Average Mean Glandular Dose Research Articles

Evaluating Factors Affecting Mean Glandular Dose in Mammography: Insights from a Retrospective Study in Dubai.

This study evaluates the mean glandular dose (MGD) in mammography screening for women aged 40-69 in Dubai, based on a retrospective analysis of a dose survey involving 2599 participants. MGD was calculated using the Dance formula. The average MGD was 0.96 ± 0.39 mGy for mediolateral oblique (MLO) views and 0.81 ± 0.33 mGy for craniocaudal (CC) views. Weak inverse correlations were found between age and organ dose (OD) for both views, while a direct relationship was observed between breast thickness and entrance skin dose (ESD). In adjusted models, ESD was strongly associated with MGD (β = 1.04, 95% CI: 0.97, 1.09), while OD showed a moderate association (β = 0.44, 95% CI: 0.40, 0.49). Significant variations in ESD, OD, and MGD were noted across age groups and breast thicknesses. Lower MGD indicates reduced radiation exposure risk, while higher MGD in MLO views suggests improved imaging quality. Monitoring and optimizing MGD are essential for enhancing patient safety and screening efficacy.

Is digital mammography reducing radiation doses to women?

This study aims to investigate the impact of national quality programs in mammography and technological advances in digital mammography units on the radiation doses delivered to women in Brazil. Radiation dose assessments in mammography units were conducted through a mail-based dosimetric system. For each unit of facilities that applied to one of the two national quality programs, a postal dosimetric system is dispatched, comprising an optically stimulated luminescent dosimeter (OSL) attached to the surface of a 4.0 cm thick polymethyl methacrylate (PMMA) phantom, simulating a compressed breast with 4.5 cm thickness. Testing instructions to expose the dosimetric phantom for assessing the mean glandular dose (MGD) are provided. Between 2012 and 2023, the programs evaluated the MGD in 1,687 mammography units of computed radiography (CR) and direct digital radiography (DR) technologies from 1,399 facilities located in all Brazilian regions. A total of 1,660 (70.5%) evaluations were carried out on CR technology mammography units and 696 (29.5%) on DR units, totaling 2,356 MGD evaluations. The overall average MGD was 1.60 ± 0.80 mGy, with 1.68 ± 0.83 mGy for CR technology and 1.42 ± 0.68 mGy for DR technology. A comparison of average MGD between the periods 2012 - 2018 and from 2019 onwards shows a dose reduction of 8.6% for CR systems and of 26.0% for DR systems (p = 0.000). As CR systems use analog mammography units, which did not undergo technological advances between the two periods, the reduction in doses observed is due to the actions of national quality certification programs and by using image plates for dual-sided reading or needle-based image plates. The reduction observed in DR systems is due to both national quality programs and technological advances in mammography units, especially the use of radiation beams generated by X-ray tubes with tungsten targets.

How Much Radiation Are Women in Saudi Arabia Receiving from Mammography? A Review

This review compiles and assesses data from recent studies on mammographic radiation doses in Saudi Arabia, aiming to evaluate mean glandular dose (MGD) exposure during mammography and its implications in breast cancer risk. The reviewed studies spanned from 2019 to 2023 and included a range of sample sizes and institutional settings, with patients’ ages from 27 to 85 years. Considerations such as the number of mammographic views and compressed breast thickness were examined. The studies reported average MGDs below the National Diagnostic Reference Level set by the Saudi Food and Drug Authority. However, limitations were noted regarding sample size selection and incomplete data on all mammographic projections. Despite these limitations, the findings highlight the need for continued assessment of patient doses to optimize mammography practices and address the absence of quality standardization acts in Saudi Arabia. These insights are critical for governing authorities to ensure that effective patient dose monitoring occurs regularly and that the establishment of minimum quality standards for breast cancer screening is intact.

