Computed Radiography Research Articles

Evaluating the Relationship of Body Mass Index and Waist Circumference on the Image Quality of Abdominal Computed Radiography

Body sizes of patients undergoing x-ray examination vary in accordance with the range of body mass index (BMI) and waist circumference (WC). The aims of this study were to determine the relationship between BMI and waist circumference on the image quality of computed radiography (CR) abdomen. Anteroposterior (AP) supine abdomen projection was conducted on 69 patients from Hospital Raja Perempuan Bainun, Ipoh using a Siemens Multixtop general x-ray unit and the images were processed with CR Carestream Direct view Max. Samples were categorized into normal BMI (n = 23), overweight (n = 23), and obese (n = 23). Image quality was measured quantitatively in signal to noise ratio (SNR) and qualitatively, visual grading analysis (VGA) based on the European Commission (CEC) image criteria. Data were analyzed by using analysis of variance (ANOVA) and Pearson's correlation for comparison and relationship between BMI, WC and the image quality. Results showed a significant difference (p < 0.01) in image quality of VGA mean (normal 4.40 ± 0.15, overweight 4.35 ± 0.13, obese 4.03 ± 0.34) and SNR mean (normal 60.79 ± 2.19, overweight 59.66 ± 1.68, obese 55.78 ± 4.31). A moderate to high negative correlation exists between SNR (r = -0.73), VGA (r = -0.7) with BMI (p < 0.01), and SNR (r = -0.83), VGA (r = -0.79) with WC (p < 0.01). This study suggests that WC has a higher negative linear relationship compared to BMI and could also be used as a better image quality predictor for CR abdominal examination. DOI : http://dx.doi.org/10.17576/JSKM-2020-1801-02

Application of computed radiography in the quality assurance of linear accelerators in radiotherapy

Introduction: The two mechanisms, optical and radiation fields, operate individually and independently in a Linear Accelerator and cause changes with respect to each other. The standard method for performing the quality assurance (QA) test in radiotherapy involves the irradiation of a radiographic film. In this study, we made an attempt to examine how we could maximize the benefit from an impending filmless environment in the radiotherapy QA program. Aim: The aim is to study the feasibility of using computed radiographs (CRs) in the radiotherapy QA program. Materials and Methods: In this study, the QA tests were performed in Linear accelerators Clinac 600c and Clinac iX, both from Varian Medical Systems, Palo Alto, CA, which was commissioned during September 2004 and July 2011, respectively, were used. Optical and radiation field congruence, radiation isocenter for the gantry, collimator, and couch rotational axis verification, in two linear accelerators were done using gafchromic (EBT3) films and CRs. The standard Gafchromic® EBT3 film, utilized for routine QA were used. The errors estimated were compared and analyzed. Results: The mean error estimated in the QA with both linear accelerators using both QA tools (CR and Film) ranged between 0.053 mm and 0.069 mm, and the standard deviation was estimated to be within 0.062-0.164 mm. Conclusion: The results infer that the QA done with CR is in good agreement with the film. This study poses new challenges to the researchers, task groups, and the regulatory bodies to estimate the frequency of QAs for the newer and the older machines and also, the onset of frequent QAs, once the machine becomes older.

Measurement Accuracy of CT Beam Width with a Portable Flat-panel Detector

X-ray film or computed radiography (CR) system has been employed in clinical setting, and these devices are gradually replaced by portable flat-panel detector (FPD) systems. They may be employed to measure the beam width instead of the traditional CR system. In this study, we estimated the accuracy of beam width measured by the portable FPD system. A CR cassette and FPD were placed at the isocenter, and the pixel values were measured in a single axial CT scanning at a tube potential of 80 kVp, tube currents of 10-40 mA (5 mA steps), and tube rotation time of 0.5 s. Then, the FPD was sandwiched between 0.5 mm copper plate and 2 mm lead plate to avoid the pixel saturation and artifact from the FPD electronic substrates. The beam widths were measured at selected nominal beam widths (40, 80, 120 and 160 mm) using a double exposure technique (tube currents of 10 and 20 mA). Log-linear relationships for two systems were obtained between the pixel value and radiation exposure for parameters less than or equal to 12.5 mAs. A test for the equivalence with confidence intervals showed that the measurement accuracy of the CR and FPD systems was equivalent. The portable FPD system could be utilized for the measurement of the CT beam width as well as CR system.

