A 3D microtomographic system with stacked fan-beam geometry

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 443; no. 2; pp. 531 - 539
• Main Authors: Kohlbrenner, Adrian, Hämmerle, Stefan, Laib, Andres, Rüegsegger, Peter
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2000
• Subjects: 3D imaging; Algorithms; CCD; Charge coupled devices; Computerized tomography; High-speed scanning; Image reconstruction; Microtomography; Optical collimators; Optical resolving power; Scanning; Sensors; Three dimensional computer graphics; Tomography; X ray tubes; 87.64.-t; CT; 3D imaging; CCD; Tomography; Microtomography; High-speed scanning; 87.59.Fm
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/S0168-9002(99)01045-1

The move from 2D to 3D analysis, and the increase in spatial resolution characterize recent improvements in CT-based structure assessment. A new desktop micro-CT system with high scanning speed has been developed. The instrument makes use of a novel multiple fan-beam technique: radiation from a line-focus X-ray tube is divided into a stack of fan-beams by a foil collimator with a 30 μm pitch. The stacked fan-beam geometry allows to design compact CT scanners with a source-to-detector distance of only 18 cm. The complete system fits into a standard 19 in. rack. Image reconstruction is based on standard fan-beam algorithms, which eliminates the difficulties and limitations associated with cone-beam reconstruction. The detector comprises a low-noise area CCD sensor, a fiber-optic light guide and a scintillator screen. A complete examination requires 2 min only. The new micro-CT system has a voxel size of 20×20×26 μm 3. Each 3D image contains a quarter of a billion voxels or a multiple of it. Samples up to 20 mm in diameter and up to 40 mm in length can be imaged. The instrument can be operated in a normal lab environment.