Diagnosis of Spontaneous Reperfusion Case in Acute Myocardial Infarction by Fusion of Technetium-99 m Pyrophosphate/Thallium-201 Dual-Isotope Single Photon Emission CT Imaging and Contrast-Enhancement Coronary CT

A 75-year-old man was hospitalized after 3 days of nausea and light-headedness. Inferior acute myocardial infarction (AMI) was diagnosed based on ECG (Supplementary Figure), elevated troponin-T at 9.010 ng/dL, and creatinine kinase at 1,775 U/mL. Emergency coronary angiography (CAG) showed a translucent region and stenosis at the segment 4AV, which was suspected to be the culprit lesion (Supplementary Movie). Primary percutaneous coronary intervention (PCI) was pending, but because of the elevated cardiac enzymes and clinical course, ^{99 m}Tc-pyrophosphate (Tc-PYP) (Figure A) and coronary CT images (Figure B) were obtained. A fusion Tc-PYP and coronary CT image was obtained, and the culprit lesion was identified (Figure C). The patient underwent staged PCI for the culprit vessel.

Figure.

(A) Tc-PYP visualizes a hot lesion in the inferior wall with deficient ²⁰¹Tl accumulation. (B) CT angiography shows a critical stenosis in the mid right coronary artery (arrowhead). (C) Fusion image of Tc-PYP and coronary CT visualizes the relationship between the culprit vessel and injured myocardium.

Spontaneous reperfusion may be associated with lower mortality,¹ but it can make it difficult to identify the culprit lesion by CAG alone. Myocardial Tc-PYP accumulation appears to indicate severe myocardial injury, so combining coronary CT and myocardial perfusion imaging is a promising approach to diagnosing and characterizing MI.² The clinical scintigraphy values are greatest in patients with angiographically ambiguous coronary findings. This technology may help physicians to understand the full implications of AMI and facilitate optimal therapy.

Disclosures

The authors declare no conflicts of interest.

Supplementary Files

Supplementary Movie. Emergency coronary angiography showed a translucent region and stenosis at the segment 4AV.

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-20-0360

References

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