The company has developed techniques to produce 2-D OEL BaFCl:Sm3+ Phosphor imaging films, which have several potential advantages.
- The OEL phosphor can be deposited on very thin (100μm) and flexible films –
⇒ application advantages with intra-oral dental films and in industrial applications.
- The BaFCl:Sm3+ phosphor nano-crystals are around ~300nm size, compared with 1-5 microns for current CR imaging phosphors –
⇒ substantial potential image resolution benefit
- This BaFCl:Sm3+ nano-crystalline OEL phosphor has been found to have a high sensitivity and efficiency –
⇒ potentially less X-ray dose versus competing CR imaging phosphors.
These benefits are being documented in imaging trials currently in progress.
Development of a novel film reading technique has been necessary to read the OEL Phosphor, because of its unique properties (refer to Technology):
- The whole film can be excited and imaged by a “single shot” image -
⇒ more rapid Image reading v. “flying spot” readers.
- The individual image “pixels” retain their signal after reading, so can be stimulated and read multiple times -
⇒ improved S/N performance.
- There is no “flying spot” geometry limiting reading resolution –
⇒ potential improved resolution.
In December the company carried out imaging trials with its Mk2 image reader, and demonstrated a spatial resolution equivalent to a leading CR imagers (using the MTF straight edge method) at the same dose. The films were also imaged with the Dental Digital Intra-Oral Performance Evaluation Phantom (Dental Imaging Consultants LLC, San Antonio, Texas, USA) and achieved 11-12 line pairs/mm spatial resolution.
But it was found that this measured resolution was at the limit by the optical design of the Mk2 film reader optics. The Company has designed and is now building its MK3 film reader, which will have the capability to measure the full potential capability of the OEL film in terms of resolution, sensitivity and efficiency.
The OEL phosphor has manufacturing advantages versus current CR phosphors:
- material costs are reduced due to the different rare earth materials used.
- manufacturing costs are less as there is no need for high temperatures in the production of the phosphor.
Our next stage of x-ray imaging trials with the new Mk3 imager are to be completed by end-April. This OEL phosphor imaging performance will also be compared, using the same test protocol, with medical x-ray film, a leading CR dental imager, and a leading DR dental imager.