scholarly journals Error Sensitivity of Fluorodeoxyglucose Method for Measurement of Cerebral Metabolic Rate of Glucose

1981 ◽  
Vol 1 (4) ◽  
pp. 391-401 ◽  
Author(s):  
Sung-Cheng Huang ◽  
Michael E. Phelps ◽  
Edward J. Hoffman ◽  
David E. Kuhl
Keyword(s):  
Metabolic Rate ◽  
Rate Constants ◽  
Normal Values ◽  
Weighted Average ◽  
Control Group ◽  
Kinetic Measurements ◽  
Normal Value ◽  
Cerebral Metabolic Rate ◽  
Scan Time ◽  
Metabolic Conditions

The fluorodeoxyglucose (FDG) method for the measurement of local cerebral metabolic rate of glucose (LCMRGlc) employs typical values of the FDG transport rate constants that have been obtained by kinetic measurements on an appropriate control group. Discrepancies between the true values of the rate constants in tissue and the typical values used in the operational equation of the FDG method will introduce error in the estimate of LCMRGlc. Computer simulations were used to evaluate the accuracy of the FDG method in cases where (1) the tissue LCMRGlc deviates greatly from the normal values (e.g., stroke) or (2) the tissue LCMRGlc changes during the experiment (e.g., epileptic seizure). The effects of the magnitude and duration of metabolic changes were studied. The rsults indicate that if tissue LCMRGlc differs greatly from the normal value, the error in the estimated LCMRGlc at a scan time of 60 min is less than 20% of the difference between the true and normal values. In the non-steady-state cases, the estimated LCMRGlc was found to be a weighted average of the metabolic rates during the experiments, with the weightings approximately proportional to the plasma FDG concentration at the corresponding times. For example, if LCMRGlc in tissue was 5 times the normal values for the first 10 min but then returned to normal state, the LCMRGlc measured by the FDG method at a scan time of 60 min would be about only 2–3 times the normal value. The results of this study provide a better understanding of the accuracy of the FDG method under various tissue metabolic conditions and is useful for interpreting metabolic values obtained with the FDG method.

scholarly journals Method for Rapid MRI Quantification of Global Cerebral Metabolic Rate of Oxygen

2015 ◽  
Vol 35 (10) ◽  
pp. 1616-1622 ◽  
Author(s):  
Suliman Barhoum ◽  
Michael C Langham ◽  
Jeremy F Magland ◽  
Zachary B Rodgers ◽  
Cheng Li ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
T Test ◽  
Quantitative Magnetic Resonance Imaging ◽  
Cerebral Metabolic Rate ◽  
Sagittal Sinus ◽  
Scan Time ◽  
Rapid Mri ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain ◽  
Good Agreement

A recently reported quantitative magnetic resonance imaging (MRI) method denoted OxFlow has been shown to be able to quantify whole-brain cerebral metabolic rate of oxygen (CMRO2) by simultaneously measuring oxygen saturation ( S v O 2) in the superior sagittal sinus and cerebral blood flow (CBF) in the arteries feeding the brain in 30 seconds, which is adequate for measurement at baseline but not necessarily in response to neuronal activation. Here, we present an accelerated version of the method (referred to as F-OxFlow) that quantifies CMRO2 in 8 seconds scan time under full retention of the parent method's capabilities and compared it with its predecessor at baseline in 10 healthy subjects. Results indicate excellent agreement between both sequences, with mean bias of 2.2% ( P = 0.18, two-tailed t-test), 3.4% ( P = 0.08, two-tailed t-test), and 2.0% ( P = 0.56, two-tailed t-test) for SvO2, CBF, and CMRO2, respectively. F-OxFlow's potential to monitor dynamic changes in SvO2, CBF, and CMRO2 is illustrated in a paradigm of volitional apnea applied to five of the study subjects. The sequence captured an average increase in SvO2, CBF, and CMRO2 of 10.1 ± 2.5%, 43.2 ± 9.2%, and 7.1 ± 2.2%, respectively, in good agreement with literature values. The method may therefore be suited for monitoring alterations in CBF and SvO2 in response to neurovascular stimuli.

