Publications by authors named "George McGill"

8 Publications

  • Page 1 of 1

A 3D printed phantom to assess MRI geometric distortion.

Biomed Phys Eng Express 2021 Mar 3. Epub 2021 Mar 3.

Queensland University of Technology, 199 Ipswich Road, Brisbane, 4102, AUSTRALIA.

Magnetic Resonance has become a standard imaging modality for target volume delineation and treatment planning in radiation oncology. Geometric distortions, however, have the potential to detrimentally affect both tumour definition and the dose delivered to the target volume. We report the design, fabrication and imaging of a 3D printed unibody MR distortion phantom along with quantitative image analysis.

Methods: The internal cavity of the phantom is an orthogonal three-dimensional planar lattice, composed of 3mm diameter rods spaced equidistantly at a 20mm centre-centre offset repeating along the X, Y and Z axes. The phantom featured an overall length of 308.5 mm, a width of 246 mm and a height of 264 mm with lines on the external surface for phantom positioning matched to external lasers. The MR phantom was 3D printed in Nylon-12 using an advancement on traditional selective laser sintering (SLS) (HP Jet Fusion 3D - 4200 machine). The phantom was scanned on a Toshiba Aquilion CT scanner to check the integrity of the 3D print and to correct for any resultant issues. The phantom was then filled with NiSO4 solution and scanned on a 3T PET-MR Siemens scanner for selected T1 and T2 sequences, from which distortion vectors were generated and analysed using in-house software written in Python.

Results: All deviations were less than 1 mm, with an average displacement of 0.228 mm. The majority of the deviations are smaller than the 0.692 mm pixel size for this dataset.

Conclusion: A cost-effective, 3D printed MRI-phantom was successfully printed and tested for assessing geometric distortion on MRI scanners. The custom phantom with markings for phantom alignment may be considered for radiotherapy departments looking to add MR scanners for simulation and image guidance.
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March 2021

Examining the UK Covid-19 mortality paradox: Pandemic preparedness, healthcare expenditure, and the nursing workforce.

J Adv Nurs 2020 Dec 10;76(12):3218-3227. Epub 2020 Oct 10.

Leicester School of Nursing and Midwifery, Faculty of Health & Life Sciences, De Montfort University, Leicester, UK.

Aim: To examine the UK pandemic preparedness in light of health expenditure, nursing workforce, and mortality rates in and relation to nursing leadership.

Background: The Global Health Security Index categorized the preparedness of 195 countries to face a biological threat on a variety of measures, producing an overall score. The United States of America and the United Kingdom were ranked 1st and 2nd most prepared in 2019.

Method: A cross-nation comparison of the top 36 countries ranked by Global Health Security Index score using a variety of online sources, including key data about each nation's expenditure on health and the nursing workforce, and compared these with mortality data for COVID-19.

Results: The extent of a country's pandemic preparedness, expenditure on healthcare and magnitude of the nursing workforce does not appear to impact mortality rates at this stage of the pandemic which is something of a paradox.

Conclusion: It is important that arrangements for dealing with future global pandemics involve a range of agencies and experts in the field, including nurse leaders.

Implications For Nursing: To achieve the best outcomes for patients, nurse leaders should be involved in policy forums at all levels of government to ensure nurses can influence health policy.
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December 2020

Discrepancies between positron emission tomography/magnetic resonance imaging and positron emission tomography/computed tomography in a cohort of oncological patients.

J Med Imaging Radiat Oncol 2020 Apr 9;64(2):204-210. Epub 2020 Feb 9.

Department of Diagnostic Radiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia.

Introduction: This study aims to evaluate discrepant findings between positron emission tomography/magnetic resonance imaging (PET/MRI) and positron emission tomography/computed tomography (PET/CT) in a cohort of oncological patients and to undertake a phantom study to assess the potential for extended PET acquisitions to lead to false-positive findings on PET/MRI.

Methods: Discrepant findings from a series of 106 patients undergoing same-day F-fluorodeoxyglucose (FDG)-PET/CT and PET/MRI were reviewed. Phantom studies explored the potential for PET acquisition time to contribute to discrepancy.

Results: There were 14 discrepant cases, 5 (35.7%) of which related to PET/MRI acquisitions that had been extended to 10 min. Three of these five cases proved to be falsely positive. Phantom studies showed greater contrast recovery and signal to noise ratio for 10-min PET/MRI acquisitions compared to 2-min acquisitions using PET/CT. There were no discrepancies when PET/CT showed disseminated disease (P = 0.036).

Conclusions: Extended PET/MRI acquisitions used to accommodate multiple MRI sequences may be associated with false-positive findings compared to PET/CT. PET/MRI is more likely to have incremental value when the prior probability for disseminated disease is low.
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April 2020

A training needs analysis of admiral nurses to facilitate advance care planning in dementia.

Palliat Care 2019 19;12:1178224219850183. Epub 2019 Jun 19.

Faculty of Health and Life Sciences, School of Nursing and Midwifery, De Montfort University, Leicester, UK.

Education of health and social care professionals is essential in preparation to confidently and effectively support families affected by dementia to undertake advance care planning. This article describes a training needs analysis of Admiral Nurses, dementia specialists, in facilitating advance care planning for future care.

Methods: A questionnaire survey was completed by Admiral Nurses attending end-of-life care masterclasses in 2017 and 2018. Both quantitative (years registered as a nurse, years as an Admiral Nurse and subjective level of confidence in completing advance care plannings) and qualitative data (interventions perceived to increase confidence) were collected.

