Scintillator materials can convert high-energy radiation, such as X-rays and gamma rays, into visible light. Scintillators are widely used in detection and non-invasive imaging technologies, such as imaging systems for medical and screening applications. In such systems, high-energy photons typically pass through the person or object undergoing imaging and, on the other side of the imaging volume, impact a scintillator associated with a light detection apparatus. The scintillator typically generates optical photons in response to the high-energy photon impacts. The optical photons may then be measured and quantified by the light detection apparatus, thereby providing a surrogate measure of the amount and location of high-energy radiation incident on the detector. Additionally, scintillators may be useful in systems used to detect radioactive objects, such as contraband or contaminants, and even underground radiation sources which might otherwise be difficult to detect.
General Electric Company (Niskayuna, NY) scientists have developed a scintillation detector using nano-scale particles of a scintillation compound embedded in a plastic matrix. The nano-scale scintillator particles may be made from metal oxides, metal oxyhalides, metal oxysulfides, or metal halides. The particles may be coated with organic compounds or polymers prior to incorporation in the plastic matrix. A technique for matching the refractive index of the plastic matrix with the nano-scale scintillator particles by incorporating nano-scale particles of titanium dioxide was also developed by inventors Sergio Paulo Martins Loureiro, James Scott Vartuli, Brent Allen Clothier, Steven Jude Duclos, Mohan Manoharan, Patrick Roland Lucien Malenfant, Venkat Subramaniam Venkataramani and Clifford Bueno
The scintillator may be coupled with one or more photodetectors to form a scintillation detection system. The scintillation detection system may be adapted for use in X-ray and radiation imaging devices, such as digital X-ray imaging, mammography, computer tomography (Cat Scan), positron emission tomography (PET), or Single photon emission computed tomography (SPECT), or may be used in radiation security detectors or subterranean radiation detectors. GE’s s scintillator device and materials earned U.S. Patent 7,608,829.
With regard to non-invasive imaging techniques, one of the most important applications for scintillators is in medical equipment for the production of radiographic images using digital detection and storage systems. For example, in current digital X-ray imaging systems, such as CT scanners, radiation from a source is directed toward a subject, typically a patient in a medical diagnostic application. A portion of the radiation passes through the patient and impacts a detector. The surface of the detector converts the radiation to light photons which are sensed. The detector is divided into a matrix of discrete picture elements, or pixels, and encodes output signals based upon the quantity or intensity of the radiation impacting each pixel. Because the radiation intensity is altered as the radiation passes through the patient, the images reconstructed based upon the output signals provide a projection of the patient's tissues similar to those available through conventional photographic film techniques.
Another high-energy radiation based imaging system is positron emission tomography (PET), which generally employs a scintillator-based detector with its pixels typically arranged in a circular array.
Another high-energy radiation based imaging system is positron emission tomography (PET), which generally employs a scintillator-based detector with its pixels typically arranged in a circular array.
