[Helical CT for lung-cancer screening: fifth report: evaluation of image quality at low-dose CT using healthy volunteers].
In order to reduce radiation dose in the application of CT for lung-cancer screening, we investigated the potential of low-dose screening helical CT (SHCT) by reducing the tube current and using an additional 10 mm aluminum filter. Six healthy volunteers were scanned at various tube currents (50 mA, 30 mA, 20 mA) with and without the filter. In comparison with the images at 50 mA without the filter, we evaluated the visualization of normal anatomical structures and the detection of simulated nodules at low-dose SHCT. Although a bias toward unclearness in the visualization of small anatomical structures was noted at 20 mA with use of the filter, no structure was assessed as having no visualization at any low-dose scan. Detection of simulated nodules was not degraded significantly by reducing the tube current to 20 mA and using the filter. Further reduction of radiation dose at SHCT may be achieved by the application of small tube current and an additional filter.
Itoh
S
S
Department of Radiology, Nagoya Memorial Hospital.
Ikeda
M
M
Ohta
T
T
Isomura
T
T
Katoh
T
T
Maruyama
K
K
Ishigaki
T
T
D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*