Study of the performance change in digital mammography systems depending on the total number of examinations

Digital mammography equipment should operate at a high-performance level for detecting breast cancer over the lifetime of the systems. This study investigates the performance of the Fujifilm Amulet Innovality full-field digital mammography system in relation to the number of exposures. The performance of twelve systems, from new and up to 17 000 examinations, was compared. The x-ray output, half-value layer (HVL), contrast-detail (C-D) detectability, contrast-to-noise ratio (CNR), mean glandular dose (MGD), signal transfer property (STP), pre-sampled modulation transfer function (MTF), normalized noise power spectra (NNPS), detective quantum efficiency (DQE) tests were performed to determine the performance change. The noise sources were also analyzed in the spatial domain. The x-ray output and HVL values at 28 kV with tungsten anode and rhodium filter were 15 μGy/mAs ± 1.0 (coefficient of variation (cov) = 7.0%) and 0.54 mmAl ± 0.008 (cov = 1.5%), respectively. The average MGDs for 60 mm equivalent breast to reach the achievable image quality level for 0.1 mm and 0.25 mm detail diameters of circular discs on the CDMAM 3.4 phantom image were 1.17 mGy ± 0.13 (cov = 11%) and 1.40 mGy ± 0.09 (cov = 6%), respectively. The average MGD for 53 mm equivalent breast was 1.08 mGy ± 0.14 (cov = 13%) at dose setting Normal in automatic exposure control (AEC) mode. All tested devices demonstrated good linearity with R2 ≥ 0.999 in the STP curves. The average MTF at 5.0 mm−1 spatial frequency was 0.66 ± 0.007 (cov = 1.0%). The average NNPS was 2.38 × 10−6 mm2 ± 2.13 × 10−7 (cov = 9.0%) at 5.0 mm−1. The average DQE value at 5.0 mm−1 was 0.33 ± 0.02 (cov = 5.0%), and the mean peak DQE was 0.66 ± 0.03 (cov = 5.0%). The mean power coefficient (b), determined from the power relationship between linearised standard deviation and detector dose while analyzing noise sources, was 0.49 ± 0.007 (cov = 1.4%). There was no gradual change in the x-ray tube and detector performance by the number of exposures, and taking up to 68 000 images did not decrease the quality of the systems.

Radiation doses in the United Kingdom breast screening programmes 2016-2019.

To record the radiation doses involved in UK breast screening and to identify any changes since previous publications related to technical factors and the population screened. Mammographic exposure factors for 68,998 women imaged using 411 X-ray sets spread across the UK were compiled. Local output and half value layer measurements for each X-ray set were used to estimate mean glandular dose (MGD) using the standard UK method. Mean MGDs in digital mammography have increased by 11% since 2010-12 for both medio-lateral oblique (MLO) and cranio-caudal (CC) views. The mean compressed breast thickness (CBT) has increased (4.8% CC, 5.2% MLO) over the same period. The mean MLO CBT value of 62.4 ± 0.1 mm is outside the 50 to 60 mm range used for diagnostic reference levels. The increase in MGD is consistent with the CBT changes. The mean MGD in the 50 to 60 mm CBT range is 1.44 ± 0.03 mGy for MLO views. CBT varies with age and peaks at 51. Mean CBT has increased with time, and this has increased mean MGDs for digital mammography. CBT also varies with age. Updated average MGDs in the UK are provided. There is evidence that breast size is increasing in the UK and that mean CBT is affected by age-related changes in the breast.

291. Digital breast tomosynthesis mean glandular dose evaluation

Purpose Digital Breast Tomosynthesis (DBT) is a 3D-imaging technique which allows a high-resolution tissues visualization. During a DBT procedure a series of single projection images is acquired over a limited-angle range. The Mean Glandular Dose (MGD) is the dosimetric index currently employed in mammography and it has been adopted as reference dosimetric index in the European guidelines [1] . Aim of this work was to evaluate the MGD in DBT procedures in order to study the unavoidable cumulative dose (DBT + conventional mammography) increasing of the whole diagnostic exam. Methods 50 2D breast examinations with associate DBT investigations of doubt sign were selected. MGD consolle values and all the exposure information (kV, mAs, HVL, tube/filter combination, breast thickness) were recorded for each 2D view and DBT acquisition. Air Kerma was measured by the use of a Piranha Detector and it was evaluated as a mAs function for fixed KVs and tube/filter combinations. These measurements allowed to calculate the MGD, using tabulated g-, c-, s- and T-Monte Carlo factors obtained by radiation transport calculations, according to European guidelines. g-, c-, s-factors convert incident air kerma to absorbed dose for a specific composition and size breast; T-factor [2] correct the MGD for the angle projection. Results For single breast DBT procedures average MGD value was 1.66 ± 0.51 mGy with 2.90 mGy max value. Average dose for single breast due to all conventional projection was 3.67 ± 1.03 mGy. The average cumulative dose for single breast was 4.77 ± 1.80 mGy. Therefore, an average increase of 34.7% of the cumulative dose was registered when a DBT investigation was performed. Conclusion DBT procedures involve an important benefit for the purpose of a more exhaustive diagnostic information with a limited increasing risks associated with the absorbed dose.

