Native T1 Mapping by 3-T CMR Imaging for Characterization of Chronic Myocardial Infarctions.

Abstract

OBJECTIVES:

The purpose of this study was to investigate whether native T1 maps at 3-T can reliably characterize chronic myocardial infarctions (MIs) in patients with prior ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI).

BACKGROUND:

Late gadolinium enhancement (LGE) cardiac magnetic resonance is the gold standard for characterizing chronic MIs, but it is contraindicated in patients with end-stage chronic kidney disease.

METHODS:

Native T1 and LGE images were acquired at 3-T in patients with prior STEMI (n = 13) and NSTEMI (n = 12) at a median of 13.6 years post-MI. Infarct location, size, and transmurality were measured using mean ± 5 SDs thresholding criterion from LGE images and T1 maps and compared against one another. Independent reviewers assessed visual conspicuity of MIs on LGE images and T1 maps.

RESULTS:

Native T1 maps and LGE images were not different for measuring infarct size (STEMI: p = 0.46; NSTEMI: p = 0.27) and transmurality (STEMI: p = 0.13; NSTEMI: p = 0.21) using thresholding criterion. Using thresholding criterion, good agreement was observed between LGE images and T1 maps for measuring infarct size (STEMI: bias = 0.6 ± 3.1%; R(2) = 0.93; NSTEMI: bias = -0.4 ± 4.4%; R(2) = 0.85) and transmurality (STEMI: bias = 2.0 ± 4.2%; R(2) = 0.89; NSTEMI: bias = -2.7 ± 7.9%; R(2) = 0.68). Sensitivity and specificity of T1 maps for detecting chronic MIs based on thresholding criterion were 89% and 98%, respectively (STEMI), and 87% and 95%, respectively (NSTEMI). Relative to LGE images, the mean visual conspicuity score for detecting chronic MIs was significantly lower for T1 maps (p < 0.001 for both cases). Median infarct-to-remote myocardium contrast-to-noise ratio was 2.5-fold higher for LGE images relative to T1 maps (p < 0.001). Sensitivity and specificity of T1 maps for visual detection were 60% and 86%, respectively (STEMI), and 64% and 91% (NSTEMI), respectively.

CONCLUSIONS:

Chronic MIs in STEMI and NSTEMI patients can be reliably characterized using threshold-based detection on native T1 maps at 3-T. Visual detection of chronic MIs on native T1 maps in both patient populations has high specificity, but modest sensitivity.

• Authors: Avinash Kali, Eui-Young Choi, Behzad Sharif, Young Jin Kim, Xiaoming Bi, Bruce Spottiswoode, Ivan Cokic, Hsin-Jung Yang, Mourad Tighiouart, Antonio Hernandez Conte, Debiao Li, Daniel S Berman, Byoung Wook Choi, Hyuk-Jae Chang, Rohan Dharmakumar
• Journal: JACC. Cardiovascular imaging (JACC Cardiovasc Imaging) Vol. 8 Issue 9 Pg. 1019-1030 (Sep 2015) ISSN: 1876-7591 [Electronic] United States
• PMID: 26298071 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Chemical References

• Contrast Media
• Organometallic Compounds
• gadobutrol

Topics

• Aged
• Chronic Disease
• Contrast Media
• Female
• Humans
• Image Interpretation, Computer-Assisted (methods)
• Magnetic Resonance Imaging, Cine (methods)
• Male
• Middle Aged
• Myocardial Infarction (diagnosis, pathology)
• Myocardium (pathology)
• Observer Variation
• Organometallic Compounds
• Predictive Value of Tests
• Reproducibility of Results
• Time Factors