Native T1 Mapping

Abstract

Since McNamara et al1 reported in 1984 that contrast-enhanced cardiovascular magnetic resonance (CMR) can detect acute myocardial ischemia in an animal model, the noninvasive characterization of acute myocardial infarction by CMR has undergone major technical development and refinement. The development of cine imaging CMR facilitated highly reliable measure of cardiac function in the acute setting and of adverse remodeling; T2-weighted (T2w) edema-sensitive imaging has been used to detect reversibly injured myocardium, and contrast-enhanced methods2 have become the method of choice for infarct detection and sizing in the follow-up period. In acute ST-segment–elevation myocardial infarction (STEMI), CMR is today used to accurately measure the area at ischemic risk, estimate salvaged myocardium, measure infarct size and to identify microvascular obstruction, hemorrhage, and left ventricular thrombus. All of these measures have been shown to contribute to risk stratification.3 See Article by Liu et al For all its merits, however, current CMR assessment based on cine, T2w imaging and late gadolinium enhancement (LGE) also has important limitations. Comprehensive CMR scan protocols that include all these methods can take an hour to complete. In clinical practice, the analysis of these images is predominantly visual, and quantification in absolute units of measurement can be challenging or not possible. Measurement of infarct extent in acute STEMI, for example, has turned out to be more challenging than expected, and LGE is well-known to overestimate acute infarct size.4 T2w edema-sensitive imaging has limitations relating to its relatively low contrast to noise, and both LGE and T2w imaging are largely used as dichotomous markers of the presence or absence of pathology rather than giving insight into the severity of tissue damage. Parametric mapping methods can overcome some of these limitations. T1 and …