scholarly journals The relationship between compression force, image quality and radiation dose in mammography

2009 ◽  
Vol 13 (4) ◽  
pp. 86 ◽  
Author(s):  
A Korf ◽  
C P Herbst ◽  
W ID Rae

Background. Mammography aims to obtain mammograms of best possible image quality with least possible radiation dose.1 Theoretically, an increase in breast compression gives a reduction in thickness, without changing the density, resulting in improved image quality and reduced radiation dose. Aim. This study aims to investigate the relationship between compression force, phantom thickness, image quality and radiation dose. The existence of a compression point beyond which increased compression gives a change in density rather than thickness is also considered. Method. Image quality is assessed with a contrast-detail phantom within Superflab phantom on a computed radiography (CR) mammography unit using automatic exposure control (AEC). Image quality is determined by visual inspection and image quality figure (IQF) scoring. The effect of compression and lesion depth on image quality is determined. Entrance and exit doses are calculated. The relationship between entrance dose, compression and thickness is investigated, as is the existence of a compression point beyond which a change in phantom density occurs. The average glandular dose (AGD) is calculated from the scanning average level (SAL) and logarithmic mean (LgM) according to Koen et al,2 and compared to the allowable limit. Results. The geometry effect was not observed. An improvement in image quality with increased compression was found. Entrance dose did decrease with increased compression. This trend was not observed with exit dose as AEC was used and exit dose was calculated from SAL values. The “change-in-density” point of compression was determined. Both LgM and SAL could be used successfully for AGD calculation.

2008 ◽  
Vol 12 (2) ◽  
pp. 28 ◽  
Author(s):  
Liebner Koen ◽  
Charles Herbst ◽  
William Rae

Studies indicate that computed radiography (CR) can lead to increased radiation dose to patients. It is therefore important to relate the exposure indicators provided by CR manufacturers to the radiation dose delivered so as to assess the radiation dose delivered to patients directly from the exposure indicators. The aim of this study was to investigate the performance of an Agfa CR system in order to characterize the dose indicators provided by the system. The imaging plate response was characterized in terms of entrance exposure to the plate and the digital signal indicators generated by the system (SAL - Scanning Average Level and lgM - Logarithmic median) for different beam qualities. Several exposures were performed on a mammography unit and the digital signal, expressed as SAL and lgM for each image was correlated with the entrance exposure on a standard ACR phantom. From this, the relationship between the Agfa dose indices (SAL and lgM) and the average glandular dose (AGD) in mammography was established. An equation was derived to calculate the AGD delivered to the patient as a function of the exposure indicator, lgM, and the kV. The results indicated that the measured AGD at 28kV for a standard breast thickness during routine calibration with the ACR phantom was 1.58mGy (lgM = 1.99), which is within 1.5% of the value calculated using the derived equation for a standard Perspex thickness of 4.2cm using the AEC (1.56mGy). The standard error in using this equation was calculated to be 8.3%.


2006 ◽  
Vol 33 (6Part4) ◽  
pp. 2016-2016
Author(s):  
X Kong ◽  
H Liu ◽  
X Rong ◽  
C Sweet ◽  
Z Yang ◽  
...  

2009 ◽  
Vol 13 (4) ◽  
pp. 80 ◽  
Author(s):  
Rupesh Baloo Daya ◽  
Maurice A Kibel ◽  
Richard Denys Pitcher ◽  
Lesley Workman ◽  
Tania S Douglas ◽  
...  

ABSTRACT Background: Chest radiography accounts for a significant proportion of ionising radiation in children. The radiation dose of radiographs performed on the Lodox Statscan system has been shown to be lower than that of a computed radiography (CR) system. The role of the Lodox Statscan (hereafter referred to as the Statscan) in routine erect chest radiography in children has not been evaluated. Objective: To evaluate the image quality and diagnostic accuracy of erect paediatric chest radiographs obtained with the Statscan and compare this with conventional erect chest images obtained with a CR system. Materials and Methods: Thirty three children with suspected chest pathology were enrolled randomly over a period of three months. Erect chest radiographs were obtained with the Statscan, and a Shimadzu R-20J X-ray machine coupled with a Fuji FCR 5000 CR system. Image quality and diagnostic accuracy and diagnostic capability were evaluated between the two modalities. Results: The erect Statscan allowed superior visualisation of the three major airways. Statscan images however, demonstrated exposure and movement artifacts with hemidiaphragms and ribs most prone to movement. Bronchovascular clarity was also considered unsatisfactory on the Statscan images. Conclusion: The Statscan has limitations in erect chest radiography in terms of movement artefacts, exposure fluctuations, and poor definition of lung markings. Despite this, the Statscan allows better visualisation of the major airways, equivalent to a ‘high KV’ film at a fraction of the radiation dose. This supports the finding of an earlier study evaluating Statscan images in trauma cases, where the images were taken supine. Statscan has great potential in assisting in the diagnosis of childhood tuberculosis where airway narrowing occurs as a result of nodal compression.


