1
|
Parmaksız A, Ataç GK, Bulur E, İnal T, Alhan A. AVERAGE GLANDULAR DOSES AND NATIONAL DIAGNOSTIC REFERENCE LEVELS IN MAMMOGRAPHY EXAMINATIONS IN TURKEY. Radiat Prot Dosimetry 2020; 190:100-107. [PMID: 32556186 DOI: 10.1093/rpd/ncaa080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 05/14/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
In order to establish national diagnostic reference levels for mammography examinations, entrance skin air kerma, entrance skin dose and average glandular doses (AGDs) were calculated for a total of 25 624 cranio-caudal (CC) and mediolateral oblique (MLO) projections of 6309 patients for 40-49 and 50-64 age groups. The average entrance skin air kerma and entrance skin dose values for both age groups were found to be higher in MLO projections compared with CC projections. The minimum and maximum values of AGDs were determined as 0.4 and 7.9 mGy for both projections. The maximum numbers of AGDs for CC and MLO projections were calculated in the range of 1.1-1.5 and 1.6-2.0 mGy, respectively. The third quartile values of AGDs were calculated for each compressed breast thickness between 20 and 99 mm. The first national diagnostic reference levels of the country were established for each 10-mm compressed breast thickness in mammography examinations.
Collapse
Affiliation(s)
- Aydın Parmaksız
- Radiation and Accelerator Technologies Department, Turkish Atomic Energy Authority, Atom Street, 06983 Kahramankazan, Ankara, Turkey
| | - Gökçe K Ataç
- Medicine Faculty, Ufuk University, Mevlana Boulevard (Konya Road), Balgat, Ankara, Turkey
| | - Emine Bulur
- Radiation and Accelerator Technologies Department, Turkish Atomic Energy Authority, Atom Street, 06983 Kahramankazan, Ankara, Turkey
| | - Tolga İnal
- Department of Electrical and Electronics Engineering, Ankara University, Dögol Street, Ankara, Turkey
| | - Aslıhan Alhan
- Statistics Department, Art and Science Faculty., Ufuk University, İncek Şehit Savcı Mehmet Selim Kiraz Boulevard, Gölbaşı, Ankara, Turkey
| |
Collapse
|
2
|
Acho SN, Boonzaier WPE, Nel IF. EXPOSURE PARAMETERS OF MAMMOGRAMS WITH AND WITHOUT MASS LESIONS FROM A SOUTH AFRICAN BREAST CARE CENTRE. Radiat Prot Dosimetry 2017; 177:348-355. [PMID: 28444247 DOI: 10.1093/rpd/ncx053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/04/2017] [Indexed: 06/07/2023]
Abstract
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).
Collapse
Affiliation(s)
- Sussan N Acho
- Department of Medical Physics, University of the Free State, Bloemfontein 9300, South Africa
| | - Willem P E Boonzaier
- Department of Medical Physics, University of the Free State, Bloemfontein 9300, South Africa
| | - Ina F Nel
- Department of Clinical Imaging Services, University of the Free State, Bloemfontein 9300, South Africa
| |
Collapse
|
3
|
Alakhras MM, Mello-Thoms C, Bourne R, Rickard M, Diffey J, Brennan PC. RELATIONSHIP BETWEEN RADIATION DOSE AND IMAGE QUALITY IN DIGITAL BREAST TOMOSYNTHESIS. Radiat Prot Dosimetry 2017; 173:351-360. [PMID: 26895769 DOI: 10.1093/rpd/ncw005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 01/06/2016] [Indexed: 06/05/2023]
Abstract
This phantom-based study aimed to examine radiation dose from digital breast tomosynthesis (DBT) and digital mammography (DM) and to assess the potential for dose reductions for each modality. Images were acquired at 10-60 mm thicknesses and four dose levels and mean glandular dose was determined using a solid-state dosemeter. Eleven readers assessed image quality and compared simulated lesions with those on a reference image, and the data produced was analysed with the Friedman and Wilcoxon signed-rank tests. For a phantom thickness of 50 mm (typical breast thickness), DBT dose was 13 % higher than DM, but this differential is highly dependent on thickness. Visibility of masses was equal to a reference image (produced at 100 % dose) when dose was reduced by 75 and 50 % for DBT and DM. For microcalcifications, visibility was comparable with the reference image for both modalities at 50 % dose. This study highlighted the potential for reducing dose with DBT.