Image-guided total-body irradiation with a movable electronic portal imaging device for bone marrow transplant conditioning

IntroductionTo prevent radiation pneumonitis following total body irradiation (TBI) clinicians usually use lung shield blocks. The correct position of these shields relative to the patient's lungs is usually verified via mega-voltage imaging and computed radiographic (CR) films. In order to improve this time-consuming procedure, we developed in our department a dedicated, movable, real-time imaging system for image-guided TBI. Material & MethodsThe system consists of an electronic portal imaging device (EPID) mounted on a dedicated support whose motion along a rail can be controlled from the linac console outside the bunker room. Images are acquired online using a stand-alone console. To test the system efficacy we retrospectively analyzed data of lung blocks positioning from two groups of 10 patients imaged with EPID or CR-films, respectively. ResultsThe median number of portal images per fraction was 2 (range 1-5) and 1 (range 1-2) for the EPID and the CR-film system, respectively. The minimum time required for an EPID image acquisition, without interpretation and no need of patient position correction in the bunker, was 20seconds against 214seconds for the CR-film. Lung shielding positioning in the right-left and superior-inferior directions was improved using the EPID system (p<0.01). ConclusionsCompared to CR-films, our movable real-time imaging EPID system is a simple technical solution able to reduce the minimum imaging time for lung shielding by a factor of 10. With the increased possibility to acquire more images as compared to CR-film system the EPID system has the potential to improve patient alignment, as well as patient's comfort and overall setup time.

Accuracy of computed radiography in osteometry: A comparison of digital imaging techniques and the effect of magnification

Abstract Introduction Osteometric data may be obtained using digital imaging techniques, such as post-mortem computed tomography (PMCT) and digital radiography, non-invasively and without ethical objection. Osteometric data from PMCT is known to be as accurate as taking direct measurements. Digital radiography is more accessible and affordable than PMCT but is limited due to the magnification of its subjects. Objectives To investigate the viability of implementing digital radiographic techniques for measurement of long bones, and to establish whether magnification can be accurately corrected for. Materials and Methods Twenty hind pig (Sus scrofa) legs were imaged using computed radiography (CR) and PMCT, and osteometric data obtained from the digital images and 3D CT volume reconstructions. Direct measurements were taken following maceration. A calibration object was imaged using CR, to provide magnification correction factors. Results Accuracy was determined by mean absolute error (AE), giving values of 3.3 ± 2.5 mm for PMCT (MPR), 2.4 ± 1.3 mm for PMCT (3D), 11.1 ± 7.4 mm for CR (PA), and 18.3 ± 14.5 mm for CR (LAT). PMCT data was more accurate than CR data. Through applying correction for magnification, CR data became closer to the direct measurement data, and stature estimation was substantially altered. Conclusion Magnification in computed radiography affects osteometric data and resulting stature estimations. Applying correction factors may be a viable option for improving accuracy. For digital radiography to be used reliably in forensic anthropology, further empirical research is needed to validate a magnification correction method.

