Optimal tube current for lung cancer screening with low-dose spiral CT.
OBJECTIVE
To determine the optimal tube current for spiral CT for lung cancer screening.


METHODS
Low-dose spiral CT images from 20 subjects were obtained with 50 mA, 25 mA, 10 mA and 5 mA tube currents. The accuracy in detecting 21 nodules measuring 3 to 14 mm in diameter was tested using receiver operating characteristics (ROC) to determine the diagnostic accuracy and statistical significance.


RESULTS
Compared with 50 mA, 25 mA showed no statistical difference. A significant difference was seen between 50 mA and 5 mA images and between 25 mA and 10 mA images, in the detection of lung parenchymal nodular lesions.


CONCLUSIONS
Approximately 25 mA is the optimal tube current for the detection of pulmonary nodules as it allows a reduction of the radiation dose without sacrificing diagnostic accuracy.
Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
K
K
Oguchi
S
S
Sone
K
K
Kiyono
S
S
Takashima
Y
Y
Maruyama
M
M
Hasegawa
L
L
Feng
D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000368:Aged; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D014057:Tomography, X-Ray Computed / Q000379:methods*