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Percent infarct mapping: An R 1 ‐map‐based CE‐MRI method for determining myocardial viability distribution
Author(s) -
Surányi Pál,
Kiss Pál,
Brott Brigitta C.,
Simor Tamás,
Elgavish Ada,
Ruzsics Balázs,
SaabIsmail Nada H.,
Elgavish Gabriel A.
Publication year - 2006
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.20979
Subject(s) - voxel , nuclear medicine , ventricle , myocardial infarction , infarction , in vivo , medicine , nuclear magnetic resonance , chemistry , cardiology , radiology , physics , biology , microbiology and biotechnology
Abstract Viability detection is crucial for the management of myocardial infarction (MI). Signal intensity (SI)‐based MRI methods may overestimate infarct size in vivo. In contrast to SI, the longitudinal relaxation‐rate enhancement (Δ R 1 ) is an intrinsic parameter that is linearly proportional to the concentration of contrast agent (CA). Determining Δ R 1 in the presence of an infarct‐avid persistent CA (PCA) allows determination of the per‐voxel percentage of infarcted tissue. Introduced here is a Δ R 1 ‐based CE‐MRI method, termed percent infarct mapping (PIM), for quantifying myocardial viability following delayed PCA accumulation. In a canine MI model ( N = 6), PIMs were generated using a persistent CA (PCA) and validated using triphenyltetrazolium‐chloride (TTC) histochemistry. Voxel‐by‐voxel R 1 maps of the entire left ventricle (LV) were generated 24 and 48 hr after PCA administration using inversion recovery (IR) with multiple inversion times (TIs). PI values were calculated voxel by voxel. Significant correlations ( P < 0.01, R = 0.97) were obtained for PI per slice (PIS) determined using PIM vs. corresponding TTC‐based values. Median deviations of PIS with PIM from that with TTC were only 1.01% and –0.53%, at 24 hr and 48 hr. Median deviations from the true infarction fraction (IF) were 1.23% and 0.49% of LV at 24 hr and 48 hr, respectively. No significant difference was found between PIM 24 hr and PIM 48 hr . Δ R 1 ‐based PIM is an accurate and reproducible method for quantifying myocardial viability distribution, and thus enhances the clinical utility of CE‐MRI. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.