PENGEMBANGAN METODE KUADRAN UNTUK PENENTUAN KEDALAMAN BENDA ASING DENGAN MENGGUNAKAN MODALITAS KOMPUTER RADIOGRAFI

Background: The existence of a foreign object in the body generally can interfere with the metabolism of the body, so it can be life-threatening. Therefore it is necessary to take medical action in the form of surgery as soon as possible and precisely with x-ray examination as the guiding. With the development of the use of CR modalities, the method of determining foreign objects with the tools in the CR is considered, which is then called the quadrant method. And this study aims to explain the procedure and then the results are compared with the triangulation method which is a method of determining the depth of foreign objects previously used. Methods: The type of research carried out is exploratory description research with an experimental approach. Where the radiograph was made in cases of foreign objects with 2 methods, namely the triangulation method and quadrant method using CR. First made phantom organ femur, humerus, and thorax in which a foreign object is placed in it. The position of a foreign object is actually measured first and then the results of measuring the depth of a foreign object using the quadrant and triangulation method are compared with the results of the measurement of the actual foreign object. Results: The results showed that the making of radiographs with quadrant methods as well as triangulation methods both used 2 exposures with an x-ray so that the radiation exposure factor obtained by patients in both methods was not much different. Whereas from the comparison of the results of the measurements of the two methods it was found that the triangulation method was better than the quadrant method with smaller measurement differences when compared with the actual measurement of foreign objects. This is because the triangulation method has displayed measurement results based on a formula that uses mathematical calculations by calculating the distance and magnification of objects. And this is not obtained in the quadrant method where measurements are based on the data presented on the CR monitor screen without calculating the distance and magnification of the object first. Conclusion: Radiographic examination procedure determines the depth of foreign matter quadrant method using a computer Radiography is carried out with two projections namely anteroposterior and lateral. While the difference in the depth of the foreign body quadrant method with the depth of the foreign body is actually found that the accuracy of the measurements carried out by the triangulation method is better than the measurements carried out by the quadrant method

Needle-based storage-phosphor detector radiography is superior to a conventional powder-based storage phosphor detector and a high-resolution screen-film system in small patients (budgerigars and mice)

This method comparison study used radiographs of 20 mice and 20 budgerigars to investigate comparability between computed radiography (CR) and high-resolution screen-film systems and study the effects of reduced radiation doses on image quality of digital radiographs of small patients. Exposure settings used with the mammography screen-film system (SF) were taken as baseline settings. A powder-based storage-phosphor system (CRP) and a needle-based storage-phosphor system (CRN) were used with the same settings (D/100%) and half the detector dose (D/50%). Using a scoring system four reviewers assessed five criteria per species covering soft tissue and bone structures. Results were evaluated for differences between reviewers (interobserver variability), systems and settings (intersystem variability, using visual grading characteristic analysis). Correlations were significant (p ≤ 0.05) for interobserver variability in 86.7% of the cases. Correlation coefficients ranged from 0.206 to 0.772. For mice and budgerigars, the CRN system was rated as superior to the SF and CRP system for most criteria, being significant in two cases each. Comparing the SF and CRP system, the conventional method scored higher for all criteria, in one case significantly. For both species and both digital systems, dose reduction to 50% resulted in significantly worse scores for most criteria. In summary, the needle-based storage-phosphor technique proved to be superior compared to the conventional storage-phosphor and mammography screen-film system. Needle-based detector systems are suitable substitutes for high-resolution screen–film systems when performing diagnostic imaging of small patients. Dose reduction to 50% of the corresponding dose needed in high-resolution film-screen systems cannot be recommended.

Optimization of simulated cranial, thorax, and abdominal examination in paediatric digital radiography

This study was aimed to obtain optimum parameter combination in simulated cranial, thorax, and abdominal examinations using computed radiography (CR) and direct digital radiography (DDR) systems. Optimization was performed using in-house phantom with contrast objects on Siemens Luminos Agile Max DDR and Siemens Axiom Luminos TF CR. Paediatric patients were separated into four age groups; 0-1 year (group A), 1-5 years (group B), 5-10 years (group C), and 10-15 years (group D). Slab phantoms with different total thickness were used to simulate patients belonging to each age group for different anatomical region (cranial, thorax, and abdomen). Optimization were performed in three steps; first kVp, followed by mAs, and then additional filter optimization. All the steps of optimization were performed based on FOM (figure of merit) values calculated as ratio of squared SDNR (signal difference to noise ratio) and entrance surface dose with the highest FOM representing the optimum condition. The results of this optimization were evaluated based on the highest FOM generated from each exposure. For both CR and DDR, optimum parameters (i.e. highest FOM) are different for each age group and anatomical region. Even with different X-Ray units, the CR device had slightly similar optimized parameters.

