Noninvasive Xenon-133 Measurements of Cerebral Blood Flow Using Stationary Detectors Compared with Dynamic Emission Tomography

Schroeder, Torben V.; Vorstrup, Sissel; Lassen, Niels A.; Engell, H. C.

doi:10.1038/jcbfm.1986.130

Cited by 8 publications

(6 citation statements)

References 27 publications

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“…On the contrary, in many instances a "steal" phenomenon may actually decrease rCBF in these regions. 8 In our studies, acetazolamide produced rCBF increases approximately three times those reported in patients. However, these rCBF increases were not sufficient to produce any systemic effect, and all the cardiovascular variables monitored remained stable.…”

Section: Figure 2 Scatterplot Of Relation Between [""Tcjethyl Cysteisupporting

confidence: 61%

Regional cerebral blood flow and distribution of [99mTc]ethyl cysteinate dimer in nonhuman primates.

Orlandi

Crane

Platts

et al. 1990

Stroke

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Increases in regional cerebral blood flow have been described in a variety of cerebral pathologic states, including stroke and seizure disorders. The usefulness of technetium-99m-labeled cysteinate dimer as a marker in the measurement of regional cerebral blood flow was tested in five cynomolgus monkeys. To expand the range of blood flow to beyond the normal limits, 40 mg/kg i.v. of the carbonic anhydrase inhibitor acetazolamide was administered. Regional cerebral blood flow in all five monkeys was measured using radiolabeled microspheres (before and after acetazolamide) and the marker (after acetazolamide) in 60-70 samples from 12 brain regions. Acetazolamide significantly increased the mean±SEM regional cerebral blood flow measured using microspheres from 0.56±0.21 to 1.71 ±0.9 ml/min/g (p<0.01 for each region). A significant positive correlation was found between regional cerebral blood flow values calculated using microspheres and the marker after normalizing the values to those in the cerebellum (r=0.773, /?< 0.0001). The mean±SEM regional cerebral blood flow determined using the marker in a single monkey (1.21 ±0.04 ml/min/g) did not differ significantly from that determined in the same monkey using microspheres (1.13±0.04 ml/min/g). These data support the potential use of this new brain perfusion imaging agent to assess regional cerebral blood flow over a clinically relevant range of blood flows. It is widely acknowledged that in several pathologic states, such as focal ictal seizures, brain tumors, and stroke during the subacute phase, locally increased metabolic demands increase rCBF to beyond the range observed under normal conditions. 45 Similar increases in rCBF are also pharmacologically induced clinically with agents such as the carbonic anhydrase inhibitor acetazolamide. These pharmacologic stress tests have been extensively used to evaluate cerebral vascular reserve in stroke patients. Received December 11, 1989; accepted March 21, 1990. cate perfusion alterations for which surgical interventions may be appropriate. A linear relation between rCBF and [ 99m Tc]ECD retention over a clinically relevant range of blood flows is needed before we can employ this new radiopharmaceutical agent in high-flow pathologic states and stress studies. We studied the relation between rCBF as measured with radiolabeled microspheres and ["""TcJECD retention during acetazolamide-induced hyperemia in nonhuman primates to evaluate the cerebral distribution of ["TcJECD at blood flow levels beyond the normal range. Materials and MethodsFive adult, male cynomolgus monkeys weighing 3.6-10.3 kg were food-deprived for approximately 20 hours, and water was removed on the morning of the study. The monkeys were anesthetized with 10 mg/kg i.m. ketamine hydrochloride and 1 mg/kg i.m. acepromazine maleate. Anesthesia was then maintained with a constant infusion of 1.5 mg/ml i.v. thiamylal sodium (Parke-Davis, Morris Plains, N.J.) delivered through a 22-gauge catheter inserted into a saphenous vein at a rate averaging <0.5 ml/mi...

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Section: Figure 2 Scatterplot Of Relation Between [""Tcjethyl Cysteisupporting

confidence: 61%

Regional cerebral blood flow and distribution of [99mTc]ethyl cysteinate dimer in nonhuman primates.

Orlandi

Crane

Platts

et al. 1990

Stroke

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“…The rCBF measurements were made with external counting and not tomographically, thus part of the rCBF increase in the contralateral nor mal ICA territory may be detected on the side of the occlusion. These considerations must balance the good correlation between CBF measurements using stationary detectors and those performed with dynamic emission tomography, which was disclosed in a previous paper [39]. In our opinion, therefore, a tomographic rCBV study is the best way for disclosing an HR impairment.…”

Section: Discussionmentioning

confidence: 83%

“…Normally CO: inhalation induces a significant bilateral symmetrical flow increase. CO: inha lation is relatively difficult to perform and may be un pleasant for the patient, therefore the use of intravenous acetazolamide as a vasodilating agent was proposed [38][39][40][41][42] , With this method, it was again shown that some patients with ICA occlusions or severe stenoses had no flow increase on the diseased side after acetazolamide [42,43] . It was also found that there was a close correlation between lack of vasodilatation and a low perioperative stump pressure and that in such cases surgery repair restored a normal or almost normal hemodynamic re sponse.…”

