In vivo R1-enhancement mapping of canine myocardium using ceMRI with Gd(ABE-DTTA) in an acute ischemia-reperfusion model.
OBJECTIVE
To demonstrate the usefulness of normalized DeltaR1 (DeltaR1(n)) mapping in myocardial tissue following the administration of the contrast agent (CA) Gd(ABE-DTTA).


METHODS
Ischemia-reperfusion experiments were carried out in 11 dogs. The method exploited the relatively long tissue lifetime of Gd(ABE-DTTA), and thus no fast R1 measurement technique was needed. Myocardial perfusion was determined with colored microspheres (MP).


RESULTS
With varying extent of ischemia, impaired wall motion (WM) and lower DeltaR1(n) values were detected in the ischemic sectors, as opposed to the nonischemic sectors where normal WM and higher DeltaR1(n) were observed. Based on the DeltaR1(n), data from the myocardial perfusion assay and the DeltaR1(n) maps were compared in the ischemic sectors. A correlation analysis of these two parameters demonstrated a significant correlation (R = 0.694, P < 0.005), validating the DeltaR1(n)-mapping method for the quantitation of ischemia. Similarly, pairwise correlations were found for the MP, DeltaR1(n), and wall thickening (WT) values in the same areas. Based on the correlation between DeltaR1(n) and MP, DeltaR1(n) maps calculated with a pixel-by-pixel resolution can be converted to similarly high-resolution myocardial perfusion maps.


CONCLUSIONS
These results suggest that the extent of the severity of ischemia can be quantitatively represented by DeltaR1(n) maps obtained in the presence of our CA.
Kiss
P
P
Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Alabama 35294-0005, USA.
Suranyi
P
P
Simor
T
T
Saab-Ismail
N H
NH
Elgavish
A
A
Hejjel
L
L
Elgavish
G A
GA
D000818:Animals; D003287:Contrast Media / Q000494:pharmacology; D004285:Dogs; D007091:Image Processing, Computer-Assisted; D007511:Ischemia / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008863:Microspheres; D008956:Models, Chemical; D009206:Myocardium / Q000473:pathology*; D009942:Organometallic Compounds / Q000494:pharmacology*; D004369:Pentetic Acid / Q000494:pharmacology; D010477:Perfusion; D015427:Reperfusion Injury / Q000473:pathology
D003287:Contrast Media; D009942:Organometallic Compounds; C120791:gadolinium N-(2-butyryloxyethyl)-N'-(2-ethyloxyethyl)-N,N'-bis(N'',N''-bis(carboxymethyl)acetamido)-1,2-ethanediamine; D004369:Pentetic Acid