Screen-film Systems Research Articles

Impact of Electronic Collimation on Reducing Unnecessary Patient Dose in Digital Radiography.

In radiology, optimizing radiation protection is crucial, and field collimation plays a critical role in minimizing patient dose. As technology has evolved, electronic collimation has become the preferred method due to its effectiveness in digital imaging systems, replacing traditional film-screen systems. The current study aimed to investigate the prevalence of cropping in digital radiography and its potential impact on patient radiation dose because of improper collimation practices. This retrospective analysis was conducted on digital X-ray machine images. Quality control tests were performed to ensure equipment accuracy, and image cropping was then measured by analyzing archived images. Finally, the cropped image fraction and associated unnecessary radiation doses were calculated. Quality control tests confirmed that all imaging equipment was functioned within acceptable alignment and angle tolerances. The analysis of 911 images revealed a high prevalence of cropping (82%), with significant variation across different projections. Lateral knee images exhibited the highest cropping rate (96.2%), while abdominal images had the lowest (36.1%). Electronic image cropping can lead radiologic technologists to inaccurately define the primary radiation field, affecting image quality and potentially increasing patient radiation exposure. Based on the obtained results, proper collimation can reduce the average Dose Area Product (DAP) by 29.01%. This approach not only enhances patient safety but also minimizes unnecessary radiation exposure and potentially reduces healthcare costs.

Diagnostične referenčne ravni v dentalni radiologiji - Sistematični pregled literature

Purpose: The purpose of this work was to review published articles in the fi eld of diagnostic reference levels in dental radiology, and to determine which areas have not been covered yet and require further scientifi c studies. The aim was also to determine if there are any dose optimization procedures suggested after DRL establishment. Materials and methods: A systematic review was performed using the Science Direct, PubMed, CINAHL (via EBSCOhost) and Dentistry & Oral Sciences Source (via EBSCOhost) databases, following the Cochrane Network study design guidelines. Articles were analysed and presented by author, year of publication, country of origin, technology (e.g. digital radiography, computed radiography and fi lm-screen), radiographic type (e.g. intraoral, panoramic and CBCT), units of measurement and main conclusions for each study. Results: Thirteen scientifi c articles on dose reference values in dental radiology were evaluated. Full-access articles published between 2001 and 2021 were used, and both reviews and original research articles were included. The studies address the defi nition or analysis of DRLs in intraoral and panoramic dental imaging and in dental CBCT imaging. Many studies report results based on diff erent image-receiving systems (e.g. DR, CR and fi lm-screen). The fi lm-screen system yielded the highest dose values of all three systems. All studies reviewed describe DRLs for the adult population, while only four also describe paediatric DRLs. Conclusion: Most EU countries have not yet set national DRLs for dental radiology. Most studies set or revise DRLs at the national level and compare them with guidelines from literature and from similar studies conducted in other countries. Most of these studies observed DRLs in the adult population. DRLs should also be set in the fi eld of dental CBCT imaging, as the use of this technology is rapidly increasing and the dose levels are incomparably higher than in general dental radiography. Keywords: dental radiography, diagnostic reference levels, intraoral imaging, panoramic dental imaging.

The Speed of Screen–Film Systems for Four Exposure Techniques According to the Requirements of GOST ISO 9236-1

The Speed of Screen–Film Systems for Four Exposure Techniques According to the Requirements of GOST ISO 9236-1

Dual-Energy, Dual-Exposure PA and Lateral Chest Radiograph: Not Your Father's Chest X-Ray.

In the last two decades, our military and federal health care facilities have transitioned from traditional X-rays exposing film screen systems, developed much like photographic film, to an entirely digital detection system that affords computer processing of images and digital image and report distribution. While health care providers are well aware of the practicality of these advancements, they may not be aware of the improved diagnostic capabilities afforded by these new methods. In this report, we outline how application of physical principles of X-rays, with digital detectors and computer data manipulation, can present images demonstrating chest and heart diseases that were previously not readily visible by traditional film screen systems. More recently, dual-energy, dual-exposure systems have been implemented. This commentary is to educate the medical community so that they may better understand not only the written report but the information on the images being provided, along with potential pitfalls to avoid. Specifically, we demonstrate improved detection of pulmonary nodules and coronary atherosclerosis with the dual-energy technique.

