Digital Radiography Image Quality: Image Acquisition Mark B. Williams, PhD a , Elizabeth A. Krupinski, PhD b , Keith J. Strauss, MS c , William K. Breeden, III, MS d , Mark S. Rzeszotarski, PhD e , Kimberly Applegate, MD, MS f , Margaret Wyatt g , Sandra Bjork, RN, JD g , J. Anthony Seibert, PhD h This article on digital radiography image acquisition is the first of two articles written as part of an intersociety effort to establish image quality standards for digital and computed radiography. The topic of the other paper is digital radiography image processing and display. The articles were developed collaboratively by the ACR, the American Association of Physicists in Medicine, and the Society for Imaging Informatics in Medicine. Increas- ingly, medical imaging and patient information are being managed using digital data during acquisition, transmission, storage, display, interpretation, and consultation. Data management during each of these oper- ations has a direct impact on the quality of patient care. These articles describe what is known to improve image quality for digital and computed radiography and make recommendations on optimal acquisition, processing, and display. The practice of digital radiography is a rapidly evolving technology that will require the timely revision of any guidelines and standards. This document provides a basis for the technologies available today in clinical practice and may be useful in guiding the future clinical practice of digital radiography. Key Words: Digital radiography, image quality, image acquisition J Am Coll Radiol 2007;4:371-388. Copyright © 2007 American College of Radiology INTRODUCTION AND DEFINITIONS Computed radiography (CR) and digital radiography (DR) are the commonly used terms for digital radiographic detectors. Computed radiography uses a photostimu- lable storage phosphor that stores the latent image with subsequent processing using a stimulating laser beam and can be easily adapted to a cassette-based system analo- gous to that used in screen-film (SF) radiography. His- torically, DR has been used to describe a digital x-ray imaging system that reads the transmitted x-ray signal immediately after exposure with the detector in place. There are several types of detectors that can be classified as DR systems, including automated (cassetteless) CR systems. In addition, some DR systems are adapted to a cassette-based x-ray system. Thus, the historical nomen- clature becomes less accurate as technology advances be- cause distinct classification into the two broad categories of CR and DR is no longer possible. More appropriate is the distinction based on cassette vs cassetteless operation. In this article, digital radiography is used to refer to all types of digital radiographic systems, including both those historically termed CR and those historically termed DR. There are many ways to categorize the current state- of-the-art digital radiography technology. One categori- zation considers (1) form factor, (2) image acquisition time, and (3) x-ray signal conversion methodology. The concept of cassette-based vs cassetteless operation is de- fined using the term form factor. A cassette-based digital detector uses the SF paradigm, which allows the use of existing imaging modality infrastructure and provides excellent positioning flexibility. On the other hand, the labor-intensive handling of cassettes and the need to wait for the image, often with batch-mode processing, leads to a loss of time efficiency. Cassetteless operation indicates the ability to acquire the x-ray signal and, without sub- sequent user intervention, produce an image at a local a Department of Radiology, University of Virginia, Charlottesville, Va. b Department of Radiology, University of Arizona, Tucson, Ariz. c Department of Radiology, Children’s Hospital, Harvard University, Boston, Mass. d St. Vincent Hospital, Indianapolis, Ind. e Department of Radiology, Case Western Reserve University, Cleveland, Ohio. f Department of Radiology, Indiana University, Indianapolis, Ind. g American College of Radiology, Reston, Va. h Department of Radiology, University of California, Davis, Sacramento, Calif. Corresponding author and reprints: J. Anthony Seibert, PhD, University of California, Davis, Department of Radiology, 4860 Y Street, Suite 3100, Sac- ramento, CA 95817; e-mail: jaseibert@ucdavis.edu. © 2007 American College of Radiology 0091-2182/07/$32.00 ● DOI 10.1016/j.jacr.2007.02.002 371