APPLIED RADIOLOGY www.appliedradiology.com
Heidi C. Roberts, MD, FRCP(C)
Computer-aided detection (CAD) software tools have been developed to support radiologists and help them cope with the ever-increasing number of images that need interpretation. The demand for computer assistance emerges from both increasing indications and technologic developments. The prototypical example of increasing CAD indications is mammography. Screening mammography is recommended in a large number of patients, and, even though the number of images per patient remains limited, the number of studies is continually rising. As such, mammography has been the first area in which companies have developed CAD software and, to date, most are working on this indication. Technologic advances, particularly the development of multidetector computed tomography (MDCT), permit CT of the chest with thin, overlapping axial slices, which results in several hundred images per study. In chest imaging, the demand for CAD has grown with new MDCT indications, such as low-dose lung cancer screening. More recently, CAD has been applied to established areas of chest CT, such as the diagnosis of acute pulmonary embolism (PE) and interstitial lung disease. This article addresses CAD software tools in use for chest CT. Several companies have CAD software in different stages of development. Based on the findings of a multireader study,1 R2 Technology, Inc. (Sunnyvale, CA) was the first company to receive FDA approval for a lung CAD product, ImageChecker CT CAD Software System. This software targets the detection and follow-up of lung nodules and the detection of pulmonary arterial filling defects. Medicsight (London, England) offers LungCAD, Siemens Medical Solutions (Malvern, PA) has syngo LungCARE, and Philips Medical Systems (Bothell, WA) has a CAD product in development that is not yet commercially available in North America. Other companies are also developing CAD software for lung CT or digital radiography, including MEDIAN Technologies, Inc. (Brookfield, WI), EDDA Technology, Inc. (Princeton Junction, NJ), and Riverain Medical (Miamisburg, OH). The author has access to the most recent software releases from R2 Technology and Medicsight; information from the other vendors is available in the literature.