Collapse
Affiliation(s)
- Maram M Alakhras
- MIOPeG, Faculty of Health Sciences, University of Sydney, Room M220, 75 East Street Lidcombe, Sydney, NSW 2141, Australia
| | - Claudia Mello-Thoms
- MIOPeG, Faculty of Health Sciences, University of Sydney, Room M220, 75 East Street Lidcombe, Sydney, NSW 2141, Australia
- Department of Biomedical Informatics and Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Roger Bourne
- MIOPeG, Faculty of Health Sciences, University of Sydney, Room M220, 75 East Street Lidcombe, Sydney, NSW 2141, Australia
| | - Mary Rickard
- MIOPeG, Faculty of Health Sciences, University of Sydney, Room M220, 75 East Street Lidcombe, Sydney, NSW 2141, Australia
- Sydney Breast Clinic, Sydney, NSW, Australia
| | | | - Patrick C Brennan
- MIOPeG, Faculty of Health Sciences, University of Sydney, Room M220, 75 East Street Lidcombe, Sydney, NSW 2141, Australia
| |
Collapse
|
4
|
Baek JE, Kang BJ, Kim SH, Lee HS. Radiation dose affected by mammographic composition and breast size: first application of a radiation dose management system for full-field digital mammography in Korean women. World J Surg Oncol 2017; 15:38. [PMID: 28153022 DOI: 10.1186/s12957-017-1107-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/25/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Relative to Western women, Korean women show several differences in breast-related characteristics, including higher rates of dense breasts and small breasts. We investigated how mammographic composition and breast size affect the glandular dose during full-field digital mammography (FFDM) in Korean women using a radiation dose management system. METHODS From June 1 to June 30, 2015, 2120 FFDM images from 560 patients were acquired and mammographic breast composition and breast size were assessed. We analyzed the correlations of patient age, peak kilovoltage (kVp), current (mAs), compressed breast thickness, compression force, mammographic breast composition, and mammographic breast size with the mean glandular dose (MGD) of the breast using a radiation dose management system. The causes of increased radiation were investigated, among patients with radiation doses above the diagnostic reference level (4th quartile, ≥75%). RESULTS The MGD per view of 2120 images was 1.81 ± 0.70 mGy. In multivariate linear regression analysis, age was negatively associated with MGD (p < 0.05). The mAs, kVp, compressed breast thickness, and mammographic breast size were positively associated with MGD (p < 0.05). The "dense" group had a significantly higher MGD than the "non-dense" group (p < 0.05). Patients with radiation dose values above the diagnostic reference value had large breasts of dense composition. CONCLUSIONS Among Korean women, patients with large and dense breasts should be more carefully managed to ensure that a constant radiation dose is maintained.
Collapse
|
5
|
Suleiman ME, McEntee MF, Cartwright L, Diffey J, Brennan PC. Diagnostic reference levels for digital mammography in New South Wales. J Med Imaging Radiat Oncol 2016; 61:48-57. [DOI: 10.1111/1754-9485.12540] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 08/31/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Moayyad E Suleiman
- Faculty of Health Sciences; The University of Sydney; Lidcombe New South Wales Australia
| | - Mark F McEntee
- Faculty of Health Sciences; The University of Sydney; Lidcombe New South Wales Australia
| | | | - Jennifer Diffey
- Hunter New England Imaging; John Hunter Hospital; New Lambton Heights New South Wales Australia
| | - Patrick C Brennan
- Faculty of Health Sciences; The University of Sydney; Lidcombe New South Wales Australia
| |
Collapse
|
6
|
Suleiman ME, Brennan PC, McEntee MF. Diagnostic reference levels in digital mammography: a systematic review. Radiat Prot Dosimetry 2015; 167:608-619. [PMID: 25543130 DOI: 10.1093/rpd/ncu365] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/03/2014] [Indexed: 06/04/2023]
Abstract
This study aims to review the literature on existing diagnostic reference levels (DRLs) in digital mammography and methodologies for establishing them. To this end, a systematic search through Medline, Cinahl, Web of Science, Scopus and Google scholar was conducted using search terms extracted from three terms: DRLs, digital mammography and breast screen. The search resulted in 1539 articles of which 22 were included after a screening process. Relevant data from the included studies were summarised and analysed. Differences were found in the methods utilised to establish DRLs including test subjects types, protocols followed, conversion factors employed, breast compressed thicknesses and percentile values adopted. These differences complicate comparison of DRLs among countries; hence, an internationally accepted protocol would be valuable so that international comparisons can be made.