P010] Radiation dose levels in digital mammography: A retrospective review in a South American imaging centre

Purpose To present results of a retrospective data analysis carried out at a large academic medical centre in South America and to establish a dose reference level (DRL) for digital mammography studies in the region. Methods All patients presenting for screening mammography between July 1 and December 30, 2017 at our imaging centre were reviewed in this study, for which the institutional review board granted approval and waived the requirement for informed consent. Technical parameters including breast compression force, compressed breast thickness, mean glandular dose (MGD), and the number of views needed for complete breast coverage were recorded and analysed. Results A total of 2492 images acquired from 623 patients with a Siemens Mammomat Inspiration digital mammography system were included. The MGD per examination was 2.88 ± 0.05 mGy, the average compressed breast thickness was 64.3 ± 0.5 mm, and the average compression force was 10.1 ± 0.4dN. Twelve percent of the cases required more than the four normal views to cover all breast tissue. When extra views were included, the MGD per subject was 3.85 ± 0.06 mGy. A DRL value of 1.64 mGy has been established by calculating the 95 th percentile of the average MGD for compressed thicknesses ranging from 55 mm to 64 mm. Conclusions Our results show that demographic factors including mean breast thickness and breast prosthesis affect MGD of patients in our region. Finally, our findings show a modest increase of radiation dose to the breast by digital mammography due to the average breast thickness of our patients.

Digital Breast Tomosynthesis (DBT) Dose Survey and the establishment of a DRL for a National Breast Screening Service

Digital breast tomosynthesis (DBT) has proven invaluable to BreastCheck as an adjunct to 2D imaging, and since 2014, BreastCheck has commissioned 15 Hologic Selenia Dimensions DBT systems. Risk assessment is one of the many important reasons for performing a breast dose survey. This study is a presentation of the results of the first dose survey performed on the new 3D imaging systems. Mean glandular dose (MGD) is the commonly accepted measure of mammographic radiation risk and was calculated for each 3D image according to Dance et al. The survey used the exposure data from at least 45 examinations per DBT unit and dose calculations were performed using the NCCPM breast dose survey software. Dose survey results were in good agreement with values published in the literature. As expected the average 3D breast dose exceeds the average 2D dose (Ratio = 1.28). The estimate of the 3D imaging DRL (2.6 mGy) was based on the average MGD of an oblique exposure of an average sized breast. Survey results indicated a drop in breast dose for breast thickness greater than 90 mm. The manufacturer has confirmed this occurs by design to minimize long exposure times and focal spot blur which could occur for the larger breast thicknesses. The strong comparison between calculated and displayed doses should simplify future surveys. Digital breast tomosynthesis (DBT) has proven invaluable to BreastCheck as an adjunct to 2D imaging, and since 2014, BreastCheck has commissioned 15 Hologic Selenia Dimensions DBT systems. Risk assessment is one of the many important reasons for performing a breast dose survey. This study is a presentation of the results of the first dose survey performed on the new 3D imaging systems. Mean glandular dose (MGD) is the commonly accepted measure of mammographic radiation risk and was calculated for each 3D image according to Dance et al. The survey used the exposure data from at least 45 examinations per DBT unit and dose calculations were performed using the NCCPM breast dose survey software. Dose survey results were in good agreement with values published in the literature. As expected the average 3D breast dose exceeds the average 2D dose (Ratio = 1.28). The estimate of the 3D imaging DRL (2.6 mGy) was based on the average MGD of an oblique exposure of an average sized breast. Survey results indicated a drop in breast dose for breast thickness greater than 90 mm. The manufacturer has confirmed this occurs by design to minimize long exposure times and focal spot blur which could occur for the larger breast thicknesses. The strong comparison between calculated and displayed doses should simplify future surveys.

EXPOSURE PARAMETERS OF MAMMOGRAMS WITH AND WITHOUT MASS LESIONS FROM A SOUTH AFRICAN BREAST CARE CENTRE.

