A system for spectroscopic imaging of bodily tissue in which a scintillation screen and a charged coupled device (CCD) are used to accurately image selected tissue. An x-ray source generates x-rays which pass through a region of a subject's body, forming an x-ray image which reaches the scintillation screen. The scintillation screen reradiates a spatial intensity pattern corresponding to the image, the pattern being detected by a CCD sensor. The image is digitized by the sensor and processed by a controller before being stored as an electronic image. Each image is directed onto an associated respective CCD or amorphous silicon detector to generate individual electronic representations of the separate images.

System for quantitative radiographic imaging

A patient positioning system for use with a radiation therapy system that monitors the location of fixed and movable components and pre-plans movement of the movable components so as to inhibit movement if a collision would be indicated. The positioning system can also coordinate movement of multiple movable components for reduced overall latency in registering a patient. The positioning system includes external measurement devices which measure the location and orientation of objects, including components of the radiation therapy system, in space and can also monitor for intrusion into the active area of the therapy system by personnel or foreign objects to improve operational safety of the radiation therapy system.

Path planning and collision avoidance for movement of instruments in a radiation therapy environment

A radiation treatment system (100) for accurately delivering radiation to a targeted site within a cancer patient (108) that includes a modular patient support system and a patient positioner (114). The modular patient support system includes a modularly expandable patient pod (200) and at least one immobilization device, such as, for example, a rigid moldable foam cradle (350). The patient pod (200) includes a generally hemi-cylindrical support shell (212) that extends longitudinally between proximal edge (214) and distal edge (216), and transversely between two lateral edges (222, 224). In one embodiment, the lateral edges (222, 224) are tapered to minimize edge effects that result when radiation beams traverse the lateral edges (222, 224).

Modular patient support system

A patient alignment system for a radiation therapy system. The alignment system includes multiple external measurement devices which obtain position measurements of components of the radiation therapy system which are movable and/or are subject to flex or other positional variations. The alignment system employs the external measurements to provide corrective positioning feedback to more precisely register the patient and align them with a radiation beam. The alignment system can be provided as an integral part of a radiation therapy system or can be added as an upgrade to existing radiation therapy systems.

Patient alignment system with external measurement and object coordination for radiation therapy system

A thin-film, flat panel, pixelated detector array serving as a real-time digital imager and dosimeter for diagnostic or megavoltage X rays or gamma rays, including a plurality of photodiodes (30) made of hydrogenated amorphous silicon arrayed in columns and rows upon a glass substrate (12). Each photodiode (30) is connected to a thin film field effect transistor (52) also located upon the glass or quartz substrate (12). Upper and lower metal contacts (38, 22) are located below and above the photodiodes (30) to provide the photodiodes (30) with a reverse bias. The capacitance of each photodiode (30) when multiplied by the resistance of the field effect transistor (52) to which it is connected yields an RC time constant sufficiently small to allow fluoroscopic or radiographic imaging in real time.

Thin-film, flat panel, pixelated detector array for real-time digital imaging and dosimetry of ionizing radiation

A multi-element-amorphous-silicon detector-array real-time imager and dosimeter for diagnostic or megavoltage X rays having megavoltage photons having a plurality of photodiodes (30) made of hydrogenated amorphous silicon arrayed in columns and rows upon a glass substrate (12). Each photodiode (30) is connected to a thin film field effect transistor (52) also located up-on the glass substrate (12). Upper and lower metal contacts (22, 38) are located below and above the photodiodes (30) to provide the photodiodes (30) with a reverse bias. The capacitance of each photodiode (30) when multiplied by the resistance of the field effect transistor (52) to which it is connected yields an RC time constant sufficiently small to allow real time imaging.

Multi-element-amorphous-silicon-detector-array for real-time imaging and dosimetry of megavoltage photons and diagnostic x-rays

In recent years, as a direct result of extensive research and development, a growing number of x-ray imagers based on the powerful concept of active matrix addressing have been introduced to clinical environments worldwide. These imagers consist of thin, large area, glass substrates onto which 2D, pixelated arrays are deposited. Each pixel comprises an amorphous silicon thin-film switch coupled to some form of pixel storage capacitor. The radiation is detected indirectly, by means of an overlying scintillators, or directly, by means of a photoconductor layer. While existing active matrix imagers offer many advantages, the present technology suffers form a variety of distinct limitations and disadvantages that pertain to imaging performance under conditions of low exposure per image frame, as well as to issues of mechanical robustness and cost. In this paper, the possibility that these restrictions could be removed through the adoption of novel, emerging technologies is discussed. The focus of the discussion is primarily on technologies under independent development for large-area electronics and other applications and for which a plausible chance of convergence with x-ray imaging technology exists.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Robert A. Street

Papers

Thin-film, flat panel, pixelated detector array for real-time digital imaging and dosimetry of ionizing radiation

Multi-element-amorphous-silicon-detector-array for real-time imaging and dosimetry of megavoltage photons and diagnostic x-rays

Technological pathways for 21 st century active matrix x-ray imager development