Findings: There were 75 completed responses (two incomplete returns). There was no correlation between levels of confidence and years registered as a nurse. However, there was a small positive correlation between confidence and number of years as an Admiral Nurse ( = 0.23;  < 0.05). Themes identified qualitatively to enhance practice were advanced communication skills, supervised practice, resources to frame conversations and a guide and template for advance care planning.

Conclusion: Although Admiral Nurses are specialists in dementia, several educational initiatives could be employed to better enable them to support advance care planning for families affected by dementia. This training needs analysis is contributed towards developing an educational intervention for Admiral Nurses to improve advance care planning support.
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June 2019

Investigation into attitudes towards older people with dementia in acute hospital using the Approaches to Dementia Questionnaire.

Dementia (London) 2020 Nov 21;19(8):2761-2779. Epub 2019 Jun 21.

First Community Health and Care CIC Redhill, UK.

Background: Health care professionals have poor recognition of cognitive impairment among older patients and often have difficulties in providing care for people with dementia in acute hospitals. There are also reported high levels of stigma and negative staff attitudes towards people with dementia.

Methodology: A one-time survey of staff working on acute medical and orthopaedic wards of five District Health Boards in New Zealand using the 'Approaches to Dementia Questionnaire'; a 19-item Questionnaire that aims to capture two attitudinal domains (Hope and Person-Centredness), towards people with dementia. A total of 563 questionnaires were distributed. Data were analysed using R.

Results: Three hundred and four (53.99%) respondents completed the survey. Ninety-four of the respondents (31.1%) were aged 51 years or older, and nearly all (88.4%) were women. One hundred and sixty-four of the respondents (53.9%) were registered nurses, 10 were student nurses (3.3%), 24 (7.9%) were healthcare assistants, 70 (23.0%) were allied health professionals, 27 (8.9%) were doctors and 9 (3%) were pharmacists. The mean total score of 72.7 reflected positive attitudes overall on the part of the respondents. Allied health professionals, student nurses and pharmacists had high scores on both scales whilst healthcare assistants scored lowest on both scales.

Conclusion: Overall, the Approaches to Dementia Questionnaire is a useful measure, but it can be difficult to differentiate between genuine attitudinal differences and confounding influences such as level of knowledge and education amongst such a diverse group of participants. Differences between staff may be considered as a reflection of the high level of direct care that is expected of some staff and not of others. Further, the Approaches to Dementia Questionnaire may not be the most appropriate measure to accurately understand attitudes to dementia care in acute environments; and that it more usefully reveals knowledge about dementia rather than attitudes related to real-time practice.
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November 2020

The management of lupus in young people.

Br J Gen Pract 2018 02;68(667):96-97

Centre for Rheumatology, University College London Hospital NHS Foundation Trust, London; Arthritis Research UK Centre for Adolescent Rheumatology, University College London, London.

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February 2018

Results from a phantom based multi-centre paediatric computed tomography dose survey.

Australas Phys Eng Sci Med 2016 Dec 11;39(4):885-893. Epub 2016 Oct 11.

Biomedical Technology Services, Princess Alexandra Hospital, Woolloongabba, QLD, Australia.

A computed tomography radiation dose survey was performed within our enterprise using three age-based paediatric phantoms representing a 1, 5 and 10 years old. Twenty-seven scanners were surveyed with volume computed tomography dose index and dose length product data collected for head, chest and abdomen-pelvis protocols at each age. Reconstruction method e.g. filtered back projection (FBP) or iterative (IR) was also recorded. About two-thirds of the 1 year old FBP chest scans exceeded the national Baby diagnostic reference level (DRL). A small number of scanners also exceeded the national Child DRL for the 1 and 5 years old phantoms. Only about half of the phantom protocols showed a difference of statistical significance between FBP and IR scanners. The results suggested the need for optimisation work at a number of sites. It was determined that the proposed local (i.e. enterprise-wide) DRLs are presented best in terms of weight or girth rather than age.
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December 2016

The readout thickness versus the measured thickness for a range of screen film mammography and full-field digital mammography units.

Med Phys 2012 Jan;39(1):263-71

Oslo and Akershus University College of Applied Sciences, Department of Radiography and Dental Technology, St. Olavs plass, NO-0130 Oslo, Norway.

Purpose: To establish a simple method to determine breast readout accuracy on mammography units.

Methods: A thickness measuring device (TMD) was used in conjunction with a breast phantom. This phantom had compression characteristics similar to human female breast tissue. The phantom was compressed, and the thickness was measured using TMD and mammography unit readout. Measurements were performed on a range of screen film mammography (SFM) and full-field digital mammography (FFDM) units (8 units in total; 6 different models/manufacturers) for two different sized paddles and two different compression forces (60 and 100 N).

Results: The difference between machine readout and TMD for the breast area, when applying 100 N compression force, for nonflexible paddles was largest for GE Senographe DMR+ (24 cm × 30 cm paddle: +14.3%). For flexible paddles the largest difference occurred for Hologic Lorad Selenia (18 cm × 24 cm paddle: +26.0%).

Conclusions: None of the units assessed were found to have perfect correlation between measured and readout thickness. TMD measures and thickness readouts were different for the duplicate units from two different models/manufacturers.
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January 2012