Collapse
Affiliation(s)
- Moayyad E Suleiman
- Faculty of Health Sciences, The University of Sydney, M205, Cumberland Campus, 75 East St, Lidcombe, Sydney, NSW 2141, Australia
| | - Patrick C Brennan
- Faculty of Health Sciences, The University of Sydney, M205, Cumberland Campus, 75 East St, Lidcombe, Sydney, NSW 2141, Australia
| | - Mark F McEntee
- Faculty of Health Sciences, The University of Sydney, M205, Cumberland Campus, 75 East St, Lidcombe, Sydney, NSW 2141, Australia
| |
Collapse
|
7
|
Kelaranta A, Toroi P, Timonen M, Komssi S, Kortesniemi M. Conformance of mean glandular dose from phantom and patient data in mammography. Radiat Prot Dosimetry 2015; 164:342-353. [PMID: 25114321 DOI: 10.1093/rpd/ncu261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/18/2014] [Indexed: 06/03/2023]
Abstract
In mammography dosimetry, phantoms are often used to represent breast tissue. The conformance of phantom- and patient-based mean glandular dose (MGD) estimates was evaluated mainly from the aspect of diagnostic reference levels. Patient and phantom exposure data were collected for eight diagnostic and three screening mammography devices. More extensive assessments were performed for two devices. The average breast thickness was close to the nationally used reference of 50 mm in diagnostic (50 mm, SD = 13 mm, n = 5342) and screening (47 mm, SD = 13 mm, n = 395) examinations. The average MGD for all breasts differed by 2% from the MGD determined for breasts in the limited compressed thickness range of 40-60 mm. The difference between phantom- and patient-based MGD estimations was up to 30%. Therefore, phantom measurements cannot replace patient dose data in MGD determination.
Collapse
Affiliation(s)
- A Kelaranta
- STUK-Radiation and Nuclear Safety Authority, Laippatie 4, PO Box 14, Helsinki FI-00881, Finland Helsinki Medical Imaging Center, University Hospital of Helsinki, PO Box 340, Helsinki FI-00290, Finland Department of Physics, University of Helsinki, PO Box 64, Helsinki FI-00014, Finland
| | - P Toroi
- STUK-Radiation and Nuclear Safety Authority, Laippatie 4, PO Box 14, Helsinki FI-00881, Finland
| | - M Timonen
- Helsinki Medical Imaging Center, University Hospital of Helsinki, PO Box 340, Helsinki FI-00290, Finland
| | - S Komssi
- Suomen Terveystalo Ltd., Jaakonkatu 3B, Helsinki FI-00100, Finland
| | - M Kortesniemi
- Helsinki Medical Imaging Center, University Hospital of Helsinki, PO Box 340, Helsinki FI-00290, Finland
| |
Collapse
|
8
|
Kawaguchi A, Matsunaga Y, Otsuka T, Suzuki S. Patient investigation of average glandular dose and incident air kerma for digital mammography. Radiol Phys Technol 2013; 7:102-8. [DOI: 10.1007/s12194-013-0239-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 10/20/2013] [Accepted: 10/21/2013] [Indexed: 11/29/2022]
|
9
|
Abstract
In this first Maltese national mammography survey, the effectiveness of direct digital (DR) mammography in breast cancer screening has been confirmed. Patient data were made available from three clinics out of the participating nine. A dose survey of mean glandular dose (MGD) calculated for 759 patients examined in the state-owned mammography facilities was performed. An MGD national diagnostic reference level was set at 1.87 mGy for patients with breast compression thicknesses (BCT) between 5.0 and 7.0 cm. This range was selected since patient data were retrieved from three clinics only and the results showed that other international BCT reference levels may be unsuitable for the Maltese population. In fact, the overall average BCT was 5.75 ± 1.4 cm. The survey results have shown that the technical standard of mammographic equipment in the Malta National Breast Screening Programme is on a par with other countries, including its Western European counterparts.
