Skip to content

Advertisement

  • Poster presentation
  • Open Access

Interobserver reproducibility of fully quantitative pixel-wise analysis of clinical CMR perfusion imaging

  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 1 and
  • 1
Journal of Cardiovascular Magnetic Resonance201416 (Suppl 1) :P350

https://doi.org/10.1186/1532-429X-16-S1-P350

  • Published:

Keywords

  • Cardiac Magnetic Resonance
  • Myocardial Blood Flow
  • Invasive Coronary Angiography
  • Regadenoson
  • Coronary Artery Disease Group

Background

Quantitative first pass cardiac magnetic resonance (CMR) perfusion imaging has shown excellent interobserver agreement at a sector level in healthy volunteers and patients. In this study, we compare the myocardial blood flow (MBF) estimates in sector-wise and pixel-wise analysis. We also study the interobserver variability in pixel-wise MBF estimates from patients with coronary artery disease (CAD).

Methods

First pass CMR imaging was performed on 29 patients with known or suspected CAD (15 females, age 54.9 ± 14.3 years). Twenty of the patients, defined as the normal group, had minimal or no stenosis ( < 30% by computed tomographic angiogram) and nine patients, defined as the CAD group, had significant CAD ( > 70% stenosis by invasive coronary angiography). All patients were scanned on a 1.5T scanner using a steady state free precession imaging sequence for regadenoson stress perfusion followed by rest perfusion 20 minutes later. Two observers independently traced the myocardial regions of interest in the mid-ventricular slice and quantified the MBF in sector-wise and pixel-wise analyses by a model-constrained deconvolution approach. Pixel-wise MBF estimates were averaged to six transmural sectors to compare with sector-wise analysis. Pearson correlation, Bland-Altman analysis, and paired student t-test were used to compare the results.

Results

There was excellent correlation between pixel-wise vs. sector-wise MBF quantification for the 20 normal and nine CAD patients (Figure 1). In both patient groups, Bland-Altman analysis showed no significant bias between the two methods of quantification (mean bias from 0.01 to 0.12 ml/min/g). Limits of agreement were good (2SD range from 0.26 to 0.98 ml/min/g, p = NS for all comparison). Interobserver agreement of pixel-wise MBF was excellent for both normal and CAD groups (Figure 2). The interobserver agreement was good (2SD range from 0.38 to 0.96 ml/min/g, p = NS for all comparisons) with no significant interobserver bias (mean bias from 0.02 to 0.15 ml/min/g). The stress MBF in the ischemic zone of patients with > 70% stenosis was 1.72 ± 0.75 ml/min/g by pixel-wise analysis which was significantly lower than remote MBF (2.85 ± 0.74 ml/min/g, p < 0.001).
Figure 1
Figure 1

Excellent correlation between pixel-wise vs. sector-wise MBF quantification.

Figure 2
Figure 2

Excellent agreement of pixel-wise MBF quantification between two independent observers.

Conclusions

Clinical first pass CMR perfusion can be quantified at the pixel level and the results agree well with sector-wise comparison. There is an excellent interobserver agreement in pixel-wise quantification of patients with CAD.

Funding

This research was supported by the Intramural Research Program of the National Heart, Lung, and Blood Institute, National Institutes of Health.

Authors’ Affiliations

(1)
National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA

Copyright

© Conn et al.; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Advertisement