Synchrotron-based phase-contrast images of zebrafish and its anatomical structures

¹ Department of Physics, Rajiv Gandhi University of Knowledge Technologies, A.P-IIIT, RK Valley, YSR (Dt), AP 516329, India
² Istituto di Matematica e Fisica, Università di Sassari, Via Vienna 2, Sassari 07100, Italy
³ National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USA
⁴ Department of Bio-System Engineering, Faculty of Engineering, Yamagata University, Yonezawa-shi, Yamagata – 992-8510, Japan
⁵ Allied Health Science, Kitasato University 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan
⁶ Dipartimento di Fisica, Università di Roma, La Sapienza, 00185 Roma, Italy

^a e-mail: dvrao@rgukt.in

Received: 20 March 2014
Revised: 11 June 2014
Accepted: 13 June 2014
Published online: 20 August 2014

Abstract

Images of vertebrates (zebrafish and zebrafish eye) have been obtained by using an X-ray phase-contrast imaging technique, namely, synchrotron-based diffraction-enhanced imaging (SY-DEI) (or analyzer based imaging) and synchrotron-based diffraction imaging in tomography mode (SY-DEI-CT). Due to the limitations of the conventional radiographic imaging in visualizing the internal complex feature of the sample, we utilized the upgraded SY-DEI and SY-DEI-CT systems to acquire the images at 20, 30 and 40 keV, to observe the enhanced contrast. SY-DEI and SY-DEI-CT techniques exploits the refraction properties, and have great potential in studies of soft biological tissues, in particular for low (Z) elements, such as, C, H, O and N, which constitutes the soft tissue. Recently, these techniques are characterized by its extraordinary image quality, with improved contrast, by imaging invertebrates. We have chosen the vertebrate sample of zebrafish (Danio rerio), a model organism widely used in developmental biology and oncology. For biological imaging, these techniques are most sensitive to enhance the contrast. For the present study, images of the sample, in planar and tomography modes offer more clarity on the contrast enhancement of anatomical features of the eye, especially the nerve bundle, swim bladder, grills and some internal organs in gut with more visibility.