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Objective: To assess the diagnostic accuracy of histogram analysis of diffusion kurtosis imaging (DKI) in breast lesions.Materials and Methods: Our institutional review board approved this retrospective study. Seventy-two breast lesions (30 benign and 42 malignant) in 71 patients were histopathologically confirmed. All breast lesions were evaluated by 3.0-T diffusion-weighted imaging (DWI) with 4 b-values of 0, 500, 800, and 2000s/mm2 and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Histogram analyses of conventional DWI and DKI were performed using FireVoxel software for whole lesions. The parameters included apparent diffusion coefficient (ADC), diffusivity (D), and kurtosis (K). The metrics of ADC and DKI parameters (D and K) for benign lesions were compared with those for malignant lesions. The effectiveness of the ADC and DKI parameters (D and K) for diagnosing breast lesions was analysed using receiver operating characteristic (ROC) regression models.Results: For the malignant breast lesions, the mean, median, and 10th/25th/75th percentile values of ADC and D were significantly lower, while the skewness of ADC and D were significantly higher in comparison of the benign lesions(all p < 0.05). The malignant lesions had significantly higher mean, median, and 10th/25th/75th/90th percentile K values than did the benign lesions (all p < 0.05). Within each set of parameters, the 10th percentile ADC (Az = 0.752) and D, (Az = 0.834) coupled with the 75th percentile K (Az = 0.904) were the best metrics for differentiating benign from malignant breast lesions. After comparing the parameters in pairs, the Az for the 75th percentile K was significantly higher than that for the 10th percentile ADC (p = 0.0321) in differentiating benign from malignant breast lesions. When comparing the combination of the 75th percentile K and the 10th percentile D (Az = 0.937) with the 10th percentile D, 75th percentile K and the mean K, a significantly higher Az was observed for the combination than that for the 10th percentile D and the mean K (p = 0.0097 and p = 0.0431, respectively). The diagnostic sensitivity and specificity of the combination of the 75th percentile K and the 10th percentile D were 85.71% and 93.33%, respectively.Conclusion: Histogram analysis of DKI can accurately reflect the histologic characteristics and heterogeneity and is a reliable method for diagnosing breast lesions. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the factors that could cause a misdiagnosis in virtual touch tissue imaging and quantification (VTIQ) when differentiating benign and malignant breast lesions, and to analyze the imaging characteristics of those lesions with incorrect findings.Methods: The conventional ultrasound (CUS) features and the VTIQ parameters of 153 benign lesions and 99 malignant lesions were retrospectively analyzed and compared with histopathological and/or core-needle biopsy (CNB)-proven results. Independent variables that led to inaccurate VTIQ results were selected by binary logistic regression analysis.Results: The maximum shear wave speed (SWS-max), the mean SWS (SWS-mean), the minimum SWS (SWS-min), the lesion-to-fat SWS ratio (SWS-L/F), and the lesion-to-gland SWS ratio (SWS-L/G) in malignant lesions were significantly higher than those in benign lesions (all P < 0.001). The false-positive rate (FPR) of benign lesions and the false-negative rate (FNR) of malignant lesions were 9.8% and 19.2%, respectively, using an SWS-max cut-off value of 4.46 m/s. Diameter, depth, and posterior acoustic features were independent variables related to false-positive VTIQ findings (P: 0.049, 0.010 and 0.032, respectively). The invasive status and the histologic grade of infiltrating carcinoma were significantly associated with false-negative VTIQ findings (P: 0.026 and 0.015).Conclusion: Diameter, depth, posterior acoustic features, invasive status, and histologic grade have a significant influence on the accuracy of VTIQ results, and these characteristics of breast lesions should be taken into account when interpreting the results of VTIQ examinations. [ABSTRACT FROM AUTHOR]

