Evaluation of microvascular obstruction after acute myocardial infarction with cardiac magnetic resonance imaging, 201-thallium and 99 m-technetium pyrophosphate scintigraphy
Journal of Cardiovascular Magnetic Resonance volume 12, Article number: P170 (2010)
There are few reports about comparison of microvascular obstruction (MO) segments detected by cardiac magnetic resonance (CMR) with scintigraphic findings using 201-thallium (Tl) and 99 m-technetium pyrophosphate (PYP).
We examined the relationship between scintigraphic and CMR characteristics of MO after acute myocardial infarction (AMI).
14 patients(age 69 ± 8 years, 11 males) underwent Tl/PYP SPECT, initial and follow-up cardiac MRI 7 ± 3 days, 16 ± 12 days and 193 ± 20 days after a first reperfused AMI, respectively. Each image was analyzed using 17-segment model. The transmural extent of delayed enhancement (DE) was scored as follows: 0: 0%, 1: 1-25%, 2: 26-50%, 3: 51-75%, 4: 76-100%, and so were wall motion (0: akinesis, 1: severe, 2: moderate, 3: mild hypokinesis, 4: normal) and Tl uptake(0: normal, 1: mildly, 2: moderately, 3: severely reduced, 4: absent).
Of all 91 MI segments detected with DE-CMR, MO was recognized in 22(25%) segments. Comparing MO-positive segments with MO-negative segments, the latter had significantly better wall motion score(1.5 ± 1.1 vs. 2.2 ± 1.2; p = 0.027) and less transmural extent of DE(3.1 ± 0.9 vs. 2.2 ± 0.9; p = 0.0001) in initial CMR. The same results were also seen in the follow-up CMR(1.9 ± 1.1 vs. 2.6 ± 1.3; p = 0.0135, 2.5 ± 1.1 vs. 1.9 ± 1.2; p = 0.026, respectively). Tl uptake was significantly better in MO-negative segments than in MO-positive segments(1.5 ± 1.1 vs. 2.0 ± 0.9; p = 0.045). Focusing on 22 MO segments, 8(36%) segments showed wall motion score improvement at the follow-up CMR. Comparing these segments with the other 14 segments which showed no wall motion improvements at the follow-up CMR, although the CMR parameters and Tl uptake were not significantly different, all of the former segments had PYP uptake while only 3 segments(21%) had PYP uptake in the latter group(p = 0.0039).
After revascularized AMI, MO segments showed worse wall motion score, more transmural extent of DE at the initial CMR and less Tl uptake than MO-negative segments. PYP uptake was significantly more recognized in MO segments with wall motion improvement at the follow-up CMR than those without wall motion improvement.
About this article
Cite this article
Ohnishi, T., Kato, N., Kawashima, T. et al. Evaluation of microvascular obstruction after acute myocardial infarction with cardiac magnetic resonance imaging, 201-thallium and 99 m-technetium pyrophosphate scintigraphy. J Cardiovasc Magn Reson 12 (Suppl 1), P170 (2010). https://doi.org/10.1186/1532-429X-12-S1-P170