Association of breast cancer risk, density, and stiffness: global tissue stiffness on breast MR elastography (MRE).

PURPOSE: Quantify in vivo biomechanical tissue properties in various breast densities and in average risk and high-risk women using Magnetic Resonance Imaging (MRI)/MRE and examine the association between breast biomechanical properties and cancer risk based on patient demographics and clinical data. METHODS: Patients with average risk or high-risk of breast cancer underwent 3.0 T breast MR imaging and elastography. Breast parenchymal enhancement (BPE), density (from most recent mammogram), stiffness, elasticity, and viscosity were recorded. Within each breast density group (non-dense versus dense), stiffness, elasticity, and viscosity were compared across risk groups (average versus high). Separately for stiffness, elasticity, and viscosity, a multivariable logistic regression model was used to evaluate whether the MRE parameter predicted risk status after controlling for clinical factors. RESULTS: 50 average risk and 86 high-risk patients were included. Risk groups were similar in age, density, and menopausal status. Among patients with dense breasts, mean stiffness, elasticity, and viscosity were significantly higher in high-risk patients (N = 55) compared to average risk patients (N = 34; all p < 0.001). Stiffness remained a significant predictor of risk status (OR = 4.26, 95% CI [1.96, 9.25]) even after controlling for breast density, BPE, age, and menopausal status. Similar results were seen for elasticity and viscosity. CONCLUSION: A structurally based, quantitative biomarker of tissue stiffness obtained from MRE is associated with differences in breast cancer risk in dense breasts. Tissue stiffness could provide a novel prognostic marker to help identify high-risk women with dense breasts who would benefit from increased surveillance and/or risk reduction measures.

Value of Elastography in Differentiating Benign from Malignant Breast Lesions Keeping Histopathology as Gold Standard.

BACKGROUND:  Breast cancer is the most common cancer in females, both in developed and developing countries. Pakistan has the highest breast cancer incidence rate in Asia. Guidelines recommend screening for detecting breast cancer with mammography and ultrasonography (US). Shear-wave elastography (SWE) is a newer technique that can aid additional characterization of breast lesions.  Objective: The aim of this study was to determine the diagnostic accuracy of breast ultrasound elastography in differentiating benign from malignant breast lesions using histology diagnosis as the gold standard. MATERIALS AND METHODS: The study was conducted at the Abbasi Shaheed Hospital and Jinnah Post Graduate Medical Centre, Karachi. All consecutive patients undergoing breast biopsy and elastography of breast lesions were enlisted; 2 x 2 tables were used to measure the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of breast ultrasound elastography for differentiation of benign from malignant breast masses. RESULTS:  A total of 155 female patients were included with a mean age of 45.41 ± 14.24 years (range 20-70 years). On histological evaluation, 115 (74.2%) lesions were malignant and 40 (25.8%) were benign. The overall average mean elastography value was 108.45 kPa ± 52.75. The mean elastography (EMean) value for benign breast lesions was 48.96 kPa ± 42.32 and 132.78 kPa ± 42.32 for malignant lesions. The difference in mean elastography values of benign and malignant breast lesions was statistically significant (48.96 kPa ± 42.32 vs 32.78 kPa ± 42.32, P <0.001). The area under the curve (AUC) was 0.952, optimal cutoff EMean value of 72 kPa and higher likelihood ratio was 9.41. A cutoff mean elastography (EMean) value of ≤ 72 kilopascal (kPa) for benign lesions had sensitivity 92.17%, specificity 90.4%, PPV 96.36%, NPV 80.0% and diagnostic accuracy 91.61%.  Conclusion: Ultrasound elastography was found to have high sensitivity and specificity and diagnostic accuracy for differentiating benign from malignant breast lesions. Use of shear-wave elastography may increase malignancy detection rate by reducing the need for biopsy in benign breast lesions.

Quantitative breast elastography from B-mode images.

