Comparison of MOLLI and ShMOLLI in Terms of T1 Reactivity and the Relationship between T1 Reactivity and Conventional Signs of Response during Adenosine Stress Perfusion CMR

Abstract

Background: One of the most important techniques of cardiacmagnetic resonance in assessment of coronary heart diseases isadenosine stress myocardial first-pass perfusion imaging. Using thisimaging method, there should be an adequate response to the drugadenosine to make an accurate evaluation. The conventional signsof drug response are not always observed and are often subjective.Methods based on splenic perfusion might possess limitations as well.Therefore, T1 mapping presents as a novel, quantitative and reliablemethod. There are several studies analyzing this newly discoveredproperty of different T1 mapping sequences. However most of thesestudies are enrolling only one of the techniques.Aims: To compare modified look-locker inversion recovery andshortened modified look-locker inversion recovery sequences interms of T1 reactivity and to determine the relationship between T1reactivity and conventional stress adequacy assessment methods inadenosine stress perfusion cardiac magnetic resonance.Study Design: A cross-sectional study using STARD reportingguideline.Methods: Thirty-four consecutive patients, who were referred foradenosine stress perfusion cardiac magnetic resonance with suspectof myocardial ischemia, were prospectively enrolled into the study.Four patients were disqualified, and thirty patients were includedin the final analysis. Using both modified look-locker inversionrecovery and shortened modified look-locker inversion recovery,midventricular short axis slices of T1 maps were acquired at rest andduring peak adenosine stress before gadolinium administration. Then,they were divided into six segments according to the 17-segmentmodel proposed by the American Heart Association, and separatemeasurements were made from each segment. Mean rest and meanstress T1 values of remote, ischemic, and infarcted myocardium werecalculated individually per subject. During adenosine administration,patients’ heart rates and blood pressures are measured and recordedevery one minute. Adenosine stress perfusion images were examinedfor the presence of splenic switch-off.Results: There was a significant difference between rest and stressT1 values of remote myocardium in both modified look-lockerinversion recovery and shortened modified look-locker inversionrecovery (p