title: The importance of rigorous testing of circumference measuring callipers.
abstract: On-screen circumference measurements are frequently made in obstetric ultrasound and are also made in other ultrasound specialties. The accuracy of electronic callipers is traditionally checked by linear measurement in a test object; this does not adequately test callipers used for nonlinear measurement. This technical note describes a simple test object designed for both linear and nonlinear calliper checks. Results show one machine to generate consistently large overmeasurements (15%). The clinical consequences of such overmeasurement may be serious. Appropriate quality control is essential.
authors.affiliation: Medical Physics & IT Services, Nottingham City Hospital NHS Trust, UK.
authors.forename: N J
authors.initials: NJ
authors.lastname: Dudley
authors.forename: K
authors.initials: K
authors.lastname: Griffith
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D019047:Phantoms, Imaging; D011247:Pregnancy; D016216:Ultrasonography, Prenatal / Q000379:methods*