title: An automatic method for determining the centre of rotation of a mechanically scanned reflection UCT system.
abstract: A method will be described for determining the centre of rotation of a mechanically scanned reflection ultrasound computed tomography system. It is based on the principle of obtaining opposing images of a test object containing many point targets. The method is automatic in the sense that the centre of rotation is calculated by a computer without the need for an operator to make direct measurements on the mechanical system. For the particular reflection UCT system described here, the centre of rotation is obtained in 3-5 min with a repeatability (+/-2 SD) of +/-0.3 mm. Ways in which even higher accuracy can be obtained are discussed. The basic principle of the method is applicable to any concentric imaging system for which a good approximation to an ideal point target can be produced.
authors.affiliation: Regional Medical Physics Department, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne NE4 6BE, UK.
authors.forename: J R
authors.initials: JR
authors.lastname: Jago
mesh_terms: D000438:Alcohols; D000465:Algorithms; D001331:Automation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D009757:Nylons; D012399:Rotation; D012984:Software; D013223:Statistics as Topic / Q000379:methods; D013696:Temperature; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods*; D014867:Water
chemical_list: D000438:Alcohols; D009757:Nylons; D014867:Water