 59.7%, 80.6%, and 0.701, respectively. The sensitivity, specificity, and AUC value for the ADCmean value (criteria ≤ 1.46 × 10(-3) mm(2) /sec) were 82.3%, 63.9%, and 0.731, respectively. Based on consensus, no correlation was observed between the DCE-MRI and DWI rim signs. CONCLUSION: In DWI, a high-signal rim is a valuable morphological feature for improving specificity in DWI.