In South African breast care centres, full-field digital mammography units provide breast imaging services to symptomatic and asymptomatic women simultaneously. This study evaluated the technical exposure parameters of 800 mammograms of which 100 mammograms had obvious mass lesions in the fibroglandular tissue. The average breast compression force of mammograms with mass lesions in the fibroglandular tissue was 18.4% less than the average breast compression force of mammograms without mass lesions. The average mean glandular dose (MGD), tube potential (kVp) and compressed breast thickness (CBT) values were 2.14 mGy, 30.5 kVp and 63.9 mm, respectively, for mammograms with mass lesions, and 1.45 mGy, 29.6 kVp and 56.9 mm, respectively, for mammograms without mass lesions. Overall, the average MGD and mean CBT of mammograms with mass lesion were significantly higher compared to those without mass lesions (p < 0.05), although there was no significant difference in their tube potentials (p > 0.05).

O53. Dosimetric data for diagnostic digital mammography employing Fully Automated Self adjusting Tilt compression

Introduction Digital mammography aims to clinically detect breast pathology or cancer. This is important as breast cancer has one of the highest incident and mortality rates worldwide for women. The aim of this study was to evaluate several imaging and demographic parameters of the 2D imaging done at Universitas Academic Hospital and to compare the mean glandular dose (MGD) values obtained to recent studies published from other institutions worldwide. Materials and methods Data were collected for 200 patients who underwent mammographic imaging at Universitas Academic Hospital. The data were analysed for the patient age, MGD, mAs, kV, target filter combination, compression force and compressed thickness from the Digital Imaging and Communications in Medicine file. Results Imaging parameter results showed that the average MGD was 1.52 ± 0.71 mGy, the average compression force, 69 N, the average kV, 30, the average mAs, 138 and the average compressed thickness, 58 mm. The mean patient age was recorded as 55 years. Conclusion The MGD from Universitas Academic Hospital compared well with the average screening MGD values of other institutions worldwide (average 1.72 ± 0.36 mGy). Higher MGD values were expected for Universitas Academic Hospital as diagnostic mammography and not screening mammography is practiced at Universitas Academic Hospital. The mean compression force is considered low if compared to the recommendations from the European guidelines of a minimum of 110 N compression force. The performance of the Fully Automated Self adjusting Tilt compression mode could explain lower registered compression values found in this study.

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.

Results of a 2011 national questionnaire for investigation of mean glandular dose from mammography in Japan

Diagnostic reference levels (DRLs) for mammography have yet to be created in Japan. A national questionnaire investigation into radiographic conditions in Japan was carried out for the purpose of creating DRLs. Items investigated included the following: tube voltage; tube current; current–time product; source–image distance; craniocaudal view; automatic exposure control (AEC) settings; name of mammography unit; image receptor system (computed radiography (CR), flat panel detector (FPD), or film/screen (F/S)); and supported or unsupported monitor diagnosis (including monitor resolution). Estimation of the mean glandular dose (MGD) for mammography was performed and compared with previous investigations. The MGD was 1.58(0.48) mGy, which did not significantly differ from a 2007 investigation. In relation to image receptors, although no difference in average MGD values was observed between CR and FPD systems, F/S systems had a significantly decreased value compared to both CR and FPDs. Concerning digital systems (FPDs), the MGD value of the direct conversion system was significantly higher than the indirect conversion system. No significant difference in MGD value was evident concerning type of monitor diagnosis for either the CR or the FPD digital systems; however, hard copies were used more often in CR. No significant difference in the MGD value was found in relation to monitor resolution. This report suggests ways to lower the doses patients undergoing mammography receive in Japan, and serves as reference data for 4.2 cm compressed breast tissue of 50% composition DRLs. Furthermore, our findings suggest that further optimisation of FPD settings can promote a reduction in the MGD value.

Mismatch in Breast and Detector Size during Screening and Diagnostic Mammography Results in Increased Patient Radiation Dose

