Improvement in cerebral blood flow and metabolism following subarachnoid hemorrhage in response to prophylactic administration of the hydroxyl radical scavenger, AVS, (±)-N,N′-propylenedinicotinamide: a positron emission tomography study in rats

2000 ◽  
Vol 92 (6) ◽  
pp. 1009-1015 ◽  
Author(s):  
Seiji Yamamoto ◽  
Weiyu Teng ◽  
Shigeru Nishizawa ◽  
Takeharu Kakiuchi ◽  
Hideo Tsukada
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Emission Tomography ◽  
Radical Scavenger ◽  
Content Type ◽  
Prophylactic Administration ◽  
Positron Emission ◽  
Hydroxyl Radical Scavenger ◽  
Fine Print

Object. The hydroxyl radical scavenger (±)-N,N′-propylenedinicotinamide (AVS) has been shown to ameliorate the occurrence of vasospasm following experimental subarachnoid hemorrhage (SAH) and to reduce the incidence of delayed ischemic neurological deficits (DINDs) in patients with SAH. The authors investigated whether prophylactic administration of AVS could improve cerebral blood flow (CBF) and cerebral glucose utilization (CGU) following SAH in rats.Methods. Anesthetized rats were subjected to intracisternal injection of blood (SAH group) or saline (control group). Either AVS (1 mg/kg/min) or saline (vehicle group) was continuously injected into the rat femoral vein. Forty-eight hours later, positron emission tomography scanning was used with the tracers 15O-H2O and 18F-2-fluoro-d-glucose to analyze quantitatively CBF and CGU, respectively, in the frontoparietal and occipital regions (12 regions of interest/group).In SAH rats receiving only vehicle, CBF decreased significantly (p < 0.05, Tukey's test) and CGU tended to decrease, compared with values obtained in control (non-SAH) rats receiving vehicle. In rats that were subjected to SAH, administration of AVS significantly (p < 0.05, Tukey's test) improved CBF and CGU in both the frontoparietal and occipital regions compared with administration of vehicle alone.Conclusions. Prophylactic administration of AVS improves CBF and CGU in the rat brain subjected to SAH, and can be a good pharmacological treatment for the prevention of DINDs following SAH.

Mapping human somatosensory cortex with positron emission tomography

1987 ◽  
Vol 67 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Peter T. Fox ◽  
Harold Burton ◽  
Marcus E. Raichle
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Somatosensory Cortex ◽  
Emission Tomography ◽  
Normative Values ◽  
Vibratory Stimulation ◽  
Content Type ◽  
Positron Emission ◽  
Cutaneous Vibration

✓ Positron emission tomography measurements of regional cerebral blood flow were used to detect focal neuronal activation in the first somatosensory cortex (SI) of humans induced by cutaneous vibratory stimulation. Intravenously administered water labeled with oxygen-15 (H215O) was used as a blood flow tracer to obtain five stimulated-state and two resting-state blood flow images in each of eight normal volunteers. Three cutaneous surfaces were tested: lips, fingers, and toes. Intense, highly focal SI responses were seen during all 39 stimulated-state trials. The SI responses from the three stimulation sites were anatomically distinct and formed a medial-to-lateral homonculus in every subject. Response magnitudes (increase in local blood flow) and response locales (expressed as proportionately measured bicommissural stereotaxic coordinates) were highly consistent among subjects and on repeated trials for each subject. These findings suggest that eliciting cerebral blood flow responses by cutaneous vibration provides a safe, rapid, and reproducible tool for locating and assessing the functional status of somatosensory cortex, and offers potential clinical and research utility. This study has established normative values for future applications of this experimental paradigm.

Relationship between residual cerebral blood flow and oxygen metabolism as predictive of ischemic tissue viability: sequential multitracer positron emission tomography scanning of middle cerebral artery occlusion during the critical first 6 hours after stroke in pigs

2000 ◽  
Vol 93 (4) ◽  
pp. 647-657 ◽  
Author(s):  
Masaharu Sakoh ◽  
Leif Østergaard ◽  
Lisbeth Røhl ◽  
Donald F. Smith ◽  
Claus Z. Simonsen ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Oxygen Metabolism ◽  
Emission Tomography ◽  
Content Type ◽  
Cerebral Metabolic Rate ◽  
Positron Emission ◽  
Ischemic Tissue ◽  
Residual Blood ◽  
Fine Print

