Emiel Verdonck

Requirements for dry hard copy in medical diagnostic applications

Today, dry process and color printers are more and more common in medical applications. The main applications for these printers are in ultrasound, nuclear medicine, medical imaging workstations and endoscopy. Each of these disciplines has its specific application requirements. Image quality and other considerations with regard to medical applications are discussed. Although the emphasis in medical imaging lies within grayscale imaging, the increased use of techniques such as doppler imaging, power doppler in ultrasound and image processing with workstations, intensify the need for high quality color output on hardcopy. For the radiology department, hardcopy must be of diagnostic quality and suitable for light box viewing. The different criteria to meet these requirements such as resolution, noise, density and physical properties are discussed. Also a short description of the implementation in the Agfa DRYSTAR 2000TM printer and its consumables will be explained. The achieved quality level will be supported by measurements. Starting from specific image processing for grayscale imaging (such as Look Up Tables) and specific imaging processing for color imaging, a new dedicated image processing method for medical dry hard copy will be presented. Both optimal grayscale imaging and color imaging combined are needed in ultrasound. In relation to this item, some non resolved issues will be explained. As a conclusion, a brief presentation of a hospital application test, validating the system for diagnostic purposes is given.