Use of short- and long-lived rubidium tracers for the study of transient ischemia

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · J. Nucl. Med.; (United States)

OSTI ID:6279168

Shea, M J; Wilson, R A; deLandsheere, C M; Deanfield, J E; Watson, I A; Kensett, M J; Jones, T; Selwyn, A P

Positron emission tomography (PET) with rubidium-82 (/sup 82/Rb) has been developed to measure regional myocardial perfusion and to detect transient ischemia both in the experimental laboratory and in humans. There are known and separate contaminating effects of the /sup 82/Rb signal by disturbances in wall motion, wall thinning, and the partial volume effect that occur during transient ischemia. In nine anesthetized greyhounds, PET with /sup 82/Rb (T1/2 = 78 sec) was used to determine the regional myocardial uptake of this cation during a control period that consisted of a mild stenosis of the left anterior descending coronary artery in the absence of ischemia (to limit reactive hyperemia), during 10 min of total occlusion and, finally, at 30 and 60 min of recovery with release of the occlusion but not of the stenosis. Separately, rubidium-81 (/sup 81/Rb); T1/2 = 4.58 hr) was given as a peripheral intravenous injection 2 hr before the study to allow this long-lived tracer to distribute in the potassium space of the myocardium. Observations during control and ischemia revealed marked decreases in /sup 82/Rb uptake (0.84 +/- 0.12 to 0.28 +/- 0.12, p = 0.001) in affected regions and were paralleled by similar decreases in microsphere blood flow (0.88 +/- 0.08 to 0.12 +/- 0.10 ml/min/g, p = 0.003), which gradually recovered by 60 min postischemia. Lesser decreases in /sup 81/Rb activity (0.84 +/- 0.11 to 0.76 +/- 0.17, p = 0.83) were observed in the same regions during ischemia, but these were immediately reversible. Separate in vitro postmortem experiments in eight rabbits confirmed a linear relationship between plasma and myocardial activities of stable potassium and /sup 81/Rb although there was a greater concentration of 81Rb in the myocardium that in the plasma relative to potassium (y = -3.29 +/- 0.79 x, s.e.e. 1.91, r = 0.95).

• Research Organization: Royal Postgraduate Medical School, London, England
• OSTI ID: 6279168
• Journal Information: J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 6; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALKALI METAL ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
COMPUTERIZED TOMOGRAPHY
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
DOGS
ELECTRON CAPTURE RADIOISOTOPES
EMISSION COMPUTED TOMOGRAPHY
HEART
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISCHEMIA
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MAN
MINUTES LIVING RADIOISOTOPES
MUSCLES
MYOCARDIUM
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANS
POSITRON COMPUTED TOMOGRAPHY
PRIMATES
RABBITS
RADIOISOTOPES
RUBIDIUM 81
RUBIDIUM 82
RUBIDIUM ISOTOPES
TOMOGRAPHY
VASCULAR DISEASES
VERTEBRATES