Myocardial Perfusion and Intracapillary Blood Volume in Rats at Rest and with Coronary Dilatation: MR Imaging in Vivo with Use of a Spin-Labeling Technique
- 1 April 2000
- journal article
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 215 (1), 189-197
- https://doi.org/10.1148/radiology.215.1.r00ap07189
Abstract
To validate a magnetic resonance (MR) imaging technique that is not first pass and that reveals perfusion and regional blood volume (RBV) in the intact rat. Measurement of perfusion was based on the perfusion-sensitive T1 relaxation after magnetic spin labeling of water protons. RBV was determined from steady-state measurements of T1 before and after administration of an intravascular contrast agent. The colored microsphere technique was used as a reference method for perfusion measurement. RBV and perfusion maps were obtained with the rats at rest and during administration of 3 mg of adenosine phosphate per kilogram of body weight per minute. At MR imaging, perfusion during resting conditions was 3.5 mL/g/min +/- 0.1 (SEM), and RBV was 11.6% +/- 0.6 (SEM). Adenosine phosphate significantly increased perfusion to 4.5 mL/g/min +/- 0.3 (SEM) and decreased mean arterial pressure from 120 mm Hg to 65 mm Hg, which implies a reduction of coronary resistance to 40% of baseline. RBV increased consistently to 23.8% +/- 0.6 (SEM). The study results show that quantitative mapping of perfusion and RBV may be performed noninvasively by means of MR imaging in the intact animal. The presented method allows determination of vasodilative and perfusion reserve, which reflects the in vivo regulation of coronary microcirculation for a given stimulus.Keywords
This publication has 33 references indexed in Scilit:
- The effect of perfusion on T1 after slice‐selective spin inversion in the isolated cardioplegic rat heart: Measurement of a lower bound of intracapillary‐extravascular water proton exchange rateMagnetic Resonance in Medicine, 1997
- Quantitative cardiac perfusion: a noninvasive spin-labeling method that exploits coronary vessel geometry.Radiology, 1996
- Regional myocardial blood volume and flow: First‐pass MR imaging with polylysine‐Gd‐DTPAJournal of Magnetic Resonance Imaging, 1995
- Magnetic resonance imaging of perfusion in the isolated rat heart using spin inversion of arterial waterMagnetic Resonance in Medicine, 1993
- In vivo relation of intramyocardial blood volume to myocardial perfusion. Evidence supporting microvascular site for autoregulation.Circulation, 1992
- First-pass entry of nonionic contrast agent into the myocardial extravascular space. Effects on radiographic estimates of transit time and blood volume.Circulation, 1991
- Effects of barium-induced cardiac contraction on large- and small-vessel intramyocardial blood volume.Circulation Research, 1991
- Differences in regional capillary distribution and myocyte sizes in normal and hypertrophic rat heartsJournal of Anatomy, 1979
- Reference sample method for cardiac output and regional blood flow determinations in the ratJournal of Applied Physiology, 1976
- The influence of coronary pressure and coronary flow on intracoronary blood volume and geometry of the left ventriclePflügers Archiv - European Journal of Physiology, 1973