2014 ◽  
Vol 25 (3) ◽  
pp. 821-829 ◽  
Author(s):  
Mireille J. M. Broeders ◽  
Marloes ten Voorde ◽  
Wouter J. H. Veldkamp ◽  
Ruben E. van Engen ◽  
Cary van Landsveld – Verhoeven ◽  
...  

2009 ◽  
Vol 10 (1) ◽  
pp. 51 ◽  
Author(s):  
Kwang Hwi Lee ◽  
Jong Won Kwon ◽  
Young Cheol Yoon ◽  
Sang-Hee Choi ◽  
Jee Young Jung ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Malene Bisgaard ◽  
Fintan J. McEvoy ◽  
Dorte Hald Nielsen ◽  
Clara Allberg ◽  
Anna V. Müller ◽  
...  

Introduction: The purpose of this study was to evaluate the effect of collimation on image quality and radiation dose to the eye lenses of the personnel involved in computed radiography of the canine pelvis.Materials and Methods: A retrospective study of canine pelvic radiographs (N = 54) was undertaken to evaluate the relationship between image quality and the degree of field the collimation used. This was followed by a prospective cadaver study (N = 18) that assessed the effects on image quality and on scattered radiation dose of different collimation field areas and exposure parameters. All radiographs were analyzed for image quality using a Visual Grading Analysis (VGA) with three observers. Finally, the potential scattered radiation dose to the eye lens of personnel restraining a dog for pelvic radiographs was measured.Results: The retrospective study showed a slightly better (statistically non-significant) VGA score for the radiographs with optimal collimation. Spatial and contrast resolution and image sharpness showed the greatest improvement in response to minimizing the collimation field. The prospective study showed slightly better VGA scores (improved image quality) with the optimal collimation. Increasing the exposure factors especially the tube current and exposure time (mAs) resulted in improved low contrast resolution and less noise in the radiographs. The potential eye lens radiation dose increased by 14, 28, and 40% [default exposures, increased the tube peak potential (kVp), increased mAs, respectively] as a result of reduced collimation (increased beam size).Conclusion: The degree of collimation has no statistically significant on image quality in canine pelvic radiology for the range of collimation used but does have an impact on potential radiation dose to personnel in the x-ray room. With regard to radiation safety, increases in kVp are associated with less potential scatter radiation exposure compared to comparable increases in mAs.


2019 ◽  
Vol 1 (3) ◽  
pp. 192-198 ◽  
Author(s):  
Brian N Dontchos ◽  
Christine E Edmonds ◽  
Sarah F Mercaldo ◽  
Randy C Miles ◽  
Katrina F Chu ◽  
...  

Abstract Objective Screening mammography is critical to reduce breast cancer mortality, yet many women cite pain from compression as a reason they avoid this test. We evaluated patient experience and image quality in screening patients opting for a handheld patient-assisted compression (PAC) device. Methods After institutional review board approval, women screened between February and July 2018 with a synthetic 2D/tomosynthesis mammography unit were offered use of a handheld PAC device. Patient experience through survey, image quality, compression thickness, compression force, and average glandular dose were evaluated and compared between women opting for PAC and women opting for technologist-controlled compression (TC). Multivariable ordinal logistic and linear regression models were estimated to control for age and breast density. In addition, for women opting for PAC, image quality obtained with their current PAC mammogram was compared with that obtained with their prior TC mammogram, by using Wilcoxon/Pearson tests. Results Seventy-three percent of women preferred their mammogram experience with PAC compared with their prior mammogram without PAC. Women using PAC reported decreased anxiety compared with those using TC, after controlling for age and breast density (adjusted odds ratio [aOR] 0.22 [95% confidence interval (CI): 0.09–0.49]). There were no significant differences in image quality, compression thickness, or average glandular dose in exams for women using PAC compared with exams for women using TC. Women using PAC had significantly more compression force than women using TC had (P = 0.012). Conclusions Mammography with PAC improves patient experience and results in similar image quality compared with mammography with TC.


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