Feasibility of Imaging Breast Implants With a Transmission-based Microwave Scanner

Breast implants are consistently one of the top 5 cosmetic procedures performed each year in North America. The Food and Drug Administration (FDA) cites a 10% risk of rupture over 10 years (1% cumulative per annum risk of device rupture).

Rupture refers to disruption in the integrity of the implant, and is typically age-related deterioration where age in this context refer to the implant. Rupture in saline implants is detected with rapid change in breast size. With silicone implants, rupture is much more challenging to detect as it is rare to have a completely collapsed implant shell.

Current recommendations for surveillance of breast implants include Magnetic Resonance Imaging (MRI) or ultrasound within 5-6 years of surgery for the initial test, then every 2-3 years. The guideline initially included only MRI but was adjusted in 2022 to include ultrasound. Patient adherence to guidelines with only MRI was very low (less than 5%), which is postulated to relate to the expense, discomfort, and inaccessibility of MRI. Mammography is a frequently used breast imaging method. However, the majority of women with implants are too young for breast screening programs that involve regular mammograms. Also, the implant is displaced during mammography to focus on the breast tissues. Finally, mammography involves exposure to x-rays, limiting regular scans in women too young for screening.

Therefore, there is a need to regularly inspect silicone implants for silent rupture. An imaging approach that is low-cost, available at point-of-care, easy to use, and reliable (i.e. sensitive to implant rupture) would be a valuable tool for plastic surgery clinics.

Microwave imaging has been proposed as a low-cost and comfortable approach to breast imaging that can be performed at point of care. This approach to imaging is low power, so no tissue heating occurs and there are no other side effects. Therefore, microwave imaging is suited to in-clinic, ongoing monitoring of the breast.

10 women with breast implants will be recruited from plastic surgery clinics. This includes women with breast implants that were surgically placed at least 6 months prior and are asymptomatic for implant rupture, as well as women who have implants with a confirmed rupture. Study participants will be scanned with the microwave imaging system. Three scans of each breast will be collected in each of the Craniocaudal (CC) and Mediolateral Oblique (MLO) views.

The breast positioning will be adjusted between scans to maximize the presentation of the implant in the imaging volume. The images will be analyzed to identify the implants, as the implants have different properties when compared to healthy breast tissues.

Inclusion criteria

• Women with breast implants placed at least 6 months prior who are asymptomatic for implant rupture as well as those with known implant rupture
• Female
• Minimum of 18 years of age
• Able to provide informed consent

Exclusion criteria

• Women who are currently pregnant or breastfeeding
• Women with active breast infections
• Women with nipple piercings (unless removed prior to scanning)
• Women with implanted electronic device
• Women with physical limitations that prevent them from placing their breasts inside the scanner