scholarly journals Letter by Powers Regarding Article, “Failure of Cerebral Hemodynamic Selection in General or of Specific Positron Emission Tomography Methodology? Carotid Occlusion Surgery Study (COSS)”

Stroke ◽  
2012 ◽  
Vol 43 (4) ◽  
Author(s):  
William J. Powers
Keyword(s):  
Positron Emission Tomography ◽  
Carotid Occlusion ◽  
Emission Tomography ◽  
Cerebral Hemodynamic ◽  
Positron Emission

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.

Positron Emission Tomography of Cocaine Binding Sites on the Dopamine Transporter

1994 ◽  
Author(s):  
Bertha K. Madras ◽  
◽  
David R. Elmaleh ◽  
Peter C. Meltzer ◽  
Anna Y. Liung ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Dopamine Transporter ◽  
Binding Sites ◽  
Emission Tomography ◽  
Positron Emission
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