MAI-Project

Effect of Propagation Speed on the Quality of Microwave Breast Images

Microwave imaging is an emerging imaging modality that has shown promising results in the detection of early-stage breast cancer. Several microwave breast imaging systems have been developed to date and some have reached the clinical trial phase. One aspect of these systems is the algorithm that is used to reconstruct an image of the breast. These algorithms use estimates of some parameters for simplification purposes, or when the structure of the breast is unknown. As clinical trials become larger, these estimates may no longer hold. One such estimate is the propagation speed, which is the speed at which a microwave propagates through breast tissue during the scan. This project aims to investigate the effect of propagation speed on image quality. To do this, a test set was created composed of scans of breast phantoms with and without tumours. The scans were grouped according to similarities including type of breast phantom, tumour size and tumour location. Images of these scans were reconstructed using the delay-and-sum algorithm at different propagation speeds. Preliminary results show that the interpretation of images may vary with propagation speed for both tumour and non-tumour images. The results also suggest that the effect that propagation speed has on image quality may vary depending on tumour size and tumour location. For most scans in the test set, it was shown that image quality was improved at speeds of 2.5-5% above the estimate used. However, more scan data is required in order to examine the validity of these results and to determine with more confidence the effect of propagation speed on the quality of images.

Links

• Interim Report
• Final Report