Publications by authors named "Kershaw L"

Background: Dysregulated myocardial calcium handling has been demonstrated in ischemic, non-ischemic and diabetic cardiomyopathy. Manganese-enhanced MRI (MEMRI) provides a unique method to quantify in-vivo myocardial calcium uptake but no studies have so far utilized MEMRI in patients with aortic stenosis (AS). We sought to: 1) determine whether myocardial calcium uptake is perturbed in people with severe AS, and 2) assess change in calcium uptake following aortic valve replacement (AVR).

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Background: Magnetic resonance spectroscopy (MRS) has been used to investigate metabolic changes within human bone. It may be possible to use MRS to investigate bone metabolism and fracture risk in the distal third metacarpal/tarsal bone (MC/MTIII) in racehorses.

Objectives: To determine the feasibility of using MRS as a quantitative imaging technique in equine bone by using the H spectra for the MC/MTIII to calculate fat content (FC).

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Training deep learning models for image registration or segmentation of dynamic contrast enhanced (DCE) MRI data is challenging. This is mainly due to the wide variations in contrast enhancement within and between patients. To train a model effectively, a large dataset is needed, but acquiring it is expensive and time consuming.

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Microdamage accumulated through sustained periods of cyclic loading or single overloading events contributes to bone fragility through a reduction in stiffness and strength. Monitoring microdamage in vivo remains unattainable by clinical imaging modalities. As such, there are no established computational methods for clinical fracture risk assessment that account for microdamage that exists in vivo at any specific timepoint.

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Article Synopsis
  • * The porosity index (PI) serves as an indirect measure of bone strength, but traditional MRI methods struggle to adequately assess bone architecture due to tightly bound water protons.
  • * A novel dual-echo ultra-short echo time (UTE) MRI technique was used to calculate PI from cadaver specimens, revealing an inverse correlation between PI and bone mineral density (BMD), indicating the need for further research on correlation patterns and PI's relevance in horses with stress injuries.
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Purpose: Software has a substantial impact on quantitative perfusion MRI values. The lack of generally accepted implementations, code sharing and transparent testing reduces reproducibility, hindering the use of perfusion MRI in clinical trials. To address these issues, the ISMRM Open Science Initiative for Perfusion Imaging (OSIPI) aimed to establish a community-led, centralized repository for sharing open-source code for processing contrast-based perfusion imaging, incorporating an open-source testing framework.

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Despite the majority of laparoscopic visceral injuries occurring with primary entry, high-fidelity training models are lacking. Three healthy volunteers underwent non-contrast 3T MRI at Edinburgh Imaging. A direct entry 12mm trocar was filled with water to improve MR visibility, placed on the skin at entry points, then images were acquired in the supine position.

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Aims: To investigate whether manganese-enhanced magnetic resonance imaging can assess functional pancreatic beta-cell mass in people with type 1 diabetes mellitus.

Methods: In a prospective case-control study, 20 people with type 1 diabetes mellitus (10 with low (≥50 pmol/L) and 10 with very low (<50 pmol/L) C-peptide concentrations) and 15 healthy volunteers underwent manganese-enhanced magnetic resonance imaging of the pancreas following an oral glucose load. Scan-rescan reproducibility was performed in 10 participants.

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Manganese-enhanced magnetic resonance imaging can provide a surrogate measure of myocardial calcium handling. Its repeatability and reproducibility are currently unknown. Sixty-eight participants: 20 healthy volunteers, 20 with acute myocardial infarction, 18 with hypertrophic and 10 with non-ischemic dilated cardiomyopathy underwent manganese-enhanced magnetic resonance imaging.

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Background: Low-field magnetic resonance imaging (MRI) is widely available to equine veterinarians yet is insensitive at detecting cartilage damage in the distal interphalangeal joint (DIPJ). T2 mapping is a quantitative imaging technique that can detect cartilage damage before morphological change is apparent.

Objectives: Validation of a T2 mapping sequence on a low-field MR system.

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Background: Takotsubo syndrome is an acute cardiac emergency characterized by transient left ventricular systolic dysfunction typically following a stressful event. Despite its rapidly rising incidence, its pathophysiology remains poorly understood. Takotsubo syndrome may pass unrecognized, especially if timely diagnostic imaging is not performed.

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Manganese-based contrast media were the first in vivo paramagnetic agents to be used in magnetic resonance imaging (MRI). The uniqueness of manganese lies in its biological function as a calcium channel analog, thus behaving as an intracellular contrast agent. Manganese ions are taken up by voltage-gated calcium channels in viable tissues, such as the liver, pancreas, kidneys, and heart, in response to active calcium-dependent cellular processes.