Objective: To analyze the observer reproducibility of breast strain elastography in elasticity image acquisition and elasticity image interpretation.Methods: This was an institutional ethics committee approved prospective study. One hundred twenty-four breast lesions in 118 women (mean age 45.39 ± 12.97 years old, range 21-77 years old) were examined with strain elastography by two blinded radiologists in turn. Three blinded observers separately reviewed and recorded the elasticity score of each lesion obtained by the two performers. The interobserver reproducibility of elasticity image acquisition between the two performers, the interobserver and intraobserver reproducibility of elasticity image interpretation among observers were evaluated. The diagnostic performance of strain elastography was compared between the two performers.Results: Fifty-three lesions were malignant and 71 were benign. The interobserver kappa value was 0.438 for the elasticity score between the two performers. Between the three observers, the overall interobserver and intraobserver kappa value was 0.365 and 0.655, respectively. There was no significant difference of the area under the receiver operator characteristic curve (Az) value for the elasticity score between performer 1 and 2 (P = 0.143).Conclusions: Our results suggested moderate interobserver reproducibility in breast strain elasticity image acquisition, poor interobserver and good intraobserver agreement in image interpretation. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of ROI placement methods and radiologists' experience on diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) parameters' diagnostic performance in differentiating benign and malignant lesions based on the mass and non-mass enhancement (NME).Methods: We evaluated 138 lesions in 131 patients retrospectively. The IVIM and DKI parameter values were measured by three radiologists with different experiences independently using two different ROI placement methods. IVIM parameters include diffusion coefficient (ADCstand), true diffusion coefficient (ADCslow), pseudo-diffusion coefficient (ADCfast) and perfusion fraction (f). DKI parameters include mean diffusivity (MD) and mean kurtosis (MK). Each radiologist measured the lesions twice with a 3-month interval. We utilized intra-class correlation (ICC) to determine the inter- and intra-reader agreement for mass and NME, respectively. ROC analysis compared the diagnostic performance of parameters between different radiologists, ROI methods, and between mass and NME.Results: In mass lesions, inter- and intra-observer agreement were perfect for all parameters (ICC: 0.800-989). In NME, the inter-observer agreement was substantial to perfect for all parameters(ICC: 0.703-877), the intra-observer agreement of the senior and intermediate radiologists was substantial to perfect(ICC: 0.748-931) and the intra-observer agreement of the junior radiologist was moderate to substantial(ICC: 0.569-784). The diagnostic performance of ADCslow (Z = 2.209, P = 0.023), MD (mean diffusivity) (Z = 2.887, P = 0.004), and MK (mean kurtosis) (Z = 2.080, P = 0.038) in the small ROI measured by the senior radiologist was better than that of the junior radiologist for NME. The diagnostic performance of ADCslow in the large ROI measured by the senior radiologist (Z = 2.281, P = 0.023) and intermediate radiologist (Z = 2.867, P = 0.0041) was better than the junior radiologist for mass lesions. The diagnostic performance of ADCslow, ADCstand, MD, and MK did not show a significant difference between the two ROI placement methods (P > 0.05).Conclusion: The observers' experience can influence the ROI selection and the diagnostic performance of ADCslow, ADCstand, MD, and MK measured using different methods show equal diagnostic performance. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To prospectively evaluate the diagnostic efficacy of conventional ultrasound (US), contrast-enhanced US (CEUS), the combined use of two modalities, and magnetic resonance imaging (MRI) in the differentiation of focal solid breast lesions. Materials and methods: 61 patients with BI-RADS category 3–5 breast lesions detected at conventional US underwent CEUS and MRI. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of conventional US, CEUS, combination of two modalities and MRI for discrimination between benign and malignant breast lesions. Results: Tissue specimens of 61 breast lesions were obtained either from surgical resection (n =46) or from needle biopsy (n =15). Histopathologic diagnosis revealed 28 benign and 33 malignant lesions. The diagnostic performance of conventional US and CEUS in differentiating benign from malignant breast lesions showed no significant difference (P =0.741). The combination of two modalities significantly improved the diagnostic accuracy compared with either conventional US or CEUS alone (P =0.031 and P =0.012, respectively). The area under the ROC curve (A z) value for the combined use of two modalities for discrimination between benign and malignant breast lesions was 0.94, and that for MRI was 0.91, whereas no statistical difference was found between them (P =0.296). Conclusion: The combined use of conventional US and CEUS has a better diagnostic performance than either method alone and displays good agreement with MRI in the differentiation capability for benign and malignant breast lesions. [Copyright &y& Elsevier]

