Breast ultrasound tomography versus magnetic resonance imaging for clinical display of anatomy and tumor rendering: Preliminary results

Abstract

*Abstract* *Objective: *To determine the clinical display thresholds of an ultrasound tomography (UST) prototype relative to magnetic resonance (MR) for comparable visualization of breast anatomy and tumor rendering. *Materials and Methods: *The study was compliant with HIPAA, approved by the IRB, and performed after obtaining informed consent. Thirty-six women were imaged with MR and our UST prototype. The UST scan generated reflection, sound speed and attenuation images. The reflection images were fused with the components of sound speed and attenuation images that achieved thresholds to represent parenchyma and/or solid masses using an image arithmetic process. Qualitative and quantitative comparisons of MR and UST clinical images were used to identify anatomical similarities, and optimized thresholds for tumor shapes and volumes. *Results: *Thresholding techniques generated UST images comparable to MR for visualizing fibrous stroma, parenchyma, fatty tissues, and tumors, of which 25 were cancer and 11 benign. Optimized sound speed thresholds of 1.46±0.1 km/s and 1.52±0.03 km/s were identified to best represent the extent of fibroglandular tissue and solid masses, respectively. An arithmetic combination of attenuation images using the threshold of 0.16±0.04 dB/cm further characterized benign from malignant masses. No significant difference in tumor volume was noted between benign or malignant masses by UST or MR (p>0.1) using these universal thresholds. *Conclusion: *UST demonstrated the ability to image and render breast tissues in a manner comparable to MR. Universal UST threshold values appear feasible for rendering of the size and distribution of benign and malignant tissues without intravenous contrast.