Simulated Breasts Help Assess Safety of Stronger MRI
Computer modeling advances potential use of latest MRI technology for breast cancer screening.
MRI is often used to screen for breast cancer, particularly in high-risk patients. It is considered especially useful for imaging dense breasts, which contain a higher percentage of fibroglandular tissue that can obscure tumors on conventional mammograms. An advanced 7 tesla (7T) MRI system, which offers higher sensitivity and image quality than standard 1.5 or 3 tesla systems, was approved by the FDA in October 2017 for use on the head, arms and legs. To be able to tap into the clinical potential of this system for breast imaging, however, researchers must develop a way to demonstrate the safety of the more powerful system for breast tissue of all types.
In a study published Sept. 14 in Magnetic Resonance in Medicine, a research team simulated how different types of breasts absorb energy and respond to heating in MRI machines. One challenge is that very few virtual models of adult female whole bodies are available for research use, and none are positioned lying face-down, the preferred position for breast imaging. The team first used patient MRI and CT images to create models of prone breasts that they computationally fused to two pre-existing female body “phantoms” to generate whole-body models suitable for simulating breast MRI. They modeled a wide range of breast tissue types to represent as many women as possible.
In the 7T MRI simulations, all the breast types showed energy absorption and tissue heating values within the recommended safety limits, although denser breasts absorbed more energy and may be more susceptible to localized temperature increases. The findings are an important step toward clinical approval of the technique for breast imaging and may enable development of additional tumor monitoring or therapeutic techniques, the authors say.