title: [Size and density determination by thin-layer CT in relation to structural diameter and the contrast of the surrounding tissue].
abstract: The reliability of CT size and density measurements has been examined by using phantom measurements with constant examination and reconstruction parameters (Somatom DRH/Siemens). Ten plexiglass rods with diameters from 2 to 15 mm. were measured singly in (1) air, (2) isodense (146 Hu) and (3) hyperdense medium (985 Hu) using 2 mm. sections. In the isodense medium there was only small variation in density measurements (124 to 131 Hu). Measurements of size showed a maximum error up to -35%. Density measurements in the hyperdense medium produced raised values (197 +/- 17 Hu at 15 mm.). There was an even greater increase for rods smaller than 5 mm. Measurement of size was correct, as it was in air (maximum deviation 8%). Density measurements in air for diameters less than 6 mm. were significantly reduced.
authors.affiliation: Institut für Radiologie und Pathophysiologie, DKFZ, Heidelberg.
authors.forename: S A
authors.initials: SA
authors.lastname: Beyer-Enke
authors.forename: J
authors.initials: J
authors.lastname: Görich
authors.forename: G
authors.initials: G
authors.lastname: van Kaick
mesh_terms: D001842:Bone and Bones / Q000000981:diagnostic imaging; D003287:Contrast Media; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008168:Lung / Q000000981:diagnostic imaging; D008961:Models, Structural; D011856:Radiographic Image Enhancement; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
chemical_list: D003287:Contrast Media
vernacular_title: Grössen- und Dichtebestimmung mit der Dünnschicht-CT in Abhängigkeit von Strukturdurchmesser und Umgebungskontrast.