The Hong Kong Polytechnic University has a Radiography Division under the Development of Optometry and Radiography. The Division trains both diagnostic and therapeutic radiographers with 60 students/year and offers a B.Sc. degree. In addition the Division together with the University Health Service operates a radiography clinic with radiology consultation from radiologists from other hospitals and clinics. This paper describers the implementation of a PACS in the Division for radiography training, and for clinical service.
A film digitizer is used when X-ray images are entered in the PACS. Dust adhering to the film causes white vertical lines on the readout image displayed on the screen. Once generated, the lines will appear on all subsequent readout film images. These white lines must be removed because they adversely affect CRT diagnosis. This paper shows why vertical lines are generated and describes how these lines are suppressed and effects on aliasing caused when a film radiographed using grid is read by the digitizer.