[Dosage monitoring as a quality control instrument in digital radiography].
OBJECTIVE
Automatic image processing procedures ensure a constant image quality. Overexposed images constitute a danger zone on account of a subjectively better image appearance (improved signal-to-noise ratio). We have examined the software "Dose-Monitoring" both for the identification of false exposures and as a quality control tool.


METHODS
Firstly the correlation between dose and present IgM (mean grey tone from the crude histogram of a 12-bit image) was examined by exposing phantoms. A further-reaching comparison of the present IgM values of some MTRAs with the department average (nominal IgM) should detect tendencies for over- and underexposure. Finally a dose reduction in 12 forms of X-ray examination was evaluated with regard to IgM course controls (median IgM).


RESULTS
A high correlation (0.987) between dose and mean grey tone (IgM). In some MRTAs tendency for over-/underexposure was detected. The dose reduction of defined types of X-ray examination lead to a trend to lower mean IgM values.


CONCLUSIONS
Numerous factors have an influence on the IgM value thus making its evaluation difficult, even so it is a suitable parameter for uncovering tendencies to incorrect exposure and for identifying processes requiring optimization.


CONCLUSIONS
The value of this tool lies in the quality assurance of dose fluctuations and a possible dose reduction.
Kurtz
C
C
Abteilung Strahlendiagnostik, Philipps-Universität Marburg. kurtz@mrs1.ukl.uni-freiburg.de
Czapp
W
W
Klose
K J
KJ
D006801:Humans; D019047:Phantoms, Imaging; D011786:Quality Control; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement; D015900:Radiography, Dual-Energy Scanned Projection / Q000592:standards*; D012984:Software; D014965:X-Rays
Dosis-Monitoring als Qualitätssicherungsinstrument in der digitalen Radiographie.