Author + information
- Received March 3, 2015
- Revision received August 25, 2015
- Accepted August 27, 2015
- Published online January 1, 2016.
- Alexander Liu, MBBS,
- Rohan S. Wijesurendra, MB BChir,
- Jane M. Francis, DCR(R), DNM,
- Matthew D. Robson, PhD,
- Stefan Neubauer, MD,
- Stefan K. Piechnik, PhD, MScEE and
- Vanessa M. Ferreira, MD, DPhil∗ ()
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
- ↵∗Reprint requests and correspondence:
Dr. Vanessa Ferreira, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, United Kingdom.
Objectives The aim of this study was to evaluate the potential of T1 mapping at rest and during adenosine stress as a novel method for ischemia detection without the use of gadolinium contrast.
Background In chronic coronary artery disease (CAD), accurate detection of ischemia is important because targeted revascularization improves clinical outcomes. Myocardial blood volume (MBV) may be a more comprehensive marker of ischemia than myocardial blood flow. T1 mapping using cardiac magnetic resonance (CMR) is highly sensitive to changes in myocardial water content, including MBV. We propose that T1 mapping at rest and during adenosine vasodilatory stress can detect MBV changes in normal and diseased myocardium in CAD.
Methods Twenty normal controls (10 at 1.5-T; 10 at 3.0-T) and 10 CAD patients (1.5-T) underwent conventional CMR to assess for left ventricular function (cine), infarction (late gadolinium enhancement [LGE]) and ischemia (myocardial perfusion reserve index [MPRI] on first-pass perfusion imaging during adenosine stress). These were compared to novel pre-contrast stress/rest T1 mapping using the Shortened Modified Look-Locker Inversion recovery technique, which is heart rate independent. T1 values were derived for normal myocardium in controls and for infarcted, ischemic, and remote myocardium in CAD patients.
Results Normal myocardium in controls (normal wall motion, MPRI, no LGE) showed normal resting T1 (954 ± 19 ms at 1.5-T; 1,189 ± 34 ms at 3.0-T) and significant positive T1 reactivity during adenosine stress compared to baseline (6.2 ± 0.5% at 1.5-T; 6.3 ± 1.1% at 3.0-T; all p < 0.0001). Infarcted myocardium showed the highest resting T1 of all tissue classes (1,442 ± 84 ms), without significant T1 reactivity (0.2 ± 1.5%). Ischemic myocardium showed elevated resting T1 compared to normal (987 ± 17 ms; p < 0.001) without significant T1 reactivity (0.2 ± 0.8%). Remote myocardium, although having comparable resting T1 to normal (955 ± 17 ms; p = 0.92), showed blunted T1 reactivity (3.9 ± 0.6%; p < 0.001).
Conclusions T1 mapping at rest and during adenosine stress can differentiate between normal, infarcted, ischemic, and remote myocardium with distinctive T1 profiles. Stress/rest T1 mapping holds promise for ischemia detection without the need for gadolinium contrast.
This study was supported by the National Institute for Health Research Oxford Biomedical Research Centre based at The Oxford University Hospitals Trust, University of Oxford, United Kingdom. Dr. Liu has received research grant support from a British Heart Foundation Clinical Research Training Fellowship (FS/15/11/31233). Drs. Wijesurendra, Neubauer, and Ferreira acknowledge support from the British Heart Foundation Centre of Research Excellence, Oxford, United Kingdom. Dr. Robson is funded by the Medical Research Council. Drs. Robson and Piechnik have patent authorship rights for: 1) U.S. patent pending 61/387,591. SYSTEMS AND METHODS FOR SHORTENED LOOK LOCKER INVERSION RECOVERY (Sh-MOLLI) CARDIAC GATED MAPPING OF T1. September 29, 2010. All rights transferred to Siemens Medical; and 2) U.S. patent pending 61/689,067: COLOR MAP DESIGN METHOD FOR IMMEDIATE ASSESSMENT OF THE DEVIATION FROM ESTABLISHED NORMAL POPULATION STATISTICS AND ITS APPLICATION TO CARDIOVASCULAR T1 MAPPING IMAGES. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received March 3, 2015.
- Revision received August 25, 2015.
- Accepted August 27, 2015.
- The Authors