Monitoring of Patients Using Radiodiagnostic Dosage EI (Exposure Index) on CR (Computed Radiography)

Most of the current radiographic examinations have used digital technology, one of which is for image readers and image processing using the CR (Computed Radiography) modality. The use of CR is more advantageous than film-screen systems because it has Faster image acquisition and processing, a wide dynamic range, easy contrast adjustment, brightness, and electronic cropping. Unfortunately, the amount of exposure radiation is difficult to assess when using digital imaging compared to screen-film systems. Based on field observations, a radiographer tends to ignore the EI (Exposure Index) value in the application of the CR modality. The success of the radiographer in the radiography process is limited to the image that is not repeated. Even though the image quality factor is not merely a matter of repeated images or not, but also those who have the breadth of information and also must maintain protection principles for patients, in this case, is the acceptance of the dose due to radiography. So it is necessary to monitor the patient's dose using the EI value.

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.

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.

ESTIMATION OF ADULT PATIENT DOSES FOR CHEST X-RAY EXAMINATIONS AND COMPARISON WITH DIAGNOSTIC REFERENCE LEVELS (DRLs).

The aim of this study was to evaluate the radiation doses to patient during chest (posterior anterior/and lateral) examinations. The study was performed in three public hospitals of İstanbul province with a total of 300 adult patients. Entrance surface dose (ESD) measurements were conducted on computed radiography, digital radiography and screen film system. ESD was estimated by using International Atomic Energy Agency (IAEA) model and Davies model which are the common indirect models. Results were compared with diagnostic reference levels from the European Commission, IAEA and National Radiological Protection Board. Although the results are compatible with the international diagnostic reference levels, they present variations between the hospitals. Dose variations for the same type of X-ray examination support the idea that further optimization is possible.

Assessment of image quality and radiation dose in some models of digital radiography systems – A Pehamed FLUORAD A + D phantom study

Digital radiography (DR) systems have been recently introduced as a developed technology that is replacing conventional film–screen systems in many countries around the world. Ideal situation in radiography is to maximize the image quality while minimizing the patient dose. The purpose of this study was to compare image quality and radiation dose in different digital radiography systems. Four different digital systems are compared in terms of their image quality performance and dose area product (DAP). Images of Pehamed FLUORAD A + D phantom were obtained for each DR system. Image quality parameters (contrast resolution (CR), spatial resolution (SR), and contrast-to-noise ratio (CNR)) and DAP were significantly different between different digital systems. It was shown that all four quantities increased with increasing exposure parameters in all systems. Image quality parameters of the SEDECAL system were higher than that in other systems (p ≤ 0.05). At the stable DAP (100 mGy.cm2), means of CR, CNR, and SR in the SEDECAL system were 6.38 ± 0.797, 29.70 ± 0.85 and 3.10 ± 0.38 lp/mm, respectively. The results of this investigation can be taken into consideration in the selection and purchasing of new systems in order to preserve patients as well as radiographers from unnecessary radiation dose.

An insight into digital radiography use in small animal practice in the UK

It is now approximately 20 years since the first UK veterinary digital x-ray machine was installed.1 Instead of x-ray film, digital radiography uses a digital image capture device. The advantages...

Mean glandular dose values used for the mammography screening program in Poland according to the type of image registration system