When using mammographic detectors of different sizes, it can be difficult to match patient breast size to optimal detector size. We studied whether a mismatch between breast size and optimal detector size resulted in increased radiation exposure. All screening and diagnostic (Dx) mammography patients during a 6-week period in November-December 2009 (864 patients) were evaluated (institutional review board exemption for quality assurance studies). Data gathered included breast size (large or small), detector size used, number of views obtained, mean glandular dose (MGD) per breast, and patient waiting time. Average MGD and average waiting time was calculated for imaging performed on appropriately matched or mismatched breast size-detector size pairs. Screening mammography patients with large breasts imaged on a small detector received a significantly higher radiation dose (4.9 vs. 3.3mGy, P<.05) and a greater number of views (5.9 vs. 4.6, P<.05) compared to optimally matched breast-detector pairs. Dx mammography patients with large breasts imaged on a small detector received a higher radiation dose (8.2 vs. 6.7mGy, P<.05) compared to optimally matched breast-detector pairs, although without an increased number of views. Waiting times were longer for a large detector. A mismatch in breast-detector sizes results in a significantly greater radiation dose to patients with large breasts imaged on a small detector. Pressure to minimize patient waiting time may inadvertently result in increased radiation dose. Detector size should be matched to breast size whenever possible, but particularly for patients with larger breast sizes.

Image quality, threshold contrast and mean glandular dose in CR mammography

In many countries, computed radiography (CR) systems represent the majority of equipment used in digital mammography. This study presents a method for optimizing image quality and dose in CR mammography of patients with breast thicknesses between 45 and 75 mm. Initially, clinical images of 67 patients (group 1) were analyzed by three experienced radiologists, reporting about anatomical structures, noise and contrast in low and high pixel value areas, and image sharpness and contrast. Exposure parameters (kV, mAs and target/filter combination) used in the examinations of these patients were reproduced to determine the contrast-to-noise ratio (CNR) and mean glandular dose (MGD). The parameters were also used to radiograph a CDMAM (version 3.4) phantom (Artinis Medical Systems, The Netherlands) for image threshold contrast evaluation. After that, different breast thicknesses were simulated with polymethylmethacrylate layers and various sets of exposure parameters were used in order to determine optimal radiographic parameters. For each simulated breast thickness, optimal beam quality was defined as giving a target CNR to reach the threshold contrast of CDMAM images for acceptable MGD. These results were used for adjustments in the automatic exposure control (AEC) by the maintenance team. Using optimized exposure parameters, clinical images of 63 patients (group 2) were evaluated as described above. Threshold contrast, CNR and MGD for such exposure parameters were also determined. Results showed that the proposed optimization method was effective for all breast thicknesses studied in phantoms. The best result was found for breasts of 75 mm. While in group 1 there was no detection of the 0.1 mm critical diameter detail with threshold contrast below 23%, after the optimization, detection occurred in 47.6% of the images. There was also an average MGD reduction of 7.5%. The clinical image quality criteria were attended in 91.7% for all breast thicknesses evaluated in both patient groups. Finally, this study also concluded that the use of the AEC of the x-ray unit based on the constant dose to the detector may bring some difficulties to CR systems to operate under optimal conditions. More studies must be performed, so that the compatibility between systems and optimization methodologies can be evaluated, as well as this optimization method. Most methods are developed for phantoms, so comparative studies including clinical images must be developed.

Evaluation of Mean Glandular Dose during Diagnostic Mammography Examination for Detection of Breast Pathology, in Ethiopia

Background: A mammography examination facilitates the early detection of breast cancer. However, the potential risk of radiation-induced carcinogenesis is also increased with such a procedure. Thus assessment of the breast dose is important. Objectives: The objectives of this study were to investigate the techniques currently used for diagnostic mammography in Ethiopia, thereby to estimate the mean glandular dose (MGD) for Ethiopian women. Materials and methods: A cross-sectional study was conducted on breast cancer patients between 40-64 years of age having compressed breast thickness (CBT) greater than 2 cm. Five mammographic units and 386 women having a total of 1463 mammograms were included in the study period from April 2011-February 2012 in Addis Ababa, Ethiopia.The characteristics of the radiographic equipment and the exposure data of each patient were recorded using designed format. The MGD was calculated from the measured Entrance Surface Air Kerma (ESAK) using appropriate conversion coefficients. The obtained data were analyzed using statistical software. Results: The range of CBT was 2.2-7.5 cm for CC mammograms with mean ± SD of 4.24 ± 1.1 cm and 2.3-8.0 cm in MLO projection with mean ± SD of 4.64 ± 1.1 cm. The average MGD per exposure was 2.57 ± 2.1 mGy while the respective averages separately for the CC and MLO projections were 2.58 ± 2.2 mGy and 2.57 ± 2.1 mGy, respectively. Conclusion: The average MGD values recorded in this study were between the limiting value of the Institute of Physical Sciences in Medicine (2.0 mGy) and American College of Radiology (3.0 mGy) recommendation. These ensure that the mammography examination performed in Ethiopia was capable of achieving acceptable dose levels for patient safety.