Optimization of digital radiography system using in-house phantom: preliminary study

The purpose of this study was to obtain information on optimum exposure parameter combination on simulated thorax and abdomen examinations using Direct-Digital Radiography (DR) and Computed Radiography (CR) systems. An in-house phantom dedicated for quick QC was utilized as an image quality quantification tool in term of contrast. The optimization was performed on Philips Essenta DR, CR Fuji Profect CS, and CR Agfa 10-X. Exposures were performed using corresponding clinical setting with combinations of kVp, mAs, filters, and a variation of simulated patient thicknesses. The Figure of Merit (FOM) was employed as optimization parameter, calculated as ratio of squared Signal Difference to Noise Ratio (SDNR) and surface dose for every measurement. The image quality was evaluated using Modulation Transfer Function (MTF) and Contrast Consistency (CV). Based on FOM, MTF, and CV calculations, acquisitions optimization for thorax examination using DR was obtained on 55-63 kVp, 5-8 mAs, with additional filter 1 mm Al + 0.1 mm Cu. For abdomen examination, the optimized results were 81-102 kVp, 8-12.5 mAs, with additional filters 1 mm Al+0.1 mm Cu and 1 mm Al+0.2 mm Cu. On the other hand, the optimized results using CR on thorax examination were on the range of 55-63 kV, 4-8 mAs, also with the same additional filters with DR. The results of optimization of abdomen examination were on the range of 85-102 kV, 8-20 mAs, and again with the same additional filters. This gave information that different receptors used on the same x-ray unit produced almost similar optimization conditions.

A hybrid genetic algorithm to reduce the radiation dose in CR images

The quality of computed radiography (CR) images typically relate to patient radiation exposure. The lower the X-ray dose exposure, the higher the level of inherent noise in the CR images. In this work, we address the noise reduction problem by using an estimation of the standard deviation in CR images as an objective function to minimize. We propose a hybrid genetic algorithm for this aim, which produces improved versions of CR images. We also applied an edge-detection method based on the Canny algorithm to preserve the edges of the original CR images. We executed our proposed algorithm for CR images obtained under different radiation exposures. Experimental results show that our solution improves lower radiation CR images reaching a quality as similar to those with higher radiation doses.

A practical method to calibrate and optimise automatic exposure control devices for computed radiography (CR) and digital radiography (DR) imaging systems using the signal-to-noise ratio (SNR) metric

We have established in recent virtual clinical trials that signal-to-noise ratio (SNR) is the most appropriate metric for calibrating AEC devices used with digital imaging systems for chest, abdomen, pelvis and spine radiography. However, the practical calibration of such devices is not straightforward. The purpose of this study was to expand on previous work by developing a practical method for AEC calibration using the validated SNR metric that may be used by medical physicists in the field for phosphor plate radiography (CR) and direct digital radiography (DR - wireless and integrated) imaging systems. This methodology used a uniform tissue equivalent phantom (Poly-methyl methacrylate (PMMA)) so comparison was made with an installation vendor’s method of using copper plates. System transfer properties (STP) of each system were derived to linearise all images required for analyses. All STP correction was done in real time. The relationship between detector air kerma (DAK) and STP corrected SNR was then derived at four tube voltages (60, 80, 100 and 120 kVp) and using this relationship, together with the target value of the calibration metric (SNRtarget), it was possible to calculate the DAK required at each tube voltage to derive a calibration curve for each system; CR systems exhibited a linear increase with kVp, DR systems exhibited a ‘U’ shape. The curve derived using the vendor’s method was not considered optimised because it did not hold SNR constant. This work has demonstrated that a relatively simple method to calibrate AEC devices, using an easily accessible tissue equivalent phantom, can be used in the field in real time by medical physicists working with installation engineers. AEC calibration curves that produce clinically adequate image quality with acceptable patient dose have been installed in our radiology department for CR and DR systems using the methodology described in this paper.

