Magnetic Resonance Imaging Subsystem for Cardiac Ischemia Evaluation

DESCRIPTION (provided by applicant): Cardiac magnetic resonance imaging (MRI) has been shown to be one of the best technologies for the evaluation of cardiovascular pathologies. The broad application of this promising technology is expected to significantly improve the treatment of patients with heart disease in general and ischemic heart diseases in particular. However, widespread adoption of this beneficial technology has been held back by the lack of both software infrastructure and specific software sequences that take advantage of this infrastructure to provide a rapid, complete cardiac ischemic examination. The aim of this application is to bridge our cardiac ischemia package to the clinical arena through targeted technical developments, phantom testing, and clinical data collections designed to facilitate FDA approval. Under previous NIH grant support through Stanford University, we established real-time rapid imaging sequences for the assessment of wall motion and perfusion. We also established theutility and accuracy of rapid coronary imaging sequences for the assessment of proximal coronary anatomy. Our goal in this proposal is to integrate these methods into a robust ischemic heart disease system to realize the clinical potential of cardiac MRI in the evaluation of coronary artery disease. During Phase I and Phase II of this proposal, HeartVista developed and tested the alpha version of the cardiovascular software infrastructure that provides an integrated environment for rapid cardiovascular imaging. This package includes real-time evaluation of myocardial function under stress conditions, volumetric perfusion imaging, high-resolution examination of myocardial viability in real-time and high-resolution examination of the proximal coronary anatomy. We installed the system at selected alpha sites and collected patient data. Generally, our methods concern obtaining adequate temporal resolution, spatial coverage, and contrast production for stress imaging using customized pulse sequences and hardware to reduce data acquisition time, developing an underlying real-time imaging platform that allows the seamless real-time integration of receiver coil functions, pulse sequences, and post-processing and display that optimizes the workflow for studying patients with ischemia. This proposal focuses on completing the final technical steps necessary for regulatory approval of our product. This combined examination would provide a robust and intuitive complete ischemic evaluation package that can be performed comfortably in less than 1 hour. During Phase IIb of this proposal, we will focus the development of our product on the safety and reliability requirements to obtain a 510(k) FDA approval. We will also conduct a clinical study to demonstrate the non-inferiority of our product compared to conventional cardiovascular MRI examinations in robustness and diagnostic accuracy. PUBLIC HEALTH RELEVANCE PUBLIC HEALTH RELEVANCE: Ischemic heart disease remains the number one cause of mortality in the United States. Current diagnostic techniques have significant shortcomings that can result in inaccurate diagnoses. The reduced accuracy leads to a large number of unnecessary procedures. Given the enormous number of these procedures, even a modest improvement in diagnostic accuracy will have a large public-health impact. Cardiac magnetic resonance imaging has been shown to be one of the best technologies for the evaluation of cardiovascular pathologies. It is the only imaging modality that could provide allof the important parameters of ischemia evaluation in function, perfusion, viability and coronary anatomy in a single examination. The broad application of this promising technology is expected to significantly improve the treatment of patients with heartdisease in general and ischemic heart diseases in particular. However, the adoption of this beneficial technology has been held back by the lack of both a software infrastructure and specific software sequences that take advantage of this infrastructure to provide a complete ischemic examination that can be performed rapidly in the clinical environment. The aim of this application is to develop a robust commercial cardiovascular subsystem that will enable the broad clinical application of this technology.