Conventional chest tomography using a variable-shaped lead-loaded acrylic glass filter

Conventional chest tomography has proved more sensitive than CT in the detection of hilar abnormalities. The authors introduce a variably shaped, lead-loaded acrylic glass filter for use in conventional chest tomography. Dodging of the x-ray beam is done by moveable filter in front of the x-ray tube. Differently shaped filters (100-300 μPb) allow the radiographer to adjust the undodged slit to the abnormality seen on the plain chest film. Eight hundred eighty-seven patients underwent conventional chest tomography performed with this filter. The diagnostic quality (DQ) of the tomograms was scored and compared with the DQ of tomograms obtained without the filter and with Hueller or Meiar filters (100 patients). Use of the new filter increased DQ and improved film density. For optimal chest tomography using the filter, an average of 1.3 test shots is needed. Introduction time is 1 day