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Updated: Jul 11, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Morphologic validation of reperfused hemorrhagic myocardial infarction by cardiovascular magnetic resonance
Cristina Basso1, Francesco Corbetti, Caterina Silva
1Department of Medic-Diagnostic Sciences and Special Therapies, University of Padua Medical School, Padua, Italy.
Insights
Cardiovascular magnetic resonance (CMR) T2 hypointense signals and susceptibility artifacts in late gadolinium enhancement areas of reperfused myocardial infarction (MI) correlate with hemorrhage, indicating irreversible vascular injury.
Area of Science:
- Cardiovascular Imaging
- Pathology
- Medical Diagnostics
Background:
- Acute myocardial infarction (MI) requires assessment of tissue injury and microvascular obstruction.
- Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) is used to identify infarcts, but its interpretation in reperfused MI can be complex.
- Hemorrhage within the infarct zone is a potential factor influencing CMR signal characteristics.
Observation:
- Ex vivo CMR T2 sequences showed low-signal intensity areas that strongly correlated with quantified hemorrhage on histology (R=0.93).
- Ex vivo LGE sequences revealed bright areas with dark rims, consistent with magnetic susceptibility effects from hemorrhage.
- In vivo CMR demonstrated corresponding hypointense T2 signals and hyperintense LGE areas with susceptibility artifacts within the MI core.
Findings:
- Pathologic examination revealed significant myocardial infarction (MI) and hemorrhage, increasing from base to apex.
- Ex vivo T2 CMR signal intensity directly correlated with the extent of hemorrhage.
- Susceptibility effects on LGE imaging corresponded to areas of hemorrhage.
Implications:
- CMR T2 hypointensity and LGE susceptibility artifacts in reperfused MI are indicative of interstitial hemorrhage.
- These findings suggest irreversible vascular injury in the infarct core.
- Pathologic correlation validates the use of specific CMR sequences for detecting hemorrhage in myocardial infarction.
Abstract:
The purposes of this study were to assess the ex vivo cardiovascular magnetic resonance (CMR) signals of pathologically proved hemorrhagic myocardial infarction (MI) and to correlate these with in vivo CMR findings. Late gadolinium hypoenhancement within a hyperenhanced area in reperfused acute MI is ascribed to severe microvascular obstruction. The hearts of 2 patients, who died from cardiogenic shock after acute MIs and who had undergone coronary recanalization and in vivo CMR, were examined by T(2) and T(1) late enhancement sequences as well as by gross and histologic investigation. Four corresponding short-axis slices of each cardiac specimen from the base to the left ventricular apex were selected to assess the extent of MI and hemorrhage and were compared with the in vivo T(2) and late enhancement CMR scans. On pathologic examination, the extent of MI was 57 +/- 30% and 44 +/- 24%, and the extent of hemorrhage was 23 +/- 13% and 19 +/- 8% of the left ventricular area, respectively, showing progressive increases from the base to the apex. The low-signal intensity areas observed by ex vivo T(2) CMR strongly correlated with the hemorrhage quantified on histology (R = 0.93, p = 0.0007). Using ex vivo late gadolinium sequences, bright areas surrounded by thin dark rims, consistent with magnetic susceptibility effects, were detected, corresponding with hemorrhage. On in vivo CMR images, low-signal intensity and hyperintense areas with peripheral susceptibility artifacts were observed within the MI core on T(2) and late gadolinium sequences, respectively. In conclusion, in reperfused MI, CMR hypointense T(2) signal and susceptibility effects within the late gadolinium hypoenhanced areas are consistent with interstitial hemorrhage due to irreversible vascular injury, as proved by pathologic study.
