Evaluation of an automated breast 3D-ultrasound system by comparing it with hand-held ultrasound (HHUS) and mammography.

PURPOSE: Automated three-dimensional (3D) breast ultrasound (US) systems are meant to overcome the shortcomings of hand-held ultrasound (HHUS). The aim of this study is to analyze and compare clinical performance of an automated 3D-US system by comparing it with HHUS, mammography and the clinical gold standard (defined as the combination of HHUS, mammography and-if indicated-histology). METHODS: Nine hundred and eighty three patients (=1,966 breasts) were enrolled in this monocentric, explorative and prospective cohort study. All examinations were analyzed blinded to the patients´ history and to the results of the routine imaging. The agreement of automated 3D-US with HHUS, mammography and the gold standard was assessed with kappa statistics. Sensitivity, specificity and positive and negative predictive value were calculated to assess the test performance. RESULTS: Blinded to the results of the gold standard the agreement between automated 3D-US and HHUS or mammography was fair, given by a Kappa coefficient of 0.31 (95% CI [0.26;0.36], p < 0.0001) and 0.25 (95% CI [0.2;0.3], p < 0.0001), respectively. Our results showed a high negative predictive value (NPV) of 98%, a high specificity of 85% and a sensitivity of 74% based on the cases with US-guided biopsy. Including the cases where the lesion was seen in a second-look automated 3D-US the sensitivity improved to 84% (NPV = 99%, specificity = 85%). CONCLUSION: The results of this study let us suggest, that automated 3D-US might be a helpful new tool in breast imaging, especially in screening.

Evaluation of virtual touch tissue imaging quantification, a new shear wave velocity imaging method, for breast lesion assessment by ultrasound.

OBJECTIVES: To evaluate virtual touch tissue imaging quantification (VTIQ) as a new elastography method concerning its intra- and interexaminer reliability and its ability to differentiate benign from malignant breast lesions in comparison to and in combination with ultrasound (US) B-mode breast imaging reporting and data system (BI-RADS) assessment. MATERIALS AND METHODS: US and VTIQ were performed by two examiners in 103 women with 104 lesions. Intra- and interexaminer reliability of VTIQ was assessed. The area under the receiver operating curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of BIRADS, VTIQ, and combined data were compared. RESULTS: Fifty-four of 104 lesions were malignant. Intraexaminer reliability was consistent, and interexaminer agreement showed a strong positive correlation (r = 0.93). The mean VTIQ values in malignant lesions were significantly higher than those in benign (7.73 m/s ± 1.02 versus 4.46 m/s ± 1.87; P < 0.0001). The combination of US-BIRADS with the optimal cut-off for clinical decision making of 5.18 m/s yielded a sensitivity of 98%, specificity of 82%, PPV of 86%, and NPV of 98%. The combination of BIRADS and VTIQ led to improved test validity. CONCLUSION: VTIQ is highly reliable and reproducible. There is a significant difference regarding the mean maximum velocity of benign and malignant lesions. Adding VTIQ to BIRADS assessment improves the specificity.

Normal breast tissue stiffness measured by a new ultrasound technique: virtual touch tissue imaging quantification (VTIQ).

OBJECTIVE: To evaluate normal breast tissue stiffness with virtual touch tissue imaging quantification (VTIQ) using prospectively collected data. MATERIALS AND METHODS: B-mode ultrasound and VTIQ were performed in 132 breasts in 97 women. Mean values of VTIQ for parenchyma and fatty tissue were compared between those measured in healthy breasts and in the surrounding of histologically proven benign and malignant breast lesions. Moreover we reviewed VTIQ values according to breast density measured by the American College of Radiology (ACR) categories. In addition we analyzed re-test reliability of VTIQ. RESULTS: In 132 breasts the mean VTIQ values in parenchyma were significantly higher than in fatty tissue (3.23 m/s ± 0.74 versus 2.5 m/s ± 0.61; p<0.0001). In healthy breasts as well as in the surrounding of a benign or malignant lesions the VTIQ values of parenchyma were similar (p=0.12). In fatty tissue, small differences between mean VTIQ values of 2.25 m/s ± 0.51, 2.52 m/s ± 0.48 and 2.65 m/s ± 0.71 (p=0.01) in the respective groups were observed. The comparison of mean VTIQ values of parenchyma and fatty tissue in more and less dense breasts (ACR 1+2 versus ACR 3+4 breasts) also yielded no statistically significant difference. The re-test reliability of VTIQ assessed with three independent measurements was moderate (interclass-correlation of 0.52 (p<0.0001)). CONCLUSION: VTIQ is a reliable method for measuring the stiffness of breast tissue. We propose standard values for healthy parenchyma and fatty tissues independent of the surrounding tissue or the ACR category.