Estimation of contrast of refraction contrast imaging compared with absorption imaging-basic approach.
OBJECTIVE
We discuss the usefulness of the refraction contrast method using highly parallel X-rays as a new approach to minute lung cancer detection. The advantages of refraction contrast images are discussed in terms of contrast, and a comparison is made with absorption images.


METHODS
We simulated refraction contrast imaging using globules with the density of water in air as models for minute lung cancer detection. The contrast intensified by bright and dark lines was compared on a globule with the contrast of absorption images. We adopted the Monte Carlo simulation to determine the strength of the profile curve of the photon counts at the detector.


RESULTS
The obtained contrasts were more intense by two to three digits than those obtainable with the absorption contrast imaging method.


CONCLUSIONS
The contrast in refraction contrast imaging was more intense than that obtainable with absorption contrast imaging. A two to three digit improvement in contrast means that it is possible to greatly reduce the exposure dose necessary for imaging. Therefore, it is expected to become possible to detect the interfaces of soft tissues, which are difficult to capture with conventional absorption imaging, at low dosages and high resolution.
Hirano
Masatsugu
M
Department of Electrical Engineering and Information Science, Niihama National College of Technology, Ehime, Japan.
Yamasaki
Katsuhito
K
Okada
Hiroshi
H
Kitazawa
Sohei
S
Kitazawa
Riko
R
Ohno
Yoshiharu
Y
Sakurai
Takashi
T
Kondoh
Takeshi
T
Ohbayashi
Chiho
C
Katafuchi
Tetsuro
T
Maeda
Sakan
S
Sugimura
Kazuro
K
Tamura
Shinichi
S
D000042:Absorption; D016477:Artifacts; D003198:Computer Simulation; D003287:Contrast Media; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D009010:Monte Carlo Method; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D012031:Refractometry; D017356:Synchrotrons; D014965:X-Rays
D003287:Contrast Media