Laboratory-based X-ray NanoCT Explores Morphology of a Zebrafish Embryo

Abstract

In recent years, the field of microCT imaging has evolved, striving for higher resolutions below the micrometre range. At synchrotron facilities, the high brilliance of the radiation already allows for resolutions in the nanometre range [1], while laboratory-based setups have used different approaches to resolve structures smaller than one micrometre. One of the two main approaches is to use X-ray optics, such as Fresnel zone plates, combined with high flux sources. Thereby resolutions below 100 nm are accomplished [2]. Another technique is based on the combination of mere geometrical magnification and an X-ray source featuring small X-ray focal spots. Until recently, this approach was limited to a maximum resolution of about 400 nm [3]. Despite the lower resolving power, setups using solely geometrical magnification have proven themselves valuable since they allow larger field of views (FOVs), shorter acquisition times and work with broad energy spectra. We present an innovative table- top setup, which is based on geometrical magnification and comprises of a nano-focus X-ray source and a photon counting detector. The setup achieves routinely resolutions down to 100 nm [4]. This allows non-destructive imaging of inner structures in 3D with very high resolution [4,5]. To explore the potential of our nanoCT setup for the field of biology, we imaged a Zebrafish embryo 48 hours post fertilization. Our comparative analyses show that the nanoCT can resolve the surface morphology of the fish embryo at a similar level of detail as scanning electron microscopy (SEM) and reproduce the internal features of the specimen.