PURPOSE: Elastography images provide information about the mechanical properties of soft tissue in a noninvasive way and can be useful to identify abnormalities and ascertain differential diagnoses of suspicious prior findings obtained through mammography ultrasound. In this work we investigate, from a physics point of view, the feasibility of quantifying the Young's modulus of breast tissue from the autocorrelation of a diffuse acoustic field computed from a sequence of B-mode images acquired through conventional ultrasound scanners. METHODS: Inspired in the seismological approach of retrieving the Green's function by cross-correlation of diffuse fields, we obtained a quantitative expression that relates the local shear modulus of soft tissue to the autocorrelation of the displacement field generated by the presence of an acoustic diffuse field in the medium. In addition, we designed a mechanical prototype device adaptable to the breast anatomy, in order to create the necessary conditions in terms of diffuse field generation. The device is easy to handle, and its positioning does not interfere with the ultrasonic probe, being friendly to use within the clinical environment. The displacement field was measured from a sequence of B-mode images acquired at standard frame rates (30-50 Hz) with conventional ultrasound equipment. This method was tested in a breast tissue mimicking phantom using two standard ultrasound scanners (Toshiba Nemio NX and SIUI (Shantou Institute of Ultrasonic Instruments) Apogee 3800) and an open source research device (Verasonics V3.07 US). We also performed an in vivo measurement as a preliminary validation. RESULTS: In the reconstructed Young's modulus maps the inclusions were identified and the obtained quantitative results for an inclusion and the background of the phantom were 60.0 ± 4.0 and 20.4 ± 0.5 KPa for the Toshiba equipment, 65.5 ± 6.9 and 22.6 ± 2.7 KPa for the SIUI equipment and 67.2 ± 7.3 KPa and 22.6 ± 2.8 KPa for the Verasonic scanner. These results are in good agreement with the values reported by the phantom's manufacturer of 60 and 20 KPa for the inclusion and the background, respectively. In the case of the in vivo measurement, the obtained images are in accordance with the patient known pathology (BI-RADS 5, Infiltrating Ductal Carcinoma, Score 6). The pathological breast showed a heterogeneous elasticity map with a mean Young's modulus of 98.1 ± 12.9 KPa, while the normal breast displayed a homogeneous map with a mean Young's modulus of 24.7 ± 8.1 KPa. CONCLUSIONS: We successfully reconstructed the Young's modulus map of the breast tissue mimicking phantom and of a real breast tumor using B-mode images acquired with conventional ultrasound scanners. The results obtained in this work support that our technique can be developed as a medical tool to obtain quantitative breast tissue elasticity maps.

Inter- and Intra-Observer Agreement in Ultrasound BI-RADS Classification and Real-Time Elastography Tsukuba Score Assessment of Breast Lesions.

Our aim was to prospectively evaluate inter- and intra-observer agreement between Breast Imaging Reporting and Data System (BI-RADS) classifications and Tsukuba elasticity scores (TSs) of breast lesions. The study included 164 breast lesions (63 malignant, 101 benign). The BI-RADS classification and TS of each breast lesion was assessed by the examiner and twice by three reviewers at an interval of 2 months. Weighted κ values for inter-observer agreement ranged from moderate to substantial for BI-RADS classification (κ = 0.585-0.738) and was substantial for TS (κ = 0.608-0.779). Intra-observer agreement was almost perfect for ultrasound (US) BI-RADS (κ = 0.847-0.872) and TS (κ = 0.879-0.914). Overall, individual reviewers are highly self-consistent (almost perfect intra-observer agreement) with respect to BI-RADS classification and TS, whereas inter-observer agreement was moderate to substantial. Comprehensive training is essential for achieving high agreement and minimizing the impact of subjectivity. Our results indicate that breast US and real-time elastography can achieve high diagnostic performance.

Breast hamartoma: ultrasound, elastosonographic, and mammographic features. Mini pictorial essay.

Hamartomas, also known as fibroadenolipomas, are rare, benign formations that can develop in various organs, including the breast. They present clinically as a soft, mobile nodular lesions and are generally asymptomatic. They may be discovered incidentally during imaging studies performed for other reasons. Owing to the increasingly widespread use of mammographic screening, the diagnosis of breast hamartomas is on the rise. The masses are associated with specific mammographic and sonographic features that reflect their diverse tissue components. They also appear to present reproducible features on elastography. This article reviews the typical features of breast hamartomas seen on these three imaging modalities.

