Gadolinium-Free Cardiac MR Stress T1-Mapping to Distinguish Epicardial From Microvascular Coronary Disease.BACKGROUND
 Novel cardiac magnetic resonance (CMR) stress T1 mapping can detect ischemia and myocardial blood volume changes without contrast agents and may be a more comprehensive ischemia biomarker than myocardial blood flow.


 Ninety subjects (60 patients with angina; 30 healthy control subjects) underwent CMR (1.5- and 3-T) to assess left ventricular function (cine), ischemia (adenosine stress/rest T1 mapping and perfusion), and infarction (late gadolinium enhancement).  FFR and IMR were assessed ≤7 days post-CMR.  CMR stress T1 mapping accurately detected and differentiated between obstructive epicardial CAD and microvascular dysfunction, without contrast agents or radiation.
CMR
Gadolinium-Free Cardiac MR Stress T1-Mapping to Distinguish Epicardial From Microvascular Coronary Disease.BACKGROUND

T1-Mapping
This study describes the performance of the first prospective validation of stress T1 mapping against invasive coronary measurements for detecting obstructive epicardial coronary artery disease (CAD), defined by fractional flow reserve (FFR <0.8), and coronary microvascular dysfunction, defined by FFR ≥0.8 and the index of microcirculatory resistance (IMR ≥25 U), compared with first-pass perfusion imaging.


 FFR and IMR were assessed ≤7 days post-CMR. 
FFR
This study describes the performance of the first prospective validation of stress T1 mapping against invasive coronary measurements for detecting obstructive epicardial coronary artery disease (CAD), defined by fractional flow reserve (FFR <0.8), and coronary microvascular dysfunction, defined by FFR ≥0.8 and the index of microcirculatory resistance (IMR ≥25 U), compared with first-pass perfusion imaging.


 FFR and IMR were assessed ≤7 days post-CMR. 
IMR