Use and Limitations of Magnetic Resonance Phase-Contrast Assessment of Coronary Flow Reserve in a Model of Collateral Dependence
Abstract:Phase-contrast magnetic resonance imaging (PC-MRI) is useful for assessing coronary artery flow reserves (CFR) in man and acute animal models with intermediate coronary lesions. The present study examines the use of PC-MRI for assessing CFR in a model with critical stenosis and collateral dependence. PC-MRI quantitative flow measurements from the proximal left anterior descending (LAD) and left circumflex (LCX) coronary arteries were compared with myocardial tissue perfusion reserve measurements (microsphere techniques) after placement of a 2.25-mm ameroid constrictor on the proximal LCX in a porcine model; measurements were obtained at implantation (n = 4) and at 3 to 4 weeks (n = 4) and 6 weeks (n = 5) postimplantation. CFR is defined as the ratio of maximal hyperemic flow to baseline flow. Hyperemia was induced using intravenous adenosine (140 mg/kg/min). Collateral dependence in the LCX distribution was evidenced by angiographic findings of critical stenosis with minimal myocardial histological changes and normal baseline myocardial perfusion (microsphere techniques). In this setting, PC-MRI CFR was correlated with microsphere measures of perfusion reserve. Collateral dependence was confirmed by Evan's blue dye injection. This study provides angiographic, myocardial perfusion, and histological correlates associated with PC-MRI epicardial CFR changes during chronic, progressive coronary artery constriction. It also demonstrates the disparity between epicardial and myocardial measures of coronary flow reserve with collateral dependence and the caveats for PC-MRI use in models of progressive coronary constriction.
Document Type: Research Article
Affiliations: 1: Brooke Army Medical Center, Fort Sam Houston, Texas 78234 2: University of Texas Health Science Center, San Antonio, Texas 78284, University of Texas Health Science Center, 7703 Floyd C Drive, San Antonio, Texas 78284-6200 3: Institute of Surgical Research, Fort Sam Houston, Texas 78234
Publication date: 2005-08-01
Comparative Medicine (CM), an international journal of comparative and experimental medicine, is the leading English-language publication in the field and is ranked by the Science Citation Index in the upper third of all scientific journals. The mission of CM is to disseminate high-quality, peer-reviewed information that expands biomedical knowledge and promotes human and animal health through the study of laboratory animal disease, animal models of disease, and basic biologic mechanisms related to disease in people and animals.
Attention Members: To access the full text of the articles, be sure you are logged in to the AALAS website.
Attention: please note, due to a temporary technical problem, reference linking within the content is not available at this time
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- For issues prior to 1998
- Institutional Subscription Activation
- Ingenta Connect is not responsible for the content or availability of external websites