To determine the infarct affinity of a low molecular weight contrast agent, ,Gd(ABE-DTTA),duringthe subacute phase of myocardial infarct (MI). Dogs (n = 7) were examined,usinga closed-chest,reperfusedMI model. MI was generated by occluding for 180 min the Left Anterior Descending (LAD) coronary artery with an angioplasty balloon. DE-MRI images with Gd(ABE-DTTA) were obtained on days 4, 14,and28 after MI. Control DE-MRI by Gd(DTPA) was carried out on day 27. T2-TSE images were acquired on day 3,13and 27. Triphenyltetrazolium chloride (TTC) histomorphometry validated postmortem the existence of infarct. Gd(ABE-DTTA) highlighted the infarct on day 4,butnot at all on day 14 or on day 28, following MI. On day 4,the mean ± SD signal intensity (SI) of infarcted myocardium in the presence of Gd(ABEDTTA) significantly differed from that of healthy myocardium (45± 6.0 vs. 1±0 5.0, P < 0.05),but it did not on day 14 (11 ± 9.4 vs. 10± 5.7, P = NS),nor on day 28 (7 ± 1.5 vs. 7± 2.4, P = NS). The mean ± SD signal intensity enhancement (SIE) induced by Gd(ABE-DTTA) was 386 ± 165% on day 4,significantlydifferent from mean SIE on day 14 (9 ±20%),andfrom mean SIE on day 28 (12 ±18%),followingMI (P <0.05). The last two mean values did not differ significantly (P = NS) from each other. As control,Gd(DTPA)was used and it did highlight the infarct on day 27,inducinga mean SIE value of 312 ±40%. The mean SIE on day 3, 13,or27 did not vary significantly (P = NS) on the T2-TSE images (114 ±41%,123 ± 41%,and150 ±79%, respectively). Post mortem,theexistence of infarcts was confirmed by TTC staining. The infarct affinity of Gd(ABE-DTTA) vanishes in the subacute phase of scar healing, allowing its use for infarct age differentiation early on, immediately following the acute phase.
- Contrast agent
- Delayed enhancement
- Magnetic resonance imaging
- Myocardial infarct
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine