title: Emphysema early diagnosis using X-ray diffraction enhanced imaging at synchrotron light source.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide, and emphysema is a common component of COPD. Currently, it is very difficult to detect early stage emphysema using conventional radiographic imaging without contrast agents, because the change in X-ray attenuation is not detectable with absorption-based radiography. Compared with the absorption-based CT, phase contrast imaging has more advantages in soft tissue imaging, because of its high spatial resolution and contrast.
  
  
  METHODS
  In this article, we used diffraction enhanced imaging (DEI) method to get the images of early stage emphysematous and healthy samples, then extract X-ray absorption, refraction, and ultra-small-angle X-ray scattering (USAXS) information from DEI images using multiple image radiography (MIR). We combined the absorption image with the USAXS image by a scatter plot. The critical threshold in the scatter plot was calibrated using the linear discriminant function in the pattern recognition.
  
  
  RESULTS
  USAXS image was sensitive to the change of tissue micro-structure, it could show the lesions which were invisible in the absorption image. Combined with the absorption-based image, the USAXS information enabled better discrimination between healthy and emphysematous lung tissue in a mouse model. The false-color images demonstrated that our method was capable of classifying healthy and emphysematous tissues.
  
  
  CONCLUSIONS
  Here we present USAXS images of early stage emphysematous and healthy samples, where the dependence of the USAXS signal on micro-structures of biomedical samples leads to improved diagnosis of emphysema in lung radiographs.
authors: Linan
authors: L
authors: Dong
authors: Jun
authors: J
authors: Li
authors: Wushuai
authors: W
authors: Jian
authors: Lu
authors: L
authors: Zhang
authors: Mingshu
authors: M
authors: Wu
authors: Hongli
authors: H
authors: Shi
authors: Department of Biomedical Engineering, Capital Medical University, Beijing 100069, China. shuqian_luo@aliyun.com.
authors: Shuqian
authors: S
authors: Luo
mesh_terms: D000042:Absorption; D000818:Animals; D042241:Early Diagnosis; D004646:Emphysema / Q000000981:diagnostic imaging*; D007091:Image Processing, Computer-Assisted; D008027:Light; D051379:Mice; D011859:Radiography / Q000295:instrumentation*; D012542:Scattering, Radiation; D017356:Synchrotrons; D014961:X-Ray Diffraction