Value of Strain Elastography Ultrasound in Differentiation of Breast Masses and Histopathologic Correlation.

OBJECTIVE: US elastography is an emerging technique that can be used during breast US examination. The increasing awareness of breast cancer led to an increase in mammography and breast US examinations. The specificity of these techniques is not high enough to prevent unnecessary biopsies. There is still a need for a more specific technique that can overcome this problem. This study aimed to evaluate the value of strain elastography in breast lesions. MATERIALS AND METHODS: In this study, 110 lesions of 96 patients were evaluated with strain elastography. Five score system was used for lesion scoring. The histopathologic results of lesions were obtained and were accepted as gold standard. The sensitivity, specificity, PPV and NPV of the technique were calculated. Histopathologic and strain elastography results were correlated. RESULTS: The sensitivity of US strain elastography was calculated as 83%, the specificity as 89%, the positive predictive value as 79% and the negative predictive value as 91%. There were no score 1 lesions. All score 2 lesions were benign. Score 5 had the highest true positivity rate. CONCLUSION: We believe that ultrasound elastography is an effective imaging technique that can be used as an adjunct for differential diagnosis, prior to the decision to biopsy a lesion in certain cases.

Breast elastography: A literature review.

Breast elastography is a new sonographic imaging technique which provides information on breast lesions in addition to conventional ultrasonography (US) and mammography. Elastography provides a noninvasive evaluation of the stiffness of a lesion. Today, two technical solutions are available for clinical use: strain elastography and shear wave elastography. Initial evaluations of these techniques in clinical trials suggest that they may substantially improve the possibility of differentiating benign from malignant breast lesions thereby limiting recourse to biopsy and considerably reducing the number of benign breast biopsy diagnoses. This article reviews the basics of this technique, how to perform the examination, image interpretation and the results of major clinical studies. Although elastography is easy to perform, training and technical knowledge are required in order to obtain images permitting a correct interpretation. This paper will highlight the technique and point out common pitfalls.Breast elastography is a new sonographic imaging technique which provides information on breast lesions in addition to conventional ultrasonography (US) and mammography. Elastography provides a noninvasive evaluation of the stiffness of a lesion. Today, two technical solutions are available for clinical use: strain elastography and shear wave elastography. Initial evaluations of these techniques in clinical trials suggest that they may substantially improve the possibility of differentiating benign from malignant breast lesions thereby limiting recourse to biopsy and considerably reducing the number of benign breast biopsy diagnoses. This article reviews the basics of this technique, how to perform the examination, image interpretation and the results of major clinical studies. Although elastography is easy to perform, training and technical knowledge are required in order to obtain images permitting a correct interpretation. This paper will highlight the technique and point out common pitfalls.

Correlation between insulin resistance and breast elasticity heterogeneity measured by shear wave elastography in premenopausal women - a pilot study.

INTRODUCTION: Recent studies have demonstrated a strong correlation between obesity, insulin resistance, increased insulin and insulin-like growth factor levels and the risk of breast cancer. Our study was aimed at exploring correlations between glucose, insulin, insulin resistance, obesity and quantitatively estimated breast elasticity in healthy women. MATERIAL AND METHODS: The pilot study included 37 premenopausal women aged 22-45 years who underwent B-mode sonography and real-time shear wave elastography. Blood was collected for fasting insulin and glucose, and HOMA insulin resistance index was calculated. RESULTS: The mean elasticity of glandular and fatty tissue measured in both breasts was 12.5 ±3.5 kPa and 10.9 ±3.7 kPa respectively. Insulin levels did not correlate with glandular tissue elasticity (Rs=-0.23, p=0.15), but nearly correlated with fat tissue elasticity (Rs=-0.30, p=0.06), in outer quadrants significantly (Rs=-0.38, p=0.02). Interestingly, a strong correlation of insulin and insulin resistance with elasticity heterogeneity was found in fatty tissue (Rs=-0.59, p<0.001 and Rs=-0.60, p<0.001 respectively). The heterogeneity of fatty tissue but not glandular elasticity also correlated with body mass index. CONCLUSIONS: Insulin levels and insulin resistance correlate with breast fat tissue heterogeneity, but their role in breast pathology remains unclear.