Related Experiment Video
Updated: Sep 12, 2025
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Time series analysis of ex-vivo ischemia-reperfused heart using Q-space imaging
Genki Ichihara1, Junichi Hata2,3, Daisuke Nakashima4,5
1Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan.
Abstract:
In the evaluation of myocardial infarction, cardiac MRI remains problematic in terms of sensitivity and quantitativeness. Thus, we sought to delineate pathological microstructural alterations across temporal phases subsequent to myocardial ischemia-reperfusion (IR) injury utilizing q-space imaging (QSI), an advanced diffusion imaging methodology proficient in assessing the non-Gaussian diffusion patterns of molecules. Rats were subjected to IR injury, and infarct was evaluated at 2, 7, and 30 days via histopathological staining and MRI using a 9.4-Tesla system. QSI was performed with gadolinium-enhanced T1-weighted imaging (T1WI) for comparative assessment. Correlation coefficients among images were computed at each level of the left ventricular short-axis cross-section to juxtapose the infarct dimensions and morphology. Axial diffusivity of the kurtosis maps at 2, 7, and 30 days revealed substantial correlations with the hyperintense areas noted on T1WI (R2 = 0.885, 0.947, and 0.929, respectively). Furthermore, a strong correlation was noted with the transmural extent of infarction. Even in the absence of gadolinium contrast, the high-intensity regions delineated by QSI were concordant with the extent of pathological infarction (R2 = 0.977). These findings highlight the capability of QSI in identifying pathological changes at the infarct site, independent of gadolinium contrast media and irrespective of the temporal phase subsequent to the IR onset.
Insights
Q-space imaging (QSI) effectively detects microstructural changes after myocardial ischemia-reperfusion injury. This advanced MRI technique accurately quantifies infarct size and characteristics, even without contrast agents.
Area of Science:
- Cardiovascular Imaging
- Biomedical Engineering
- Diffusion MRI
Background:
- Cardiac MRI faces challenges in sensitivity and quantitation for myocardial infarction evaluation.
- Microstructural alterations in myocardial ischemia-reperfusion (IR) injury require advanced imaging techniques.
- q-space imaging (QSI) offers potential for assessing non-Gaussian diffusion patterns.
Purpose of the Study:
- To delineate pathological microstructural alterations in myocardial IR injury using QSI.
- To assess the capability of QSI in quantifying infarct dimensions and morphology across temporal phases.
- To evaluate QSI's performance independent of gadolinium contrast agents.
Main Methods:
- Rats underwent IR injury, with infarct evaluation at 2, 7, and 30 days.
- Magnetic Resonance Imaging (MRI) utilized a 9.4-Tesla system with QSI and T1-weighted imaging (T1WI).
- Correlation analyses were performed on left ventricular short-axis cross-sections to compare QSI and T1WI findings.
Main Results:
- Axial diffusivity from QSI kurtosis maps strongly correlated with T1WI hyperintense areas (R² = 0.885–0.947) and infarct transmural extent.
- QSI delineated infarct regions concordantly with histopathology, even without gadolinium contrast (R² = 0.977).
- QSI demonstrated high accuracy in identifying pathological changes at the infarct site across different time points.
Conclusions:
- QSI is a capable tool for identifying pathological changes in myocardial infarction.
- QSI provides quantitative infarct assessment irrespective of gadolinium contrast administration.
- QSI demonstrates potential for sensitive and quantitative evaluation of myocardial IR injury.
More Related Videos
11:50High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart
Published on: July 9, 2010
13:42A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion
Published on: July 17, 2012