Between 2007–2014, there have been considerable changes in the use of different types of detector systems at mammography facilities undertaking screening programs in Poland. The use of screen-film systems (termed SF systems) has largely decreased and been replaced by either computed radiography (termed CR systems) or digital radiography systems (termed DR systems); this inevitably affecting mean glandular dose values. The study aim was to evaluate changes of mean glandular dose values for a dose exposure of 4.5 cm (MGD 4,5cmPMMA ) achieved by using different image detectors. The study consisted of analysing 1499 protocols for quality control tests carried out by medical physicists at 16 Regional Coordination Offices in 2007, 2011, 2012 and 2013. The mean CR system values were higher than for SF systems; by 25% in 2011, by 26% in 2012, and by 28% in 2013. In subsequent years, the MGD 4,5cmPMMA mean values for DR systems were higher than for SF systems by respectively 15%, 4% and 5%. Also in the subsequent years, the MGD 4,5cmPMMA mean values for CR systems were higher than for DR systems by respectively 13%, 23% and 24%. In all cases, the MGD 4,5cmPMMA mean values were within the acceptable level of 2.5 mGy. The MGD 4,5cmPMMA mean values were different, depending on the detection system used for mammography screening in Poland

Due to potential concerns of bias and conflicts of interest, regulatory bodies should not do evaluation methodology research related to their regulatory missions.

Due to potential concerns of bias and conflicts of interest, regulatory bodies should not do evaluation methodology research related to their regulatory missions.

Study on patient dosimetry and image quality in digital mammography

Abstract Introduction Digital mammography present many advantages in comparison to conventional mammography, such as high dynamic range and the post-processing of acquired images. One problem is that protocols may not be optimized, resulting in higher absorbed doses to patients. The objective of this work is to evaluate image quality and to estimate mean glandular doses (MGD) in patients submitted to mammography examinations with three digital systems and one screen-film system in Recife, Brazil. Methods To estimate the MGD, the parameters used to acquire images of 5475 patients, with ages between 40 and 64 years and compressed breasts between 2 and 9 cm, were registered. The MGD was calculated by multiplying the incident air kerma with conversion coefficients depending on the anode/filter, breast glandularity and half-value layer. The image quality evaluation of the digital systems was made using objective and subjective European criteria. Results The results showed MGDs in the range of 0.4-10.3 mGy and the higher values were observed with digital systems. It was also observed that in the digital systems the use of compression force is not adequate and the irradiation parameters are not optimized. The images failed to reproduce the pectoral muscle and the contrast-to-noise ratio was not adequate for one system, indicating the need to improve the patient’s positioning and the exposure parameters. Conclusion It can be concluded that the use of non-optimized irradiation parameters is causing the higher doses with digital systems, highlighting the insufficient compression force.

Analysis of Quality Assurance Items of Film Screen and CR Systems

Background/Objectives: Korea is currently using F/S and CR systems for diagnostic radiation equipment. However, due to the lack of quality assurance items, further research regarding the criteria and items of diagnostic radiation equipment for analog and digital systems is needed. Methods/Statistical analysis: Diagnostic radiation equipment installed at H University in Chungnam, Korea, was used for testing and both F/S and CR systems were scrutinized. For the F/S system, a 10×12inch cassette, 10×12inch films and an automatic developing machine (JP-33) were used. The CR system was assessed using a 10x12 inch IP cassette and an image reader. The measurement items comprised the uniformity of images, resolution, and high-contrast resolution. Findings: In the uniformity test, the difference in optical density between the F/S system and the CR system was ±0.1%. Regarding uniformity, the IEC recommends an optical density baseline difference to be less than ±0.10. The uniformity of this test meets international standards. In the high-contrast resolution test, F/S system and CR system values were 4.0 and 3.0, respectively. In the resolution test, F/S system and CR system values were 5.62 and 4.61 at 5mAs, respectively. At 10mAs, the F/S system’s value was 5.62 and that of the CR system was 4.84. Improvements/Applications: The uniformity test, high-contrast resolution test, and resolution test results showed the F/S system to be superior to the CR system. Therefore, it is considered that the uniformity test, the high-contrast resolution test, and the resolution test should be performed as common items in the quality assurance of each system’s diagnostic radiation equipment.

