scholarly journals Error Analysis of a Quantitative Cerebral Blood Flow Measurement Using H215O Autoradiography and Positron Emission Tomography, with Respect to the Dispersion of the Input Function

1986 ◽  
Vol 6 (5) ◽  
pp. 536-545 ◽  
Author(s):  
Hidehiro Iida ◽  
Iwao Kanno ◽  
Shuichi Miura ◽  
Matsutaro Murakami ◽  
Kazuhiro Takahashi ◽  
...  
Keyword(s):  
Steady State ◽  
Time Constant ◽  
Input Function ◽  
Inverse Laplace Transform ◽  
Dispersion Function ◽  
Sampling System ◽  
Continuous Sampling ◽  
Steady State Method ◽  
Positron Emission ◽  
Analytical Correction

The effect of the inaccuracy of the input function on CBF measured by the H152O autoradiographic method was investigated. In H152O autoradiography the measured input function usually includes a larger dispersion than the true input function, as well as the absolute time axis having been already lost. The time constant of the external dispersion that occurred in our continuous sampling system was evaluated as 10–12 s when the dispersion function was approximated by a monoexponential function. The internal dispersion occurring in arterial lines in a human body was evaluated as 4–6 s. Such dispersion, indispensable in a patient study, was found to produce large errors in calculating CBF, e.g., 5(10) s of the dispersion caused + 15(33) and + 10(20)% systematic overestimations for the 40- and 60-s accumulation time, respectively. An analytical correction employing an inverse Laplace transform was applied to clinical CBF studies, and the results were compared with those from the C15O2 steady-state inhalation method. Correction by 10 s in time constant, corresponding to the external dispersion, reduced the overestimation significantly from 70–100% to ∼20%. Further correction by 5 s, corresponding to the internal dispersion, resulted in a negligible difference (less than a few percent) from the steady-state method.

scholarly journals Development of an H215O Steady-State Method Combining a Bolus and Slow Increasing Injection with a Multiprogramming Syringe Pump

2010 ◽  
Vol 31 (2) ◽  
pp. 527-534 ◽  
Author(s):  
Masato Kobayashi ◽  
Yasushi Kiyono ◽  
Rikiya Maruyama ◽  
Tetsuya Mori ◽  
Keiichi Kawai ◽  
...  
Keyword(s):  
Steady State ◽  
Animal Studies ◽  
Quantitative Measurement ◽  
Small Animal ◽  
Syringe Pump ◽  
Arterial Blood ◽  
Steady State Method ◽  
Positron Emission ◽  
State Method ◽  
Pet Scans

An 15O-labeled water (H215O) steady-state method for quantitative measurement of cerebral blood flow ( CBF), which is less stressful to small animals with a few point blood sampling, was developed. After a simulation using a dose meter to achieve stable H215O radioactivity in the blood with a multiprogramming syringe pump programmed for slowly increasing injection volume, 10 rats were studied with the injection method. Arterial blood was sampled every minute during 6-minute positron emission tomography (PET) scans. After the PET scan, N-isopropyl- p-[125I]-iodoamphetamine (125I-IMP) was injected into the same rat to measure CBF using the autoradiography method based on a microsphere model. Regions of interest were placed on the whole brain in H215O-PET and 125I-IMP-autoradiography images, and CBF values calculated from both methods were compared. Radioactivity in the dose meter achieved equilibrium ~1 minute after starting the H215O injection. In rat studies, radioactivity in the blood and brain rapidly achieved equilibrium at 2 minutes after administration. The correlation of CBF values of H215O PET (49.2 ± 5.4 mL per 100 g per minute) and those of 125I-IMP autoradiography (49.1 ± 5.2 mL per 100 g per minute) was excellent ( y = 1.01 x −0.37, r2 = 0.97). The H215O steady-state method with a continuously increasing injection is useful for CBF measurement in small animal studies, especially when multiple scans are required in the same animal.

