Single-bolus low-dose galactose clearance for estimation of effective hepatic blood flow (EHBF) is superior to steady-state method for routine clinical use

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.

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Cerebral Blood Flow Sensitivities to CO2 with the Steady-State Method and Read’s Rebreathing Method

Advances in Experimental Medicine and Biology - Frontiers in Modeling and Control of Breathing ◽

10.1007/978-1-4615-1375-9_44 ◽

2001 ◽

pp. 279-284 ◽

Cited By ~ 4

Author(s):

Jaideep J. Pandit ◽

Ravi M. Mohan ◽

Nicole D. Paterson ◽

Marc J. Poulin

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Steady State ◽

Steady State Method ◽

State Method ◽

Rebreathing Method

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Steady State Measurement of Oxygenation Capacity

Water Science & Technology ◽

10.2166/wst.1985.0139 ◽

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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