Room E, 10/16/2000 2: 00 PM - 4: 00 PM (PS) Cerebral Blood Flow Sensitivities to CO2 Determined by Read's Rebreathing Method and the Steady-State Method Are Not Equal 

2000 ◽  
Vol 93 (3A) ◽  
pp. A-737
Author(s):  
Jaideep J. Pandit ◽  
Ravi M. Mohan ◽  
Nicole D. Paterson ◽  
Marc J. Poulin
1988 ◽  
Vol 8 (1_suppl) ◽  
pp. S52-S60 ◽  
Author(s):  
Atsushi Inugami ◽  
Iwao Kanno ◽  
Kazuo Uemura ◽  
Fumio Shishido ◽  
Matsutaro Murakami ◽  
...  

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.


1989 ◽  
Vol 411 (1) ◽  
pp. 367-377 ◽  
Author(s):  
A Berkenbosch ◽  
J G Bovill ◽  
A Dahan ◽  
J DeGoede ◽  
I C Olievier

1984 ◽  
Vol 4 (2) ◽  
pp. 224-234 ◽  
Author(s):  
Iwao Kanno ◽  
Adriaan A. Lammertsma ◽  
Jon D. Heather ◽  
Jeremy M. Gibbs ◽  
Christopher G. Rhodes ◽  
...  

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.


1985 ◽  
Vol 17 (2-3) ◽  
pp. 303-311
Author(s):  
Kees de Korte ◽  
Peter Smits

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.


Sign in / Sign up

Export Citation Format

Share Document