Collapse
Affiliation(s)
- M Borg
- Medical Imaging Department, Mater Dei Hospital, Tal-Qroqq, Msida MSD2090, Malta.
| | | | | |
Collapse
|
10
|
Vano E, Ten JI, Fernandez-soto JM, Sanchez-casanueva RM. Experience With Patient Dosimetry and Quality Control Online for Diagnostic and Interventional Radiology Using DICOM Services. AJR Am J Roentgenol 2013; 200:783-90. [DOI: 10.2214/ajr.12.10179] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
11
|
Chen B, Wang Y, Sun X, Guo W, Zhao M, Cui G, Hu L, Li P, Ren Y, Feng J, Yu J. Analysis of patient dose in full field digital mammography. Eur J Radiol 2012; 81:868-72. [DOI: 10.1016/j.ejrad.2011.02.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Accepted: 02/10/2011] [Indexed: 11/16/2022]
|
12
|
Thierry-Chef I, Simon SL, Weinstock RM, Kwon D, Linet MS. Reconstruction of absorbed doses to fibroglandular tissue of the breast of women undergoing mammography (1960 to the present). Radiat Res 2012; 177:92-108. [PMID: 21988547 PMCID: PMC3876279 DOI: 10.1667/rr2241.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The assessment of potential benefits versus harms from mammographic examinations as described in the controversial breast cancer screening recommendations of the U.S. Preventive Task Force included limited consideration of absorbed dose to the fibroglandular tissue of the breast (glandular tissue dose), the tissue at risk for breast cancer. Epidemiological studies on cancer risks associated with diagnostic radiological examinations often lack accurate information on glandular tissue dose, and there is a clear need for better estimates of these doses. Our objective was to develop a quantitative summary of glandular tissue doses from mammography by considering sources of variation over time in key parameters, including imaging protocols, X-ray target materials, voltage, filtration, incident air kerma, compressed breast thickness, and breast composition. We estimated the minimum, maximum and mean values for glandular tissue dose for populations of exposed women within 5-year periods from 1960 to the present, with the minimum to maximum range likely including 90% to 95% of the entirety of the dose range from mammography in North America and Europe. Glandular tissue dose from a single view in mammography is presently about 2 mGy, about one-sixth the dose in the 1960s. The ratio of our estimates of maximum to minimum glandular tissue doses for average-size breasts was about 100 in the 1960s compared to a ratio of about 5 in recent years. Findings from our analysis provide quantitative information on glandular tissue doses from mammographic examinations that can be used in epidemiological studies of breast cancer.
Collapse
|
13
|
Hauge IHR, Pedersen K, Sanderud A, Hofvind S, Olerud HM. Patient doses from screen-film and full-field digital mammography in a population-based screening programme. Radiat Prot Dosimetry 2012; 148:65-73. [PMID: 21335333 DOI: 10.1093/rpd/ncq598] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The aim of this study was to compare mean glandular dose (MGD) in all full-field digital mammography (FFDM) and screen film mammography (SFM) systems used in a national mammography screening program. MGD from 31 screening units (7 FFDM and 24 SFM), based on an average of 50 women at each screening unit, representing 12 X-ray models (6 FFDM and 6 SFM) from five different manufacturers were calculated. The MGD was significantly lower for FFDM compared with SFM (craniocaudal): 1.19 versus 1.27 mGy, respectively, mediolateral oblique: 1.33 versus 1.45 mGy, respectively), but not all of the FFDM units provided lower doses than the SFM units. Comparing FFDMs, the photon counting scanning-slit technology provides significantly lower MGDs than direct and indirect conversion digital technology. The choice of target/filter combination influences the MGD, and has to be optimised with regard to breast thickness.
