Original Jpn J Radiol Technol 1999 ;
Improvement of Image Quality and Patient Dose by Optimization
of X-ray Spectrum

ETSUKO ISHIDA, KEN-ICHIRO YASUI, AKIYOSHI OTSUKA, SHUICHI YAMAUCHI, KEN-ICHI YOSHIDA, KATSUHIKO UEDA, and KEIKO NAKAMURA
Department of Radiology, Yamaguchi University Hospital
Received Nov. 6, 1998; Revision accepted March 31, 1999; Code Nos. 621, 734
Summary
We studied reduction in patient dose and improvement of image contrast in drip infusion pyelography(DIP)and bone radiography using a copper filter. More suitable x-ray spectra for the K-absorption edge of iodine contrast media were investigated by using various combinations of tube voltage and copper filter. Image contrast and patient dose from 60-70 kV with a copper filter were compared with those at 80 kV without the filter. We found that patient dose could be reduced by 13-40% with the copper filter compared with that for an 80 kV tube voltage without the filter. Image contrast was improved 1.2 times compared with the result for an 80 kV tube voltage without filter. An x-ray spectrum suitable for the object improves image contrast and reduces patient dose.
Key words: Copper filter, Patient dose reduction, X-ray spectrum, Iodine contrast media, Image contrast