Section: Discussionmentioning

confidence: 99%

Impaired Cerebral Hemodynamics in Internal Carotid Occlusion

Derlon¹,

Bouvard²,

Viader³

et al. 1992

Cerebrovasc Dis

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We performed a hemodynamic assessment involving the measurement of regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) with single-photon-emitting isotopes in 75 patients with unilateral or bilateral carotid occlusions. rCBF was measured by following the clearance of inhaled ¹³³Xe and rCBV by single-photon emission tomographic recording of the distribution of ^99mTc-labeled autologous erythrocytes. Four patterns were observed, one of which appears to represent a state of hemodynamic compromise associated with an impaired hemodynamic reserve (HR) manifesting as compensatory vasodilation and impaired autoregulation to changes in PACO2. Impaired hemodynamics were noted in 27% of patients and in 35% of the 51 patients that would have been ''eligible'' for randomization in the extracranial-intracranial (ECIC) bypass study of Barnett et al. [Surg Neurol 1986;26:222–226]. Thirty-three patients thus ''eligible'' had normal HR and only 1 suffered a delayed stroke ipsilateral to an occluded artery in 21 months of follow-up. Eighteen ''eligible'' patients with impaired HR were also followed during a mean of 21 months. Fourteen of the patients with impaired HR underwent ECIC bypass and suffered a high (18%) perioperative morbidity and mortality; 4 were not operated upon, and 2 of these developed hemiplegia due to infarction ipsilateral to the ICA occlusion. We conclude that relatively few patients considered suitable for ECIC bypass on clinical and radiological grounds have an impaired HR which might justify revascularization. The clinical benefit of revascularization in those selected because of impaired hemodynamics remains to be demonstrated. In this context it appears from our small series that there is a high risk for surgery as well as spontaneous stroke in this population.

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“…Three-dimensional measurement by '33Xe single photon emission computed tomography (Xe SPECT) was developed for clinical use around 1980 (10,14), and clinical application of the Xe CT was also started around that time (2,4,12). Two-dimensional quantitative measurement of rCBF using radioactive tracer, xenon-133 ( 133Xe), has been the standard method sine the 1960s.…”

mentioning

confidence: 99%

“…Two-dimensional quantitative measurement of rCBF using radioactive tracer, xenon-133 ( 133Xe), has been the standard method sine the 1960s. Three-dimensional measurement by '33Xe single photon emission computed tomography (Xe SPECT) was developed for clinical use around 1980 (10,14), and clinical application of the Xe CT was also started around that time (2,4,12). However, comparative study between the Xe CT and the Xe SPECT has been few.…”

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confidence: 99%

Comparative study of regional cerebral blood flow values measured by Xe CT and Xe SPECT

Matsuda

Lee

Kuribayashi

et al. 1996

Acta Neurologica Scandinavica

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Comparative study of regional cerebral blood flow values measured by Xe CT and Xe SPECT. Acta Neurol Scand 1996: Suppl. 166: 13-16The regional cerebral blood flow (rBCF) values measured by stable xenonenhanced computed tomography (Xe XT) and by radioactive xenon-1 33 single photon emission computed tomography (Xe SPECT) were compared in 16 patients with cerebral infarct. On the non-lesion side Xe SPECT recorded 10.7% higher rCBF values than Xe CT in the anterior cerebral artery territory, while Xe CT recorded 9.6% higher values than Xe SPECT in the middle cerebral artery territory. These differences were not statistically significant. Although the rCBF values were almost the same, no correlation was found between the two methods in the posterior cerebral artery territory and the basal ganglia. Only hemispheric CBF on the non-lesion side showed the same value and a good correlation between the Xe CT and the Xe SPECT. There was a good correlation in the hemispheric CBF values on the lesion side, too. The difference of rCBF between the non-lesion side and the lesion side was expressed smaller in the Xe SPECT than in the Xe CT. This is in agreement with the previous reports that Xe SPECT overestimates the flow in the low flow areas. The higher rCBF values in the anterior cerebral artery territory measured by the Xe SPECT was ascribed to the artifact from the radioactivities in the inhalation mask and the air passages as reported previously. In conclusion, there is no good correlation between the rCBF values measured by the Xe CT and by the Xe SPECT. Only hemispheric CBF shows a good correlation between the two methods.Stable xenon-enhanced computed tomography (Xe CT) is a method of quantitative measurement of regional cerebral blood flow (rCBF), and it is now used as one of the routine examinations in neurological and neurosurgical patients. Two-dimensional quantitative measurement of rCBF using radioactive tracer, xenon-133 ( 133Xe), has been the standard method sine the 1960s. Three-dimensional measurement by '33Xe single photon emission computed tomography (Xe SPECT) was developed for clinical use around 1980 (10, 14), and clinical application of the Xe CT was also started around that time (2, 4, 12). However, comparative study between the Xe CT and the Xe SPECT has been few. We compared the rCBF values measured by the Xe CT and those measured by the Xe

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Noninvasive Xenon-133 Measurements of Cerebral Blood Flow Using Stationary Detectors Compared with Dynamic Emission Tomography

Cited by 8 publications

References 27 publications

Regional cerebral blood flow and distribution of [99mTc]ethyl cysteinate dimer in nonhuman primates.

Regional cerebral blood flow and distribution of [99mTc]ethyl cysteinate dimer in nonhuman primates.

Impaired Cerebral Hemodynamics in Internal Carotid Occlusion

Comparative study of regional cerebral blood flow values measured by Xe CT and Xe SPECT

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