Thallium-201 myocardial imaging during coronary vasodilation induced by oral dipyridamole
Myocardial perfusion imaging of /sup 201/TI injected during maximum exercise has been an important diagnostic tool for coronary artery disease. Pharmacologic coronary vasodilation by i.v. infusion of dipyridamole may be used in lieu of exercise stress for purposes of diagnostic perfusion imaging. However, i.v. dipyridamole is not currently available from commercial sources for widespread routine use. Accordingly, this study was carried out in order to determine whether high dose, oral dipyridamole would be useful as a coronary vasodilator for purposes of diagnostic perfusion imaging. Fifty-eight patients undergoing diagnostic coronary arteriography also had myocardial perfusion imaging with 201TI under conditions of rest, maximum exercise stress, and high dose oral dipyridamole. Of those patients who had a defect on exercise thallium images, 75% also had a perfusion defect on thallium images after high dose oral dipyridamole. These results indicate that oral dipyridamole causes sufficient coronary arteriolar vasodilation and increase of coronary flow in nonstenotic arteries to identify perfusion defects comparable to those seen on maximum exercise stress in at least 75% of cases. In 25% of patients with exercise defects, no perfusion defect was seen after oral dipyridamole. Thus, oral dipyridamole is a potent coronary vasodilator, comparable to exercise stress in most cases, but in a minority of patients may not be comparable to exercise stress.
- Research Organization:
- Univ. of Texas Health Science Centers, Houston
- OSTI ID:
- 5590729
- Journal Information:
- J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 1; ISSN JNMEA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
ARTERIES
BETA DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
COMPARATIVE EVALUATIONS
CORONARIES
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EXERCISE
HEART
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MUSCLES
MYOCARDIUM
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PATIENTS
RADIOISOTOPE SCANNING
RADIOISOTOPES
SCINTISCANNING
SECONDS LIVING RADIOISOTOPES
TESTING
THALLIUM 201
THALLIUM ISOTOPES
VASODILATION