Objective: To investigate the accuracy of virtual touch tissue imaging and quantification (VTIQ) in the diagnosis of benign and malignant breast lesions under four different precompression levels. The shear wave velocity (SWV) ratios of lesion to surrounding tissue were also added for diagnosis.Methods: 167 female patients with breast lesions were included in this single center prospective study. VTIQ was performed under four different precompression levels. The SWV of the lesion, surrounding fat, and gland tissue were measured at the same depth as much as feasible 7 times. The breast lesions studied were all histopathologically confirmed. The VTIQ parameters were compared between precompression levels. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the diagnostic performance of each parameter of the VTIQ.Results: The VTIQ parameters of the malignant lesions were significantly higher than those of benign lesions in all precompression levels (P < 0.001). SWV of the lesion, fat, and gland tissue increased significantly with increasing precompression. The VTIQ parameters had great diagnostic performance for breast lesions in all precompression levels (AUC = 0.765-0.911). There was no significant difference between the precompression levels of the lesion-to-fat SWV ratio and the lesion-to-gland SWV ratio in benign and malignant lesions, and the cut-off coefficients of variation were 7.42% and 8.55%, respectively.Conclusions: Precompression can increase the stiffness of breast lesions, fat and gland tissues, but does not reduce diagnostic value of VTIQ parameters in the breast. Under different precompression levels, the diagnosis of breast lesions by the ratio of the SWV of the lesion to the surrounding tissues is more stable. [ABSTRACT FROM AUTHOR]

Abstract: Impalpable breast lesions have always been a challenge for breast surgeons. Stereotactic wire placement is frequently employed for lesion localisation. To improve the accuracy of preoperative localisation in these cases we introduced a supplementary ultrasound scan to identify the exact location of the wire tip. We studied two groups of 15 patients, from periods before and after the introduction of the new technique. Specimen mammograms from each case were examined to determine the proximity of the lesion to the centre of the specimen. The excision of the lesion was graded into excellent, accurate, satisfactory and inaccurate depending on the location of centre of the lesion with respect to the centre of the excised specimen. Our study shows an increase in the accuracy of localisation of screen detected breast lesions, following the introduction of the supplementary ultrasound scan. Furthermore, there is evidence of a benefit in terms of ease of surgery and reduced operation time. Theoretically the technique should also improve clearance margins and reduce the need for further surgery in therapeutic operations. [Copyright &y& Elsevier]

Abstract: Purpose: To develop and evaluate a computer-assisted method of quantifying five-point elasticity scoring system based on ultrasound real-time elastography (RTE), for classifying benign and malignant breast lesions, with pathologic results as the reference standard. Materials and methods: Conventional ultrasonography (US) and RTE images of 145 breast lesions (67 malignant, 78 benign) were performed in this study. Each lesion was automatically contoured on the B-mode image by the level set method and mapped on the RTE image. The relative elasticity value of each pixel was reconstructed and classified into hard or soft by the fuzzy c-means clustering method. According to the hardness degree inside lesion and its surrounding tissue, the elasticity score of the RTE image was computed in an automatic way. Visual assessments of the radiologists were used for comparing the diagnostic performance. Histopathologic examination was used as the reference standard. The Student's t test and receiver operating characteristic (ROC) curve analysis were performed for statistical analysis. Results: Considering score 4 or higher as test positive for malignancy, the diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 93.8% (136/145), 92.5% (62/67), 94.9% (74/78), 93.9% (62/66), and 93.7% (74/79) for the computer-assisted scheme, and 89.7% (130/145), 85.1% (57/67), 93.6% (73/78), 92.0% (57/62), and 88.0% (73/83) for manual assessment. Area under ROC curve (A z value) for the proposed method was higher than the A z value for visual assessment (0.96 vs. 0.93). Conclusion: Computer-assisted quantification of classical five-point scoring system can significantly eliminate the interobserver variability and thereby improve the diagnostic confidence of classifying the breast lesions to avoid unnecessary biopsy. [Copyright &y& Elsevier]