Publications by authors named "John Dickson"

Introduction: The use of in-house developed software as a medical device (IHD-SaMD) is core to many nuclear medicine (NM) services in the UK, including applications in nonimaging studies and image processing. Expected regulatory changes in 2025 could have significant implications due to a lack of resources and expertise in the implementation and maintenance of software Quality Management Systems (QMS) and associated standards. This survey investigated the national use of IHD-SaMD and the readiness of services to adapt to the upcoming regulatory changes.

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Background: Unilateral condylar hyperplasia (UCH) of the mandible is a rare condition characterized by asymmetric growth of the mandibular condyles. Bone scintigraphy with SPECT(/CT) is commonly used to diagnose UCH and guide treatment. Still, varying results have been reported using the traditional threshold of 55%:45% in relative tracer uptake.

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Background: The dopamine transporter striatal binding ratio (DAT SBR) has been used as an outcome measure in Parkinson's disease (PD) trials of potential disease-modifying therapies; however, both patient characteristics and analysis approach potentially complicate its interpretation.

Objective: The aim was to explore how well DAT SBR reflects PD motor severity across different striatal subregions and the relationship to disease duration, and side of onset.

Methods: DAT SBR for the anterior and posterior putamen and caudate in both hemispheres was obtained using validated automated quantitative software on baseline scans of 132 patients recruited for the Exenatide PD2 and PD3 trials.

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Background: There is a paucity of organized human biomonitoring, including that of carbon monoxide (CO) in the Niger Delta, Nigeria. The study aims to quantify the impact of maternal exposure to CO in the first trimester of pregnancy and its modification by maternal demographic and obstetric factors.

Methodology: It was of cross-sectional design conducted at the Rivers State University Teaching Hospital (RSUTH) in Nigeria.

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The role of bacteria in the etiology of dental caries is long established, while the role of fungi has only recently gained more attention. The microbial invasion of dentin in advanced caries especially merits additional research. We evaluated the fungal and bacterial community composition and spatial distribution within carious dentin.

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Background And Objectives: Degeneration of the presynaptic nigrostriatal dopaminergic system is one of the main biological features of Parkinson disease (PD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD), which can be measured using single-photon emission CT imaging for diagnostic purposes. Despite its widespread use in clinical practice and research, the diagnostic properties of presynaptic nigrostriatal dopaminergic (DAT) imaging in parkinsonism have never been evaluated against the diagnostic gold standard of neuropathology. The aim of this study was to evaluate the diagnostic parameters of DAT imaging compared with pathologic diagnosis in patients with parkinsonism.

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Anti-amyloid immunotherapies have recently emerged as treatments for Alzheimer's disease. While these therapies have demonstrated efficacy in clearing amyloid-β and slowing cognitive decline, they have also been associated with amyloid-related imaging abnormalities (ARIA) which include both edema (ARIA-E) and hemorrhage (ARIA-H). Given that ARIA have been associated with significant morbidity in cases of antithrombotic or thrombolytic therapy, an understanding of mechanisms of and risk factors for ARIA is of critical importance for stroke care.

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Background: Although age is the biggest known risk factor for dementia, there remains uncertainty about other factors over the life course that contribute to a person's risk for cognitive decline later in life. Furthermore, the pathological processes leading to dementia are not fully understood. The main goals of Insight 46-a multi-phase longitudinal observational study-are to collect detailed cognitive, neurological, physical, cardiovascular, and sensory data; to combine those data with genetic and life-course information collected from the MRC National Survey of Health and Development (NSHD; 1946 British birth cohort); and thereby contribute to a better understanding of healthy ageing and dementia.

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Background: Consistent patterns of reduced cortical thickness have been identified in early Alzheimer's disease (AD). However, the pathological factors that influence rates of cortical thinning within these AD signature regions remain unclear.

Methods: Participants were from the Insight 46 substudy of the MRC National Survey of Health and Development (NSHD; 1946 British birth cohort), a prospective longitudinal cohort study.

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Sustained delivery of protein therapeutics remains a largely unsolved problem across anatomic locations. Miniaturized devices that can provide sustained delivery of protein formulations have the potential to address this challenge via minimally invasive administration. In particular, methodologies that can optimize protein formulation independent of device manufacture have the greatest potential to provide a platform suitable for wide applications.

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Background And Aim: Workplace humanization, when effectively managed can be instrumental in steering an organization towards efficient, and effective work processes. It is on this backdrop that this study aimed at determining the inter-relationship between employee productivity, dignity and empathy.

Materials And Methods: This was a cross-sectional study that identified the relationship between the study variables.

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Background: Single photon emission tomography (SPECT) can detect early changes in brain perfusion to support the diagnosis of dementia. Inflammation is a driver for dementia progression and measures of inflammation may further support dementia diagnosis.

Objective: In this study, we assessed whether combining imaging with markers of inflammation improves prediction of the likelihood of Alzheimer's disease (AD).

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We investigate associations between normal-appearing white matter microstructural integrity in cognitively normal ∼70-year-olds and concurrently measured brain health and cognition, demographics, genetics and life course cardiovascular health. Participants born in the same week in March 1946 (British 1946 birth cohort) underwent PET-MRI around age 70. Mean standardized normal-appearing white matter integrity metrics (fractional anisotropy, mean diffusivity, neurite density index and orientation dispersion index) were derived from diffusion MRI.

