Cardiovascular Positron Emission Tomography: A Possible Tool for Assessment of New Pharmaceuticals
- PDF / 426,411 Bytes
- 6 Pages / 504 x 719.759 pts Page_size
- 112 Downloads / 148 Views
Drug Information Journal. Vol. 31. pp. 1029-1034. 1997 Printed in the USA. All rights reserved.
CARDIOVASCULAR POSITRON EMISSION TOMOGRAPHY A POSSIBLE TOOL FOR ASSESSMENT OF NEW PHARMACEUTICALS M. SCHWAIGER, MD, AND 1. KOSA, MD Technische Universitaet Muenchen, Muenchen. Germany
Positron emission tomography (PET)represents the most advanced scintigraphic imaging technology. This technology is being employed for cardiovascular research as well as for clinical applications in patients with various cardiovascular diseases. Together with a considerable number of radiophannaceuticals, PET allows the noninvasive assessment of myocardial perfirsion, myocardial substrate metabolism, and cardiac innervation. This article will briefly review the various aspects of scintigraphic tissue characterization provided by this technology in the heart. Key Words: Positron emission tomography; Cardiovascular research
METHODOLOGY POSITRON EMISSION tomography offers advantages over conventional single photon tomography with regard to quantification of regional tissue tracer distribution. Using transmission imaging, regional attenuation can be measured and the emission data corrected. Images with high spatial resolution (6-8 mm) can be generated to quantify regional myocardial tracer concentration (1). Modem tornographs provide an axial field of view of more than 10 cm, allowing simultaneous assessment of tracer distribution within the entire heart. The ring design provides high temporal resolution which is necPresented at the DIA Workshop “Positron Emission Tomography,” November 20-21, 1995, Bruges, Belgium. Reprint address: Prof. Dr. M. Schwaiger, Nuklearmedizinische Klinik u. Poliklinik, Klinikum r.d. Isar der TU Muenchen, Ismaninger Str. 22, 81675 Muenchen, Gemt~Y.
essary for the dynamic assessment of tracer uptake and washout in blood as well as myocardial tissue. Using quantitative image analysis, activity curves in blood and myocardium can be defined. Tracer kinetic modeling has been successfully employed to quantitate physiological parameters such as perfusion, myocardial oxygen consumption, and myocardial glucose utilization (2).
ASSESSMENT OF MYOCARDIAL PERFUSION Various tracer approaches have been introduced to assess myocardial perfusion with PET. Myocardial blood is measured under resting condition and following pharmacological stress. Due to the fact that attenuation correction is performed, the motion of the body within the scanner has to be minimized. Therefore, physical exercise is not possible during acquisition of PET data. Pharmaco-
1029 Downloaded from dij.sagepub.com by guest on June 12, 2015
M. Schwaiger and I. Kosa
1030
logical stress testing with vasodilating drugs such as adenosine or dipyridamol or with positive inotropic agents such as dobutamin represent an acceptable alternative to physical exercise. Extensive experimental and clinical validation exists for pharmacological stress testing using dipyridamol and adenosine (3-6). These interventions allow the evaluation of regional coronary flow reserve
Data Loading...
