The goal of this clinical trial is to measure the electrical properties of breast tissues using microwave technology and to compare these collected measurements to clinical information in mammograms and/or breast ultrasound for women that have been recalled for follow-up breast imaging or further investigation. The main questions it aims to answer are:

1. Can the breast area and plate separation in the microwave scan be compared to mammogram data (where available) to assess similarity in breast positioning and the feasibility of image registration?
2. Can the distribution of electrical properties specifically glandular tissue distribution in the microwave image be compared to that observed in the mammogram (where available)?
3. Can the characteristics of the microwave image in the localized region corresponding to an identified anomaly in the breast imaging data be examined?

Study participants will be scanned with the Wave View microwave scanner on the same day as their follow-up breast imaging appointment. Each breast will be scanned up to 3 times with the scanner oriented in both the horizontal position and oriented at 45 degrees. Study participants will also be asked to fill out three surveys, one relating to breast health and the other two relating to their scanning experience.

A new approach to imaging that uses low-power microwaves to scan the breast has been developed. Since the imaging system uses low power, there is no risk of tissue heating. The imaging system places the sensors in contact with the breast tissue. The research team at the University of Calgary has previously developed microwave imaging systems that have been tested on healthy volunteers and breast cancer patients. A group of healthy volunteers were repeatedly scanned to evaluate the consistency of the imaging approach. Another study involved scanning breast cancer patients before each round of neoadjuvant chemotherapy. The information collected from experiences scanning volunteers and patients have been reviewed and translated into a next-generation imaging system design. Aspects of this system have been further improved by Wave View Imaging, which is a company formed by members of the University's research team.

The proposed study involves collecting electrical property measurements of breast tissues and comparing these measurements to clinical information in mammograms and/or breast ultrasounds. The investigators also aim to compare regions of interest in the microwave scans with regions of interest in the mammograms (where available). This includes regions dominated by fibroglandular tissues, as well as regions of interest that correspond to anomalies identified in the mammograms and/or breast ultrasounds.

The plan is to scan both breasts of up to 100 volunteers that have been recalled for follow-up breast imaging or further investigation. Each volunteer will participate in a single scanning session during their follow-up appointment. Breast tissue composition will be compared with the microwave properties and registration of mammograms (where available) with microwave images will be performed for a more detailed comparison.

Inclusion Criteria:

• Female sex
• 18-74 years of age
• Able to provide informed consent
• Had a screening or diagnostic mammogram or breast ultrasound within the previous 6 weeks
• Recalled for additional breast imaging due to BIRADS 3 or 4 or 5 findings.

Exclusion Criteria:

• Participants who have not received a mammogram or breast ultrasound
• Participants who are currently undergoing breast cancer treatment or have had treatment in the past 6 months
• Participants with breast implants
• Participants who are pregnant or breastfeeding
• Participants with active breast skin infections
• Participants with nipple piercings (unless they are removed prior to scanning)
• Participants with an implanted electronic device
• Participants with physical limitations that prevent them from placing their breasts inside the Wave View scanner.