Screen-film versus full-field digital mammography: Radiation dose and image quality in a large teaching hospital

The objective of this paper is to measure the radiation dose and image quality in conventional screen-film mammography and full-field digital mammography in women referred to mammography examination. Participants underwent bilateral, two-view screen-film mammography or full-field digital mammography. The visibility of anatomical regions and overall clinical image quality was rated by experienced radiologists. Total of 387 women and 1548 mammograms were enrolled in the study. Image quality was assessed in terms of image quality score, whereas patient dose assessment was performed in terms of mean glandular dose. Average mean glandular dose for cranio-caudal projection was 1.5 mGy and 2.1 mGy in full-field digital mammography and screen-film mammography, respectively. For medio-lateral oblique projection, corresponding values were 2.3 and 2.1 mGy. Overall image quality criteria scoring was 0.82 and 0.99 for screen-film and digital systems, respectively. The scores were in the range from 0.11 to 1.0 for different anatomical structures. Overall, full-field digital mammography was superior both in terms of image quality and dose over the screen-film mammography. The results have indicated that phantom dose values can assist in setting the optimisation activities in mammography and for comparison between mammography units. To obtain accurate diagnostic information with an acceptable radiation dose to breast, it is necessary to periodically perform patient dose and image quality surveys in all mammography units.

Towards proposition of a diagnostic reference level for mammographic examination in the greater Khorasan Province, Iran

Although, over the past few years, the application of mammography has risen up sharply in Iran, very little, if any, has been reported of the extent of patient's dose from this type of imaging. The purpose of this study was to establish local diagnostic reference level (DRL) arising from mammography in the great Khorasan province of Iran. It is generally assumed that the glandular tissue is the most vulnerable type of breast tissue. Therefore, the mean glandular dose (MGD) has been widely accepted as the most appropriate dosimetric quantity to predict the risk of radiation-induced cancer. Literary, DRL for mammography is defined as the 75th percentile of MGD distribution. In Khorasan province, 7 out of 40 centres were randomly selected. In this work, 100 patients were studied. Thermoluminescence dosimeters have been used to measure entrance surface doses (ESDs). Since, it is difficult to directly measure MGD, Monte Carlo model-based conversion factors were utilised to conclude MGD from ESD. The results have revealed that patients dose is varied widely. The measured ESDs ranged from 0.74 to 19.81 mGy for the craniocaudal (CC) view and 1.20 to 25.79 mGy for the mediolateral oblique (MLO) view. The average MGDs per image were 0.88 and 1.11 mGy for CC and MLO views, respectively. Based on the internationally adopted definition, DRL arising from mammography tests for Khorasan is 1.33 mGy. Implementation of a dose reduction programme is suggested because of the large variations observed in patient MGD values. In this study, the DRL value is significantly lower than the corresponding values suggested by other researchers elsewhere.

Comparison of Radiologist Performance with Photon-Counting Full-Field Digital Mammography to Conventional Full-Field Digital Mammography