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Objectives: With disease-modifying therapies in development for neurological disorders, quantitative brain imaging techniques become increasingly relevant for objective early diagnosis and assessment of response to treatment. The aim of this study was to evaluate the use of Brain SPECT and PET scans in the UK and explore drivers and barriers to using quantitative analysis through an online survey.

Methods: A web-based survey with 27 questions was used to capture a snapshot of brain imaging in the UK.

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Introduction: The Centiloid scale aims to harmonize amyloid beta (Aβ) positron emission tomography (PET) measures across different analysis methods. As Centiloids were created using PET/computerized tomography (CT) data and are influenced by scanner differences, we investigated the Centiloid transformation with data from Insight 46 acquired with PET/magnetic resonanceimaging (MRI).

Methods: We transformed standardized uptake value ratios (SUVRs) from 432 florbetapir PET/MRI scans processed using whole cerebellum (WC) and white matter (WM) references, with and without partial volume correction.

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Background: The study was prompted by the high prevalence of hyperglycaemia first detected in pregnancy (HIP) which is classified into diabetes mellitus in pregnancy (DIP) and gestational diabetes mellitus (GDM). This study aimed to determine the usefulness of Glycosylated Haemoglobin (HBA1c) in the diagnosis of HIP in the first trimester of pregnancy.

Methodology: The study was of a prospective cross-sectional design carried out between January 2020 and August 2020 at the University of Port Harcourt Teaching (UPTH) and Rivers State University Teaching Hospital (RSUTH).

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Unlabelled: Microsurgical breast reconstruction accounts for 22% of breast reconstructions in the UK. Despite thromboprophylaxis, venous thromboembolism (VTE) occurs in up to 4% of cases. Using a Delphi process, this study established a UK consensus on VTE prophylaxis strategy, for patients undergoing autologous breast reconstruction using free-tissue transfer.

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National Institute for Health and Care Excellence (NICE) has published an updated guideline on melanoma assessment and management in July 2022, which has included recommendation on BRAF analysis of primary melanoma tissue samples, staging with sentinel lymph node biopsy, guidance on patient follow-up as well as surveillance imaging requirement based on patients' melanoma stages. However, very often, assimilating this considerable amount of information in an efficient and accurate way can be challenging, especially in the setting of a busy multidisciplinary team (MDT) meeting. Human factors are well recognised as a key principle to mitigate against mistakes and human errors and thereby aiming to optimise patient care.

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Introduction: In Alzheimer's disease (AD), hyperphosphorylated tau is closely associated with focal neurodegeneration, but the mechanism remains uncertain.

Methods: We quantified cortical microstructure using neurite orientation dispersion and density imaging in 14 individuals with young onset AD. Diffusion tensor imaging measured mean diffusivity (MD).

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Nucleoporin 98 is a nuclear pore complex component that is mislocalized in Alzheimer's disease and the alteration in nucleoporin 98 has been attributed to tau. In order to determine if nucleoporin 98 mislocalization is a general feature of tauopathies, we assessed the localization of nucleoporin 98 in neurons in primary tauopathies, including frontotemporal lobar degeneration-tau, corticobasal degeneration and progressive supranuclear palsy. Immunofluorescence staining was performed on frontal cortex and occipital cortex tissue from cases of primary tauopathies and controls without neurodegenerative disease using antibodies to identify nucleoporin 98, phospho-tau (Ser202, Thr205) monoclonal antibody and neuronal marker microtubule-associated protein 2.

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Purpose: Quantitative SPECT-CT is a modality of growing importance with initial developments in post radionuclide therapy dosimetry, and more recent expansion into bone, cardiac and brain imaging together with the concept of theranostics more generally. The aim of this document is to provide guidelines for nuclear medicine departments setting up and developing their quantitative SPECT-CT service with guidance on protocols, harmonisation and clinical use cases.

Methods: These practice guidelines were written by members of the European Association of Nuclear Medicine Physics, Dosimetry, Oncology and Bone committees representing the current major stakeholders in Quantitative SPECT-CT.

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Article Synopsis
  • The guidelines from the European Association of Nuclear Medicine (EANM) focus on quality control (QC) for PET-CT and PET-MR systems, building on previous nuclear medicine standards while addressing the unique features of these multimodal scanners.
  • They provide a detailed overview of essential quality control procedures to keep PET systems functioning optimally in clinical settings, along with discussions on regulatory frameworks from the International Electrotechnical Commission (IEC) and European Commission (EC).
  • The recommendations include the rationale for various tests, their suggested frequency, specific tests for MR and CT integration, and a preventive approach to maintain acceptable performance levels in routine clinical use.
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Background: Neuroinflammation is an integral part of Alzheimer's disease (AD) pathology. Inflammatory mediators can exacerbate the production of amyloid-β (Aβ), the propagation of tau pathology and neuronal loss.

Objective: To evaluate the relationship between inflammation markers and established markers of AD in a mixed memory clinic cohort.

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