Imaging of idle breast implants with ultrasound-strain elastography- A first experimental study to establish criteria for accurate imaging of idle implants via ultrasound-strain elastography

Ultrasonic elastography for the prevention of breast implant rupture: Detection of an increase with stiffness over implantation time

Breast implants are widely used after breast cancer resection and must be changed regularly to avoid a rupture. To date, there are no quantitative criteria to help this decision. The mechanical evolution of the gels and membranes of the implants is still underinvestigated, although it can lead to early rupture. In this study, 35 breast explants having been implanted in patients for up to 17 years were characterized by ex vivo measurements of their mechanical properties. Using Acoustic Radiation Force Impulse (ARFI) ultrasound elastography, an imaging method for non-destructive mechanical characterization, an increase in the stiffness of the explants has been observed. This increase was correlated with the implantation duration, primarily after 8 years of implantation. With an increase of the shear modulus of up to a factor of nearly 3, the loss of flexibility of the implants is likely to lead to a significant increase of their risk of rupture. A complementary analysis of the gel from the explants by mass spectrometry imaging (MSI) and liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) confirms the presence of metabolites of cholesterol originating from the breast tissues, which most likely crossed the membrane of the implants and most likely degrades the gel. By observing the consequences of the physical-chemical mechanisms at work within patients, this study shows that ultrasound elastography could be used in vivoas a quantitative indicator of the risk of breast implant rupture and help diagnose their replacement.

Imaging of breast implant and implant-associated complications: Capsular contracture and intra- or extracapsular rupture

BACKGROUND

In recent years, follow-up after breast reconstruction with silicone implants and the detection of complications have been relieved by the possibility of improved diagnostic methods.

METHODS

Between January 2015 and December 2019 a total of 40 patients (29-84 years) with silicone implants were included in this retrospective study. The implants were examined clinically and with modern imaging: general ultrasound imaging (US), magnetic resonance imaging (MRI), high resolution computed tomography (CT) and positron emission tomography -computed tomography (PET-CT). If necessary, a histological/cytological sample was taken. The breast implants were assessed by three radiologists specialized in breast imaging. The grade of capsular contracture was classified according to the Baker classification.

RESULTS

All 40 women obtained a clinical examination and an US diagnostic to identify early and more common complications such as implant folding and capsular fibrosis. Depending on the clinical examination and ultrasound findings additional MRI (n = 10), CT (n = 9) and/or PET-CT (n = 2) were performed. 16 patients had implants folding proven with US (n = 16), MRI (n = 6) and CT (n = 1). The grade of capsular fibrosis was determined according to the Baker classification. The following results were obtained in our study: 25 breast implants with Baker grade I and eleven breast implants with Baker grade II, both proven with US; one breast implants with Baker grade III and one breast implant with Baker grade IV, proven with US (n = 2), MRI (n = 1) and CT (n = 1). One patient had intracapsular rupture and one patient had extracapsular rupture, both detected on CT and surgically proven. No patient had a silicone accumulation in the lymph nodes. One patient had pathologically enlarged axillary lymph nodes, which were evaluated as inflammatory changes in PET-CT. Long-term complications such as the development of malignant breast tumors could not be observed.

CONCLUSION

To detect early complications after breast implant surgery, a regular clinical examination is indispensable. Imaging methods complement each other and if they are used multimodal, it is easier to identify early complications. Modern diagnostic modalities like ultrasound and magnetic resonance imaging expand the spectrum and improve diagnostic safety.

A novel two-dimensional quantitative shear wave elastography to make differential diagnosis of breast lesions: Comprehensive evaluation and influencing factors

BACKGROUND

Virtual touch imaging quantification (VTIQ), a form of shear wave elastography, may help in the diagnosis of breast lesions.

OBJECTIVE

We aimed to evaluate the diagnostic performance of combined VTIQ and conventional ultrasound (US), and assess the factors influencing VTIQ measurement.

METHODS

From September 2014 to December 2014, 162 patients with breast lesions were examined by US and VTIQ to assess shear wave speed (SWS) and morphological characteristics (lesion shape, orientation, margin and echo pattern). The sensitivity, specificity and accuracy of VTIQ, US and VTIQ+US for the diagnosis of breast lesions was evaluated in comparison to pathological results. Factors influencing deviations in SWS measurements were assessed by logistic regression.

RESULTS

The SWS cut-off between malignant and benign lesions was 3.73 m/s. The sensitivity, specificity and accuracy were: 98.07%, 55.96%, and 69.57% for US; 76.92%, 78.89% and 78.26% for VTIQ; and 98.07%, 84.40% and 88.82% for US+VTIQ. The two factors that influenced the SWS results were the lesion margin (odds ratio [OR], 16.363; 95% confidence interval [CI], 3.220-29.020) and vascularity (OR, 6.712; 95% CI, 1.358-9.072).

CONCLUSIONS

The lesion margin and vascularity could affect the measurement of SWS as well as the experience of examiner. However, VTIQ is still a reliable method that provides valuable information in the differential diagnosis of breast lesions, and may reduce unnecessary biopsies.