Publications by authors named "Fergus Mckiddie"

Background: Patients with breast cancer undergoing biological therapy and/or chemotherapy perform multiple radionuclide angiography (RNA) or multigated acquisition (MUGA) scans to assess cardiotoxicity. The association between RNA imaging parameters and left ventricular (LV) ejection fraction (LVEF) remains unclear.

Objectives: This study aimed to extract and evaluate the association of several novel imaging biomarkers to detect changes in LVEF in patients with breast cancer undergoing chemotherapy.

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High-dimensional radiomics features derived from pre-treatment positron emission tomography (PET) images offer prognostic insights for patients with head and neck squamous cell carcinoma (HNSCC). Using 124 PET radiomics features and clinical variables (age, sex, stage of cancer, site of cancer) from a cohort of 232 patients, we evaluated four survival models-penalized Cox model, random forest, gradient boosted model and support vector machine-to predict all-cause mortality (ACM), locoregional recurrence/residual disease (LR) and distant metastasis (DM) probability during 36, 24 and 24 months of follow-up, respectively. We developed models with five-fold cross-validation, selected the best-performing model for each outcome based on the concordance index (C-statistic) and the integrated Brier score (IBS) and validated them in an independent cohort of 102 patients.

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. Accurate and reproducible tumor delineation on positron emission tomography (PET) images is required to validate predictive and prognostic models based on PET radiomic features. Manual segmentation of tumors is time-consuming whereas semi-automatic methods are easily implementable and inexpensive.

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Background: Positron emission tomography (PET) images of head and neck squamous cell carcinoma (HNSCC) patients can assess the functional and biochemical processes at cellular levels. Therefore, PET radiomics-based prediction and prognostic models have the potentials to understand tumour heterogeneity and assist clinicians with diagnosis, prognosis and management of the disease. We conducted a systematic review of published modelling information to evaluate the usefulness of PET radiomics in the prediction and prognosis of HNSCC patients.

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The Ionising Radiation (Medical Exposure) Regulations require employers to appoint suitable medical physics experts (MPE) for nuclear medicine services, and they also define the areas where MPEs are required to provide advice and specify matters that they must contribute towards. Applications for employer licences under IR(ME)R require employers to specify the level of MPE support available and if this is provided by onsite MPEs or remotely. Assessment of these applications by the Administration of Radioactive Substances Advisory Committee (ARSAC) has highlighted variability in the levels of MPE support being provided for similar services across the UK.

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Objective: To explore differences in position emission tomography-computed tomography (PET-CT) service provision internationally to further understand the impact variation may have upon cancer services. To identify areas of further exploration for researchers and policymakers to optimize PET-CT services and improve the quality of cancer services.

Design: Comparative analysis using data based on pre-defined PET-CT service metrics from PET-CT stakeholders across seven countries.

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Objectives: This study investigated the subcentimetre lesion detection gains of a Bayesian penalised likelihood reconstruction (BPLR) (Q.Clear, GE Healthcare, Milwaukee, USA) in PET/computed tomography (CT) phantom images and compares observer performance with ordered subset expectation maximisation (OSEM) reconstruction images (VUE Point HD, GE Healthcare).

Methods: Images were presented to three blinded experienced observers to identify lesions and assign confidence ratings.

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Background Exercise-induced pulmonary hypertension is common in heart failure with preserved ejection fraction ( HF p EF ). We hypothesized that this could result in pericardial constraint and diastolic ventricular interaction in some patients during exercise. Methods and Results Contrast stress echocardiography was performed in 30 HF p EF patients, 17 hypertensive controls, and 17 normotensive controls (healthy).

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Recently heart failure with preserved ejection fraction (HFpEF) has emerged as a huge epidemic. Increasing evidence shows the role of energy deficiency in the pathophysiology of HFpEF. In the current study, we hypothesize that the use of metabolic modulator perhexiline would correct myocardial energy deficiency and improve exercise capacity and diastolic abnormalities in patients with this syndrome.

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TauroH-23-(Se) selena-25-homocholic acid retention values are used in the diagnosis of bile acid malabsorption. The standard method for measuring values is with an uncollimated gamma camera, which can create some logistic difficulties, with other background sources of activity, which are irrelevant when a collimator is used, becoming significant. In this study we compare the retention values obtained with a collimated and an uncollimated gamma camera in phantoms and in 23 patients.

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Dimercaptosuccinic acid imaging is the 'gold standard' for the detection of cortical defects and diagnosis of scarring of the kidneys. The Siemens planar processing package, which implements adaptive noise reduction using the Pixon algorithm, is designed to allow a reduction in image noise, enabling improved image quality and reduced acquisition time/injected activity. This study aimed to establish the level of improvement in image quality achievable using this algorithm.

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Background: The aim of this study was to examine the quality of nitrogen 13-labeled ammonia (NH(3)) perfusion data from coincidence-capable gamma camera positron emission tomography (GC-PET) systems compared with that from full-ring positron emission tomography (FR-PET).

Methods And Results: The performance parameters of the GC-PET system were examined and found adequate for imaging at the activity levels used clinically. We studied 15 patients who underwent stress and rest N-13-labeled NH(3) perfusion imaging on FR-PET and GC-PET systems.

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