Improved detection of lung cancer arising in diffuse lung diseases on chest radiographs using temporal subtraction.
OBJECTIVE
The purpose of this study was to evaluate the usefulness of temporal subtraction for the detection of lung cancer arising in pneumoconiosis, idiopathic pulmonary fibrosis, and pulmonary emphysema.


METHODS
Fifteen cases of lung cancer arising in diffuse lung diseases, including three cases of pneumoconiosis, six of idiopathic pulmonary fibrosis, and six of pulmonary emphysema, were evaluated. Pathologic proof was obtained by surgery or transbronchial lung biopsy. The average interval between previous and current radiographs was 356 days (range, 31-947 days). All chest radiographs were obtained with a computed radiography system, and temporal subtraction images were produced by subtracting of a previous image from a current one with a nonlinear image-warping technique. The effect of the temporal subtraction image was evaluated by observer performance study with receiver operating characteristic analysis.


RESULTS
The average observer performance with temporal subtraction was significantly improved (Az = 0.935) compared with that without temporal subtraction (Az = 0.857, P < .0001).


CONCLUSIONS
The temporal subtraction technique is useful for the detection of lung cancer arising in pneumoconiosis, idiopathic pulmonary fibrosis, and pulmonary emphysema.
Okazaki
Hiroko
H
Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Japan. Hiroko1.Okazaki@mitsui-chem.co.jp
Nakamura
Katsumi
K
Watanabe
Hideyuki
H
Matsuki
Yuichi
Y
Uozumi
Toshimi
T
Kakeda
Shingo
S
Kamada
Kouji
K
Oda
Nobuhiro
N
Nakata
Hajime
H
Katsuragawa
Shigehiko
S
Doi
Kunio
K
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000209:etiology; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011009:Pneumoconiosis / Q000150:complications; D011656:Pulmonary Emphysema / Q000150:complications; D011658:Pulmonary Fibrosis / Q000150:complications; D012372:ROC Curve; D011859:Radiography; D013382:Subtraction Technique