49 research outputs found
Visual grading characteristics and ordinal regression analysis during optimisation of CT head examinations
Objectives: To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation.Methods: Patient images (n = 66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n = 6) performed VGA followed by VGC and ordinal regression analysis.Results: VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examinations (including trauma) in one centre, achieving radiation dose reductions ranging from 24 % to 36 %. In the second centre a 29 % reduction in radiation dose was achieved for follow-up cases.Conclusions: The combined use of VGC and ordinal logistic regression analysis led to clinical decisions being taken on the implementation of the optimised protocols. This improved method of image quality analysis provided the evidence to support imaging protocol optimisation, resulting in significant radiation dose savings.peer-reviewe
Breast screening attendance of Aboriginal and Torres Strait Islander women in the Northern Territory of Australia
Objective: To compare breast screening attendances of Indigenous and non-Indigenous women. Methods: A total of 4,093 BreastScreen cases were used including 857 self-identified Indigenous women. Chi-squared analysis compared data between Indigenous and non-Indigenous women. Logistic regression was used for groupings based on visits-to-screening frequency. Odds ratios and 95% confidence intervals were calculated for associations with low attendance. Results: Indigenous women were younger and had fewer visits to screening compared with non-Indigenous women. Non-English speaking was mainly associated with fewer visits for Indigenous women only (OR 1.9, 95%CI 1.3-2.9). Living remotely was associated with fewer visits for non-Indigenous women only (OR 1.3, 95%CI 1.1-1.5). Shared predictors were younger age (OR 12.3, 95%CI 8.1-18.8; and OR 11.5, 95%CI 9.6-13.7, respectively) and having no family history of breast cancer (OR 2.1, 95%CI 1.3-3.3; and OR 1.8, 95%CI 1.5-2.1, respectively). Conclusions: Factors associated with fewer visits to screening were similar for both groups of women, except for language which was significant only for Indigenous women, and remoteness which was significant only for non-Indigenous women. Implications for public health: Health communication in Indigenous languages may be key in encouraging participation and retaining Indigenous women in BreastScreen; improving access for remote-living non-Indigenous women should also be addressed
The pop-up research centre - Challenges and opportunities
Objectives: This article sets out to describe the concept of the “pop-up” research centre as a means to promote and develop radiography research locally, nationally and internationally, and to empower professional colleagues to set up similar initiatives in the future. Key findings: A detailed overview of the development and management of “pop-up” research is provided based on the experiences of the authors, including specific examples. Matters such as study design, approvals, equipment and software, environment, participant recruitment and management, research teams and activity costs are discussed. Quantifiable benefits of “pop-up” research such as resultant peer reviewed publications, development of researchers' skills and potential collaborations are described. A number of “soft skill” benefits are also apparent and include enhanced organisational profiles, team building and the development of leadership skills. Conclusions: “Pop-up” research centres are a valuable option for conducting research and offer the radiography profession an achievable mechanism to increase and enhance research activity. However, careful planning and execution are essential
Strategies for dose reduction with specific clinical indications during computed tomography
Increasing integration of computed tomography (CT) into routine patient care has escalated concerns regarding associated radiation exposure. Specific patient cohorts, particularly those with cystic fibrosis (CF) and Crohn's disease, have repeat exposures and thus have an increased risk of high lifetime cumulative effective dose exposures. Thoracic CT is the gold standard imaging method in the diagnosis, assessment and management of pulmonary disease. In the setting of CF, CT demonstrates increased sensitivity compared with pulmonary function tests and chest radiography. Furthermore, in specific cases of Crohn's disease, CT demonstrates diagnostic superiority over magnetic resonance imaging (MRI) for radiological evaluation. Low dose CT protocols have proven beneficial in the evaluation of CF, Crohn's disease and renal calculi, and in the follow up of testicular cancer patients. For individuals with chronic conditions warranting frequent radiological follow up, the focus must continue to be the incorporation of appropriate CT use into patient care. This is of particular importance for the paediatric population who are most susceptible to potential radiation induced malignancy. CT technological developments continue to focus on radiation dose optimisation. This article aims to highlight these advancements, which prioritise the acquisition of diagnostically satisfactory images with the least amount of radiation possible
