A Five-Step Approach to Digital Image Manipulation for the Radiologist

Abstract

Digital manipulation of images plays a key role in development of multimedia presentations. Five basic steps to digitizing images and preparing them for publication and computer presentation are scanning, correction, editing and labeling, saving files, and producing final output. These steps can be completed with commercially available hardware and image manipulation software (eg, Photoshop). The higher the quality of the original scanned image, the more image data there will be to edit: A good image cannot be created from an inferior scan. The most important functions for properly scanning images are size, resolution, and color. Resolutions of 300 ppi and 72 ppi should be used for print publication and computer presentations, respectively. The higher resolution image has the larger file size. The scanned image should be saved as a TIFF (tagged image file format), which is an uncompressed file type used for printed images. The Joint Photographic Experts Group (JPEG) format compresses the size of the image file but also reduces image quality. The JPEG format is a good choice if a small file size is needed, such as in Web and PowerPoint presentations. If the user needs to save an image as a JPEG file, the image should be edited first and then saved once in JPEG format. With Photoshop, the user can rotate and crop an image; adjust its brightness, contrast, and color; remove unwanted patient information, dust, and scratches; and add text and symbol labels to enhance images for teaching purposes. Digital manipulation can be fast and effective if the user has some basic knowledge and tools.