Title :
Development and evaluation of a digital radiographic system based on CMOS image sensor
Author :
Kim, H.K. ; Cho, G. ; Lee, S.W. ; Shin, Y.H. ; Cho, H.S.
Author_Institution :
Dept. of Nucl. Eng., Korea Adv. Inst. of Sci. & Technol., Taejon, South Korea
Abstract :
A cost-effective digital radiographic system with a large field-of-view (FOV) of 17"×17" has been developed. The cascaded imaging system mainly consists of 3 parts: (1) a phosphor screen to convert incident X-rays into visible photons, (2) an 8×8 array matrix lens assembly to efficiently collect visible photons emitted by the phosphor screen; and (3) 8×8 complementary metal-oxide-semiconductor (CMOS) image sensors, aligned to the corresponding lens assembly. Although low in cost due to economical CMOS image sensors, the overall performance features are comparable with other commercial digital radiographic systems. From the analysis of signal and noise propagation, the system is not an “X-ray quantum-limited” system, rather the system has a secondary quantum sink at the light collecting stage. The system resolution is about 2 line-pairs per millimeter from both of the measurement from X-ray images of a line-pair test pattern and the calculation of the modulation-transfer function. Detailed experimental and theoretical analysis of performance is discussed
Keywords :
CMOS image sensors; biomedical electronics; diagnostic radiography; image resolution; phosphors; cascaded imaging system; digital radiographic system; light collecting stage; line-pair test pattern; matrix; medical diagnostic imaging; medical instrumentation; modulation-transfer function calculation; phosphor screen; secondary quantum sink; system resolution; Assembly systems; CMOS image sensors; Image converters; Lenses; Optical imaging; Optoelectronic and photonic sensors; Phosphors; Radiography; Sensor arrays; X-rays;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2000 IEEE
Conference_Location :
Lyon
Print_ISBN :
0-7803-6503-8
DOI :
10.1109/NSSMIC.2000.949394