The effect of breast shielding outside the field of view on breast entrance surface dose in axial X-ray examinations: a phantom study
PURPOSEThe purpose of this study was to evaluate the effect of outside-field-of-view (FOV) lead shielding on the entrance surface dose (ESD) of the breast on an anthropomorphic X-ray phantom for a variety of axial skeleton X-ray examinations.METHODSUsing an anthropomorphic phantom and radiation dosimeter, the ESD of the breast was measured with and without outside-FOV shielding in anterior-posterior (AP) abdomen, AP cervical spine, occipitomental 30° (OM30) facial bones, AP lumbar spine, and lateral lumbar spine radiography. The effect of several exposure parameters, including a low milliampere-seconds technique, grid use, automatic exposure control use, wraparound lead (WAL) use, trolley use, and X-ray table use, on the ESD of the breast with and without outside-FOV shielding was investigated. The mean ESD (μSv) and standard deviation for each radiographic protocol were calculated. A one-tailed Student’s t-test was carried out to evaluate whether ESD to the breast was reduced with the use of outside-FOV shielding.RESULTSA total of 920 breast ESD measurements were recorded across the different protocol parameters. The largest decrease in mean ESD of the breast with outside-FOV shielding was 0.002 μSv (P = 0.084), recorded in the AP abdomen on the table with a grid, OM30 on the table with a grid, OM30 standard protocol on the trolley, and OM30 on the trolley with WAL protocols. This decrease was found to be statistically non-significant.CONCLUSIONThis study found no significant decrease in the ESD of the breast with the use of outside-FOV shielding for the AP abdomen, AP cervical spine, OM30 facial bones, AP lumbar spine, or lateral lumbar spine radiography across a range of protocols
Analysis of motion during the breast clamping phase of mammography
Objectives: To measure paddle motion during the clamping phase of a breast phantom
for a range of machine/paddle combinations.
Methods: A deformable breast phantom was used to simulate a female breast. Twelve
mammography machines from three manufacturers with twenty two flexible and twenty
fixed paddles were evaluated. Vertical motion at the paddle was measured using two
calibrated linear potentiometers. For each paddle, the motion in millimeters was
recorded every 0.5 seconds for 40 seconds while the phantom was compressed with
80 N. Independent t-tests were used to determine differences in paddle motion
between flexible and fixed, small and large, GE Senographe Essential and Hologic
Selenia Dimensions paddles. Paddle tilt in the medial-lateral plane for each
machine/paddle combination was calculated.
Results: All machine/paddle combinations demonstrate highest levels of motion during
the first 10s of the clamping phase. Least motion is 0.17±0.05 mm/10s (n=20) and the
most is 0.51±0.15 mm/10s (n=80). There is a statistical difference in paddle motion
between fixed and flexible (p<0.001), GE Senographe Essential and Hologic Selenia
Dimensions paddles (p<0.001). Paddle tilt in the medial-lateral plane is independent of
time and varied from 0.04° to 0.69°.
Conclusions: All machine/paddle combinations exhibited motion and tilting and the
extent varied with machine and paddle sizes and types.
Advances in knowledge: This research suggests that image blurring will likely be
clinically insignificant 4 seconds or more after the clamping phase commences
Mammographic densities of Aboriginal and non-Aboriginal women living in Australia's Northern Territory
Objectives: To compare the mammographic densities and other characteristics of Aboriginal and non-Aboriginal women screened in Australia. Methods: Population screening programme data of Aboriginal (n = 857) and non-Aboriginal women (n = 3236) were used. Mann–Whitney U test compared ages at screening and Chi-square tests compared personal and clinical information. Logistic regression analysis was used for density groupings. OR and 95% CI were calculated for multivariate association for density. Results: Mammographic density was lower amongst Aboriginal women (P < 0.001). For non-Aboriginal women, higher density was associated with younger age (OR 2.4, 95% CI 2.1–2.8), recall to assessment (OR 2.2, 95% CI 1.6–3.0), family history of breast cancer (OR 1.4, 95% CI 1.2–1.6), English-speaking background (OR 1.4, 95% CI 1.2–1.6), and residence in remote areas (OR 1.2, 95% CI 1.1–1.4). For Aboriginal women, density was associated with younger age (OR 2.7, 95% CI 2.0–3.5; P < 0.001), and recall to assessment (OR 2.3, 95% CI 1.4–3.9; P < 0.05). Conclusions: Significant differences between Aboriginal and non-Aboriginal women were found. There were more significant associations for dense breasts for non-Aboriginal women than for Aboriginal women
Establishment of diagnostic reference levels in cardiac computed tomography
