title: Subtle lung cancers: impact of edge enhancement and gray scale reversal on detection with digitized chest radiographs.
abstract: The authors studied the impact of edge enhancement and gray scale polarity reversal on the detection of subtle lung cancers. Three experienced readers reviewed 46 biopsy-proved subtle lung cancers and 46 normal controls on chest radiographs that had been digitized into a 1,024 X 1,536-pixel matrix 8 bits deep. Receiver-operating characteristics (ROC) analysis of 1,656 pooled observations indicated that performance was best with the unmodified images (ROC area = 0.83), degraded by moderate enhancement of medium frequencies (ROC area = 0.80), and markedly impaired by severe enhancement of low frequencies (ROC area = 0.69). Gray scale polarity reversal further degraded performance (unenhanced ROC area = 0.74; moderately enhanced ROC area = 0.76; severely enhanced ROC area = 0.76). The authors conclude that edge enhancement and gray scale polarity reversal can impair the detectability of subtle lung cancers on digitized radiographs of medium resolution.
authors: Department of Radiology, Massachusetts General Hospital, Boston.
authors: J W
authors: JW
authors: Oestmann
authors: D C
authors: DC
authors: Kushner
authors: P M
authors: PM
authors: Bourgouin
authors: H J
authors: HJ
authors: Llewellyn
authors: B W
authors: BW
authors: Mockbee
authors: R
authors: R
authors: Greene
mesh_terms: D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D012372:ROC Curve; D011856:Radiographic Image Enhancement