[Examination of the image quality from digital fluoroscopy equipment with 1k- and 2k-image matrix].
OBJECTIVE
The image quality of 1k- and 2k-radiographs from digital fluoroscopy equipments (Sireskop SX and Polystar SX--Siemens) are characterized by comparison with each other to evaluate the relevance of this technique in clinical routine.


METHODS
We examined fabricated and evaluated images with 1k- and 2k-image matrix from several high and low contrast phantoms and from skeleton phantoms. On the one hand, the digital image values can be used directly for the evaluation, on the other hand the comparing evaluation by experienced radiologists resulted from a visual consideration in a blind study.


RESULTS
The quality difference of the 1k- and 2k-images depends mainly on the distance of the investigated sector of the object to the image intensifier and on the scattering of the radiation in the object positioned between the investigated sector and the image intensifier. The nearer the investigated object is located to the intensifier and the smaller the radiation is scattered in the object, the more the image quality of a radiograph with a 2k-matrix is increasing in comparison to an image with 1k-matrix. The higher the tube voltage, the smaller are the differences.


CONCLUSIONS
The image quality enhancement because of the more sensitive sampling of the Saticon target in the 2k-matrix is limited by the opening of the iris positioned in the light distributor. Therefore the image quality differences of medical 1k- and 2k-radiographs in many cases are small.
Kunz
G
G
Abteilung für Radiologie, Krankenhaus der Barmherzigen Brüder Trier. gkunz@gmx.de
Busch
H P
HP
D001842:Bone and Bones / Q000000981:diagnostic imaging*; D005471:Fluoroscopy / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012542:Scattering, Radiation