GENERATION OF CR MAMMOGRAPHIC IMAGE FOR EVALUATION QUALITY PARAMETERS

Currently, among the diseases most feared by women, breast cancer ranks first in the world with an incidence of more than 1.6 million cases and a mortality of more than 521.9 thousand cases by year, which makes this disease the type of cancer with higher incidence and mortality compared to the other types of cancer that mainly affect the female gender, without considering non-melanoma skin cancer. In Brazil, more than 14.4 thousand deaths were registered in 2013 and more than 57 thousand new cases were estimated for 2016. The use of computerized radiography (CR) for the generation of mammographic digital images is widely used in Brazil for the screening of breast cancer. The aim of this investigation is to study the variation of CR plate response to exposure to X-ray beams in a mammography unit. Two CR plates from different manufacturers and a compressed breast phantom containing calcium carbonate structures of different sizes simulating calcifications were used for this study. An X-ray beam generated by 30 kV was selected to realize successive exposures of each plate by performing a time variation of 0.5 to 3.5 s, obtaining the raw images. The acquired images were evaluated with the ImageJ software to determine the saturation time of the plates when exposed to X-ray beams and the qualitative resolution of each plate. The plates were found to saturate at different times when exposed under the same conditions to X-ray beams. By means of the images acquired with the breast phantom, it was possible to observe only structures of calcium carbonate with sizes greater than 177 μm.

Implementation of exposure index for optimize image quality and patient dose estimation with computed radiography (a clinical study of adult posteroanterior chest and anteroposterior abdomen radiography)

Chest and abdomen Radiographic are most commonly performed and contribute to doses. For this reason, the examination needs to be controlled to obtain image quality with a safe radiation level. This study aims to obtain standardized radiographic exposure index (EI) in Computed Radiography (CR) which is capable of displaying the image quality optimally and to obtain lower radiation dose based on techniques and EI standardized radiographic exposure without reducing the quality of the image information.This research is a quantitative study with descriptive analysis. Data collected by random sampling technique. The total sample was 61 image editors that have been done by selecting Look Preference Editor (LPE) predetermined. Visual Grading Analysis (VGA) used to analyze quality assessment of the image viewer.The results showed for the chest’s VGA image quality is best viewed directly on the monitor CR with EI value 1430/220.99, whereas to the abdomen by using CR directly, with the best image has EI 1725/496.7. Good criteria image, with low dose estimation and optimal image quality, both chest and abdominal remain below the required range of Bapeten, which chest with 0.003 mGy and abdomen 0.0069 mGy.

Diagnosing a solitary pulmonary nodule using multiple bronchoscopic guided technologies: A prospective randomized study

BackgroundThe rate of detection of pulmonary nodules on computed radiography (CR) is approximately 0.09–0.2%, so rapid identification of the nature of solitary pulmonary nodules (SPNs) with a likelihood of malignancy is a critical challenge in the early diagnosis of lung cancer. ObjectiveWe conducted this study to compare the diagnostic yield and safety of endobronchial ultrasonography with a guide sheath (EBUS-GS), and the combination of EBUS-GS and virtual bronchoscopic navigation (VBN). MethodsThis was a prospective, multicenter, multi-arm, randomized controlled trial involving a total of 1010 subjects. All the patients recruited underwent a chest CT scan which found SPNs that needed to be diagnosed. The subjects were randomly divided into one of three groups: a traditional, non-guided, bronchoscopy biopsy group (NGB group), an EBUS-GS guided bronchoscopy biopsy group (EBUS group), and a guided bronchoscopy biopsy group that combined EBUS-GS with VBN (combined group). The primary endpoint was to investigate the differences between the diagnostic yields of the three groups. ResultsThere was no significant difference in the diagnostic yield between the EBUS group (72.3%) and the combined group (74.3%), but the diagnostic yield for the NGB group was 41.2%. The time required to reach biopsy position was significantly less in the combined group (7.96 ± 1.18 min in the combined group versus 11.92 ± 5.37 min in the EBUS group, p < 0.05). However, the bronchoscope operation time was the same in the EBUS-GS and combined groups. The diagnostic yield for peripheral pulmonary lesions (PPLs) >20 mm in diameter was significantly higher than for those <20 mm in diameter. ConclusionThe results of our study suggest that guided bronchoscopy could increase the diagnostic yield in the context of peripheral lesions. There was no significant difference in the diagnostic yield between the EBUS and combined groups, but use of EBUS-GS with VBN could significantly shorten the bronchoscope arrival time.

