55 results match your criteria: "UCL Centre for Medical Imaging[Affiliation]"

Noninvasive measurements of liver perfusion and fibrosis in cirrhotic small animals can help develop treatments for haemodynamic complications of liver disease. Here, we measure liver perfusion in cirrhotic rodents using flow-sensitive alternating inversion recovery arterial spin labelling (FAIR ASL), evaluating agreement with previously validated caval subtraction phase-contrast magnetic resonance imaging (PCMRI) total liver blood flow (TLBF). Baseline differences in cirrhotic rodents and the haemodynamic effects of acute inflammation were investigated using FAIR ASL and tissue T1.

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Clinical experience suggests that there is a cohort of patients with refractory colitis who do have faecal stasis that contributes to symptoms. The underlying physiology is poorly understood, partly because until recently the technology to examine segmental colonic motility has not existed. Patients are given little information on how proximal faecal stasis can complicate colitis.

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(1) Background: Intestinal failure-associated liver disease (IFALD) in adults is characterized by steatosis with variable progression to fibrosis/cirrhosis. Reference standard liver biopsy is not feasible for all patients, but non-invasive serological and quantitative MRI markers for diagnosis/monitoring have not been previously validated. Here, we examine the potential of serum scores and feasibility of quantitative MRI used in non-IFALD liver diseases for the diagnosis of IFALD steatosis; (2) Methods: Clinical and biochemical parameters were used to calculate serum scores in patients on home parenteral nutrition (HPN) with/without IFALD steatosis.

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Translating pH-sensitive PROgressive saturation for QUantifying Exchange rates using Saturation Times (PRO-QUEST) MRI to a 3T clinical scanner.

Magn Reson Med

October 2020

Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, UK.

Purpose: To translate the recently developed PRO-QUEST (Progressive saturation for quantifying exchange rates using saturation times) sequence from preclinical 9.4T to 3T clinical magnetic field strength.

Methods: Numerical simulations were performed to define the optimal saturation flip angles for PRO-QUEST saturation pulses at 3T and demonstrate the effect of a ∆T error on the exchange rate (k ) estimation at various field strengths.

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Purpose: To prospectively evaluate interobserver agreement for small bowel ultrasound (SBUS) in newly diagnosed and relapsing Crohn's disease.

Methods: A subset of patients recruited to a prospective trial comparing the diagnostic accuracy of MR enterography and SBUS underwent a second SBUS performed by one of a pool of six practitioners, who recorded the presence, activity and location of small bowel and colonic disease. Detailed segmental mural and extra-mural observations were also scored.

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Background: Nomenclature for mesh insertion during ventral hernia repair is inconsistent and confusing. Several terms, including 'inlay', 'sublay' and 'underlay', can refer to the same anatomical planes in the indexed literature. This frustrates comparisons of surgical practice and may invalidate meta-analyses comparing surgical outcomes.

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Background: No standardized written or volumetric definition exists for 'loss of domain' (LOD). This limits the utility of LOD as a morphological descriptor and as a predictor of peri- and postoperative outcomes. Consequently, our aim was to establish definitions for LOD via consensus of expert abdominal wall surgeons.

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Magnetic Resonance Imaging of Fistula-In-Ano.

Magn Reson Imaging Clin N Am

February 2020

UCL Department of Imaging, UCL Centre for Medical Imaging, Second Floor, Charles Bell House, 43-45 Foley Street, London W1W 7TS, UK. Electronic address:

This article explains the pathogenesis of fistula-in-ano and details the different classifications of fistula encountered, describe their features on MR imaging, and explains how imaging influences subsequent surgical treatment and ultimate clinical outcome. Precise preoperative characterization of the anatomic course of the fistula and all associated infection via MR imaging is critical for surgery to be most effective. MR imaging is the preeminent imaging modality used to answer pertinent surgical questions.

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Challenges in glucoCEST MR body imaging at 3 Tesla.

Quant Imaging Med Surg

October 2019

Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, UK.