The aim of this study was to determine diagnostic reference levels (DRLs) for cardiac computed tomography (CCT) in Jordan. Volume computed tomography dose index (CTDIvol) and dose–length product (DLP) were collected from 228 CCTs performed at seven Jordanian hospitals specialized in cardiac CT. DRLs for cardiac CT were defined at the 75th percentile of CTDIvol and DLP. CTDIvol and DLP were collected from 30 successive cardiac CT in each center except for one center (18 scans). The 75th percentile of the CTDIvol and the DLP of the centers calculated from mixed retrospective and prospective gated modes were 47.74 milligray (mGy) and 1035 mGy/cm, respectively. This study demonstrated wide dose variations among the surveyed hospitals for cardiac CT scans; there was a 5.1-fold difference between the highest and lowest median DLP with a range of 223.2–1146.7 mGy/cm. Differences were associated with variations in the mAs and kVp. This study confirmed large variability in CTDIvol and DLP for cardiac CT scans; variation was associated with acquisition protocols and highlights the need for dose optimization. DRLs are proposed for CCT; there remains substantial potential for optimization of cardiac CT examinations for adults in Jordan
Potential for CT dose reduction based on QA phantom and human cadaver images
Purpose: CT centres having higher radiation doses when compared to many CT centres locally and internationally have been identified through a nationwide dose survey carried in Nigeria for CT examinations of the brain, chest and abdomen. This provides a basis for dose reduction methods to be explored. This study proposes a methodology using a quality assurance (QA) phantom and human cadaver images.Materials and methods: The study proposes a methodology consisting of three phases. Phase I: Manipulation of scan parameters to monitor their effect on radiation dose indices and psycho-physical parameters using a GE QA phantom, leading to determination of the optimal parameter settings. Phase II: Application of the identified optimal QA phantom protocols on the human cadaver as a starting point for further optimisation, which was followed with analysis of results based on VGA, VGC and VGR from evaluation of cadaveric images. Phase III: Clinical implementation of the finally optimised protocols and further image quality evaluation based on VGA, VGC and VGR.Results: Fifteen adult QA optimised protocols were established in five CT centres. Of the 15 QA phantom protocols, nine protocols from three centres were tested on cadaver as two of the centres did not give permission for cadaver scanning. Of the nine protocols, six were further optimised as three protocols could not be further optimised due to severe loss of image quality. Furthermore, two of the six cadaver optimised protocols, were not implemented due to the radiologists preference of image quality, rather the established QA optimised protocols were retained which still achieved dose reduction when compared to standard protocols. The implemented optimised protocols in two of the three CT centre showed evidence of dose reductions based on the new CTDIvol DRLs as follows: 36% for brain; 18% for chest and 21% for abdomen, whilst the DLPs were: 44% for brain, 54% for chest and 30% for abdomen with acceptable image quality based on the VGA, VGC and VGR. Conclusion: The study established optimised protocols in selected CT centres providing acceptable image quality based on the VGA, VGC and VGR using a methodology with a lot of advantages such as low cost resources (QA phantom and human cadaver) which is ideal for countries lacking expensive equipment (Catphan and anthropometric phantoms).peer-reviewe
Radiographers' knowledge, attitudes and expectations of artificial intelligence in medical imaging
Introduction: Artificial intelligence (AI) is increasingly utilised in medical imaging systems and processes, and radiographers must embrace this advancement. This study aimed to investigate perceptions, knowledge, and expectations towards integrating AI into medical imaging amongst a sample of radiographers and determine the current state of AI education within the community. Methods: A cross-sectional online quantitative study targeting radiographers based in Europe was conducted over ten weeks. Captured data included demographical information, participants’ perceptions and understanding of AI, expectations of AI and AI-related educational backgrounds. Both descriptive and inferential statistical techniques were used to analyse the obtained data. Results: A total of 96 valid responses were collected. Of these, 64% correctly identified the true definition of AI from a range of options, but fewer (37%) fully understood the difference between AI, machine learning and deep learning. The majority of participants (83%) agreed they were excited about the advancement of AI, though a level of apprehensiveness remained amongst 29%. A severe lack of education on AI was noted, with only 8% of participants having received AI teachings in their pre-registration qualification. Conclusion: Overall positive attitudes towards AI implementation were observed. The slight apprehension may stem from the lack of technical understanding of AI technologies and AI training within the community. Greater educational programs focusing on AI principles are required to help increase European radiography workforce engagement and involvement in AI technologies. Implications for practice: This study offers insight into the current perspectives of European based radiographers on AI in radiography to help facilitate the embracement of AI technology and convey the need for AI-focused education within the profession