Influence of the Input Function on the Calculation of the Local Cerebral Metabolic Rate for Glucose in the Deoxyglucose Method
Open Access
- 1 March 1984
- journal article
- research article
- Published by SAGE Publications in Journal of Cerebral Blood Flow & Metabolism
- Vol. 4 (1), 41-46
- https://doi.org/10.1038/jcbfm.1984.6
Abstract
We describe here a modification of Sokoloff's deoxyglucose method which requires fewer blood samples but does not diminish accuracy. To calculate the local cerebral metabolism for glucose (LCMRglu), the input function containing the initial peak must be known. This requires many blood samples for accurate definition. To estimate the influence of the peak on the LCMRglu, a dummy input function was generated by extrapolating the data points after 2 min back to 0 min. Next, a biexponential curve, fitted to a reduced number of samples, was applied for the input function. The error introduced into the LCMRglu by using these different approximations was analyzed with an error function derived from an operational equation. The results indicate that the error of LCMRglu caused by neglecting the peak is <3%. Furthermore, the error of LCMRglu resulting from use of the biexponential approximation is a function of LCMRglu: the error decreases as the LCMRglu increases and remains at <3% even when only seven data points are used (half the usual number of the standard method). Finally, the LCMRglu was calculated by the biexponential curve-fitting, using the experimental data, and compared with that calculated by Sokoloff's computer program. Both methods were in good agreement. This modified method offers great advantage for simultaneous measurement of CMRglu, CBF, and other physiological parameters by means of the multiple tracer autoradiographic technique in the small laboratory animal.Keywords
This publication has 6 references indexed in Scilit:
- Use of 2-Deoxy-D[1-11C]Glucose for the Determination of Local Cerebral Glucose Metabolism in Humans: Variation within and between SubjectsJournal of Cerebral Blood Flow & Metabolism, 1982
- Error Sensitivity of Fluorodeoxyglucose Method for Measurement of Cerebral Metabolic Rate of GlucoseJournal of Cerebral Blood Flow & Metabolism, 1981
- Simultaneous measurement of blood flow and glucose metabolism by autoradiographic techniques.Stroke, 1981
- Use of 123I and 14C in a double radionuclide autoradiographic technique for simultaneous measurement of LCBF and LCMRgl. Theory and method.Stroke, 1981
- Noninvasive determination of local cerebral metabolic rate of glucose in manAmerican Journal of Physiology-Endocrinology and Metabolism, 1980
- THE [14C]DEOXYGLUCOSE METHOD FOR THE MEASUREMENT OF LOCAL CEREBRAL GLUCOSE UTILIZATION: THEORY, PROCEDURE, AND NORMAL VALUES IN THE CONSCIOUS AND ANESTHETIZED ALBINO RAT1Journal of Neurochemistry, 1977