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Updated: Jun 24, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
[Quantification of microvascular obstruction in acute myocardial infarction using cardiac MRI]
K Nassenstein1, K Waltering, M Hollenhorst
1Institut für Diagnostische und Interventionelle Radiologie und Neuroradiologie, Universitätsklinikum Essen. Kai.Nassenstein@uni-due.de
Purpose:
Microvascular obstruction (MO) and the extent of infarction are important prognostic factors in acute myocardial infarction. Our study aimed to investigate the effect of the time interval between contrast administration and image acquisition on the quantification of microvascular obstruction and myocardial infarction.
Materials And Methods:
50 consecutive patients with acute myocardial infarction (40 male, mean age 58.1 +/- 11.7 years) treated by percutaneous coronary revascularization resulting in a grade 3 flow according to the thrombolysis in myocardial infarction flow classification were examined on a 1.5 T MR scanner within the first 5 days after infarction. 2, 5, 10, and 20 minutes after I.V. administration of 0.2 mmol/kg per kg body weight of Gadodiamid (Omniscan), GE Healthcare Buchler, Germany), a single shot IR-SSFP sequence (TR 2.4 ms, TE 1.08 ms, TI 180 - 280 ms, FA 50 degrees) covering the entire left ventricle was acquired. Areas of MO and myocardial infarction were measured for all times after contrast injection (p. i.).
Results:
MO was detected in 32 of 50 patients two minutes p. i., while 23 patients showed evidence of MO (p = 0.002) 20 min. p. i. In all patients with MO, the extent of MO decreased over time (7.4 +/- 9.0 % of the LV myocardium 2 min. p. i. vs. 2.4 +/- 4.6 % 20 min. p. i. p < 0.0001). The area of myocardial infarction increased from 13.9 +/- 13.5 % 2 min. p. i. to 18.6 +/- 14.2 % 10 min. p. i. (p < 0.0001), and then remained unchanged (18.7 +/- 14.3 % at 20 min. p = 0.57).
Conclusion:
Our study shows that the time delay between contrast media injection and image acquisition has a significant impact on the delimitable extent of MO and infarct size.
Insights
The time interval between contrast injection and imaging significantly impacts measurements of microvascular obstruction (MO) and infarct size in acute myocardial infarction patients. Delayed imaging reduces detected MO but increases apparent infarct size, affecting prognostic accuracy.
Area of Science:
- Cardiovascular Imaging
- Medical Physics
- Radiology
Context:
- Acute myocardial infarction (AMI) management relies on accurate prognostic factors.
- Microvascular obstruction (MO) and infarct size are critical indicators of patient outcomes.
- Standardized imaging protocols are essential for reliable assessment.
Purpose:
- To evaluate the influence of varying time intervals between contrast administration and image acquisition on quantifying MO and myocardial infarction.
- To determine the optimal imaging timing for accurate assessment of AMI complications.
Summary:
- This study analyzed 50 AMI patients using cardiac MRI at 2, 5, 10, and 20 minutes post-contrast injection.
- Microvascular obstruction (MO) detection decreased significantly over time (32/50 at 2 min vs. 23/50 at 20 min).
- Infarct size quantification increased from 2 to 10 minutes post-injection and stabilized thereafter.
Impact:
- Findings highlight the critical role of imaging timing in the accurate assessment of microvascular obstruction and infarct size.
- Results suggest that current imaging protocols may lead to underestimation of MO and altered infarct size measurements.
- Standardizing the post-contrast imaging delay is crucial for consistent prognostic evaluation in acute myocardial infarction.
