Repeated least squares analysis of simulated xenon computed tomographic measurements of regional cerebral blood flow.
J Cereb Blood Flow Metab
; 2(4): 408-14, 1982 Dec.
Article
em En
| MEDLINE
| ID: mdl-7142304
ABSTRACT
Computer simulations were done as a feasibility study of xenon computed tomographic measurements of regional cerebral blood flow. Accuracy of initial least squares estimates of gray matter and white matter rate constants from a two-compartment model depended very little on the number and timing of scans, but did depend significantly on the enhancement-to-noise ratio as well as on the true values of the rate constants and gray/white ratio. Nonlinear least squares gives an optimal fit of the predicted wash-in--wash-out curve to the data rather than optimal estimates of the rate constants. A polynomial correction factor was obtained by regressing initial estimates on the true values used to generate the simulations. The correction factor substantially reduced error in the estimates and, in particular, eliminated large outliers.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Computadores
/
Circulação Cerebrovascular
/
Modelos Biológicos
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
1982
Tipo de documento:
Article