COMPARISON OF IMAGING PLATES & HIGH-RESOLUTION CCD FOR X-RAY MICRO-FOCUS IMAGING OF COCHLEAR IMPLANTS

Xu J (1, 3), Stevenson AW (2), Cowan RSC (1, 4).

(1) The HEARing CRC, Melbourne, Australia; (2) CSIRO Materials Science and Engineering, Australia; (3) The Bionic Ear Institute, Melbourne, Australia; (4) The Department of Otolaryngology, University of Melbourne, Australia

Introduction: Recording high-resolution X-ray images of inner-ear structures and inserted implants is a challenging issue at the forefront of current radiography techniques.  Previous studies have shown that micro-focus radiography, using the new concept of phase contrast combined with traditional absorption contrast, can greatly improve in vitro temporal bone imaging. In this study we will compare the performance of two imaging detectors, Imaging Plates (IPs) and high-resolution charge-coupled devices (CCD).

Methods: Formalin-fixed cadaver temporal bone was implanted with Nucleus 24 Contourä electrode array. A Feinfocus micro-focus X-ray source with a minimum spot size of 4μm was used. The temporal bones were imaged in projections of Cochlear View and Side View by using both Imaging plates and a high-resolution CCD detector.

Results: Both of the imaging detectors provide good visualisation of anatomical details of inner ear and micro-electrode structures. IP has very good sensitivity and large dynamic range. The CCD detector has higher spatial resolution, but over a smaller field-of-view.

Conclusions and future prospects: IP and CCD detectors are valuable and complementary imaging devices for capturing high-resolution X-ray images. The CCD detector has the advantage of being very useful for recording multiple images as required for X-ray micro-tomography studies.

E-mail: r.cowan@unimelb.edu.au