title: Evaluation of a stereotactic frame for repositioning of the rat brain in serial positron emission tomography imaging studies.
abstract: For serial imaging studies of the rat brain with positron emission tomography (PET), reproducible positioning of the head can facilitate spatial alignment of images and quantitative analysis. To achieve this aim, we constructed a plastic head frame and tested the positioning reproducibility on a high-resolution small-animal PET scanner, microPET. Two sets of ear bars, with tapers of either 18 degrees (sharp) or 45 degrees (blunt), were evaluated for their relative precision in securing the animal to the frame. For sequential positioning of an animal, average distances from the mean position of 0.51 mm (SD 0.41 mm) and 0.91 mm (SD 0.48 mm) were measured with the sharp and blunt ear bars, respectively. These results show that a rat brain can be reproducibly positioned using the frame, with a variation of position less than the spatial resolution of modern animal PET scanners. Brain regions of interest defined on one scan and copied across subsequent scans of a frame-repositioned animal resulted in an average coefficient of variation of 5.4% (SD 2.7%) using the sharp ear bars and 6.8% (SD 2.5%) using the blunt ear bars. This methodology has the potential to improve quantitative assessment for serial PET studies.
authors.affiliation: Department of Molecular and Medical Pharmacology, UCLA School of Medicine, 1833 Leconte Ave, CHS 28-115, Los Angeles, CA, USA. drubins@mednet.ucla.edu
authors.forename: D J
authors.initials: DJ
authors.lastname: Rubins
authors.forename: A K
authors.initials: AK
authors.lastname: Meadors
authors.forename: S
authors.initials: S
authors.lastname: Yee
authors.forename: W P
authors.initials: WP
authors.lastname: Melega
authors.forename: S R
authors.initials: SR
authors.lastname: Cherry
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000378:metabolism; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000033:anatomy & histology* / Q000378:metabolism / Q000601:surgery*; D013238:Stereotaxic Techniques; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18