Dogs chest homogeneous phantom for image optimization

Introduction There has been an increasing substitution of image acquisition screen-film systems for computed radiology (CR) equipment without technical charts adequacy. To carry out a radiographic examination in veterinary patient is required human assistance for restraint this, which can compromise image quality by generating dose increasing to the animal and for Occupationally Exposed. The image optimization procedures are performed with the use of homogeneous phantoms. Purpose We propose the development of a homogeneous phantom of canine chest to be applied to optimization of images for the CR system. Materials and methods A database with retrospectives chest images of computed tomography (CT) was created. The thickness of biological tissues was quantified in 80 animals, separated in groups of 20 animals according to their weights: Small, Medium, Large and Giant. An algorithm was developed to classify and quantify biological tissues present images and convert them in simulator materials. To classify tissues presents, membership functions were created from the retrospective CT scans according to the type of tissue (adipose, muscle, bone trabecular or cortical and lung tissue). Results Biologic tissue thickness was converted in equivalent material thicknesses (acrylic simulating soft tissues, aluminum simulating bones and air to the lung). Four different homogeneous phantoms were obtained, Small with 5 cm of acrylic, 0,14 cm of aluminum and 1,8 cm of air; medium with 8,7 cm of acrylic, 0,2 cm of aluminum and 2,4 cm of air; large with 10,6 cm of acrylic, 0,27 cm of aluminum and 3,1 cm of air and giant with 14,8 cm of acrylic, 0,33 cm of aluminum and 3,8 cm of air. Conclusion The canine homogeneous phantom is a practical tool, which will be employed to optimize veterinary X-ray procedures. Disclosure The authors declare that there are no interest conflicts.

A Derived Exposure Chart for Computed Radiography in a Negroid Population

Background: Computed radiography has a wider exposure latitude when compared with film-screen imaging system. Consequently, the risk of dose creep is high. A conscientious effort is there-fore, needed by the radiographer to keep exposure as low as reasonably achievable. Objective: To derive a computed radiography exposure chart for a negroid population using AGFA photostimulable phosphor plates and a GE static X-ray machine. Materials and Method: A static X-ray machine, a digitizer, and photostimulable phosphor plates were used for the X-ray examination. Chest examinations were done at a Focus-Film-Distance (FFD) of 150 - 180 cm while all other examinations were conducted at 90 - 100 cm FFD. The range of exposure factors (kVp, mA and mAs) used by radiog-raphers in the centre was noted and the 90th percentile calculated. Over a three-month period, the patients were examined with the 90th percentile of tube potential (kVp) while keeping other factors constant. The kVp was gradually decreased and halted if radiologists and radiographers uncon-nected with the work expressed misgivings about the quality of the image. A similar procedure was adopted for the tube current (mA). The threshold adopted as low as reasonably achievable was the factor preceding the point of observation by other personnel. Metrics for central tendency from the statistical packages for social sciences, version 17.0 was used to analyze the data. Results: 335 subjects of both gender aged 0 - 92 years were examined by the researchers. Adult exposure factors used by the radiographers (and those derived by the researchers) had a range of 45 - 130 kVp (62 - 94 kVp), 63 - 320 mA (100 - 250 mA) and 4.0 - 25.0 mAs (5.0 - 20.0 mAs) respectively. Pediatric chest (and researchers-derived) factors were 50 - 75 kVp (52 - 65 kVp), 50 - 250 mA (100 - 220 mA) and 3.20 - 10.0 mAs (3.2 - 6.5 mAs) respectively. Conclusion: Upper threshold of adult (and paediatric) exposure factors in computed radiography with comparable equipment and accessories should not exceed 94 kVp (65 kVp), 250 mA (220 mA) and 20.0 mAs (6.5 mAs) respectively. The derived exposure chart is also adequate to address motion unsharpness in chest examinations.

Radiation doses received in the United Kingdom breast screening programme in 2010 to 2012.