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Children on the autism spectrum often experience anxiety. Mindfulness is growing in popularity as a method to support children with anxiety; however, there is limited evidence on mindfulness for children on the autism spectrum. This study investigated the feasibility of a 10-week group-based mindfulness intervention for 14 children on the autism spectrum.

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Objective: Soft tissue sarcoma (STS) is a rare malignancy with a 5 year overall survival rate of 55%. Neoadjuvant radiotherapy is commonly used in preparation for surgery, but methods to assess early response are lacking despite pathological response at surgery being predictive of overall survival, local recurrence and distant metastasis. Multiparametric MR imaging (mpMRI) is used to assess response in a variety of tumours but lacks a robust, standardised method.

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Objectives: To determine the contribution of comorbidities on the reported widespread myocardial abnormalities in patients with recent COVID-19.

Methods: In a prospective two-centre observational study, patients hospitalised with confirmed COVID-19 underwent gadolinium and manganese-enhanced MRI and CT coronary angiography (CTCA). They were compared with healthy and comorbidity-matched volunteers after blinded analysis.

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Objective: In a proof-of-concept study, to quantify myocardial viability in patients with acute myocardial infarction using manganese-enhanced MRI (MEMRI), a measure of intracellular calcium handling.

Methods: Healthy volunteers (n=20) and patients with ST-elevation myocardial infarction (n=20) underwent late gadolinium enhancement (LGE) using gadobutrol and MEMRI using manganese dipyridoxyl diphosphate. Patients were scanned ≤7 days after reperfusion and rescanned after 3 months.

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Study Question: Can markers of human endometrial hypoxia be detected at menstruation in vivo?

Summary Answer: Our in vivo data support the presence of hypoxia in menstrual endometrium of women during physiological menstruation.

What Is Known Already: Current evidence from animal models and human in vitro studies suggests endometrial hypoxia is present at menstruation and drives endometrial repair post menses. However, detection of human endometrial hypoxia in vivo remains elusive.

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Objectives: To assess non-invasive imaging for detection and quantification of gland structure, inflammation and function in patients with primary Sjogren's syndrome (pSS) using PET-CT with 11C-Methionine (11C-MET; radiolabelled amino acid), and 18F-fluorodeoxyglucose (18F-FDG; glucose uptake marker), to assess protein synthesis and inflammation, respectively; multiparametric MRI evaluated salivary gland structural and physiological changes.

Methods: In this imaging/clinical/histology comparative study (GSK study 203818; NCT02899377) patients with pSS and age- and sex-matched healthy volunteers underwent MRI of the salivary glands and 11C-MET PET-CT. Patients also underwent 18F-FDG PET-CT and labial salivary gland biopsies.

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Aims: The aim of this study is to quantify altered myocardial calcium handling in non-ischaemic cardiomyopathy using magnetic resonance imaging.

Methods And Results: Patients with dilated cardiomyopathy (n = 10) or hypertrophic cardiomyopathy (n = 17) underwent both gadolinium and manganese contrast-enhanced magnetic resonance imaging and were compared with healthy volunteers (n = 20). Differential manganese uptake (Ki) was assessed using a two-compartment Patlak model.

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The endometrium is a multicellular tissue that is exquisitely responsive to the ovarian hormones. The local mechanisms of endometrial regulation to ensure optimal function are less well characterised. Transient physiological hypoxia has been proposed as a critical regulator of endometrial function.

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Background: Up to 50% of heart transplant candidates require bridging with left ventricular assist devices (VAD). This study describes hospital activity and cost 1 year preceding and 1 year following VAD implant (pre-VAD) and for the year before transplant (pre-HTX). The sample comprises an Australian cohort and is the first study to investigate costs using both institutional and linked administrative data.

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Objective: Soft tissue sarcomas (STS) are a rare, heterogeneous tumour group. Radiotherapy improves local control. CT is used to plan radiotherapy, but has poor soft tissue definition.

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Objectives: The aim of this study was to describe patient level costing methods and develop a database of healthcare resource use and cost in patients with AHF receiving ventricular assist device (VAD) therapy.

Methods: Patient level micro-costing was used to identify documented activity in the years preceding and following VAD implantation, and preceding heart transplant for a cohort of seventy-seven consecutive patients listed for heart transplantation (2009-12). Clinician interviews verified activity, established time resource required for each activity, and added additional undocumented activities.

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