Application of computerised radiography in lieu of film radiography to streamline on-site pipe weld quality inspection process

Conventional film radiography has long been the dominant method of non-destructive testing in the Australian pipeline industry. Although proven, the process has disadvantages, including environmental issues with chemical processing and film disposal, significant archival space requirements, film deterioration, and difficulty in traceability and safe sharing with others. In contrast, computerised radiography (CR), using a phosphorus-laden reusable imaging plate and X-ray radiation to generate a latent digitally scannable image, is a clean, compact and efficient process. Although CR has been used on other applications, such as profile radiography for more than a decade, the process has not been considered advanced enough for weld testing until now. After a comprehensive qualification/validation process, CR was successfully used on 481 km of the 622-km-long Northern Gas Pipeline (NGP) Project by McConnell Dowell in the Northern Territory. Proven on approximately 26000 welds, this thinking has changed for good.

Image Quality Assessment of the Digital Radiography Units in Tabriz, Iran: A Phantom Study.

Creating a high-quality image with the low patient dose is one of the most important goals in medical X-ray imaging. In this study, the image quality parameters of the digital radiographic units in Tabriz city were considered and compared with the international protocols. The image quality parameters were measured at 11 high workload digital radiography (DR) imaging centers in Tabriz city, and the results were compared to DINN 6868/58 standards. All centers equipped with the direct DR units passed the spatial resolution, low contrast detectability, contrast dynamic range, and noise tests, while the computed radiography (CR) units only could pass the two last tests. The highest spatial resolution was observed 3.2 lp/mm in the DR unit while the lowest one was 1.8 lp/mm in the CR unit. The highest noise was measured to be 0.03 OD that was observed in the DR unit. The most difference between the nominal and measured peak kilovoltage and mAs was 3.1% and 6.8%, respectively. The entrance surface air kerma in all units was obtained <0.63 mGy. The measured half-value layer range was between 2.4 and 3.54 mmAl. The physical parameters of image quality such as spatial resolution, contrast, and noise are robustness quantitative parameters for the assessment of the image quality performance of the units. Therefore, measurement and control of these parameters using two-dimensional phantoms are very critical.

Comparison of Grayscale and Histogram Thorax Computed Radiography (CR) Image in Tuberculosis (TBC) Patients with Normal Thorax Image

Comparison of Grayscale and Histogram Thorax Computed Radiography (CR) Image in Tuberculosis (TBC) Patients with Normal Thorax Image

Estimation of Mean Estimation of Mean Glandular Dose in Mammography Examination in some of Radiology Centers in Tehran city