To review the radiation doses received by women attending the UK breast-screening programme between 2010 and 2012. To compare doses with previous years and to quantify the impact on dose of changing from analogue to digital imaging and to analyse doses by type of imaging system. Measurements of doses to samples of about 50-100 women attending for screening were collected across the whole of the UK breast-screening programme. Data were collected for 87,122 exposures, using 449 X-ray sets, for 25,408 women. The average mean glandular dose (MGD) was 1.79 mGy for mediolateral oblique images and 1.58 mGy for craniocaudal images. The average MGD per two-view examination was 4.01 mGy for film-screen imaging and 3.03 mGy for direct digital radiography (DR) and 4.69 mGy for computed radiography. The MGD to women attending breast screening has been reduced on average by about 25% where DR systems have replaced film-screen systems. The dose reduction was greatest for breasts with the largest compressed thickness. There are large variations in dose between the different models of DR system provided by different manufacturers. There should be further work to ensure that all DR systems are operated at the optimal dose level to ensure the best cancer detection while balancing the detriment caused by using radiation. Changes in the radiation dose in breast screening over time have been determined. Specifically, the impact on radiation dose of introducing different types of DR and computed radiography system into breast screening has been quantified.

Sensitometric analyses of screen-film systems for mammography exams in Brazil

A determination of the sensitometric parameters of screen-film systems to evaluate their qualities was performed. The quality control of the automatic film processor was carried out to ensure a high level of efficiency. Based on ISO 9236-3, the following potentials were applied on the X-ray tubes: 25 kV, 28 kV, 30 kV and 35 kV. Four different mammography films from different manufacturers with and without screens were tested for curve shape, speed and average gradient. The results indicated that film 1 exhibited better contrast, film 3 demonstrated the highest energy dependence, and film 4 presented the largest base+fog density. None of the four mammographic films tested achieved satisfactory results in all parameters analyzed. Improvements in the manufacturing process for these films must be completed to avoid losses in the image quality.

A Study of Heart and Thoracic Size and Cardiothoracic Ratio on Chest Radiography in Digital-Radiography System

Due to changes to Digital-Radiography system (DR system), its distance of film and object is longer than that in Film-Screen system (F/S system). However, current chest radiography exam has been the same as in F/S system. The objective of this study was to present real Heart Size (HS), Thoracic Size (TS), and Cardiothoracic Ratio (CTR) on chest Posterior-Anterior (chest PA) and chest Anterior-Posterior (chest AP) in the DR system and to determine the statistical correlation between Focal-Film Distance (FFD) and HS, TS, or CTR during chest AP. Our results revealed that HS, TS, and CTR in chest PA and chest AP of the DR system were larger than their real sizes. HS was especially magnified 8% and 22% in chest PA and chest AP, respectively. HS, TS, and CTR all had significant (p<0.05) negative correlation with FFD. In addition, HS and TS as well as HS and CTR had significant (p<0.05) positive correlation.Keywords: Chest AP, Chest PA, Cardiothoracic Ratio, Heart Size, Thoracic Size

Radiation dose to patients from X-ray radiographic examinations using computed radiography imaging system.

The screen-film system is replaced by computed radiography system for recording the images of the patients during X-ray radiography examinations. The change in imaging system requires the re-establishment of the institutional diagnostic reference levels (DRLs) for different types of X-ray examinations conducted at the hospital. For this purpose, patient specific parameters [age, height, weight, body mass index (BMI), object to image distance (OID)] and machine specific parameters (kVp, mAs, distance and field sizes) of 1875 patients during 21 different types of X-ray examinations were recorded for estimating the entrance skin dose (ESD). The ESD for each of these patients were estimated using measured X-ray beam output and the standard value of the back scatter factor. Five number summary was calculated for all the data for their presentation in the Box-Whisker plot, which provides the statistical distribution of the data. The data collected indicates that majorly performed examinations are cervical spine AP, Chest PA and Knee Lat with percentage contributions of 16.05, 16 and 8.27% respectively. The lowest contribution comes from Hip Lat which is about 1.01%. The ratio of measured ESD (maximum to minimum) for these examinations is found to be highest for the cervical spine AP with a value of 50 followed by Thoracic spine AP of 32.36. The ESD ratio for Chest PA, Knee Lat and Lumbar Spine AP are 30.75, 30.4 and 30.2 respectively. The lowest ESD ratio is for Hip Lat which is 2.68. The third quartile values of ESDs are established as the institutional DRLs. The ESD values obtained for 21 different X-ray projections are either comparable or lesser than the reported national/international values.