Screening for brain lesions with digital radiography of the head using a CT scanner

Digital radiography was tested in a clinical setting as a screening device for detecting brain lesions and for following the response of known enhancing cranial masses to therapy. A concurrent phantom study was conducted to determine the low contrast sensitivity of the system. Contrast resolution was superior to that of film -- screen systems but suffered at a density level of 2 to 4% because of system noise. This noise appeared to be nonquantum in nature, related to electronic and mechanical inconsistencies of the computed tomographic instrument. System noise and patient motion combined to nullify the advantages of digital radiography for screening and monitoring intracranial masses.