RÉSUMÉ
Objective To investigate the application value of multifunctional dynamic flat panel X-ray detector in intravenous pyelography.Methods Total 540 patients with intravenous pyelography were divided into multifunctional dynamic flat panel X-ray detector group (300 cases) and conventional flat panel X-ray detector group (240 cases) by random digits table method.Image quality,radiation dosage and examination time were analyzed and compared between the two groups.Results There was no statistical difference between the two groups in image quality (P > 0.05).The examination time and radiation dosage was (25.5 ± 8.2) min and (12.5 ± 6.8) mAs respectively in multifunctional dynamic flat panel X-ray detector group and (39.2 ± 12.1) min and (23.6 ± 7.6) mAs in conventional flat panel X-ray detector group.The differences had statistical significance (P < 0.01).Conclusions Multifunctional dynamic flat panel X-ray detector in intravenous pyelography can provide lower radiation dose,shorter examination time and higher image quality.It has obvious advantages in urography.
RÉSUMÉ
For the use of Indirect-conversion CMOS (complementary metal-oxide-semiconductor) detectors for digital x-ray radiography and their better designs, we have theoretically evaluated the spatial-frequency-dependent detective quantum efficiency (DQE) using the cascaded linear-systems transfer theory. In order to validate the developed model, the DQE was experimentally determined by the measured modulation-transfer function (MTF) and noise-power spectrum, and the estimated incident x-ray fluence under the mammography beam quality of W/Al. From the comparison between the theoretical and experimental DQEs, the overall tendencies were well agreed. Based on the developed model, we have investigated the DQEs values with respect to various design parameters of the CMOS x-ray detector such as phosphor quantum efficiency, Swank noise, photodiode quantum efficiency and the MTF of various scintillator screens. This theoretical approach is very useful tool for the understanding of the developed imaging systems as well as helpful for the better design or optimization for new development.
Sujet(s)
Mammographie , Bruit , Amélioration d'image radiographiqueRÉSUMÉ
Objective To upgrade the current X-ray vehicle.Methods Modern digital X-ray radiography was analyzed and 3 kinds of X-ray detectors were compared.Canon CXDI digital X-ray detector was used to update field X-ray vehicle into a field digital X-ray radiography vehicle.Results Real-time X-ray signal synchronization was realized.Digital images could be edited and labeled with detection information.Conclusion The working efficiency is enhanced and the support ability is improved.
RÉSUMÉ
S2001 field X-ray vehicle is used to perform X-ray examination in the field hospital, while the disadvantages of the traditional film-screen radiography restrict its role of field examination in this digital era. By analyzing the detail of modern digital X-ray radiography, and comparing three different digital X-ray flat detectors, a solution is put forward to update S2001 field X-ray vehicle to a field digital X- ray radiography vehicle by using Canon CXDI digital X- ray detector.