Background: The aim of this study was to translate dynamic glucose enhancement (DGE) body magnetic resonance imaging (MRI) based on the glucose chemical exchange saturation transfer (glucoCEST) signal to a 3 T clinical field strength.

Methods: An infusion protocol for intravenous (i.v.

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Background: Ventral hernias (VHs) often recur after surgical repair and subsequent attempts at repair are especially challenging. Rigorous research to reduce recurrence is required but such studies must be well-designed and report representative and comprehensive outcomes.

Objective: We aimed to assesses methodological quality of non-randomised interventional studies of VH repair by systematic review.

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MRI plays an important role in the clinical management of pancreatic disorders and interpretation is reliant on qualitative assessment of anatomy. Conventional sequences capturing pancreatic structure can however be adapted to yield quantitative measures which provide more diagnostic information, with a view to increasing diagnostic accuracy, improving patient stratification, providing robust non-invasive outcome measures for therapeutic trials and ultimately personalizing patient care. In this review, we evaluate the use of established techniques such as secretin-enhanced MR cholangiopancreatography, diffusion-weighted imaging, , * and fat fraction mapping, but also more experimental methods such as MR elastography and arterial spin labelling, and their application to the assessment of diffuse pancreatic disease (including chronic, acute and autoimmune pancreatitis/IgG4 disease, metabolic disease and iron deposition disorders) and cystic/solid focal pancreatic masses.

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VERDICT MRI for Prostate Cancer: Intracellular Volume Fraction versus Apparent Diffusion Coefficient.

Radiology

May 2019

From the UCL Centre for Medical Imaging, University College London, 2nd Floor Charles Bell House, 43-45 Foley Street, London W1W 7TS, England (E.W.J., E.B.C., H.S.S., J.O., M.B.A., D. Atkinson, S.P.); UCL Centre for Medical Image Computing, London, England (E.B.C., U.F., B.Y., S.O., D.H., D. Alexander, E.P.); UCL Centre for Molecular Intervention, London, England (H.P., S.H., H.W.); Department of Histopathology, University College Hospital, London, England (D.P., M.R.J., A.F.); Department of Radiology (J.C.) and Centre for Medical Imaging (J.C., W.P., A.S.), University College Hospital, London, England; Division of Surgery and Interventional Science, Faculty of Medical Sciences, University College London, London, England (F.G., A.G., C.M.M., M.E.); and Department of Surgery and Cancer, Imperial College London, London, England (H.U.A.).

Background Biologic specificity of diffusion MRI in relation to prostate cancer aggressiveness may improve by examining separate components of the diffusion MRI signal. The Vascular, Extracellular, and Restricted Diffusion for Cytometry in Tumors (VERDICT) model estimates three distinct signal components and associates them to intracellular water, water in the extracellular extravascular space, and water in the microvasculature. Purpose To evaluate the repeatability, image quality, and diagnostic utility of intracellular volume fraction (FIC) maps obtained with VERDICT prostate MRI and to compare those maps with apparent diffusion coefficient (ADC) maps for Gleason grade differentiation.

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Alveolar hydatid disease or alveolar echinococcosis (AE) is caused by the parasite Echinococcus multilocularis and is increasingly seen as an imported disease in non-endemic areas such as the UK. It is rare compared to cystic echinococcosis (CE), but like CE commonly affects the liver. AE does have imaging features that can aid in diagnosis, but is often initially misdiagnosed as liver malignancy.

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Objectives: To determine the diagnostic accuracy and interobserver concordance of whole-body (WB)-MRI, vs. Tc bone scintigraphy (BS) and fluoro-ethyl-choline (F-choline) PET/CT for the primary staging of intermediate/high-risk prostate cancer.

Methods: An institutional review board approved prospective cohort study carried out between July 2012 and November 2015, whereby 56 men prospectively underwent 3.