The purpose of this study was to assess the performance of a MicroDose photon-counting full-field digital mammography (PCM) system in comparison to full-field digital mammography (FFDM) for area under the receiver-operating characteristic (ROC) curve (AUC), sensitivity, specificity, and feature analysis of standard-view mammography for women presenting for screening mammography, diagnostic mammography, or breast biopsy. A total of 133 women were enrolled in this study at two European medical centers, with 67 women who had a pre-existing 10-36 months FFDM enrolled prospectively into the study and 66 women who underwent breast biopsy and had screening PCM and diagnostic FFDM, including standard craniocaudal and mediolateral oblique views of the breast with the lesion, enrolled retrospectively. The case mix consisted of 49 cancers, 17 biopsy-benign cases, and 67 normal cases. Sixteen radiologists participated in the reader study and interpreted all 133 cases in both conditions, separated by washout period of ≥4 weeks. ROC curve and free-response ROC curve analyses were performed for noninferiority of PCM compared to FFDM using a noninferiority margin Δ value of 0.10. Feature analysis of the 66 cases with lesions was conducted with all 16 readers at the conclusion of the blinded reads. Mean glandular dose was recorded for all cases. The AUC for PCM was 0.947 (95% confidence interval [CI], 0.920-0.974) and for FFDM was 0.931 (95% CI, 0.898-0.964). Sensitivity per case for PCM was 0.936 (95% CI, 0.897-0.976) and for FFDM was 0.908 (95% CI, 0.856-0.960). Specificity per case for PCM was 0.764 (95% CI, 0.688-0.841) and for FFDM was 0.749 (95% CI, 0.668-0.830). Free-response ROC curve figures of merit were 0.920 (95% CI, 0.881-0.959) and 0.903 (95% CI, 0.858-0.948) for PCM and FFDM, respectively. Sensitivity per lesion was 0.903 (95% CI, 0.846-0.960) and 0.883 (95% CI, 0.823-0.944) for PCM and FFDM, respectively. The average false-positive marks per image of noncancer cases were 0.265 (95% CI, 0.171-0.359) and 0.281 (95% CI, 0.188-0.374) for PCM and FFDM, respectively. Noninferiority P values for AUC, sensitivity (per case and per lesion), specificity, and average false-positive marks per image were all statistically significant (P < .001). The noninferiority P value for free-response ROC was <.025, from the 95% CI for the difference. Feature analysis resulted in PCM being preferred to FFDM by the readers for ≥70% of the cases. The average mean glandular dose for PCM was 0.74 mGy (95% CI, 0.722-0.759 mGy) and for FFDM was 1.23 mGy (95% CI, 1.199-1.262 mGy). In this study, radiologist performance with PCM was not inferior to that with conventional FFDM at an average 40% lower mean glandular dose.

SU‐E‐I‐87: Pilot Testing of Software for Automated Remote Quality Control of Digital Mammography Equipment for Use in the Ontario Breast Screening Program

Purpose: We have evaluated the feasibility of using a software package to monitor the results of quality control (QC) testing on digital mammography units in the Ontario Breast Screening Program. The intent is to make the quality control process more efficient for the technologist and physicist, and improve the consistency of test performance and results interpretation. Methods: A DICOM service class provider, “GLADYS” (originally developed at University Hospitals Leuven) was installed at pilot screening sites. All images acquired on the sitesˈ mammography systems are automatically sent to GLADYS over the PACS networks. GLADYS recognizes QC images by predetermined patient names and performs an automated analysis, measuring various parameters and generating summary thumbnail images. Clinical images are de‐identified and the technique factors and dose are extracted for tracking. The QC and dose reports are sent by email to the central monitoring site. At the central site QC image measures are plotted and thumbnail images displayed for artefact evaluation. The patient header information is stored such that dose reports can be generated. Results: GLADYS has been installed at two remote screening sites, and locally for a total of six machines. QC and dose data have been collected for the past 5.5 months. 285 QC images have been analyzed. Artefacts and changes in automatic exposure control or detector behaviour are easily perceived. Dosimetry information from 18282 patient images has been collected, with an average mean glandular dose of 1.3 mGy. Conclusions: The automated analysis works well, and reduces the technologistˈs QC workload. The addition of features to allow for automated immediate feedback to the remote sites of test results to ensure rapid response to detected problems is under development. Incorporation of centralized automatic quality control has the potential to improve the consistency and reliability of the tests and results, while streamlining QC procedures.

Comprehensive dose survey of breast screening in Ireland

The primary purpose of this study was to evaluate the impact of digital mammography screening on breast dose by analysing the results of a patient dose survey of the Irish breast screening programme. Results from the survey were used to determine a dose reference level for the screening programme. Approximately, 100 examinations were acquired for each of the digital mammography systems operational in the screening programme. Each examination consisted of two standard views of each breast. The mean glandular dose for each acquired image was calculated. The dose reference level was established by calculating the 95th percentile of the average mean glandular dose for the average compressed breast thickness of the mediolateral oblique views. The overall average mean glandular dose per examination was 2.72 ± 0.04 mGy. The average compressed breast thickness was 61.4 ± 0.03 mm. The average compression force was 109 ± 7 N. A dose reference level value of 1.75 mGy was established for the screening programme. The results of this clinical dose survey provide a valuable indication of the dose performance of modern full field digital mammographic imaging systems. The results demonstrate clearly the dose benefits of digital mammography. The dose benefit of digital screening was further demonstrated by the establishment of a comparatively lower diagnostic reference level for the screening programme. The comparison of the dose performance of individual X-ray systems with the diagnostic reference level highlights the need for more optimisation within the service.