scholarly journals Linearization Correction of 99mTc-Labeled Hexamethyl-Propylene Amine Oxime (HM-PAO) Image in Terms of Regional CBF Distribution: Comparison to C15O2 Inhalation Steady-State Method Measured by Positron Emission Tomography

1988 ◽  
Vol 8 (1_suppl) ◽  
pp. S52-S60 ◽  
Author(s):  
Atsushi Inugami ◽  
Iwao Kanno ◽  
Kazuo Uemura ◽  
Fumio Shishido ◽  
Matsutaro Murakami ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Steady State ◽  
Emission Tomography ◽  
Emission Computed Tomography ◽  
Whole Brain ◽  
Steady State Method ◽  
Positron Emission ◽  
State Method

The radioisotope distribution following intravenous injection of 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) in the brain was measured by single photon emission computed tomography (SPECT) and corrected for the nonlinearity caused by differences in net extraction. The “linearization” correction was based on a three compartment model, and it required a region of reference to normalize the SPECT image in terms of regional cerebral blood flow distribution. Two different regions of reference, the cerebellum and the whole brain, were tested. The uncorrected and corrected HM-PAO images were compared with cerebral blood flow (CBF) image measured by the C15O2 inhalation steady state method and positron emission tomography (PET). The relationship between uncorrected HM-PAO and PET–CBF showed a correlation coefficient of 0.85 but tended to saturate at high CBF values, whereas it was improved to 0.93 after the “linearization” correction. The whole-brain normalization worked just as well as normalization using the cerebellum. This study constitutes a validation of the “linearization” correction and it suggests that after linearization the HM-PAO image may be scaled to absolute CBF by employing a global hemispheric CBF value as measured by the nontomographic 133Xe clearance method.

scholarly journals Quantitative Comparison of the Bolus and Steady-State Methods for Measurement of Cerebral Perfusion and Oxygen Metabolism: Positron Emission Tomography Study Using 15O-Gas and Water

2001 ◽  
Vol 21 (7) ◽  
pp. 793-803 ◽  
Author(s):  
Hidehiko Okazawa ◽  
Hiroshi Yamauchi ◽  
Kanji Sugimoto ◽  
Masaaki Takahashi ◽  
Hiroshi Toyoda ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Steady State ◽  
Blood Volume ◽  
Cerebral Perfusion ◽  
Oxygen Metabolism ◽  
Emission Tomography ◽  
Parametric Images ◽  
Steady State Method ◽  
Positron Emission ◽  
State Method

To evaluate a new simplified bolus method for measurement of cerebral perfusion and metabolism, the parametric images with that method were compared with those obtained from the conventional steady-state method with 15O-gas. The new method also provided images of arterial blood volume (V0), which is a different parameter from cerebral blood volume (CBV) obtained using a C15O technique. Seven healthy volunteers and 10 patients with occlusive cerebrovascular diseases underwent positron emission tomography (PET) scans with both methods. Three-weighted integration was applied to calculate regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of oxygen (rCMRO2) in the bolus method. Global and regional CBF and CMRO2 in volunteers were compared between the two methods and used as control data. Regional values in patients also were evaluated to observe differences between the bilateral hemispheres. Both rCBF and rCMRO2 were linearly well correlated between the two methods, although global difference in CMRO2 was significant. The difference in each parametric image except for V0 was significant between the bilateral hemispheres in patients. The bolus method can simplify oxygen metabolism studies and yield parametric images comparable with those with the steady-state method, and can allow for evaluation of V0 simultaneously. Increase in CBV without a change in V0 suggested the increase might mainly be caused by venous dilatation in the ischemic regions.

scholarly journals Cerebral Oxygen Metabolism of Rats using Injectable 15O-Oxygen with a Steady-State Method

2011 ◽  
Vol 32 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Masato Kobayashi ◽  
Tetsuya Mori ◽  
Yasushi Kiyono ◽  
Vijay Narayan Tiwari ◽  
Rikiya Maruyama ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Steady State ◽  
Emission Tomography ◽  
Tracer Injection ◽  
Simple Method ◽  
Whole Brain ◽  
Steady State Method ◽  
Positron Emission ◽  
State Method ◽  
Cerebral Arterial Occlusion

