title: A flat-panel detector based micro-CT system: performance evaluation for small-animal imaging.
abstract: A dedicated small-animal x-ray micro computed tomography (micro-CT) system has been developed to screen laboratory small animals such as mice and rats. The micro-CT system consists of an indirect-detection flat-panel x-ray detector with a field-of-view of 120 x 120 mm2, a microfocus x-ray source, a rotational subject holder and a parallel data processing system. The flat-panel detector is based on a matrix-addressed photodiode array fabricated by a CMOS (complementary metal-oxide semiconductor) process coupled to a CsI:T1 (thallium-doped caesium iodide) scintillator as an x-ray-to-light converter. Principal imaging performances of the micro-CT system have been evaluated in terms of image uniformity, voxel noise and spatial resolution. It has been found that the image non-uniformity mainly comes from the structural non-uniform sensitivity pattern of the flat-panel detector and the voxel noise is about 48 CT numbers at the voxel size of 100 x 100 x 200 microm3 and the air kerma of 286 mGy. When the magnification ratio is 2, the spatial resolution of the micro-CT system is about 14 1p/mm (line pairs per millimetre) that is almost determined by the flat-panel detector showing about 7 1p/mm resolving power. Through low-contrast phantom imaging studies, the minimum resolvable contrast has been found to be less than 36 CT numbers at the air kerma of 95 mGy. Some laboratory rat imaging results are presented.
authors.affiliation: Graduate School of East-West Medical Science, Kyung Hee University, 1 Seochun, Kiheung, Yongin, Kyungki 449-701, Korea.
authors.forename: Sang Chul
authors.initials: SC
authors.lastname: Lee
authors.forename: Ho Kyung
authors.initials: HK
authors.lastname: Kim
authors.forename: In Kon
authors.initials: IK
authors.lastname: Chun
authors.forename: Myung Hye
authors.initials: MH
authors.lastname: Cho
authors.forename: Soo Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Min Hyoung
authors.initials: MH
authors.lastname: Cho
mesh_terms: D000818:Animals; D004867:Equipment Design; D019544:Equipment Failure Analysis; D051379:Mice; D008904:Miniaturization; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000295:instrumentation* / Q000379:methods; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000662:veterinary; D014159:Transducers