A Study of Computer-Assisted Tomography: I. The Incidence of Positive CAT Scans in an Asymptomatic Group of PatientsWIESEL, SAM W., MD; TSOURMAS, NICHOLAS, MD; FEFFER, HENRY L., MD; CITRIN, CHARLES M., MD; PATRONAS, NICHOLAS, MDSpine: September 1984 - Volume 9 - Issue 6 - p 549–551 1984 Volvo Award in Clinical Sciences: PDF Only Buy Abstract Author InformationAuthors In order to study the type and number of CAT scan abnormalities of the lumbar spine that occur in asymptomatic people, 52 studies from a control population with no history of back trouble were mixed randomly with six scans from patients with surgically proven spinal disease, and all were interpreted by three neuroradiologists in a blinded fashion. Irrespective of age, 35.4% (26.6%, 51.0%, and 31.3%) were found to be abnormal. Spinal disease was identified in an average of 19.5% (23.8%, 22.7%, and 12.5%) of the under 40-year-olds, and it was a herniated nucleus pulposus in every instance. In the over 40-year-old age group, there was an average of 50% (29.2%, 81.5%, and 48.1%) abnormal findings, with diagnoses of herniated disc, facet degeneration, and stenosis occurring most frequently. Department of Orthopaedic Surgery, George Washington University, Washington, DC. © Lippincott-Raven Publishers.