Development of a GSO detector assembly for a continuous blood sampling system

Kudomi, Nobuyuki; Choi, Eunjoo; Yamamoto, Seiichi; Watabe, Hiroshi; Kim, Kyeong Min; Shidahara, Miho; Ogawa, Mikako; Teramoto, Noboru; Sakamoto, E.; Iida, Hidehiro

doi:10.1109/tns.2002.807869

Cited by 51 publications

(29 citation statements)

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“…The inhalation period was 1 min for each gas. Arterial blood was continuously withdrawn during this dynamic scan, and the radioactivity concentration of the blood in the catheter tube was monitored using a scintillator block detector system (BeCON; Molecular Imaging Lab Inc., Suita City, Japan) [11]. Arterial blood samples were also taken before and after the dynamic scan, and arterial oxygen content (PO 2 ) and arterial PCO 2 were measured.…”

Section: Methodsmentioning

confidence: 99%

The Leptomeningeal Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Positron Emission Tomography Study

Kaku¹,

Iihara²,

Nakajima³

et al. 2013

Cerebrovasc Dis

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Background: The ivy sign is sometimes seen on fluid-attenuated inversion recovery (FLAIR) images in moyamoya disease (MMD). In recent studies using single-photon emission computed tomography, ivy sign proliferation correlated with decreases in cerebrovascular reserve. However, a decreased vascular reserve is not concrete. The purpose of this study was to evaluate the correlation between ivy sign proliferation and the findings of ¹⁵O gas positron emission tomography (PET). Methods: In 19 MMD patients (12 women, age 31-69 years) with ischemic symptoms, FLAIR magnetic resonance imaging and ¹⁵O gas PET were performed. We classified the middle cerebral artery (MCA) territory into 2 regions in each hemisphere, and the degree of the ivy sign (ivy sign score) in each region was classified into 3 grades (0-2), where grade 0 indicated an absence of the ivy sign, grade 1 indicated that the ivy sign was seen on less than half of the cortical surface in each region, and grade 2 indicated that the ivy sign was seen on more than half of the cortical surface. We examined the relationship among the ivy sign score, the severity of ischemic symptoms and PET parameters in 76 MCA regions of 19 patients. Results: Ivy sign scores of the regions were 0 (n = 19), 1 (n = 40), and 2 (n = 17). Total ivy sign score of a hemisphere increased as clinical symptoms became more severe. Cerebral blood flow (CBF) values were lower, cerebral blood volume (CBV) values were higher, and CBF/CBV values were lower than those of controls as symptoms became severe (p < 0.05). CBF and CBF/CBV values decreased and CBV values increased as the ivy sign score increased, and were significantly higher and lower, respectively, than control values (p < 0.05). No significant differences in cerebral metabolic rate of oxygen and oxygen extraction fraction were found between the 3 ivy sign scores. A positive correlation was found between ivy sign score and increases in CBV (p < 0.01), and a more obvious negative correlation was found between ivy sign score and decreases in CBF/CBV (p < 0.001). Conclusions: We evaluated the correlation between ivy sign proliferation and the findings of ¹⁵O gas PET. We suggested that ivy sign proliferation was associated with both dilated pial vasculature and the slow flow of developed leptomeningeal collaterals in patients with MMD.

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Section: Methodsmentioning

confidence: 99%

The Leptomeningeal Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Positron Emission Tomography Study

Kaku¹,

Iihara²,

Nakajima³

et al. 2013

Cerebrovasc Dis

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“…Some groups have successfully implemented micro-blood sampling techniques to reduce the impact of these problems [2,3]. Blood counter systems have also been described for both humans and animals [4-8] which allow continuous counting in a flowing catheter to achieve high time resolution. Beta microprobe systems have also been used to continuously measure IF without the need for blood sampling, in humans, primates, and rodents [9-13].…”

Section: Introductionmentioning

confidence: 99%

Use of a beta microprobe system to measure arterial input function in PET via an arteriovenous shunt in rats

