Myocardial Area at Risk and Salvage Measured by T2-weighted Cardiovascular Magnetic Resonance: Reproducibility and Comparison of Two T2-weighted Protocols

J Cardiovasc Magn Reson. 2011 Sep 15;13(1):50. doi: 10.1186/1532-429X-13-50.

Abstract

Background: Late gadolinium enhancement (LGE) and T2-weighted cardiovascular magnetic resonance (CMR) provides a means to measure myocardial area at risk (AAR) and salvage. Several T2-weighted CMR sequences are in use, but there is no consensus in terms of which sequence to be the preferred. Therefore, the aim of the present study was to: (1) Assess the reproducibility and (2) compare the two most frequently used T2-weighted CMR protocols for measuring AAR and salvage.

Methods: 91 patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention underwent a CMR scan 1-7 days after initial treatment. Two different T2-weighted protocols, varying in slice thickness and echo time (TE), were applied covering the entire left ventricle (LV) (protocol 1: TE 65 msec and slice thickness 15 mm; protocol 2: TE 100 msec and slice thickness of 8 mm). On a second scan performed 3 months later, infarct size was assessed with a standard LGE sequence. The two protocols were compared in terms of AAR and salvage index. Furthermore, intra- and interobserver reproducibility were assessed.

Results: Protocol 1 measures a larger AAR and salvage index than protocol 2 with a mean difference in AAR of 1±8%LV (p<0.01) and 6±12 g (p<0.01) and salvage index of 0.04±0.12 (p<0.01). Both protocols had a high intra- and interobserver reproducibility with acceptable limits of agreement (6-8%LV and 6-12 g in AAR and 0.06-0.08 in salvage index).

Conclusions: We report acceptable reproducibility for AAR and salvage index measured by T2-weighted images. Thus CMR is a reliable tool for measuring AAR and salvage index. Protocol 2 (8 mm slice thickness and 100 msec TE) measures slightly smaller AAR than protocol 1 (15 mm slice thickness and 65 msec TE), but the present study does not allow for a clear recommendation of either of the protocols.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Angioplasty, Balloon, Coronary*
  • Chi-Square Distribution
  • Contrast Media
  • Denmark
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnosis*
  • Myocardial Infarction / pathology
  • Myocardial Infarction / therapy*
  • Myocardium / pathology*
  • Observer Variation
  • Organometallic Compounds
  • Predictive Value of Tests
  • Reproducibility of Results
  • Time Factors
  • Treatment Outcome

Substances

  • Contrast Media
  • Organometallic Compounds
  • gadobutrol