To develop a less-stressful and simple method for measurement of the cerebral metabolic rate of oxygen ( CMRO2) in small animals, the steady-state method was applied to injectable 15O2-PET (15O2-positron emission tomography) using hemoglobin-containing vesicles (15O2-HbV). Ten normal rats and 10 with middle cerebral arterial occlusion (MCAO) were studied using a small animal PET scanner. A series of 15O-PET scans with C15O-labeled HbV, H215O, and 15O2-HbV were performed with 10 to 15 minutes intervals to measure cerebral blood volume (CBV), cerebral blood flow (CBF), and CMRO2. Positron emission tomography scans were started with a tracer injection using a multiprogramming syringe pump, which provides a slowly increasing injection volume to achieve steady-state radioactivity for H215O and 15O2-HbV scans. The radioactivity concentration of 15O rapidly achieved equilibrium in the blood and whole brain at about 2 minutes after H215O and 15O2-HbV administration, which was stable during the scans. The whole brain mean values of CBF, CBV, and CMRO2 were 54.3 ± 2.0 mL per 100 g per minute, 4.9 ± 0.4 mL/100 g, and 2.8 ±0.2 μmoL per g per minute (6.2 ± 0.4 mL per 100 g per minute) in the normal rats, respectively. In the MCAO model rats, all hemodynamic parameters of the infarction area on the occlusion side significantly decreased. The steady-state method with 15O-labeled HbV is simple and useful to analyze hemodynamic changes in studies with model animals.

scholarly journals Measurement of Cerebral Blood Flow Using Bolus Inhalation of C15O2 and Positron Emission Tomography: Description of the Method and its Comparison with the C15O2 Continuous Inhalation Method

1984 ◽  
Vol 4 (2) ◽  
pp. 224-234 ◽  
Author(s):  
Iwao Kanno ◽  
Adriaan A. Lammertsma ◽  
Jon D. Heather ◽  
Jeremy M. Gibbs ◽  
Christopher G. Rhodes ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Steady State ◽  
Emission Tomography ◽  
Single Breath ◽  
Steady State Method ◽  
Positron Emission ◽  
State Technique ◽  
The Difference

This article describes a rapid method for the regional measurement of cerebral blood flow using a single breath of C15O2 and positron emission tomography. The technique is based on the bolus distribution principle and utilises a reference table for the calculation of flow. Seven subjects were studied using both this method and the C15O2 continuous inhalation steady-state technique. The single-breath method gave flow values 20% higher than those obtained using the steady-state method. A simulation study was performed in an attempt to define the reasons for the difference between the two techniques. Estimations were made of identified sources of error in the measurement of regional cerebral blood flow using the single-breath technique and compared with results from a similar study previously described for the steady-state technique. However, further comparative studies will be necessary to satisfactorily explain the difference between both techniques.

Steady State Measurement of Oxygenation Capacity

1985 ◽  
Vol 17 (2-3) ◽  
pp. 303-311
Author(s):  
Kees de Korte ◽  
Peter Smits
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Plug Flow ◽  
Usual Method ◽  
Steady State Method ◽  
State Measurement ◽  
Flow Systems ◽  
Air System ◽  
State Method ◽  
Steady State Measurement

The usual method for OC measurement is the non-steady state method (reaeration) in tapwater or, sometimes, in activated sludge. Both methods are more or less difficult and expensive. The steady state method with activated sludge is presented. Fundamentals are discussed. For complete mixed aeration tanks, plug flow systems with diffused air aeration and carousels the method is described more in detail and the results of measurements are presented. The results of the steady state measurements of the diffused air system are compared with those of the reaeration method in tapwater. The accuracy of the measurements in the 3 systems is discussed. Measurements in other aeration systems are described briefly. It is concluded that the steady state OC measurement offers advantages in comparison with the non-steady state method and is useful for most purposes.

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