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.

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.

Hemodynamic and metabolic effects of cerebral revascularization

1987 ◽  
Vol 66 (4) ◽  
pp. 529-535 ◽  
Author(s):  
Richard Leblanc ◽  
Jane L. Tyler ◽  
Gérard Mohr ◽  
Ernst Meyer ◽  
Mirko Diksic ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Oxygen Metabolism ◽  
Carotid Occlusion ◽  
Emission Tomography ◽  
Cerebral Revascularization ◽  
Metabolic Effects ◽  
Content Type ◽  
Positron Emission ◽  
Hemodynamic Function ◽  
Fine Print

✓ Pre- and postoperative positron emission tomography (PET) was performed in six patients undergoing extracranial to intracranial bypass procedures for the treatment of symptomatic extracranial carotid occlusion. The six patients were all men, aged 52 to 68 years. Their symptoms included transient ischemic attacks (five cases), amaurosis fugax (two cases), and completed stroke with good recovery (one case). Positron emission tomography was performed within 4 weeks prior to surgery and between 3 to 6 months postoperatively, using oxygen-15-labeled CO, O2, and CO2 and fluorine-18-labeled fluorodeoxyglucose. Cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rates for oxygen and glucose (CMRO2 and CMRGlu), and the oxygen extraction fraction (OEF) were measured in both hemispheres. Preoperatively, compared to five elderly control subjects, patients had increased CBV, a decreased CBF/CBV ratio, and decreased CMRO2, indicating reduced cerebral perfusion pressure and depressed oxygen metabolism. The CBF was decreased in only one patient who had bilateral carotid occlusions; the OEF, CMRGlu, and CMRO2/CMRGlu and CMRGlu/CBF ratios were not significantly different from control measurements. All bypasses were patent and all patients were asymptomatic following surgery. Postoperative PET revealed decreased CBV and an increased CBF/CBV ratio, indicating improved hemodynamic function. This was associated with increased CMRO2 in two patients in whom the postoperative OEF was also increased. The CMRGlu and CMRGlu/CBF ratio were increased in five patients. Changes in CBF and the CMRO2/CMRGlu ratio were variable. One patient with preoperative progressive mental deterioration, documented by serial neuropsychological testing and decreasing CBF and CMRO2, had improved postoperative CBF, CBV, and CMRO2 concomitant with improved neuropsychological functioning and oxygen hypometabolism. It is concluded that symptomatic carotid occlusion is associated with altered hemodynamic function. Cerebral revascularization results in decreased CBV, indicating improved hemodynamic reserve, but does not consistently improve oxygen metabolism.

Cerebral hyperglycolysis following severe traumatic brain injury in humans: a positron emission tomography study

1997 ◽  
Vol 86 (2) ◽  
pp. 241-251 ◽  
Author(s):  
Marvin Bergsneider ◽  
David A. Hovda ◽  
Ehud Shalmon ◽  
Daniel F. Kelly ◽  
Paul M. Vespa ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Positron Emission Tomography ◽  
Brain Injury ◽  
Head Injury ◽  
Fdg Pet ◽  
Emission Tomography ◽  
Content Type ◽  
Cerebral Metabolic Rate ◽  
Positron Emission ◽  
Fine Print

✓ Experimental traumatic brain injury studies have shown that cerebral hyperglycolysis is a pathophysiological response to injury-induced ionic and neurochemical cascades. This finding has important implications regarding cellular viability, vulnerability to secondary insults, and the functional capability of affected regions. Prior to this study, posttraumatic hyperglycolysis had not been detected in humans. The characteristics and incidence of cerebral hyperglycolysis were determined in 28 severely head injured patients using [18F]fluorodeoxyglucose—positron emission tomography (FDG-PET). The local cerebral metabolic rate of glucose (CMRG) was calculated using a standard compartmental model. In six of the 28 patients, the global cerebral metabolic rate of oxygen (CMRO2) was determined by the simultaneous measurements of arteriovenous differences of oxygen and cerebral blood flow (xenon-133). Hyperglycolysis, defined as an increase in glucose utilization that measures two standard deviations above expected levels, was documented in all six patients in whom both FDG-PET and CMRO2 determinations were made within 8 days of injury. Five additional patients were found to have localized areas of hyperglycolysis adjacent to focal mass lesions. Within the 1st week following the injury, 56% of patients studied had presumptive evidence of hyperglycolysis. The results of this study indicate that the metabolic state of the traumatically injured brain should be defined differentially in terms of glucose and oxygen metabolism. The use of FDG-PET demonstrates that hyperglycolysis occurs both regionally and globally following severe head injury in humans. The results of this clinical study directly complement those previously reported in experimental brain-injury studies, indicating the capability of imaging a fundamental component of cellular pathophysiology characteristic of head injury.

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.

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.

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.

