title: Imaging of renal and prostate carcinoma with refractive index radiology.
abstract: OBJECTIVE
  Having better edge enhancement and penetrating power, refractive index radiology is suitable for the imaging of weakly absorbing objects such as tissue specimens. In this study the potential of refractive index radiology was evaluated for the imaging of renal cell carcinoma (RCC) and prostate cancer (PCA).
  
  
  METHODS
  Specimens were cut in 3 mm and 4 microm thickness for X-ray radiology and hematoxylin and eosin (HE) staining, respectively. Radiographic images of RCC and PCA were obtained using the synchrotron hard X-rays from the 7B2 beam-line of the Pohang Light Source (PLS). The imaging technique applied was phase-contrast radiology based on the refraction enhancement mechanism. The resulting radiographic images were analyzed in correlation with those of optical microscopy.
  
  
  RESULTS
  Using unmonochromatized hard X-rays, it was possible to obtain images with clear edge enhancement and relatively large field of view (6 cm x 6 cm). Even with overlapping signals from thick samples (more than 700-fold thicker than microscopic images), radiographic images clearly showed histological information of organelles in normal kidney such as glomeruli, tubules, and collecting ducts. Histological information of RCC including tumor subtypes and minute changes such as cystic degeneration could be identified without difficulty. The radiographic images of the prostate were comparable with those of low magnification optical microscopy, providing good visualization of normal microstructures such as adenoma, smooth muscle, and normal glands, or differentiation of tiny tumors from surrounding normal tissues.
  
  
  CONCLUSIONS
  These results suggest the potential of refractive index radiology to provide a new way of imaging biological tissues with low absorption contrast such as RCC and PCA.
authors.affiliation: Department of Urology, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Cheol Yong
authors.initials: CY
authors.lastname: Yoon
authors.forename: Duck Je
authors.initials: DJ
authors.lastname: Sung
authors.forename: Ju Han
authors.initials: JH
authors.lastname: Lee
authors.forename: Ae Ri
authors.initials: AR
authors.lastname: Kim
authors.forename: Chil Whan
authors.initials: CW
authors.lastname: Oh
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Je
authors.forename: Byung Mook
authors.initials: BM
authors.lastname: Weon
authors.forename: Seung Kwon
authors.initials: SK
authors.lastname: Seol
authors.forename: Aram
authors.initials: A
authors.lastname: Pyun
authors.forename: Yeukuang
authors.initials: Y
authors.lastname: Hwu
authors.forename: Giorgio
authors.initials: G
authors.lastname: Margaritondo
authors.forename: Kwan Joong
authors.initials: KJ
authors.lastname: Joo
authors.forename: Duck Ki
authors.initials: DK
authors.lastname: Yoon
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology*; D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography