Percent infarct mapping for delayed contrast enhancement magnetic resonance imaging to quantify myocardial viability by Gd(DTPA)
✍ Scribed by Tamás Simor; Pál Surányi; Balázs Ruzsics; Attila Tóth; Levente Tóth; Pál Kiss; Brigitta C. Brott; Ákos Varga-Szemes; Ada Elgavish; Gabriel A. Elgavish
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 601 KB
- Volume
- 32
- Category
- Article
- ISSN
- 1053-1807
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✦ Synopsis
Abstract
Purpose
To demonstrate the advantages of signal intensity percent‐infarct‐mapping (SI‐PIM) using the standard delayed enhancement (DE) acquisition in assessing viability following myocardial infarction (MI). SI‐PIM quantifies MI density with a voxel‐by‐voxel resolution in clinically used DE images.
Materials and Methods
In canines (n= 6), 96 hours after reperfused MI and administration of 0.2 mmol/kg Gd(DTPA), ex vivo DE images were acquired and SI‐PIMs calculated. SI‐PIM data were compared with data from DE images analyzed with several thresholding levels using SI~remote+2SD~, SI~remote+6SD~, SI full width half maximum (SI~FWHM~), and with triphenyl‐tetrazolium‐chloride (TTC) staining. SI‐PIM was also compared to R1 percent infarct mapping (R1‐PIM).
Results
Left ventricular infarct volumes (IV) in DE images, IV~SIremote+2SD~ and IV~SIremote+6SD~, overestimated (P < 0.05) TTC by medians of 13.21 mL [10.2; 15.2] and 6.2 mL [3.79; 8.23], respectively. SI~FWHM~, SI‐PIM, and R1‐PIM, however, only nonsignificantly underestimated TTC, by medians of −0.10 mL [−0.12, −0.06], −0.86 mL [−1.04; 1.54], and −1.30 mL [−4.99; −0.29], respectively. The infarct‐involved voxel volume (IIVV) of SI‐PIM, 32.4 mL [21.2, 46.3] is higher (P < 0.01) than IIVVs of SI~FWHM~ 8.3 mL [3.79, 19.0]. SI‐PIM~FWHM~, however, underestimates TTC (−5.74 mL [−11.89; −2.52] (P < 0.01)). Thus, SI‐PIM outperforms SI~FWHM~ because larger IIVVs are obtained, and thus PIs both in the rim and the core of the infarcted tissue are characterized, in contradistinction from DE‐SI~FWHM~, which shows mainly the infarct core.
Conclusion
We have shown here, ex vivo, that SI‐PIM has the same advantages as R1‐PIM, but it is based on the scanning sequences of DE imaging, and thus it is obtainable within the same short scanning time as DE. This makes it a practical method for clinical studies. J. Magn. Reson. Imaging 2010;32:859–868. © 2010 Wiley‐Liss, Inc.