Collapse
Affiliation(s)
- I H R Hauge
- Faculty of Health Sciences, Oslo University College, PO Box 4 St. Olavs plass, NO-0130 Oslo, Norway.
| | | | | | | | | |
Collapse
|
14
|
Alizadeh Riabi H, Mehnati P, Mesbahi A. Evaluation of mean glandular dose in a full-field digital mammography unit in Tabriz, Iran. Radiat Prot Dosimetry 2010; 142:222-227. [PMID: 20823039 DOI: 10.1093/rpd/ncq218] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This study was aimed at evaluating the mean glandular dose (MGD) and affecting factors during mammography examinations by a full-field digital mammography unit. An extensive quality control program was performed to assure that the unit is properly working. Required information including compressed breast thickness (CBT), breast parenchymal pattern and technical factors used for imaging were recorded. An entrance skin exposure measurement was also performed using slabs of polymethylmethacrylate with 2-8 cm thickness. On the basis of recorded information and measured data, the MGD was estimated for 1145 mammography examinations obtained from 298 patients. Mean CBTs of 4.9 and 5.8 cm and MGDs of 2 and 2.4 mGy were observed for craniocaudal and mediolateral oblique views, respectively. Significant correlation was seen between MGD and CBT, breast parenchymal pattern and applied kVp and mAs.
Collapse
Affiliation(s)
- Hamed Alizadeh Riabi
- Department of Medical Physics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | | |
Collapse
|
15
|
Elbakri IA, McIntosh BJ, Rickey DW. Physical characterization and performance comparison of active- and passive-pixel CMOS detectors for mammography. Phys Med Biol 2009; 54:1743-55. [PMID: 19242050 DOI: 10.1088/0031-9155/54/6/022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We investigated the physical characteristics of two complementary metal oxide semiconductor (CMOS) mammography detectors. The detectors featured 14-bit image acquisition, 50 microm detector element (del) size and an active area of 5 cm x 5 cm. One detector was a passive-pixel sensor (PPS) with signal amplification performed by an array of amplifiers connected to dels via data lines. The other detector was an active-pixel sensor (APS) with signal amplification performed at each del. Passive-pixel designs have higher read noise due to data line capacitance, and the APS represents an attempt to improve the noise performance of this technology. We evaluated the detectors' resolution by measuring the modulation transfer function (MTF) using a tilted edge. We measured the noise power spectra (NPS) and detective quantum efficiencies (DQE) using mammographic beam conditions specified by the IEC 62220-1-2 standard. Our measurements showed the APS to have much higher gain, slightly higher MTF, and higher NPS. The MTF of both sensors approached 10% near the Nyquist limit. DQE values near dc frequency were in the range of 55-67%, with the APS sensor DQE lower than the PPS DQE for all frequencies. Our results show that lower read noise specifications in this case do not translate into gains in the imaging performance of the sensor. We postulate that the lower fill factor of the APS is a possible cause for this result.
Collapse
|
16
|
Abstract
Medical uses of radiation have grown very rapidly over the past decade, and, as of 2007, medical uses represent the largest source of exposure to the U.S. population. Most physicians have difficulty assessing the magnitude of exposure or potential risk. Effective dose provides an approximate indicator of potential detriment from ionizing radiation and should be used as one parameter in evaluating the appropriateness of examinations involving ionizing radiation. The purpose of this review is to provide a compilation of effective doses for radiologic and nuclear medicine procedures. Standard radiographic examinations have average effective doses that vary by over a factor of 1000 (0.01-10 mSv). Computed tomographic examinations tend to be in a more narrow range but have relatively high average effective doses (approximately 2-20 mSv), and average effective doses for interventional procedures usually range from 5-70 mSv. Average effective dose for most nuclear medicine procedures varies between 0.3 and 20 mSv. These doses can be compared with the average annual effective dose from background radiation of about 3 mSv.
