[Study of X-ray filter and peak kilovoltage in Fuji Computed Radiography in regard to the detection of simulated pulmonary nodules].
To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), to provide better detection of pulmonary nodules and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that 1) nodule detection was superior for the images obtained with 135 kVp as compared with 100 kVp; 2) approximately equal detection rates were obtained for the three X-ray filter sets, although results with the tungsten filter were slightly inferior to the other two filters; and 3) the absorbed dose may be reduced by 30% with the use of a lead filter backed by yttrium and aluminium compared with a copper filter backed by aluminium. We conclude that chest radiography with FCR should preferably be conducted with a higher kilovoltage, e.g., 135 kVp rather than 100 kVp, to ensure a higher detection rate of pulmonary nodules and in conjunction with a lead filter backed by yttrium and aluminium to reduce X-ray exposure to the patient.
Kiyono
K
K
Department of Radiology, Shinshu University, School of Medicine.
Sone
S
S
Sakai
F
F
Kawai
T
T
Karakida
O
O
Oguchi
K
K
Kasuga
T
T
Hirano
H
H
Miyasaka
T
T
Matsumoto
T
T
D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D015588:Observer Variation; D019047:Phantoms, Imaging; D012372:ROC Curve; D011835:Radiation Protection / Q000295:instrumentation*; D011856:Radiographic Image Enhancement / Q000295:instrumentation*; D013902:Radiography, Thoracic / Q000295:instrumentation; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*