Activation of the anterior cingulate cortex by thalamic stimulation in patients with chronic pain: a positron emission tomography study

2000 ◽  
Vol 92 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Karen D. Davis ◽  
Ethan Taub ◽  
Frank Duffner ◽  
Andres M. Lozano ◽  
Ronald R. Tasker ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Chronic Pain ◽  
Pain Relief ◽  
Anterior Cingulate Cortex ◽  
Analgesic Effect ◽  
Anterior Cingulate ◽  
Emission Tomography ◽  
Content Type ◽  
Positron Emission ◽  
Fine Print

Object. Deep brain stimulation (DBS) of the sensory thalamus has been used to treat chronic, intractable pain. The goal of this study was to investigate the thalamocortical pathways activated during thalamic DBS.Methods. The authors compared positron emission tomography (PET) images obtained before, during, and after DBS in five patients with chronic pain. Two of the five patients reported significant DBS-induced pain relief during PET scanning, and the remaining three patients did not report any analgesic effect of DBS during scanning. The most robust effect associated with DBS was activation of the anterior cingulate cortex (ACC). An anterior ACC activation was sustained throughout the 40 minutes of DBS, whereas a more posteriorly located ACC activation occurred at a delay after onset of DBS, although these activations were not dependent on the degree of pain relief reported during DBS. However, implications specific to the analgesic effect of DBS require further study of a larger, more homogeneous patient population. Additional effects of thalamic DBS were detected in motor-related regions (the globus pallidus, cortical area 4, and the cerebellum) and visual and association cortical areas.Conclusions. The authors demonstrate that the ACC is activated during thalamic DBS in patients with chronic pain.

Measurement of brain tissue oxygenation performed using positron emission tomography scanning to validate a novel monitoring method

2002 ◽  
Vol 96 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Arun K. Gupta ◽  
Peter J. Hutchinson ◽  
Tim Fryer ◽  
Pippa G. Al-Rawi ◽  
Dot A. Parry ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Brain Injury ◽  
Brain Tissue ◽  
Tissue Oxygenation ◽  
Emission Tomography ◽  
Brain Tissue Oxygenation ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scans ◽  
Fine Print

Object. The benefits of measuring cerebral oxygenation in patients with brain injury are well accepted; however, jugular bulb oximetry, which is currently the most popular monitoring technique used has several shortcomings. The goal of this study was to validate the use of a new multiparameter sensor that measures brain tissue oxygenation and metabolism (Neurotrend) by comparing it with positron emission tomography (PET) scanning. Methods. A Neurotrend sensor was inserted into the frontal region of the brain in 19 patients admitted to the neurointensive care unit. After a period of stabilization, the patients were transferred to the PET scanner suite where C15O, 15O2, and H215O PET scans were obtained to facilitate calculation of regional cerebral blood volume, O2 metabolism, blood flow, and O2 extraction fraction (OEF). Patients were given hyperventilation therapy to decrease arterial CO2 by approximately 1 kPa (7.5 mm Hg) and the same sequence of PET scans was repeated. For each scanning sequence, end-capillary O2 tension (PvO2) was calculated from the OEF and compared with the reading of brain tissue O2 pressure (PbO2) provided by the sensor. In three patients the sensor was inserted into areas of contusion and these patients were eliminated from the analysis. In the subset of 16 patients in whom the sensor was placed in healthy brain, no correlation was found between the absolute values of PbO2 and PvO2 (r = 0.2, p = 0.29); however a significant correlation was obtained between the change in PbO2 (ΔPbO2) and the change in PvO2 (ΔPvO2) produced by hyperventilation in a 20-mm region of interest around the sensor (ρ = 0.78, p = 0.0035). Conclusions. The lack of correlation between the absolute values of PbO2 and PvO2 indicates that PbO2 cannot be used as a substitute for PvO2. Nevertheless, the positive correlation between ΔPbO2 and ΔPvO2 when the sensor had been inserted into healthy brain suggests that tissue PO2 monitoring may provide a useful tool to assess the effect of therapeutic interventions in brain injury.

Localization of somatosensory function by using positron emission tomography scanning: a comparison with intraoperative cortical stimulation

1999 ◽  
Vol 90 (3) ◽  
pp. 478-483 ◽  
Author(s):  
Richard G. Bittar ◽  
André Olivier ◽  
Abbas F. Sadikot ◽  
Frederick Andermann ◽  
Roch M. Comeau ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Somatosensory Cortex ◽  
Cortical Stimulation ◽  
Emission Tomography ◽  
Primary Somatosensory Cortex ◽  
Vibrotactile Stimulation ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Fine Print

Object. To investigate the utility of [15O]H2O positron emission tomography (PET) activation studies in the presurgical mapping of primary somatosensory cortex, the authors compared the magnitude and location of activation foci obtained using PET scanning with the results of intraoperative cortical stimulation (ICS).Methods. The authors used PET scanning and vibrotactile stimulation (of the face, hand, or foot) to localize the primary somatosensory cortex before surgical resection of mass lesions or epileptogenic foci affecting the central area in 20 patients. With the aid of image-guided surgical systems, the locations of significant activation foci on PET scanning were compared with those of positive ICS performed at craniotomy after the patient had received a local anesthetic agent. In addition, the relationship between the magnitude and statistical significance of blood flow changes and the presence of positive ICS was examined.In 22 (95.6%) of 23 statistically significant (p < 0.05) PET activation foci, spatially concordant sites on ICS were also observed. Intraoperative cortical stimulation was positive in 40% of the PET activation studies that did not result in statistically significant activation. In the patients showing these results, there was a clearly identifiable t-statistic peak that was spatially concordant with the site of positive ICS in the sensorimotor area. All PET activation foci with a t statistic greater than 4.75 were associated with spatially concordant sites of positive ICS. All PET activation foci with a t statistic less than 3.2 were associated with negative ICS.Conclusions. Positron emission tomography is an accurate method for mapping the primary somatosensory cortex before surgery. The need for ICS, which requires local anesthesia, may be eliminated when PET foci with high (> 4.75) or low (< 3.20) t-statistic peaks are elicited by vibrotactile stimulation.

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