Hemodynamic and metabolic disturbances in patients with intracranial dural arteriovenous fistulas: positron emission tomography evaluation before and after treatment

1997 ◽  
Vol 86 (5) ◽  
pp. 806-811 ◽  
Author(s):  
Toru Iwama ◽  
Nobuo Hashimoto ◽  
Yasushi Takagi ◽  
Michihiro Tanaka ◽  
Satoshi Yamamoto ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Clinical Symptoms ◽  
Venous Drainage ◽  
Cerebral Hemodynamics ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Arteriovenous Fistulas ◽  
Positron Emission ◽  
Dural Arteriovenous Fistulas ◽  
Angiographic Findings

✓ In patients with intracranial dural arteriovenous fistulas (AVFs), clinical symptoms and angiographic findings vary. The relevance of disturbed venous drainage to clinical symptoms and prognosis has been recognized. However, the roles of cerebral hemodynamics and metabolism, which are impaired by shunt flow or disturbed venous drainage, have not been fully evaluated. The authors studied the cerebral hemodynamic and metabolic status in 10 patients with intracranial dural AVFs using positron emission tomography (PET) scanning. Ten patients with dural AVFs underwent a PET study before treatment. The regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rOEF), regional cerebral metabolic rate of oxygen (rCMRO2), and regional cerebral blood volume (rCBV) were measured using the 15O-labeled gas inhalation steady-state method. The PET parameters that were obtained were analyzed and compared with the patients' neurological and angiographic findings. In six of the 10 patients, a PET study was also performed after treatment. Before treatments, all four patients with cerebral symptoms showed a severe reduction in rCBF and a mild elevation in the rOEF. The areas showing reduced rCBF corresponded with areas in which retrograde venous drainage into the cortical veins and delayed parenchymal circulation were seen on angiograms. In another two patients with occlusion of the affected sinus and/or retrograde drainage into the cortical veins, mild abnormalities were demonstrated in rCBF mapping. In the remaining four patients, all PET parameters except rCBV were within normal limits and venous flow was not impaired on the angiograms. In four patients who underwent surgical excision or transvenous embolization of the affected sinus, the cerebral hemodynamics and metabolism were improved, as were the clinical symptoms. In two patients who underwent transarterial embolization of the feeding vessels only or craniotomy, no hemodynamic improvement was achieved. Our results indicate that hemodynamic insufficiency detected by the PET study corresponded well with cerebral symptoms and angiographic findings of retrograde venous drainage into the cortical veins and delayed parenchymal circulation, but not with sinus occlusion or arterial blood supply. Eradication or prevention of retrograde venous drainage from the affected sinus into the cortical veins should be a treatment goal in patients with dural AVFs.

Cerebral circulation and oxygen metabolism in childhood moyamoya disease: a perioperative positron emission tomography study

1994 ◽  
Vol 81 (6) ◽  
pp. 843-850 ◽  
Author(s):  
Kiyonobu Ikezaki ◽  
Toshio Matsushima ◽  
Yasuo Kuwabara ◽  
Satoshi O. Suzuki ◽  
Tomojiro Nomura ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Moyamoya Disease ◽  
Cerebral Circulation ◽  
Bypass Surgery ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Positron Emission ◽  
Angiographic Findings ◽  
Fine Print

✓ Thirteen children with moyamoya disease who had no apparent cerebral infarction or hemorrhage were examined pre- and postoperatively by means of positron emission tomography (PET) to investigate the underlying cerebral circulation and metabolism and the effect of bypass surgery. The preoperative regional cerebral blood flow (rCBF) and mean transit time were significantly decreased and increased, respectively, in the cerebral cortex of these patients compared to control values. The regional cerebral blood volume (rCBV) and the regional oxygen extraction fraction (rOEF) had significantly increased to compensate for the reduced rCBF and perfusion pressure and also to maintain the regional cerebral metabolic rate of oxygen (rCMRO2). In the basal ganglia, rCBV elevation was more prominent than that in the cerebral cortex, although changes in rCBF, rOEF, and rCMRO2 were relatively minor. Postoperative improvements were observed predominantly near the cortex where bypass surgery had been performed and in the basal ganglia. Direct and combined indirect bypass procedures improved cerebral circulation more effectively than single indirect bypass surgery. Although the angiographic findings were not always compatible with the clinical results, the postoperative improvements on PET scans correlated with the disappearance of transient ischemic attacks. In addition to the clinical courses and angiographic findings, PET analysis was indispensable in evaluating the cerebral circulation and metabolism in childhood moyamoya disease.