Pretreatment and Posttreatment Evaluation of Hemodynamic and Metabolic Parameters in Intracranial Dural Arteriovenous Fistulae with Cortical Venous Reflux

Neurosurgery ◽  
2004 ◽  
Vol 54 (3) ◽  
pp. 585-592 ◽  
Author(s):  
Satoshi Kuroda ◽  
Koji Furukawa ◽  
Tohru Shiga ◽  
Satoshi Ushikoshi ◽  
Chietsugu Katoh ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Dural Arteriovenous Fistula ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Venous Reflux ◽  
Arteriovenous Fistulae ◽  
Cerebral Metabolic Rate ◽  
Positron Emission ◽  
Metabolic Conditions ◽  
Cortical Venous Reflux

Abstract OBJECTIVE Retrograde drainage into the cortical veins results in poor outcome in patients with an intracranial dural arteriovenous fistula. However, the pathophysiological features of dural arteriovenous fistulae remain obscure. This study aimed to clarify hemodynamic and metabolic conditions in these patients using positron emission tomography. METHODS This study included eight patients with an intracranial dural arteriovenous fistula. All patients had cortical venous reflux, as demonstrated by angiography. Regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional cerebral metabolic rate for oxygen, and regional oxygen extraction fraction (rOEF) were measured before and after surgical or endovascular treatment using positron emission tomography. RESULTS Pretreatment positron emission tomographic studies revealed that all patients had abnormal hemodynamic and metabolic parameters in the area that was drained by the involved cortical veins. A severe increase in rCBV was noted in seven of the eight patients. A significant decrease in rCBF also was observed in all eight patients. A negative correlation was observed between rCBF and rCBV. Three patients had an elevated rOEF. Oxygen metabolism was impaired in seven patients. All patients underwent successful treatment. Follow-up studies demonstrated significant improvements in rCBF, rCBV, and regional cerebral metabolic rate for oxygen. The improvement in regional cerebral metabolic rate for oxygen varied among the patients. Normalization of rOEF also was confirmed in three patients who had increased rOEF before the treatment. CONCLUSION The present results suggest that hemodynamic and metabolic characteristics vary widely among patients with cortical venous reflux. It is essential to precisely evaluate hemodynamic and metabolic conditions to predict their outcomes and therapeutic effects.

The Q10 ratio for basal cerebral metabolic rate for oxygen in rats

1996 ◽  
Vol 85 (3) ◽  
pp. 482-487 ◽  
Author(s):  
Richard Klementavicius ◽  
Edwin M. Nemoto ◽  
Howard Yonas
Keyword(s):  
Metabolic Rate ◽  
Temperature Sensitivity ◽  
Brain Temperature ◽  
Control Group ◽  
Content Type ◽  
Cerebral Metabolic Rate ◽  
Thiopental Sodium ◽  
C 30 ◽  
Lower Temperature ◽  
Electroencephalogram Eeg

✓ Previously the authors showed that hypothermia exerts a greater effect on the cerebral metabolic rate for oxygen (CMRO2) that is associated with the maintenance of cellular viability, or “basal” CMRO2, than on electroencephalogram (EEG)-associated CMRO2 or “functional” CMRO2. On the basis of their findings, the authors hypothesized that the ratio of CMRO2 over a 10°C temperature range (Q10) for basal CMRO2 was greater than that for functional and total CMRO2. They tested their hypothesis by determining the Q10 for basal CMRO2 from 38°C to 28°C. They measured whole-brain cerebral blood flow (CBF) and CMRO2 in six rats during progressive hypothermia at a brain temperature of 38°C and, after induction of an isoelectric EEG signal (50 µV/cm) with thiopental sodium, they repeated the measurements at 38°C, 34°C, 30°C, and 28°C. In a control group (five rats), six sequential measurements of CBF and CMRO2 were made while the animals were anesthetized by 0.5% isoflurane/70% N2O/30% O2 at a brain temperature of 38°C over a time span equivalent to the hypothermic group, that is, approximately 3 hours. The Q10 for basal CMRO2 calculated over 38°C to 28°C was 5.2 ± 0.92. However, the decrease in basal CMRO2 between 38°C and 28°C was nonlinear on a log plot, revealing a two-component response: a high temperature sensitivity component between 38°C and 30°C with a Q10 of 12.1, and a lower temperature sensitivity component between 30°C and 28°C with a Q10 of 2.8. The combined overall Q10 for basal CMRO2 between 38° and 28°C was 5.2. The energy-requiring processes associated with these high and low temperature sensitivity components of basal CMRO2 have yet to be identified.