et al. 2011

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BackgroundKinetic modeling of physiological function using imaging techniques requires the accurate measurement of the time-activity curve of the tracer in plasma, known as the arterial input function (IF). The measurement of IF can be achieved through manual blood sampling, the use of small counting systems such as beta microprobes, or by derivation from PET images. Previous studies using beta microprobe systems to continuously measure IF have suffered from high background counts.MethodsIn the present study, a light-insensitive beta microprobe with a temporal resolution of up to 1 s was used in combination with a pump-driven femoral arteriovenous shunt to measure IF in rats. The shunt apparatus was designed such that the placement of the beta microprobe was highly reproducible. The probe-derived IF was compared to that obtained from manual sampling at 5-s intervals and IF derived from a left ventricle VOI in a dynamic PET image of the heart.ResultsProbe-derived IFs were very well matched to that obtained by "gold standard" manual blood sampling, but with an increased temporal resolution of up to 1 s. The area under the curve (AUC) ratio between probe- and manually derived IFs was 1.07 ± 0.05 with a coefficient of variation of 0.04. However, image-derived IFs were significantly underestimated compared to the manually sampled IFs, with an AUC ratio of 0.76 ± 0.24 with a coefficient of variation of 0.32.ConclusionsIF derived from the beta microprobe accurately represented the IF as measured by blood sampling, was reproducible, and was more accurate than an image-derived technique. The use of the shunt removed problems of tissue-background activity, and the use of a light-tight probe with minimal gamma sensitivity refined the system. The probe/shunt apparatus can be used in both microprobe and PET studies.

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“…Venous blood collected from each monkey was infused into the system and was circulated by a peristaltic pump at a flow rate of 100 mL/minute, with the introduction of 15 O 2 and/or C 15 O gases at ∼7,000 MBq/minute/500 mL into the artificial lung for 5 to 15 minutes, producing the 15 O 2 –Hb and C 15 O–Hb samples of ∼60 MBq/mL. A coincidence detector block containing a pair of GSO scintillator 13 was implemented to monitor the radioactivity in the circulating blood. The 15 O 2 –Hb and C 15 O–Hb samples were adjusted to contain radioactivity of ∼17 MBq in 0.4 mL at the time of injection into the ICA.…”

Section: Methodsmentioning

confidence: 99%

Adequacy of a Compartment Model for CMRO₂ Quantitation Using ¹⁵O-Labeled Oxygen and PET: A Clearance Measurement of ¹⁵O-Radioactivity Following Intracarotid Bolus Injection of ¹⁵O-Labeled Oxyhemoglobin on Macaca Fascicularis

Iida

Iguchi

Teramoto

et al. 2014

J Cereb Blood Flow Metab

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We aimed at evaluating the adequacy of the commonly employed compartmental model for quantitation of cerebral metabolic rate of oxygen (CMRO2) using 15O-labeled oxygen (15O2) and positron emission tomography (PET). Sequential PET imaging was carried out on monkeys following slow bolus injection of blood samples containing 15O2–oxyhemoglobin (15O2–Hb), 15O-labeled water (H215O), and C15O-labeled hemoglobin (C15O–Hb) into the internal carotid artery (ICA). Clearance slopes were assessed in the middle cerebral artery territory of the injected hemisphere. The time–activity curves were bi-exponential for both 15O2–Hb and H215O. Single exponential fitting to the early (5 to 40 seconds) and late (80 to 240 seconds) periods after the peak was performed and the 15O2–Hb and H215O results were compared. It was found that a significant difference between the clearance rates of the 15O2–Hb and H215O injections is unlikely, which supports the mathematical model that is widely used to describe the kinetics of 15O2–Hb and H215O in cerebral tissues and is the basis of recent approaches to simultaneously assess CMRO2 and cerebral blood flow in a single PET session. However, it should be noted that more data are necessary to unequivocally confirm the result.

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Development of a GSO detector assembly for a continuous blood sampling system

Cited by 51 publications

References 4 publications

The Leptomeningeal Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Positron Emission Tomography Study

The Leptomeningeal Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Positron Emission Tomography Study

Use of a beta microprobe system to measure arterial input function in PET via an arteriovenous shunt in rats

Adequacy of a Compartment Model for CMRO₂ Quantitation Using ¹⁵O-Labeled Oxygen and PET: A Clearance Measurement of ¹⁵O-Radioactivity Following Intracarotid Bolus Injection of ¹⁵O-Labeled Oxyhemoglobin on Macaca Fascicularis

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Development of a GSO detector assembly for a continuous blood sampling system

Cited by 51 publications

References 4 publications

The Leptomeningeal Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Positron Emission Tomography Study

The Leptomeningeal Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Positron Emission Tomography Study

Use of a beta microprobe system to measure arterial input function in PET via an arteriovenous shunt in rats

Adequacy of a Compartment Model for CMRO2 Quantitation Using 15O-Labeled Oxygen and PET: A Clearance Measurement of 15O-Radioactivity Following Intracarotid Bolus Injection of 15O-Labeled Oxyhemoglobin on Macaca Fascicularis

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Adequacy of a Compartment Model for CMRO₂ Quantitation Using ¹⁵O-Labeled Oxygen and PET: A Clearance Measurement of ¹⁵O-Radioactivity Following Intracarotid Bolus Injection of ¹⁵O-Labeled Oxyhemoglobin on Macaca Fascicularis