Comparison of clinical and physical measures of image quality in chest and pelvis computed radiography at different tube voltages (original) (raw)
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Flat-Panel-Detector Chest Radiography: Effect of Tube Voltage on Image Quality
Radiology, 2005
Author contributions: Guarantor of integrity of entire study, C.S.P.; study concepts, M.U., M.P., C.S.P.; study design, M.U., U.N.; literature research, N.K., M.U.; clinical studies, M.U., N.K.; data acquisition, N.K., M.U., C.S.P., U.N.; data analysis/ interpretation, U.N., M.U., M.W., C.J.H.; statistical analysis, M.W.; manuscript preparation, M.U., C.S.P., U.N.; manuscript definition of intellectual content, M.P., U.N., M.U.; manuscript editing, C.S.P., M.U.; manuscript revision/review, M.P., N.K., M.W., C.J.H.; manuscript final version approval, all authors PURPOSE: To compare the visibility of anatomic structures in direct-detector chest radiographs acquired with different tube voltages at equal effective doses to the patient.
Optimization of Image Quality and Patient Dose in Digital Radiography of the Chest
Journal of Babol University of Medical Sciences, 2017
BACKGROUND AND OBJECTIVE: Digital systems have been replacing with screen-film analogue systems in diagnostic radiology departments, rapidly. Despite the differences in the properties of new x-ray imaging detectors, the same radiographic protocols that had been used for radiographic film-screen are used for digital imaging systems, without any review yet. In this study, the image quality and the patient dose in digital imaging of the chest are evaluated and optimized. METHODS: Two digital radiography machines, Shimadzu RDA Speed and Siemens G2107 have been used in this experimental research. Imaging and dose measurement are carried out at different source to phantom distances and kilo-voltages. For measurement of the image quality, a contrast-detail radiography (CDRAD) phantom is used. For evaluation of optimization, the Inverse Image Quality Figure per patient dose squared (IQFinv/E 2) is used. FINDINGS: Evaluation of measured data for optimization shows that for both of these two digital radiography machines, despite of increasing in patent dose, with reducing of kilo-voltage, the IQFinv/E 2 is increased. The maximum values of this parameter for Imam Khomeini and Bu Ali Hospitals are measured 0.0180 and 0.0083, respectively. CONCLUSION: The results of this study indicate that despite the traditional notion of using higher kilo-voltages for chest radiography, with increasing kilo-voltage, the ratio of image quality per patient dose is reduced. So, for optimization of chest radiography, as much as possible the kilo-voltage should be reduced based on the size of patient and clinical purpose.
Flat-Panel–Detector Chest Radiography: Effect of Tube Voltage on Image Quality1
Radiology, 2005
Author contributions: Guarantor of integrity of entire study, C.S.P.; study concepts, M.U., M.P., C.S.P.; study design, M.U., U.N.; literature research, N.K., M.U.; clinical studies, M.U., N.K.; data acquisition, N.K., M.U., C.S.P., U.N.; data analysis/ interpretation, U.N., M.U., M.W., C.J.H.; statistical analysis, M.W.; manuscript preparation, M.U., C.S.P., U.N.; manuscript definition of intellectual content, M.P., U.N., M.U.; manuscript editing, C.S.P., M.U.; manuscript revision/review, M.P., N.K., M.W., C.J.H.; manuscript final version approval, all authors PURPOSE: To compare the visibility of anatomic structures in direct-detector chest radiographs acquired with different tube voltages at equal effective doses to the patient.
The Practice of Chest Radiography Using Different Digital Imaging Systems: Dose and Image Quality
Original Article Introduction: The study was undertaken to evaluate the practice of chest radiography using different digital imaging systems and its influence on dose and image quality. Materials and Methods: The study was carried out in two hospitals from March 2016 to June 2016. Sixty ambulatory patients aged 21 to 60 years who were able to cooperate without difficulty and weighed between 60 to 80 kg were selected randomly. The active matrix flat panel imagers technology was employed in the direct radiography (DR) system for Hospital A, whilst Hospital B used the single read out computed radiography (CR) system. The dose area product (DAP) meter was utilized in measuring the entrance surface air kerma. The chest radiographs were evaluated by two radiologists. Results: The mean entrance surface doses (ESDs) for posteroanterior chest in Hospital A (0.098 mGy) was lower than that obtained in Hospital B (0.161 mGy). However, the ESDs at both centres were lower than the recommended value by the International Atomic Energy Agency (IAEA; 0.3 mGy). The quality of the images for chest radiography in both hospitals was adequate to make a diagnosis with ESDs and effective doses lower than those recommended by IAEA and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Conclusion: The study serves to highlight the practice of chest radiography with two different systems and its influence on image quality and dose. It can be concluded that there were significant differences in image quality and radiation dose for chest radiography practice using CR and DR.
