Edge-enhanced radiology with broadband synchrotron X-rays W.L. Tsai a , P.C. Hsu a ,Y.Hwu a, * , J.H. Je b , Y. Ping c , H.O. Moser c , A. Groso d , G. Margaritondo d a Institute of Physics, Academia Sinica, 128 Academica Rd., Sec. 2, Nankang, Taipei, Taiwan, ROC b Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, South Korea c SSLS, National University of Singapore, Singapore d Ecole Polytechnique F ed erale (EPFL), Lausanne CH-1015, Switzerland Abstract BroadbandsynchrotronX-rayswithlimitedcoherencecanbeusedforhighresolutionphasecontrastradiology.Our experimental results confirm the prediction that the extreme spatial coherence of third-generation synchrotron sources although helpful but not strictly necessary for refraction-based or diffraction-based edge enhancement. Source with ratherlimitedlateralcoherencecanproduceFresneldiffractionfringes.Thedirectobservationofthesamefringesusing broadband synchrotron lights demonstrates that high time coherence is also not required. Broadband light produces a highphotonfluxandhighaveragephotonenergy,thatwasexploitedforreal-timeradiology(5msframe)studieswith high lateral resolution (1 lm) and excellent contrast, without using a sophisticated detecting system. These results enhance the potential impact of phase contrast on medical X-ray applications, materials science and other domains. Ó 2002 Elsevier Science B.V. All rights reserved. PACS: 81.05.)t; 81.05.Bx; 81.16.)c Keywords: Phase contrast imaging; Radiology; Broadband synchrotron light 1. Introduction The high coherence levels of the third-genera- tionsynchrotronlightsourcesplayedanimportant role in triggering revolutionary new approaches to radiology [1–8]. Such approaches utilize the dif- ferences between different object areas in the real part of the refractive index, instead of the imagi- nary part (the absorption) – as conventional ra- diography has done for more than a century. Dramatic improvements of the image quality, in spite of the limited X-ray absorption contrast, were obtained in several synchrotron facilities using this so-called ‘‘phase contrast’’ radiology techniques – that shows promise of effective diag- nostic applications with a reduced radiation dose. The future impact could be quite important, for example in mammography [3]. Phase-contrast radiology was initially imple- mented in third generation synchrotron facilities [1–3]. However, techniques requiring very sophis- ticated and expensive X-ray sources like third- generation synchrotrons would have limited applications. Interestingly, similarly spectacular results were more recently obtained with novel approaches at synchrotron radiation sources with * Corresponding author. Tel.: +886-2-2789-6721; fax: +886- 2-2783-4187. E-mail address: phhwu@ccvax.sinica.edu.tw (Y. Hwu). 0168-583X/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0168-583X(02)01537-9 Nuclear Instruments and Methods in Physics Research B 199 (2003) 436–440 www.elsevier.com/locate/nimb