Determining Appropriate Window and Level Settings for Displaying DICOM Images in a Desktop Publishing Format

When harvesting images from a Picture Archiving and Communication System (PACS), window and level settings continue to present a major obstacle for the conversion of images from the Digital Imaging and Communications in Medicine (DICOM) standard file format to the Joint Photographic Experts Group (JPEG) image format, a desktop publishing format. Evaluation of the window and level values in the DICOM header demonstrated that they cannot be relied upon for generation of useful JPEG images for key image selection. An algorithm was developed to automatically calculate window and level settings for Magnetic Resonance (MR) images. As images are received by a vendor-neutral digital teaching file server, pixel data is read and a histogram of the grayscale values is generated. A portion of the grayscale values are then used to calculate the appropriate window and level settings for image conversion, allowing exported series to be displayed in JPEG format. The algorithm was evaluated and found to be effective for appropriate window and level calculation for key image selection.