Exercise Stress Cardiac Magnetic Resonance

DESCRIPTION (provided by applicant): Exercise stress testing with imaging is widely used to detect heart disease, but current stress imaging systems suffer from false positives that may lead to unnecessary invasive testing, and false negatives that may miss disease detection until a serious event occurs. Thus, consistently accurate stress imaging remains an important target for technology development. Cardiac magnetic resonance (CMR) provides superior imaging of the heart without ionizing radiation, but technology has not been developed to allow CMR immediately following maximal exercise stress. A revolutionary change to the current landscape of cardiac stress testing could result by adding exercise testing to CMR, thus establishing a one-stop imaging modality for accurately assessing heart disease in a single examination. This project focuses on the research and commercialization of an MRI-based system for enhanced exercise stress testing for patients with suspected cardiovascular disease. The key enabling technology is an innovative non-ferromagnetic treadmill that enables convenient placement immediately adjacent to the MRI machine. Standard treadmills would have to be placed far from the MRI magnet outside the MRI room, leading to critical delays between exercise and image acquisition, as well as safety concerns for compromised patients who must, in a fatigued and stressed state, traverse the distance from the treadmill to the MRI table. Our innovative design will overcome these problems and furthermore, enable image acquisition immediately post-exercise. The resulting high resolution images are expected to be superior to nuclear single photon emission tomography (SPECT) and ultrasound, and clearly show stress wall motion, stress perfusion, and viability. The design, implementation, and feasibility testing of this new technology by a coordinated team of engineers and clinicians (Phase I), followed by a multi-center investigation showing improved accuracy over existing stress imaging methods (Phase II) is expected to lead to a sizeable commercial opportunity for the manufacture and sale of MRI stress testing equipment. Phase I of this project will be accomplished by meeting the following specific aims: Design and construct an MRI-compatible treadmill capable of performing the standard Bruce stress test protocol immediately adjacent to MRI systems up to 3T field strength. Demonstrate feasibility of treadmill exercise stress MRI of cardiac function and perfusion in patients with suspected coronary artery disease. Successful achievement of the aims of this Phase I project will lead to Phase II multi-center validation of this new stress imaging modality, including direct comparison with nuclear SPECT. The combination of exercise stress testing and CMR could greatly enhance our understanding of CAD, and enable earlier diagnosis and more effective treatment strategies. PUBLIC HEALTH RELEVANCE: Exercise testing and magnetic resonance imaging (MRI) have independently shown tremendous utility in the diagnosis and treatment of heart disease. Exercise stress testing provides important information about the heart's response to physical exertion, and MRI is a non-invasive imaging method that has many advantages over other imaging techniques. This project develops and evaluates the new equipment needed to combine exercise testing with MRI, and is expected to result in an improved test for the diagnosis of heart disease.