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VERDICT (vascular, extracellular and restricted diffusion for cytometry in tumours) estimates and maps microstructural features of cancerous tissue non-invasively using diffusion MRI. The main purpose of this study is to address the high computational time of microstructural model fitting for prostate diagnosis, while retaining utility in terms of tumour conspicuity and repeatability. In this work, we adapt the accelerated microstructure imaging via convex optimization (AMICO) framework to linearize the estimation of VERDICT parameters for the prostate gland.

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Large ventral hernias are a significant surgical challenge. "Loss of domain" (LOD) expresses the relationship between hernia and abdominal volume, and is used to predict operative difficulty and success. This systematic review assessed whether different definitions of LOD are used in the literature.

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The role of imaging in obesity special feature.

Br J Radiol

September 2018

2 Department of Radiology, VCU Health System , Richmond, VA , United States.

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Obesity, metabolic disease and the pancreas-Quantitative imaging of pancreatic fat.

Br J Radiol

September 2018

1 UCL Centre for Medical Imaging, Division of Medicine, University College London, London , UK.

The association between pancreatic fat, obesity and metabolic disease is well-documented, and although a potentially exciting target for novel therapies, remains poorly understood. Non-invasive quantitative imaging-derived biomarkers can provide insights into pathophysiology and potentially provide robust trial endpoints for development of new treatments. In this review, we provide an overview of the pathophysiology of non-alcoholic fatty pancreas disease and associations with metabolic factors, obesity and diabetes.

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Liver dynamic contrast enhanced (DCE) MRI pharmacokinetic modelling could be useful in the assessment of diffuse liver disease and focal liver lesions, but is compromised by errors in arterial input function (AIF) sampling. In this study, we apply cardiac output correction to arterial input functions (AIFs) for liver DCE MRI and investigate the effect on dual-input single compartment hepatic perfusion parameter estimation and reproducibility. Thirteen healthy volunteers (28.

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Background: Whilst multi-parametric magnetic resonance imaging (mp-MRI) has been a significant advance in the diagnosis of prostate cancer, scanning all patients with elevated prostate specific antigen (PSA) levels is considered too costly for widespread National Health Service (NHS) use, as the predictive value of PSA levels for significant disease is poor. Despite the fact that novel blood and urine tests are available which may predict aggressive disease better than PSA, they are not routinely employed due to a lack of clinical validity studies. Furthermore approximately 40 % of mp-MRI studies are reported as indeterminate, which can lead to repeat examinations or unnecessary biopsy with associated patient anxiety, discomfort, risk and additional costs.

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Delays between contrast agent (CA) arrival at the site of vascular input function (VIF) sampling and the tissue of interest affect dynamic contrast enhanced (DCE) MRI pharmacokinetic modelling. We investigate effects of altering VIF CA bolus arrival delays on liver DCE MRI perfusion parameters, propose an alternative approach to estimating delays and evaluate reproducibility. Thirteen healthy volunteers (28.

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Comparison of PET/MRI With PET/CT in the Evaluation of Disease Status in Lymphoma.

Clin Nucl Med

January 2017

From the *Institute of Nuclear Medicine, University College London, and University College London Hospitals NHS Foundation Trust, London, United Kingdom; †UCL Centre for Medical Imaging, University College London, London, United Kingdom; ‡Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Linkou, Taiwan; §Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY; ∥UCL Cancer Institute, University College London, London UK; and ¶Department of Clinical Haematology, University College London Hospitals NHS Foundation Trust, London, United Kingdom.

Purpose: The primary aim was to compare the diagnostic performance of PET/MRI (performed with basic anatomical MRI sequences) in detecting sites of disease in adult patients with lymphoma compared with the current standard of care, PET/CT. Secondary aims were to assess the additional value of diffusion-weighted imaging to PET/MRI in disease detection and to evaluate the relationship between the standardized uptake value on PET/MR and the apparent diffusion coefficient on diffusion-weighted imaging.

Methods: Sixty-eight studies in 66 consecutive patients with histologically proven Hodgkin or non-Hodgkin lymphoma were prospectively evaluated.

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