Electroencephalographic Burst Suppression Is Not Required to Elicit Maximal Neuroprotection from Pentobarbital in a Rat Model of Focal Cerebral Ischemia

1996 ◽  
Vol 84 (6) ◽  
pp. 1475-1484 ◽  
Author(s):  
David S. Warner ◽  
Seiji Takaoka ◽  
Bo Wu ◽  
Paula S. Ludwig ◽  
Robert D. Pearlstein ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Glucose Utilization ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Group Versus ◽  
Cerebral Infarct ◽  
Burst Suppression ◽  
Control Group ◽  
Sodium Pentobarbital ◽  
Cerebral Metabolic Rate

Background Barbiturates have previously been demonstrated to reduce focal cerebral ischemic brain damage. However, the dose of drug required to elicit maximal neuroprotection has not been defined. The authors' hypothesized that doses of pentobarbital substantially lower than those required to cause electroencephalographic burst suppression would result in maximal magnitudes of reduction of cerebral infarct volume. Methods Wistar rats underwent 90 min of filament occlusion of the middle cerebral artery while either awake (control), or anesthetized with intravenous sodium pentobarbital administered to preserve an active electroencephalogram (15-23 mg.kg-1.h-1) or a pattern of burst suppression (45-60 mg.kg-1.h-1; n = 17). During ischemia and for the first 6 h of recirculation, brain temperature was rigorously controlled at 38.0 +/- 0.2 degrees C. Rats were allowed a recovery interval of 7 days after which neurologic function and cerebral infarct volume were assessed. In nonischemic rats undergoing a similar anesthetic protocol, the cerebral metabolic rate of glucose utilization was measured at each anesthetic depth. Results Relevant physiologic values were similar between groups. Total infarct volume (mean +/- SD) was smaller in the active electroencephalogram group than in the control group (124 +/- 68 mm3 versus 163 +/- 66 mm3; P < 0.05). Increasing the dose of pentobarbital (burst suppression) did not further decrease infarct volume (128 +/- 54 mm3). Neurologic score and infarct volume were positively correlated (P < 0.001). Cerebral metabolic rate of glucose utilization was reduced by 56% in the burst suppression group versus 43% in the active electroencephalogram pentobarbital group (P < 0.001). Conclusions Sodium pentobarbital administered at either dose (active electroencephalogram or burst suppression) resulted in an approximately equal to 25% reduction of cerebral infarct size, indicating that burst suppression is not required to elicit maximal neuroprotective efficacy.

scholarly journals Cerebral Glucose Metabolism as a Function of Age in Man: Influence of the Rate Constants in the Fluorodeoxyglucose Method

1983 ◽  
Vol 3 (2) ◽  
pp. 250-253 ◽  
Author(s):  
Randall A. Hawkins ◽  
John C. Mazziotta ◽  
Michael E. Phelps ◽  
Sung-Cheng Huang ◽  
David E. Kuhl ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Metabolic Rate ◽  
Rate Constants ◽  
Cerebral Glucose Metabolism ◽  
Cerebral Metabolic Rate

Measurement of the local cerebral metabolic rate of glucose (LCMRGlc) with the fluorodeoxyglucose (FDG) method requires the utilization of appropriate values for the rate constants of the transport and phosphorylation processes. We measured these rate constants as a function of age to determine whether a decline in LCMRGlc as a function of age, in prior studies with the FDG method, actually represents changes in the rate constants. We found that measurements of LCMRGlc are not significantly affected by changes in rate constants as a function of aging, and that LCMRGlc did not change significantly with age.

scholarly journals Effect of Ischemia on Quantification of Local Cerebral Glucose Metabolic Rate in Man

