CMR and Advanced Imaging in Myocardial Ischemia

Stress perfusion CMR emerges as a non-invasive alternative for obstructuve coronary artery detection, relying on qualitiative evaluation of stress perfusion images to pinpoint ischemic regions in the myocardium. Unfortunately, visual analysis in CMR perfusion imaging is hampered by several limitations. These include interobserver and intraobserver variability, leading to inconsistencies in diagnosis. Moreover, visual assessment is inherently subjective, influenced by factors like experience and biases. Finally, visuals analysis can be time-consuming. To overcome these challenges, advanced perfusional imaging techniques are necessary, offering more objective and needle-free methods to enhance myocardial perfusion imaging to a higher level.

Quantitative Perfusion CMR (QP-CMR)

Quantitative Perfusion CMR (QP-CMR) allows absolute quantification of myocardial blood flow (MBF) and the creation of color pixel perfusion maps representing the value of myocardial perfusion. The MBF is measured by evaluating the signal intensity curves of the first-pass perfusion of a contrast agent. With the latest advancements, an AI-based, fully automatic pixel-wise QP-CMR image processing framework can be established, which is reproducible, time-efficient, and does not require manual adjustments.

T1 Mapping Reactivity (T1-CMR)

Currently, the detection of coronary artery disease by CMR remains the necessity of contrast-based agents. The novel CMR technique native T1 mapping can potentially improve ischemia detection by measuring the myocardial blood volume and water content. By comparison of T1 values in rest and T1 values during stress environments, ischemia can be detected, without the need for contrast-based agents.

Oxygen Sensitive CMR (OS-CMR)

Oxygenation-sensitive cardiac magnetic resonance imaging (OS-CMR) is a novel, non-invasive, contrast agent-free method to assess myocardial oxygenation. It uses the magnetic properties of deoxygenated hemoglobin to create a tissue contrast source. When combined with a vasoactive breathing maneuver, OS-CMR can detect oxygenation deficits in the myocardium. In Obstructive Coronary artery disease, there are increased levels of deoxygenated hemoglobin in the capillaries, indicating a perfusion defect. This promising vasodilator-free, contrast-free, and needle-free technique is one step closer to implementation in clinical practice.