Object. The authors tested the hypothesis that oxygen metabolism is the key factor linking the long-term viability of ischemic brain tissue to the magnitude of residual blood flow during the first 6 hours following a stroke.Methods. Eleven anesthetized pigs underwent a series of positron emission tomography studies to measure cerebral blood flow (CBF) and metabolism before and for 7 hours after the animals were subjected to permanent middle cerebral artery (MCA) occlusion. The extent of collateral blood supply was assessed using angiography. Abnormal metabolism of the ischemic tissue progressed as a function of time in inverse proportion to the magnitude of residual CBF, and the volume of the infarct grew in inverse proportion to the residual blood supply. Ten hours after occlusion of the MCA, the infarct topographically matched the tissue with a cerebral metabolic rate of oxygen consumption below 50% of values measured on the contralateral side. This was also the threshold for the decline of the oxygen extraction fraction below normal, which was critical for the prediction of nonviable ischemic tissue. Mildly ischemic tissue (CBF > 30 ml/100 g/min) did not reach the cerebral metabolic rate of oxygen threshold of viability during the first 6 hours after MCA occlusion; moderately ischemic tissue (CBF 12–30 ml/100 g/ min) reached the threshold of viability in 3 hours; and severely ischemic tissue (CBF < 12 ml/100 g/min) remained viable for less than 1 hour.Conclusions. The relationship between the residual CBF and both oxygen metabolism and extraction is critical to the evolution of metabolic deficiency and lesion size after stroke.

The integration of metabolic imaging in stereotactic procedures including radiosurgery: a review

2002 ◽  
Vol 97 ◽  
pp. 542-550 ◽  
Author(s):  
Marc Levivier ◽  
David Wikler ◽  
Nicolas Massager ◽  
Philippe David ◽  
Daniel Devriendt ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Brain Tumors ◽  
Treatment Planning ◽  
Target Volume ◽  
Emission Tomography ◽  
Low Grade ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Fine Print

Object. The authors review their experience with the clinical development and routine use of positron emission tomography (PET) during stereotactic procedures, including the use of PET-guided gamma knife radiosurgery (GKS). Methods. Techniques have been developed for the routine use of stereotactic PET, and accumulated experience using PET-guided stereotactic procedures over the past 10 years includes more than 150 stereotactic biopsies, 43 neuronavigation procedures, and 34 cases treated with GKS. Positron emission tomography—guided GKS was performed in 24 patients with primary brain tumors (four pilocytic astrocytomas, five low-grade astrocytomas or oligodendrogliomas, seven anaplastic astrocytomas or ependymomas, five glioblastomas, and three neurocytomas), five patients with metastases (single or multiple lesions), and five patients with pituitary adenomas. Conclusions. Data obtained with PET scanning can be integrated with GKS treatment planning, enabling access to metabolic information with high spatial accuracy. Positron emission tomography data can be successfully combined with magnetic resonance imaging data to provide specific information for defining the target volume for the radiosurgical treatment in patients with recurrent brain tumors, such as glioma, metastasis, and pituitary adenoma. This approach is particularly useful for optimizing target selection for infiltrating or ill-defined brain lesions. The use of PET scanning contributed data in 31 cases (93%) and information that was specifically utilized to adapt the target volume in 25 cases (74%). It would seem that the integration of PET data into GKS treatment planning may represent an important step toward further developments in radiosurgery: this approach provides additional information that may open new perspectives for the optimization of the treatment of brain tumors.

scholarly journals Effects of Acetazolamide on Cerebral Blood Flow, Blood Volume, and Oxygen Metabolism: A Positron Emission Tomography Study with Healthy Volunteers

2001 ◽  
Vol 21 (12) ◽  
pp. 1472-1479 ◽  
Author(s):  
Hidehiko Okazawa ◽  
Hiroshi Yamauchi ◽  
Kanji Sugimoto ◽  
Hiroshi Toyoda ◽  
Yoshihiko Kishibe ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Capillary Blood ◽  
Emission Tomography ◽  
Positron Emission ◽  
Capillary Blood Volume

