Related Experiment Video
Updated: Jun 17, 2025
Tissue Preparation Techniques for Contrast-Enhanced Micro Computed Tomography Imaging of Large Mammalian Cardiac Models with Chronic Disease
Published on: February 8, 2022
Conditions for late gadolinium enhancement MRI in myocardial infarction model rats that better reflect microscopic
Junpei Ueda1,2, Hayato Kurata3, Miwa Ota3
1Division of Health Sciences, Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka, 560-0871, Japan.
Abstract:
Late gadolinium enhancement (LGE) is a widely used magnetic resonance imaging method for assessing cardiac disease. However, the relationship between different LGE signal thresholds and microscopic tissue staining images is unclear. In this study, we performed cardiovascular MRI on myocardial infarction (MI) model rats and evaluated the relationship between LGE with different signal thresholding methods and tissue staining images. We prepared 16 rats that underwent MRI 14-18 days following a surgery to create an MI model. We captured cine and LGE images of the cardiac short-axis and longitudinal two- and four-chamber views. The mean ± 2SD, ± 3SD, and ± 5SD of the pixel values in the non-infarcted area were defined as the LGE area. We compared areas of Sirius red staining, determined by the color tone, with their respective LGE areas at end-diastole and end-systole. We observed that the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole demonstrated a significant positive correlation with the area of Sirius red staining (Pearson's correlation coefficient in both: 0.81 [p < 0.01]). Therefore, the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole best reflected the MI area in tissue staining.
Insights
Late gadolinium enhancement (LGE) using the mean ± 2SD threshold in cardiac MRI best correlates with myocardial infarction (MI) scar tissue. This finding aids in accurately assessing heart damage in clinical practice.
Area of Science:
- Cardiovascular Magnetic Resonance Imaging
- Cardiac Pathology
- Histopathology
Background:
- Late gadolinium enhancement (LGE) is a key MRI technique for evaluating cardiac disease, particularly myocardial infarction (MI).
- The precise correlation between LGE signal thresholds and actual scar tissue size (histopathology) remains incompletely understood.
- Accurate quantification of infarct size is crucial for patient management and prognosis.
Purpose of the Study:
- To investigate the relationship between various LGE signal thresholding methods and microscopic tissue staining in a rat model of MI.
- To determine which LGE threshold best represents the extent of myocardial scar tissue.
Main Methods:
- Cardiovascular MRI, including cine and LGE sequences, was performed on 16 rats with surgically induced MI.
- LGE areas were defined using mean ± 2SD, ± 3SD, and ± 5SD thresholds based on signal intensity in the non-infarcted myocardium.
- Areas of Sirius red-stained scar tissue were quantified and compared with LGE areas at end-diastole and end-systole.
Main Results:
- The LGE area calculated using the mean ± 2SD threshold of the non-infarcted area at end-diastole showed a significant positive correlation (Pearson's r = 0.81, p < 0.01) with Sirius red-stained scar area.
- Other LGE thresholds (± 3SD, ± 5SD) did not demonstrate as strong a correlation with histopathological findings.
- End-diastolic LGE measurements provided a more robust correlation compared to end-systolic measurements.
Conclusions:
- The LGE area derived from the mean ± 2SD threshold of the non-infarcted region at end-diastole is the most reliable MRI-based method for quantifying myocardial infarction scar size.
- This thresholding technique improves the accuracy of assessing infarct size using cardiovascular MRI.
- Findings support the use of mean ± 2SD thresholding for improved clinical assessment of MI extent.
