Effect of Calcifications on Breast Ultrasound Shear Wave Elastography: An Investigational Study

Abstract

PurposeTo investigate the effects of macrocalcifications and clustered microcalcifications associated with benign breast masses on shear wave elastography (SWE).MethodsSuperSonic Imagine (SSI) and comb-push ultrasound shear elastography (CUSE) were performed on three sets of phantoms to investigate how calcifications of different sizes and distributions influence measured elasticity. To demonstrate the effect in vivo, three female patients with benign breast masses associated with mammographically-identified calcifications were evaluated by CUSE.ResultsApparent maximum elasticity (Emax) estimates resulting from individual macrocalcifications (with diameters of 2mm, 3mm, 5mm, 6mm, 9mm, 11mm, and 15mm) showed values over 50 kPa for all cases, which represents more than 100% increase over background (~21kPa). We considered a 2cm-diameter circular region of interest for all phantom experiments. Mean elasticity (Emean) values varied from 26 kPa to 73 kPa, depending on the macrocalcification size. Highly dense clusters of microcalcifications showed higher Emax values than clusters of microcalcification with low concentrations, but the difference in Emean values was not significant.ConclusionsOur results demonstrate that the presence of large isolated macrocalcifications and highly concentrated clusters of microcalcifications can introduce areas with apparent high elasticity in SWE. Considering that benign breast masses normally have significantly lower elasticity values than malignant tumors, such areas with high elasticity appearing due to presence of calcification in benign breast masses may lead to misdiagnosis.

Differentiation of Benign and Malignant Thyroid Nodules by Using Comb-push Ultrasound Shear Elastography

“…These results correlate with previous findings (31). Figure 7 shows an example of a false positive benign nodule by SWE containing macrocalcifications.…”

“…Furthermore, from the 16 thyroid nodules identified as false positives cases, 9 (56.25%) nodules contained macrocalcifications and 2 (12.5%) nodules had microcalcifications. Thus, benign nodules with calcifications can be perceived as malignant nodules based on ultrasound SWE (31). Additional nodule features such as cystic component and nodule size did not have an effect on shear wave speed measurements among benign and malignant nodules; on the other hand, benign nodules in patients with goiter and benign nodules with a vascular component (identified by using color Doppler imaging) showed reduced elasticity compared to nodules inside normal size thyroid glands and avascular nodules, respectively.…”

Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis?

“…Another issue comes from the effect of calcification: the surrounding zones are hardened, making the elasticity estimation higher. If the ROI selected matches this area, a misdiagnosis may be expected [193].…”

Do Histopathological Features and Microcalcification Affect the Elasticity of Breast Cancer?

“…This result may have been a consequence of the amount of microcalcification. It was suggested by Gregory et al that highly concentrated microcalcifications can influence stiffness more than low concentrations …”

“…Furthermore, the presence of calcification may be another factor affecting stiffness in breast cancer. In a recent study, Gregory et al found that large isolated macrocalcifications and highly concentrated clusters of microcalcifications showed higher stiffness in benign breast masses …”