To evaluate changes in cerebral hemodynamics and metabolism induced by acetazolamide in healthy subjects, positron emission tomography studies for measurement of cerebral perfusion and oxygen consumption were performed. Sixteen healthy volunteers underwent positron emission tomography studies with15O-gas and water before and after intravenous administration of acetazolamide. Dynamic positron emission tomography data were acquired after bolus injection of H215O and bolus inhalation of15O2. Cerebral blood flow, metabolic rate of oxygen, and arterial-to-capillary blood volume images were calculated using the three-weighted integral method. The images of cerebral blood volume were calculated using the bolus inhalation technique of C15O. The scans for cerebral blood flow and volume and metabolic rate of oxygen after acetazolamide challenge were performed at 10, 20, and 30 minutes after drug injection. The parametric images obtained under the two conditions at baseline and after acetazolamide administration were compared. The global and regional values for cerebral blood flow and volume and arterial-to-capillary blood volume increased significantly after acetazolamide administration compared with the baseline condition, whereas no difference in metabolic rate of oxygen was observed. Acetazolamide-induced increases in both blood flow and volume in the normal brain occurred as a vasodilatory reaction of functioning vessels. The increase in arterial-to-capillary blood volume made the major contribution to the cerebral blood volume increase, indicating that the raise in cerebral blood flow during the acetazolamide challenge is closely related to arterial-to-capillary vasomotor responsiveness.

Neural Mechanism of Propofol Anesthesia in Severe Depression

2003 ◽  
Vol 98 (5) ◽  
pp. 1101-1111 ◽  
Author(s):  
Kenichi Ogawa ◽  
Takeshi Uema ◽  
Nobutaka Motohashi ◽  
Masami Nishikawa ◽  
Harumasa Takano ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Statistical Parametric Mapping ◽  
Severe Depression ◽  
Dose Effect ◽  
Emission Tomography ◽  
Association Cortex ◽  
Depressed Patients ◽  
Positron Emission

Background The precise neural mechanisms of propofol anesthesia in humans are still unknown. The authors examined the acute effects of propofol on regional cerebral blood flow (rCBF) using positron emission tomography in patients with severe depression. Methods In six severely depressed patients (mean age, 55.0 yr) scheduled for electroconvulsive therapy, anesthetic levels were monitored by electroencephalography, and rCBF was serially quantified in the awake, sedated, and anesthetized states. The authors used high-resolution positron emission tomography with 15O-labeled water and statistical parametric mapping 99 for imaging and analysis of the data. Results Global cerebral blood flow showed sharp decreases from the awake level during the administration of propofol, decreasing 26.8% in the sedated state and 54.4% in the anesthetized state. Moreover, a dose effect was seen in both parietal cortices and the left lateral prefrontal region with larger regions of relative decrease in rCBF at higher propofol doses. At the higher dose, the values of rCBF in the pulvinar nucleus of the thalamus, the pontine tegmentum, and the cerebellar cortex were also affected. Meanwhile, there were few changes of relative rCBF in the basal frontal lobes during both sedated and anesthetized states. Conclusions As in earlier studies using normal subjects, pronounced suppression in rCBF in the brain stem reticular formation, the thalamus, and the parietal association cortex occurred even in severely depressed patients. However, previously reported decreases in rCBF in the basal frontal lobe were absent in depressed patients.

A positron emission tomography study of cerebrovascular reserve before and after shunt surgery in patients with idiopathic chronic hydrocephalus

1999 ◽  
Vol 91 (4) ◽  
pp. 605-609 ◽  
Author(s):  
Petra M. Klinge ◽  
Georg Berding ◽  
Thomas Brinker ◽  
Wolfram H. Knapp ◽  
Madjid Samii
Keyword(s):  
Positron Emission Tomography ◽  
Emission Tomography ◽  
Chronic Hydrocephalus ◽  
Content Type ◽  
Cerebrovascular Reserve ◽  
Shunt Placement ◽  
Positron Emission ◽  
Group A ◽  
Group B ◽  
Fine Print

