ABSTRACT
With recent advancement of the medical imaging systems and picture archiving and communication system (PACS), installation of digital radiography has been accelerated over past few years. Moreover, Computed Radiography (CR) which was well established for the foundation of digital x-ray imaging systems at low cost was widely used for clinical applications. This study analyzes imaging characteristics for two systems with different pixel sizes through the Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE). In addition, influence of radiation dose to the imaging characteristics was also measured by quantitative assessment. A standard beam quality RQA5 based on an international electro-technical commission (IEC) standard was used to perform the x-ray imaging studies. For the results, the spatial resolution based on MTF at 10% for Agfa CR system with I.P size of 8x10 inches and 14x17 inches was measured as 3.9 cycles/mm and 2.8 cycles/mm, respectively. The spatial resolution based on MTF at 10% for Fuji CR system with I.P size of 8X10 inches and 14x17 inches was measured as 3.4 cycles/mm and 3.2 cycles/mm, respectively. There was difference in the spatial resolution for 14x17 inches, although radiation dose does not effect to the MTF. The NPS of the Agfa CR system shows similar results for different pixel size between 100 micrometer for 8x10 inch I.P and 150 micrometer for 14x17 inch I.P. For both systems, the results show better NPS for increased radiation dose due to increasing number of photons. DQE of the Agfa CR system for 8X10 inch I.P and 14x17 inch I.P resulted in 11% and 8.8% at 1.5 cycles/mm, respectively. Both systems show that the higher level of radiation dose would lead to the worse DQE efficiency. Measuring DQE for multiple factors of imaging characteristics plays very important role in determining efficiency of equipment and reducing radiation dose for the patients. In conclusion, the results of this study could be used as a baseline to optimize imaging systems and their imaging characteristics by measuring MTF, NPS, and DQE for different level of radiation dose.
Subject(s)
Humans , Diagnostic Imaging , Noise , Photons , Radiographic Image EnhancementABSTRACT
Computed Radiology(CR) has been used widely with the development of digital imaging technology.CR technique has shown many advantages over traditional radiography.However,the control to radioactive exposure dose is an indispensable issue during clinical practice.
ABSTRACT
Objective CR's advantages of flexibility are analysed, and its reasonable clinical use are evaluated. Methods To compare CR and general roentgenography. Results CR system is one of main X-ray photography. Conclusion Because of the unique advantages of CR, CR and DR will be still clinically equally important in the future for a long period of time.
ABSTRACT
Over exposal dose often occurs in CR system because of reduction of performance, contamination, dilapidation and aging of IP board, etc. The exposal dose tester is used to test and calibrate CR system. In this way, the problem of incorrect exposal dose of CR system is solved and image in high definition is obtained under proper exposal dose.
ABSTRACT
Objective To investigate the applied of CR system in X-ray photography bedside.Methods X-ray photography bedside was proformed in 900 cases.The imaging quality in excellent,good and poor was evaluated.Results Of 900 cases,the imaging quality was excellent in 780 cases (86.7%),good in 116 cases (12.9%) and poor in 4 cases(0.4%).Conclusion The imaging quality of CR in excellent,to the back processings,it is conveninent in the digital store and longdistance transport.