An X-ray micro-radiographic system for dynamic high spatial resolution imaging of living small animals has been developed. Our system is based on a micro-focus X-ray tube and the hybrid single photon counting silicon pixel detector Medipix2 (matrix 256 x 256 sq. pixels of 55 µm pitch). Performance of the system allows real-time observation of inner processes in living organisms. However, soft tissue shows a similar value of the absorption coefficient within the whole volume causing insufficiency of the classical radiographic techniques. We thus decided to adopt a novel method Phase enhanced imaging. The phase of spatially coherent X-ray waves passing through an object is shifted according to effective refractive index. This process causes edge contrast enhancement in the obtaine images.

    Experimental setup

< ex set
  Settings  

Used geometrical magnification: 1x – 20x
           
Detector temperature stabilized at 10 and 0°C
                   
Tube voltage 40 – 90 kV, current 70 – 240 uA
    
Detector energy threshold set to ~5keV

Response of each pixel calibrated for different attenuator thicknesses

*Exposition time 100 msec – 30 sec per frame


Experimental setup for X-ray µ-radiography and µ-tomography: µ-focus X-ray tube, automatic sample holder and calibration carrousel with images behind.


Biological Samples