Radiography, 2004
The rapid development in digital acquisition technology in radiography has not been accompanied by information regarding optimum radiographic technique for use with newly developed systems. Three of the most common technologies for digital radiographic examinations of the chest are flat panel amorphous Silicon Caesium Iodide systems (FPD), amorphous Selenium drums (DSD) and photostimulable storage phosphor computed radiography (CR). Published data on the effect of X-ray beam energy on image quality and patient dose when using these digital image acquisition devices are reviewed. It is important that radiographers are aware of optimum kVp selection for these systems, particularly for the commonly performed chest examination.
The British Journal of Radiology, 2001
The ability to predict clinical image quality from physical measures is useful for optimization in diagnostic radiology. In this work, clinical and physical assessments of image quality are compared and correlations between the two are derived. Clinical assessment has been made by a group of expert radiologists who evaluated fulfilment of the European image criteria for chest and lumbar spine radiography using two scoring methods: image criteria score (ICS) and visual grading analysis score (VGAS). Physical image quality measures were calculated using a Monte Carlo simulation model of the complete imaging system. This model includes a voxelized male anatomy and was used to calculate contrast and signal-to-noise ratio of various important anatomical details and measures of dynamic range. Correlations between the physical image quality measures on the one hand and the ICS and VGAS on the other were sought. 16 chest and 4 lumbar spine imaging system configurations were compared in frontal projection. A statistically significant correlation with clinical image quality was found in chest posteroanterior radiography for the contrast of blood vessels in the retrocardiac area and a measure of useful dynamic range. In lumbar spine anteroposterior radiography, a similar significant correlation with clinical image quality was found between the contrast and signal-to-noise ratio of the trabecular structures in the L1-L5 vertebrae. The significant correlation shows that clinical image quality can, at least in some cases, be predicted from appropriate measures of physical image quality.
Evaluation of dose–image-quality optimization in digital chest radiography
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007
In this study, we aimed to evaluate the operation conditions and reduce patient doses while maintaining acceptable image quality in digital chest radiography. A geometric chest phantom with built-in regional test objects for quantitative assessment of image quality was used to produce images that simulate a chest projection. Images of the chest phantom were obtained using a GE Revolution XR/d digital X-ray system operated at tube potentials from 62 to 132 kVp with the grid and a distance of 180 cm between the source and image system. The X-ray images were obtained with the automatic exposure control (AEC) mode. Raw data of the acquired images were used for image-quality analysis. The signal-to-noise ratio (SNR) was used as an image-quality indicator and a figure of merit (FOM) computed by dividing the SNR 2 by the effective dose was used to estimate the optimization of the chest radiography. The routine operation tube potential of 112 kVp seems optimal for subdiaphragm examinations but not for lung and heart examinations.
The British Journal of Radiology
Objectives: The aim of this study was to investigate via computer simulation a proposed improvement to clinical practice by deriving an optimised tube voltage (kVp) range for digital radiography (DR) chest imaging. Methods: A digitally reconstructed radiograph algorithm was used which was capable of simulating DR chest radiographs containing clinically relevant anatomy. Five experienced image evaluators graded clinical image criteria, i.e., overall quality, rib, lung, hilar, spine, diaphragm and lung nodule in images of 20 patients at tube voltages across the diagnostic energy range. These criteria were scored against corresponding images of the same patient reconstructed at a specific reference kVp. Evaluators were blinded to kVp. Evaluator score for each criterion was modelled with a linear mixed effects (LME) algorithm and compared with the score for the reference image. Results: Score was dependent on tube voltage and image criteria in a statistically significant manner for both...