Sources of variability in quantification of cardiovascular magnetic resonance infarct size - reproducibility among three core laboratories.
Abstract
BACKGROUND: Acute myocardial infarct (AMI) size depicted by late gadolinium enhancement
cardiovascular magnetic resonance (CMR) is increasingly used as an efficacy endpoint
in randomized trials comparing AMI therapies. Infarct size is quantified using manual
planimetry (MANUAL), visual scoring (VISUAL), or automated techniques using signal-intensity
thresholding (AUTO). Although AUTO is considered the most reproducible, prior studies
did not account for the subjective determination of endocardial/epicardial borders,
which all methods require. For MANUAL and VISUAL, prior studies did not address how
to treat intermediate signal intensities due to partial volume. METHODS: To assess
sources of variability, AMI size was measured in 30 patients and 12 controls by 3
core-laboratories using 8 methods, each separated by more than 2 months time (n = 720
evaluations). The methods were: (1,2) AUTOSegment, AUTOFWHM (using Segment software
or the full-width-at-half-maximum algorithm, respectively); (3,4) AUTO-UCSegment,
AUTO-UCFWHM (user correction for endocardial border pixels, no-reflow, etc.); (5)
MANUAL; (6) MANUAL-ISI (adjustment for intermediate signal-intensities); (7) VISUAL;
(8) VISUAL-ISI. RESULTS: Mean infarct size varied between 16.8% and 27.2% of LV mass
depending on method. Even automated techniques with no user interaction for infarct
borders resulted in significant within-patient variability given the need to subjectively
trace endocardial/epicardial contours. The coefficient-of-variation (CV) was 10.6%
and 14.6% for AUTOSegment and AUTOFWHM, respectively. For manual and visual categories,
reproducibility was improved when intermediate signal-intensities were considered
(MANUAL-ISI vs MANUAL: CV = 8.3% vs 14.4%; p = 0.03; VISUAL-ISI vs VISUAL: CV = 8.4%
vs 10.9%; p = 0.01). For AUTO-UCSegment, MANUAL-ISI, and VISUAL-ISI (best technique
in each category) within-patient variability due to the quantification method was
less than 10% of total variability, and the required sample sizes for detecting a
5% absolute difference in infarct size were 62, 63, and 62 patients, respectively.
CONCLUSION: Among CMR core-laboratories, an important source of variability in infarct
size quantification is the subjective delineation of endocardial/epicardial borders.
When intermediate signal intensities are considered in manual planimetry and visual
scoring, reproducibility and impact on sample size are similar to automated techniques.
Type
Journal articlePermalink
https://hdl.handle.net/10161/15962Published Version (Please cite this version)
10.1186/s12968-017-0378-yPublication Info
Klem, Igor; Heiberg, Einar; Van Assche, Lowie; Parker, Michele A; Kim, Han W; Grizzard,
John D; ... Kim, Raymond J (2017). Sources of variability in quantification of cardiovascular magnetic resonance infarct
size - reproducibility among three core laboratories. J Cardiovasc Magn Reson, 19(1). pp. 62. 10.1186/s12968-017-0378-y. Retrieved from https://hdl.handle.net/10161/15962.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
Collections
More Info
Show full item recordScholars@Duke
Han Woong Kim
Associate Professor of Medicine
Igor Klem
Associate Professor of Medicine
Alphabetical list of authors with Scholars@Duke profiles.

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info