Researchers at the Space Research Centre at the University of Leicester have developed a Mini Gamma-Ray Camera(MGRC) for use in nuclear medicine. The camera employs solid-state detector technology originally developed for x-ray astronomy applications.
Key application for the MGRC will be the detection and imaging of sentinel lymph nodes, which forms part of the diagnosis of cancer. Current procedures can require investigative surgery to assess the spread of primary tumours. The device will help to reduce the cost and trauma of surgery. Other non-intrusive techniques are coming to the market, although an assessment of these indicates they do not achieve the projected performance of the Space Research Centre MGRC systems.
The MGRC has been developed as a collimated, scintillator-coated, low noise device which complements whole-body gamma cameras as a generic low cost, high performance, hand held gamma camera. These cameras have an intrinsic sub-mm spatial resolution (~0.5mm) and excellent energy resolution over an energy range of 30-160keV.
The MGRC is based on an existing class of detector, incorporating a scintillator which converts gamma-rays into photons, made from CsI(Tl) in a columnar layer placed in direct contact with a silicon CCD. The specific goal is to image, with high spatial resolution and good scatter-rejection, the 140.5keV gamma-ray emissions from 99mTechnetium-labelled tracers.
Standard whole body gamma cameras are expensive and offer only a moderate spatial resolution (approx. 10mm). The cost of such systems often precludes their widespread use. MGRC cameras will be significantly cheaper than the standard gamma cameras.
Small gamma cameras will be a natural complement to whole body gamma cameras by offering imaging of small volumes of tissue, joints etc. at higher spatial resolutions (~0.4mm cf. 4mm).
