Retention of {sup 99m}{Tc}-bicisate in the human brain after intracarotid injection

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Journal of Cerebral Blood Flow and Metabolism

OSTI ID:68482

Friberg, L; Lassen, N A ^[1]; Andersen, A R ^[2]; Dam, M ^[3]

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1. Bispebjerg Hospital, Copenhagen (Denmark)
2. Rigshospitalet, Copenhagen (Denmark)
3. Hvidovre Hospital (Denmark)

{sup 99m}{Tc}-bicisate (ECD) was injected as a bolus into the internal carotid artery, and cerebral uptake and retention were recorded with fast-rotating single photon emission computed tomography (SPECT) equipment in four patients suffering from temporal lobe epilepsy. Quantitative regional cerebral blood flow (rCBF) was measured tomographically with the {sup 133}Xe inhalation technique. The authors applied a three-compartment kinetic model and algorithms modified from a previous analysis of {sup 99m}{Tc} d,l-hexamethylpropyleneamine oxide (HM-PAO) kinetics. The bicisate brain uptake and retention curve was very similar to that of HM-PAO, and it can be described by a triexponential function including an initial steep component representing the vascular transmitted spike, a second less steep component representing back-diffusion from brain tissue to blood, and a third, very slow component, representing the very slow loss due to incomplete retention of the deesterified hydrophilic metabolites. Computerized curve-fitting on data from three patients gave average kinetic values for the first-passage (unilateral) extraction of E = 0.60 (range, 0.59-0.61); the overall retained fraction of the tracer supplied was R = 0.44 (0.43-0.45), and the conversion/clearance ratio was {alpha} = k{sub 3}/k{sub 2} = 2.59 (2.38-2.77). This {alpha} is higher than that for HM-PAO, and therefore bicisate uptake as a function of blood flow is more linear than in HM-PAO. Less correction for backdiffusion is therefore needed. From 1 to 24 h there was an average loss of hydrophilic tracer of 3.5%/h, but the late distribution images were essentially unchanged over time, pointing to practically the same rate of loss in all regions. 18 refs., 5 figs., 2 tabs.

• OSTI ID: 68482
• Journal Information: Journal of Cerebral Blood Flow and Metabolism, Journal Name: Journal of Cerebral Blood Flow and Metabolism Journal Issue: Suppl.1 Vol. 14; ISSN JCBMDN; ISSN 0271-678X
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BRAIN
METABOLISM
RADIOPHARMACEUTICALS
TECHNETIUM 99
TISSUE DISTRIBUTION
UPTAKE