Collapse
Affiliation(s)
- Fred A Mettler
- Department of Radiology and Nuclear Medicine, New Mexico Veterans Administration Healthcare System, 1501 San Pedro Blvd, Albuquerque, NM 87108, USA.
| | | | | | | |
Collapse
|
17
|
Thierens H, Bosmans H, Buls N, De Hauwere A, Bacher K, Jacobs J, Clerinx P. Typetesting of physical characteristics of digital mammography systems for screening within the Flemish breast cancer screening programme. Eur J Radiol 2008; 70:539-48. [PMID: 18374533 DOI: 10.1016/j.ejrad.2008.01.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Accepted: 01/28/2008] [Indexed: 11/15/2022]
Abstract
To investigate compliance with the acceptance criteria of the European guidelines for quality assurance in breast cancer screening, a typetesting programme of the physical characteristics of digital mammography systems based on direct readout (DR) technology or computed radiography (CR) was organised and executed within the Flemish breast cancer screening programme. While in general image quality/dose characteristics of flat panel DR systems passed the acceptance criteria more easily than CR systems, the slit-scanning direct photon counting system included in present study was outstanding in combining a very low dose with a good image quality. The data obtained up to now indicate the necessity of retuning the AEC for DR systems according to constant contrast to noise ratio (CNR) over the whole range of PMMA thicknesses (20-70 mm) to improve image quality in imaging breasts of large thickness at the cost of higher doses. For the two CR systems which passed the typetesting procedure dose levels do not allow a similar improvement of CNR for thick objects for these systems. The obtained results highlight the importance of the use of high Z target/filter combinations in X-ray generating systems for imaging thick objects to meet the image quality/dose criteria. With respect to image display aspects high-quality 3-megapixel LCD monitors succeeded also in the typetesting procedure in addition to 5-megapixel monitors. However, as zooming and scrolling are necessary for 3-megapixel monitors to get the full resolution capabilities of the image capture system, 5-megapixel monitors are preferred in a busy screening environment.
Collapse
Affiliation(s)
- Hubert Thierens
- Department of Medical Physics and Radiation Protection, QCC, Ghent University, Proeftuinstraat 86, B-9000 Ghent, Belgium.
| | | | | | | | | | | | | |
Collapse
|
18
|
Fischmann A. Full-field Digital Mammography versus Film-screen Mammography. Cancer Imaging 2008. [DOI: 10.1016/b978-012374212-4.50038-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
19
|
Abstract
The physical characteristics of charge-coupled device (CCD) mammography detector with 16-bit dynamic range and 27 microm detector element size were investigated. The detector, with an active area of 1 cm x 20 cm is suitable for slot-scanning systems. We evaluated the detector resolution by measuring the modulation transfer function (MTF) using a tilted edge. We also measured the noise power spectra (NPS) and detective quantum efficiency (DQE) using tungsten spectra filtered with 3 mm Al. We carried out measurements in two modes of operation: the frame mode where the detector is stationary and the scan mode where the detector operates in a slot-scanning configuration. The specific beam qualities and exposure ranges employed were 30 kVp, HVL 1.4 mm Al, 1.24 microC kg(-1) to 12.44 microC kg(-1), and 40 kVp, HVL 2.1 mm Al and 3.26 microC kg(-1) to 16.64 microC kg(-1). The product of the normalized noise power spectrum and exposure was also computed to evaluate the quantum limited characteristic of the detector. The detector MTF was 12% at 15 lp mm(-1). The product of the noise power spectra and exposure was independent of exposure level, indicating a quantum limited detector. The DQE in the scan and frame modes near zero frequency was 40% and 60%, respectively. Our results show that the slot-scanning configuration was less efficient than the performance capabilities of the detector. This detector is comparable to other digital mammography sensors evaluated in the literature.
Collapse
|