Diagnostic performance of 2D-shear wave elastography in the diagnosis of breast cancer: a clinical appraisal of cutoff values.

PURPOSE: To assess the role of 2D-shear wave elastography (2D-SWE) in differentiating benign from malignant focal breast lesions (FBLs), providing new vendor-specific cutoff values. METHODS: 158 FBLs (size: 3.5-50 mm) detected in 151 women (age: 21-87 years) were prospectively evaluated by means 2D-SWE. For each lesion, an expert radiologist assessed US BI-RADS category and calculated the following four 2D-SWE parameters: (1) elasticity maximum (Emax); (2) mean elasticity (Emean); (3) minimum elasticity (Emin); (4) elasticity ratio (Eratio). US-guided core-biopsy was considered as standard of reference for all the FBLs classified as BI-RADS 4 or 5. For each 2D-SWE parameter, the optimal cutoff value for a diagnostic test was calculated using the Youden method. Diagnostic performance of the US BI-RADS and 2D-SWE parameters was calculated accordingly. RESULTS: 83/158 (52.5%) FBLs were benign and 75/158 (47.5%) were malignant. Statistically significant higher stiffness values were observed in malignant FBLs for all 2D-SWE parameters than in benign ones (p < 0.001). 2D-SWE cutoff values were 82.6 kPa, 66.0 kPa and 53.6 kPa, respectively, for Emax, Emean, Emin and 330.8% for Eratio. The 2D-SWE parameter showing the best diagnostic accuracy was Emax (85.44%). Considering US BI-RADS 3 (n = 60) and 4a (n = 32) FBLs, Emax and Emean showed the best diagnostic accuracy (85.87% for both), without a statistically significant decrease in sensitivity (p = 0.7003 and p = 1, respectively). CONCLUSION: Our study provides new vendor-specific cutoff values for 2D-SWE, suggesting its possible clinical use in the adjunctive assessment of category US-BI-RADS 3 and 4a breast masses.

Ultrasonographic Detection of Vascularity of Focal Breast Lesions: Microvascular Imaging Versus Conventional Color and Power Doppler Imaging.

To compare microvascular flow imaging (MVFI) to conventional Color-Doppler (CDI) and Power-Doppler (PDI) imaging in the detection of vascularity of Focal Breast Lesions (FBLs). A total of 180 solid FBLs (size: 3.5-45.2 mm) detected in 180 women (age: 21-87 years) were evaluated by means of CDI, PDI, and MVFI. Two blinded reviewers categorized lesion vascularity in absent or present, and vascularity pattern as (a) internal; (b) vessels in rim; (c) combined. The presence of a "penetrating vessel" was assessed separately. Differences in vascularization patterns (chi2 test) and intra- and inter-observer agreement (Fleiss method) were calculated. ROC analysis was performed to assess performance of each technique in differentiating benign from malignant lesions. About 103/180 (57.2%) FBLs were benign and 77/180 (42.8%) were malignant. A statistically significant (p < .001) increase in blood flow detection was observed for both readers with MVFI in comparison to either CDI or PDI. Benign FBLs showed mainly absence of vascularity (p = .02 and p = .01 for each reader, respectively), rim pattern (p < .001 for both readers) or combined pattern (p = .01 and p = .04). Malignant lesions showed a statistically significant higher prevalence of internal flow pattern (p < .001 for both readers). The prevalence of penetrating vessels was significantly higher with MVFI in comparison to either CDI or PDI (p < .001 for both readers) and in the malignant FBLs (p < .001). ROC analysis showed MVFI (AUC = 0.70, 95%CI = [0.64-0.77]) more accurate than CDI (AUC = 0.67, 95%CI = [0.60-0.74]) and PDI (AUC = 0.67, 95%CI = [0.60-0.74]) though not significantly (p = .5436). Sensitivity/Specificity values for MVFI, PDI, and CDI were 76.6%/64.1%, 59.7%/73.8% and 58.4%/74.8%, respectively. Inter-reader agreement with MVFI was always very good (k-score 0.85-0.96), whereas with CDI and PDI evaluation ranged from good to very good. No differences in intra-observer agreement were noted. MVFI showed a statistically significant increase in the detection of the vascularization of FBLs in comparison to Color and Power-Doppler.

High-frequency ultrasound in the study of male breast palpable masses.

PURPOSE: To evaluate the role of high frequency colour-Doppler ultrasound in the study of diffuse or local breast nodules in males, and compare these results with those of mammography. MATERIALS AND METHODS: We studied 105 men aged between 12 and 82 years (mean age 42.3 years) with a palpable breast mass with or without pain. All patients underwent clinical and ultrasound examination. Seventy-eight also underwent mammography, whereas 27 did not because of young age (under 25 years) (n=10), no clinical or sonographic suspicion of a malignant mass (n=16), and ulcerated neoplastic lesion (n=1). The final diagnosis derived from surgery in six patients and from three-year follow-up for 99 patients. RESULTS: Eighty-nine patients had gynecomastia (85%), nine had adipomastia (8%), one had fibrolipoma (1%), five had carcinoma (5%) (invasive ductal carcinoma in four and bifocal ductal carcinoma and lobular carcinoma in one patient) and one had liposarcoma (1%). The clinical examination detected a bilateral (n=66) or unilateral (n=39) breast mass. Ultrasonography provided the correct diagnosis of diffuse nodular pathology in all cases and orientated diagnosis towards malignancy (6 cases) or benignity (1 case) of the lesions. No additional information was obtained from mammography, as compared to high-frequency ultrasonography. The integration of colour-Doppler in the examination was of little use as it demonstrated extensive vascularisation of most (5 cases) of the malignant lesions. CONCLUSIONS: Our results indicate that ultrasound allows the detection and characterization of palpable breast masses as well as correct local staging of neoplasms by identifying the degree of infiltration of the surrounding tissues.

Breast lesion characterization with contrast-enhanced US. Work in progress.

PURPOSE: To characterise breast lesions on the basis of microcirculation features detected with contrast-enhanced US. MATERIALS AND METHODS: Thirty-six patients aged 42-63 years (mean age 55 years) with a single breast lesion previously detected at standard mammography were studied. All US examinations were performed using an ATL HDI 5000 ultrasound device with a 5-10 MHz linear-array transducer, before and after administration of ultrasound contrast medium Levovist (Schering(R), Berlin) was administered by bolus injection (2 ml/s) via a 20 G catheter probe. The mechanical index was set to high to obtain instant rupture of the microbubbles under insonation. Intensity/time curves of the transient scattering in the region of interest (ROI) after contrast administration were extrapolated. The areas under the ROI curves were also evaluated to quantitatively assess the scattering. RESULTS: The US baseline study and colour Doppler US identified 19 benign lesions (15 histologically proven) and 17 malignant lesions (16 histologically proven). The administration of contrast medium did not improve the specificity of the examination. Only by plotting the intensity/time curves of the regions of interest (ROI) and evaluating the areas under the ROI curves, was a significant correlation detected between US and histopathologic diagnosis. CONCLUSIONS: Although further evaluation on a larger series is needed, the analysis of breast lesions by contrast-enhanced perfusion US seems to be a promising technique. Perfusion US can usefully complement high-frequency US, especially when mammography is inconclusive.