Title :
Recent results with a CdTe imaging portal scanner for radiation therapy
Author :
Entine, G. ; Redus, R.H. ; Feyder, A. ; Biggs, P.J.
Author_Institution :
Radiation Monitoring Devices, Inc., Watertown, MA, USA
Abstract :
A prototype portal imager has been constructed using a linear array of 256 CdTe photovoltaic detectors, each 2×2×2 mm. The array is attached to a compact linear scanner which is to be mounted in a cassette-shaped package located below the patient table. The array of detectors is moved under the patient during image acquisition. The high stopping power of CdTe allows a high-contrast image to be made using a single linac pulse for each array position. In tests conducted with a 4 MV linac, this system produced 50 cm×35 cm near-real-time images with an open field signal-to-noise ratio (SNR) of 143 and 2 mm spatial resolution in less than three seconds. This corresponds to a SNR of 1 for 1% contrast objects. Ultimately, a SNR greater than 5 at 1% contrast should be achievable with no loss of spatial resolution or increase in acquisition time
Keywords :
biomedical equipment; cadmium compounds; radiation therapy; 4 MV; CdTe imaging portal scanner; acquisition time; cassette-shaped package; compact linear scanner; high-contrast image; medical instrumentation; near-real-time images; open field signal-to-noise ratio; patient table; photovoltaic detectors; radiotherapy equipment; single linac pulse; spatial resolution; Detectors; Linear particle accelerator; Packaging; Photovoltaic systems; Portals; Prototypes; Sensor arrays; Solar power generation; Spatial resolution; System testing;
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference, 1992., Conference Record of the 1992 IEEE
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-0884-0
DOI :
10.1109/NSSMIC.1992.301535
