title: Evaluation of a commercial radiochromatography module as an arterial blood activity monitor.
abstract: Input functions required for positron emission tomography (PET) tracer kinetic modeling are often obtained from arterial blood. In some situations, using short-lived radiotracers, e.g. [(15)O]water, rapid sample handling is required. A method used at several facilities is to pump blood through a detector system at a constant rate. We investigate the suitability of a commercial radiochromatography module (IN/US Posi-RAM) for this new use. The Posi-RAM consists of two 2.5 cm (length) x 2.5 cm (diameter) cylindrical bismuth germanate (BGO) detectors that can operate in coincidence mode. Arterial blood is transported through the system via a length of tubing with flow rate controlled by a peristalsis pump. A custom-counting loop and support frame were designed for the Posi-RAM for PET studies. System sensitivity was determined to be 1.1 x 10(4) cps/(MBq ml(-1)). Dead time as a function of count-rate was found to be less than 1% for concentrations below 3.5 MBq ml(-1), a range encompassing all human-study values. In a human study, the performance of the device was found to be similar to that of the facility's current blood monitor (Siemens Fluid Monitor). We conclude that the Posi-RAM has the necessary sensitivity and count-rate capabilities to be used as a real-time blood activity monitor.
authors.affiliation: University of Pittsburgh, Department of Radiology, Pittsburgh, PA 15213, USA. CML14@pitt.edu
authors.forename: C M
authors.initials: CM
authors.lastname: Laymon
authors.forename: D
authors.initials: D
authors.lastname: Sashin
authors.forename: J P
authors.initials: JP
authors.lastname: Carney
authors.forename: J
authors.initials: J
authors.lastname: Ruszkiewicz
authors.forename: D
authors.initials: D
authors.lastname: Altenburger
authors.forename: C R
authors.initials: CR
authors.lastname: Becker
authors.forename: B J
authors.initials: BJ
authors.lastname: Lopresti
authors.forename: N S
authors.initials: NS
authors.lastname: Mason
authors.forename: J M
authors.initials: JM
authors.lastname: Mountz
authors.forename: J C
authors.initials: JC
authors.lastname: Price
authors.forename: R
authors.initials: R
authors.lastname: Schavey
authors.forename: C A
authors.initials: CA
authors.lastname: Mathis
mesh_terms: D001158:Arteries / Q000378:metabolism*; D001769:Blood / Q000000981:diagnostic imaging*; D001774:Blood Chemical Analysis / Q000295:instrumentation* / Q000379:methods; D002845:Chromatography / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D011854:Radiochemistry / Q000295:instrumentation / Q000379:methods; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D019275:Radiopharmaceuticals / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*
chemical_list: D019275:Radiopharmaceuticals