1981 ◽  
Vol 1 (1) ◽  
pp. 37-51 ◽  
Author(s):  
Randall A. Hawkins ◽  
Michael E. Phelps> ◽  
Sung-Cheng Huang ◽  
David E. Kuhl
Keyword(s):  
Glucose Metabolism ◽  
Metabolic Rate ◽  
Rate Constants ◽  
Normal Values ◽  
Cerebral Glucose Metabolism ◽  
Stroke Rate ◽  
Metabolic Rates ◽  
Lumped Constant ◽  
Glucose Metabolic Rate ◽  
The Stability

The model for quantifying local cerebral glucose metabolic rates originally developed by Sokoloff et al. and modified by Phelps, Huang and co-workers was applied to humans with cerebral ischemia (i.e., stroke). Rate constants for fluorodeoxyglucose were measured in ischemic and nonischemic regions with positron computed tomography. Using measured rate constants for ischemia, the model generates more accurate estimates of local cerebral glucose metabolism as compared to the use of rate constants from normal young adults, because the local metabolic rate is significantly underestimated, and temporal instability of the model is observed when normal values are applied to ischemic regions. A method was also developed to test the stability of the local lumped constant. The estimates of the lumped constant showed no or only small variations between ischemic and nonischemic types. Thus, errors introduced in the calculated local cerebral glucose metabolism by inappropriate rate constants appear to be more significant than those caused by any potential change in the lumped constant in ischemia.

Quantitative measurement of cerebral metabolic rate of glucose by means of dual-head coincidence gamma camera and 2-deoxy-2- [18F] fluoro-D-glucose

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S670-S670
Author(s):  
Katsufumi Kajimoto ◽  
Naohiko Oku ◽  
Yasuyuki Kimura ◽  
Makiko Tanaka ◽  
Hiroki Kato ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Gamma Camera ◽  
Quantitative Measurement ◽  
Cerebral Metabolic Rate

Increased oxidative stress and plasma Hsp70 levels among gasoline filling station attendants

2016 ◽  
Vol 33 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Bing Xia ◽  
Kangcheng Chen ◽  
Yingnan Lv ◽  
Damin Huang ◽  
Jing Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Protein ◽  
Weighted Average ◽  
Exposed Group ◽  
Cumulative Exposure ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Gasoline Station ◽  
Filling Station ◽  
Exposed Workers

Objectives: Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn) and is used as an antiknock agent and octane enhancer in gasoline. In this article, we tested the oxidative stress and heat stress protein (Hsp) 70 levels of gasoline station attendants to explore potential plasma biomarkers. Furthermore, the dose–response relationship was also identified. Methods: A total of 144 workers, including 96 petrol fillers and 48 cashiers, participated in the study. Ambient concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) and Mn were monitored at nine filling stations. During the measuring process, the individual cumulative exposure index was calculated. Plasma oxidative stress and Hsp70 levels were also analysed using enzyme-linked immunosorbent assay. Results: The BTEX time-weighted average in office areas was significantly lower than in refuelling areas ( p < 0.05). In refuelling areas, the content of Mn ranged from 6.44 μg/m3 to 127.34 μg/m3, which was much higher than that in office areas (3.16–7.22 μg/m3; p < 0.05). Exposed workers had significantly different plasma oxidative stress indicators compared with the control group, respectively: superoxide dismutase (SOD), 39.18 ± 6.05 U/mL versus 52.84 ± 3.87 U/mL; glutathione peroxidase (GSH-Px), 186.07 ± 15.63 U versus 194.38 ± 10.42 U; and malondialdehyde (MDA), 1.68 ± 0.52 nmol/L versus 1.43 ± 0.64 nmol/L (in all comparisons, p < 0.05). Plasma Hsp70 level in the exposed group (2.77 ± 0.64 ng/mL) was significantly higher than in the control group (2.32 ± 0.87 ng/mL; p < 0.05). Furthermore, Hsp70 levels were inversely correlated with the activities of SOD ( r = −0.305) and GSH-Px ( r = −0.302) in the exposed group ( p < 0.05). Moreover, a positive correlation ( r = 0.653) was found between plasma Hsp70 levels and plasma MDA levels ( p < 0.05). Conclusion: Exposure to MMT-containing gasoline may result in increasing reactive oxygen stress among filling station attendants. Plasma Hsp70 levels could be used as a sensitive responsive biomarker for exposed workers.

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