Object. In this study the authors use positron emission tomography (PET) to investigate cerebral blood flow (CBF) and cerebrovascular reserve (CVR) in chronic hydrocephalus.Methods. Ten patients whose mean age was 67 ± 10 years (mean ± standard deviation [SD]) were compared with 10 healthy volunteers who were 25 ± 3 years of age. Global CBF and CVR were determined using 15O—H2O and PET prior to shunt placement and 7 days and 7 months thereafter. The CVR was measured using 1 g acetazolamide. Neurological status was assessed based on a score assigned according to the methods of Stein and Langfitt.Seven months after shunt placement, five patients showed clinical improvement (Group A) and five did not (Group B). The average global CBF before shunt deployment was significantly reduced in comparison with the control group (40 ± 8 compared with 61 ± 7 ml/100 ml/minute; mean ± SD, p < 0.01). In Group A the CBF values were significantly lower than in Group B (36 ± 7 compared with 44 ± 8 ml/100 ml/minute; p < 0.05). The CVR before surgery, however, was not significantly different between groups (Group A = 43 ± 21%, Group B = 37 ± 29%). After shunt placement, there was an increase in the CVR in Group A to 52 ± 37% after 7 days and to 68 ± 47% after 7 months (p < 0.05), whereas in Group B the CVR decreased to 14 ± 18% (p < 0.05) after 7 days and returned to the preoperative level (39 ± 6%) 7 months after shunt placement.Conclusions. The preliminary results indicate that a reduced baseline CBF before surgery does not indicate a poor prognosis. Baseline CBF before shunt placement and preoperative CVR are not predictive of clinical outcome. A decrease in the CVR early after shunt placement, however, is related to poor late clinical outcome, whereas early improvement in the CVR after shunt placement indicates a good prognosis.

scholarly journals Cerebral Blood Flow and Metabolism Measurement Using Positron Emission Tomography before and during Internal Carotid Artery Test Occlusions: Feasibility of Rapid Quantitative Measurement of CBF and OEF/CMRO2

2012 ◽  
Vol 18 (3) ◽  
pp. 264-274 ◽  
Author(s):  
N. Kawai ◽  
M. Kawanishi ◽  
A. Shindou ◽  
N. Kudomi ◽  
Y. Yamamoto ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
False Negative ◽  
Photon Emission ◽  
Emission Tomography ◽  
Positron Emission

Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study is a sensitive test for predicting the outcome of permanent ICA occlusion. However, false negative results sometimes occur using single photon emission tomography (SPECT). We have recently developed a rapid positron emission tomography (PET) protocol that measures not only the CBF but also the cerebral oxygen metabolism before and during BTO in succession. We measured acute changes in regional CBF and OEF/CMRO2 before and during BTO in three cases with large or giant cerebral aneurysms using the rapid PET protocol. Although no patients showed ischemic symptoms during BTO, PET studies exhibited mildly to moderately decreased CBF (9∼34%) compared to the values obtained before BTO in all cases. The average OEF during BTO was significantly increased (21% and 43%) than that of before BTO in two cases. The two cases were considered to be non-tolerant for permanent ICA occlusion and treated without ICA sacrifice. Measurement of the CBF and OEF/CMRO2 using a rapid PET protocol before and during BTO is feasible and can be used for accurate assessment of tolerance prediction in ICA occlusion.

Fluorine-18—labeled fluorodeoxyglucose—positron emission tomography studies of acute brainstem Lyme neutoborreliosis

2005 ◽  
Vol 102 (5) ◽  
pp. 927-929 ◽  
Author(s):  
Michail Plotkin ◽  
Hubertus Hautzel ◽  
Bernd Joachim Krause ◽  
Stephan Mohr ◽  
Karl Josef Langen ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Magnetic Resonance Images ◽  
Emission Tomography ◽  
Fluorodeoxyglucose Positron Emission Tomography ◽  
Brainstem Tumor ◽  
Content Type ◽  
Positron Emission ◽  
Fluorodeoxyglucose Positron Emission ◽  
Fine Print

✓ The authors report on a patient suffering from acute Lyme borreliosis who underwent two consecutive [18F]fluorodeoxyglucose—positron emission tomography (FDG-PET) studies demonstrating the course of the disease. The first FDG-PET study revealed markedly increased glucose metabolism in the brainstem, matching exactly the signal abnormalities exhibited on magnetic resonance images and indicating a brainstem tumor. A second PET scan demonstrated no abnormality in this region, thus reflecting clinical remission following antibiotic therapy. Data in the present case indicate that hypermetabolic findings on FDG-PET studies in the brainstem region should be regarded with caution and that neuroborreliosis must be considered as a possible differential diagnosis.

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