A method of image registration for three-dimensional reconstruction of microscopic structures using an IBAS 2000 image analysis system.

Registration of histological tissue sections is a longstanding problem in three-dimensional reconstruction. Our solution is to insert rigid straight narrow birefringent structures namely cactus spines as artificial registration points (ARPs) into the tissue block before embedding in wax or resin. The microscopic image of the tissue section with ARPs in situ is presented to an IBAS 2000 Image Analyser and digitised. Registration is performed in two stages using the ARP nearest to the area to be reconstructed as the principle reference point for alignment. The automatic stage is then used to align the structure under reconstruction. These reconstructions are more accurate than those produced without the use of ARPs.