- Meeting abstract
- Open Access
2132 Assessment of myocardial oxygenation in the canine heart using blood oxygen level-dependent magnetic resonance imaging
© Voehringer et al; licensee BioMed Central Ltd. 2008
- Published: 22 October 2008
- Canine Heart
- Intracoronary Infusion
- Bold Signal Intensity
- Bold Sensitivity
- Sufficient Diagnostic Accuracy
Blood Oxygen Level-Dependent Magnetic Resonance Imaging (BOLD-MRI) has been used to assess myocardial oxygenation but implementation in clinical application has suffered from long scan times and inconsistent image quality. Steady-state free precession (SSFP) based sequences have been shown to have BOLD sensitivity. In addition they tend to have fewer artifacts.
To test whether a new SSFP-based sequence is robust and has sufficient diagnostic accuracy for detecting changes in myocardial oxygenation induced by endothelium-dependent and endothelium-independent coronary flow changes in the canine heart.
A T2-prepared SSFP sequence with T2- and T2*-sensitivity was developed. Three anesthetized dogs were instrumented with a coronary infusion catheter in the circumflex coronary artery (LCX), an MR compatible epivascular flow probe around the LCX and a catheter in the coronary sinus. Using a clinical 1.5 T MRI system (Avanto, Siemens Medical Solutions, Germany), BOLD-sensitive imaging with the new sequence and additional T2* mapping were performed during LCX intracoronary infusion of adenosine and acetylcholine (ACh). The perfusion territory of the LCX was identified by intracoronary injection of a small Gd-DTPA bolus. Images were analyzed using validated software. Paired T-tests were used to compare results before and after intracoronary infusion. Correlations of BOLD signal intensity and T2* values in the LCX territory with coronary venous oxygen saturation (SaO2) were calculated by linear regression analysis (SPSS13).
SSFP-based BOLD-sensitive MRI allows for imaging of myocardial oxygenation induced by endothelium dependent and independent vasodilation. Signal intensities correlate with coronary venous SaO2 and T2* of the myocardium. Further studies should address its feasibility in clinical settings.
This article is published under license to BioMed Central Ltd.