Objectives The purpose of this study was to determine the sensitivity and specificity of real‐time compression elasticity imaging in characterizing breast lesions as benign or malignant. Methods A cohort of 578 women scheduled for sonographically guided biopsy of breast lesions were recruited from 6 sites under an Institutional Review Board–approved protocol. All participants received an elastogram, which displayed both the B‐mode and elasticity images in real time. The longest dimensions of the lesion on the B‐mode and elasticity imaging were measured. An elasticity imaging/B‐mode ratio of at least 1.0 was considered positive for malignant lesions. The reference standard was based on biopsy. Results A total of 635 lesions were imaged and biopsied. There were 222 (35%) malignant or borderline lesions and 413 (65%) benign lesions. The benign lesions were either cystic (145 [35%]) or solid (268 [65%]). Of the 222 malignant lesions, 219 had an elasticity imaging/B‐mode ratio of at least 1.0. Of the 413 benign lesions, 361 had an elasticity imaging/B‐mode ratio less than 1.0. These results corresponded to overall sensitivity of 98.6% and overall specificity of 87.4%. Individual site sensitivities ranged from 96.7% to 100% whereas specificities ranged from 66.7% to 95.4%. Conclusions Elasticity imaging has high sensitivity in characterizing malignant lesions of the breast. Variability in specificity between sites and sonographers is possibly due to individual technique differences in performing elastography and measuring lesions. Further work in standardizing the technique is required.

Although only limited long-term studies evaluating thermal ablation of renal masses have been performed, it appears that thermal ablation has a comparable 5-year success rate to that of partial or total nephrectomy. This technique is often used in patients who are not good candidates for partial or total nephrectomy. Contrast-enhanced ultrasound (CEUS) has been recently approved by the Food and Drug Administration for characterization of focal liver lesions in adults and pediatric patients. CEUS can be used off label for renal applications and has been used for years in Europe and Asia. It has several advantages over contrast-enhanced computed tomography for use as the technique to guide and evaluate efficacy of thermal ablation of renal masses. These include the ability to visualize small amounts of enhancement, repeat dosing to evaluate efficacy of an ablation during a procedure, thin slice thickness, and real-time visualization. Ultrasound contrast is also non-nephrotoxic and non-hepatotoxic, allowing evaluation of patients with renal insufficiency. This article reviews the use of CEUS for the guidance and follow-up of thermal ablative procedures of renal masses.Keywords: contrast-enhanced ultrasound; radiofrequency ablation; renal tumor ablation; small renal masses; ultrasound contrast agents