Comparison of positron emission tomography study results of cerebral hemodynamics in patients with bleeding- and ischemic-type moyamoya disease

1998 ◽  
Vol 5 (5) ◽  
pp. E5 ◽  
Author(s):  
Toru Iwama ◽  
Yoshinori Akiyama ◽  
Masafumi Morimoto ◽  
Akio Kojima ◽  
Kohei Hayashida
Keyword(s):  
Positron Emission Tomography ◽  
Moyamoya Disease ◽  
Cerebral Hemodynamics ◽  
Adult Patients ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Regional Cerebral Blood ◽  
Positron Emission ◽  
Regional Cerebral Blood Volume ◽  
Study Results

The purpose of this study was to elucidate the difference in cerebral hemodynamics and metabolic status between patients with bleeding- and ischemic-type moyamoya disease. Regional cerebral blood flow (rCBF), regional cerebral metabolic rate of oxygen (rCMRO2), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) in the cortex of the middle cerebral artery (MCA) territories and rCBV in the striatum were measured using positron emission tomography (PET) in 17 patients with moyamoya disease. Patients were divided into three subgroups according to type of disease manifestation and age: adult bleeding type (five cases), adult ischemic type (10 cases), and childhood ischemic type (two cases). When compared with adult controls, statistically significant reductions in rCBF and rCMRO2, elevation in rOEF in the MCA territories, and elevation of rCBV in the striatum were observed in PET studies for all three subgroups. Between the adult bleeding type and ischemic type, rCBF, rCMRO2, and rOEF in the MCA territories were not different, but rCBV in the striatum was higher in patients with ischemic-type moyamoya disease than in those with the bleeding type. In adult patients with bleeding and ischemic types, rOEF and rCBV in the MCA territories and rCBV in the striatum were significantly lower than in patients with childhood ischemic-type moyamoya disease. In adult patients with bleeding-type moyamoya disease, cerebral hemodynamics were impaired and similar to those in adult ischemic type.

scholarly journals A Simplified in vivo Autoradiographic Strategy for the Determination of Regional Cerebral Blood Flow by Positron Emission Tomography: Theoretical Considerations and Validation Studies in the Rat

1982 ◽  
Vol 2 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Myron D. Ginsberg ◽  
Alan H. Lockwood ◽  
Raul Busto ◽  
Ronald D. Finn ◽  
Cathy M. Butler ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Animal Studies ◽  
Blood Flow Rate ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Positron Emission

A simplified mathematical model is described for the measurement of regional cerebral blood flow by positron emission tomography in man, based on a modification of the autoradiographic strategy originally developed for experimental animal studies. A modified ramp intravenous infusion of radiolabeled tracer is used; this results in a monotonically increasing curvilinear arterial activity curve that may be accurately described by a polynomial of low degree (= z). Integrated cranial activity C̄ B is measured in regions of interest during the latter portion of the tracer infusion period (times T1 to T2). It is shown that [Formula: see text] where each of the terms A x is a readily evaluated function of the blood flow rate constant k, the brain:blood partition coefficient for the tracer, the cranial activity integration limits T1 and T2, the coefficients of the polynomial describing the arterial curve, and an iteration factor n that is chosen to yield the desired degree of precision. This relationship permits generation of a table of C̄ B vs. k, thus facilitating on-line computer solution for blood flow. This in vivo autoradiographic paradigm was validated in a series of rats by comparing it to the classical autoradiographic strategy developed by Kety and associates. Excellent agreement was demonstrated between blood flow values obtained by the two methods: CBF in vivo = CBFclassical X 0.99 − 0.02 (units in ml g−1 min−1; correlation coefficient r = 0.966).

Destination of Mental Disorders Through Biochemical and Neuropathological Analysis?

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
P. Falkai
Keyword(s):  
Positron Emission Tomography ◽  
Mental Disorders ◽  
Psychiatric Disorders ◽  
Clinical Symptoms ◽  
Emission Tomography ◽  
Imaging Findings ◽  
Severe Mental Disorders ◽  
Positron Emission ◽  
Dopamine Hypothesis

In the first half of the last century researchers believed that severe mental disorders like schizophrenia have a neuropathological basis. Up to now it has been difficult to prove any consistent core finding for this disorder. Reason for this might be that it is a network disorder and therefore regional specific findings will unlikely be found. Parallel to that describing the dopamine hypothesis of schizophrenia and the catechol amine deficit hypothesis of depression were very helpful for understanding the mechanisms of antipsychotics and antidepressants working in these disorders. Especially the introduction of the positron emission tomography has helped to link symptoms with the transmitter systems. However, none of these findings are specific for schizophrenia or depression. During the talk it will be discussed when the combination of core clinical symptoms, imaging findings and genetic variables are helpful for a future classification of psychiatric disorders.

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