Introduction: the objectives of this research were determination of Mean Glandular Dose in film- screen and digital mammography examinations, estimation of accumulated effective dose in some of mammography centers in Tehran city and estimating cancer risk due to these examinations. Materials and Methods: the clinical data were collected from the 1318 mammograms taken from 333 women who were referred to 4 mammography centers in Tehran. The mammography instruments in this study were one film-screen system, one DDR system and two CR system. An RTI dosimeter, piranha system version 3.1, was used for measurement of ESAK and HVL. Compressed breast thickness determined by the mammography systems which was calibrated by a millimeteric ruler. Dgn conversion factor was determined from a program written in C by Bouzarjomehri and et al. Height and weight patients were also measured. Results: The mean ±SD results of MGD per film and per woman were respectively 2.04±0.75 mGy and 8.12 ± 2.75 mGy. The mean effective dose ± SD of patient was 0.4±0.13 m Sv. the number of patients referring to these four mammography centers estimated 8352 per year, so accumulated dose was 3.34 ±1.08 man. Sv With considering of 8% per Sv cancer risk, according to BEIR VII report, the carcinogenic risk of the mammography examinations in these centers will be 0.26 women per year. The MGD results showed a relatively linear correlation with CBT, but age, weight, BMI of the patients haven’t a correlation with MGD, r2<0.3. Conclusion: The average MGD per mammogram of this study was higher than other references, which may be due to the higher average breast thickness of these women relative of the other references but the mean MGD of this study was lower than the RLs values reported by ICRP (3 mGy). The average MGD resulted in this study for the analogue mammography device was lower than the computed radiography (CR) and the direct digital radiography (DDR) devices of.

74. Mean glandular dose survey in the Emilia-Romagna region breast screening program

Purpose We have evaluated the Mean Glandular Doses (MGDs) of Full Field Digital Mammography (FFDM) systems, actually implemented in the Emilia Romagna Screening Program, using the same Plexiglas phantoms. This work aims to evidence the relevance of a large survey to estimate the variability of the doses provided by different mammographic systems available in this screening program. Methods 75 FFDM systems, consisting of 1 Photon-Counting, 33 a-Se Direct, 30 CsI Indirect and 11 Computed Radiography (CR), were characterized by the average values of MGD (mGy) measurements of semi-circular phantom thicknesses of 20 mm, 45 mm and 60 mm. Images were acquired in automatic mode. MGDs were measured in accordance with the Mammo Protocol of the European Federation of Organisations for Medical Physics (EFOMP) [1] . Where available, Organ Doses (ODGs), calculated by manufacturers, were collected from the Header DICOM of the corresponding images and the differences with respect MGDs were evaluated. Results All the MGDs values are within the EFOMP Mammo Protocol limits. Differences from MGDs and ODGs values are in between ±20% for the majority of systems, except for few ones. For 20 mm, 45 mm and 60 mm phantom thickness, the ranges of MGDs extend from 0.37 mGy to 1.00 mGy, 0.65 mGy to 2.40 mGy and from 1.33 mGy to 4.19 mGy respectively. As expected, MGDs show a strong dependence on FFDM system technology: the Photon Counting system has the lowest MGDs values, while the CR systems exhibit the highest ones. Conclusions Our results confirm the importance of monitoring periodically the level of technology employed in a regional screening program by means of a dose survey, in order to promote a renewal of the FFDM imaging systems in accordance with the image quality preferences of the radiologists involved. This survey procedure would be functional also to guarantee the homogeneity of the Risk-Benefit Ratio.

357. iQA: Quality assurance management software in hospital radiology

Purpose iQA takes its bases on the necessity to share QA (Quality Assurance) radiologic information among different professionals such as physician as responsible of technology, technicians and medical physicists. Our medical physics department is involved in the QA of radiologic equipment on several hospitals in the Ferrara district. Methods and materials iQA is a web-based software with a client/server architecture achievable from different navigator browser. Each user has an account that allows to view and modify data according to his permission limited to his equipment. For each radiological center, the equipment (RX tube, workstation monitor, computed radiography (CR) and digital radiography (DR) detectors, magnetic resonance) are listed with their location and technical information. Details on QA protocols and reports, status of maintenance, final evaluation to clinical use are always available. In case of some parameters are out of tolerance an alert is provided to the user by e-mail. Results The use of iQA started from December 2017, after a training of each professional involved. From the beginning it results so useful to a real time monitoring of the equipment status. Conclusion The future developments see the implementation in iQA of the nuclear medicine, radiotherapy equipment and also a radioprotection module. It could be develop iQA mobile application to enhance the users feedback. Download : Download high-res image (201KB) Download : Download full-size image