356 research outputs found

    Assessment of bone marrow fat fractions in the mandibular condyle head using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method

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    The prevalence of temporomandibular joint disorder (TMD) is gradually increasing, and magnetic resonance imaging (MRI) is becoming increasingly common as a modality used to diagnose TMD. Edema and osteonecrosis in the bone marrow of the mandibular condyle have been considered to be precursors of osteoarthritis, but these changes are not evaluated accurately and quantitatively on routine MRI. The iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method, as a cutting-edge MRI technique, can separate fat and water using three asymmetric echo times and the three-point Dixon method. The purpose of this study was to analyze the quantitative fat fraction (FF) in the mandibular condyle head using the IDEAL-IQ method. Seventy-nine people who underwent MRI using IDEAL-IQ were investigated and divided into 1) the control group, without TMD symptoms, and 2) the TMD group, with unilateral temporomandibular joint (TMJ) pain. In both groups, the FF of the condyle head in the TMJ was analyzed by two oral and maxillofacial radiologists. In the TMD group, 29 people underwent cone-beam computed tomography (CBCT) and the presence or absence of bony changes in the condylar head was evaluated. The FF measurements of the condyle head using IDEAL-IQ showed excellent inter-observer and intra-observer agreement. The average FF of the TMD group was significantly lower than that of the control group (p < 0.05). In the TMD group, the average FF values of joints with pain and joints with bony changes were significantly lower than those of joints without pain or bony changes, respectively (p < 0.05). The FF using IDEAL-IQ in the TMJ can be helpful for the quantitative diagnosis of TMD.ope

    Automated Measurement of Pancreatic Fat and Iron Concentration Using Multi-Echo and T1-Weghted MRI Data

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    We present an automated method for estimation of proton density fat fraction and iron concentration in the pancreas using both structural and quantitative imaging data present in the UK Biobank abdominal MRI acquisition protocol. Our method relies on automatic segmentation of 3D T1-weighted MRI data using a convolutional neural network and extracting the location of the multi-echo slice through the segmented volume. We finally estimate the fat and iron content in the pancreas using the extracted segmentation as a mask on the multi-echo data. Our segmentation model achieves a mean dice similarity coefficient of 0.842Ā±0.071 on unseen data, which is comparable to the current state of the art for 3D segmentation of the pancreas. The proposed method is efficient and robust and enables an enhanced analysis of spatial distribution of proton density fat fraction and iron concentration over the current practice of manually placing regions of interest on often ambiguous multi-echo data

    MRI-Measured Pancreatic Fat Correlates with Increased Arterial Stiffness in Patients Who are Overweight and Obese

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    Chenxi Li,1,&ast; Xiaolei Chen,2,&ast; Xiaowen Zhu,1 Mengjiao Cao,3 Qunfeng Tang,3 Wenjun Wu1,4 1Department of Endocrinology, The Affiliated Wuxi Peopleā€™s Hospital of Nanjing Medical University, Wuxi Peopleā€™s Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, Peopleā€™s Republic of China; 2Department of Neurology, Jiangnan University Medical Center, Wuxi No. 2 Peopleā€™s Hospital, Wuxi, Peopleā€™s Republic of China; 3Department of Radiology, The Affiliated Wuxi Peopleā€™s Hospital of Nanjing Medical University, Wuxi Peopleā€™s Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, Peopleā€™s Republic of China; 4Jinshan Branch of Shanghai Sixth Peopleā€™s Hospital, Shanghai, Peopleā€™s Republic of China&ast;These authors contributed equally to this workCorrespondence: Wenjun Wu, Department of Endocrinology, The Affiliated Wuxi Peopleā€™s Hospital of Nanjing Medical University, Wuxi Peopleā€™s Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, 214023, Peopleā€™s Republic of China, Tel +86-15358008856, Fax +86-510-85737592, Email [email protected]: Arterial stiffness is often increased in overweight or obese individuals before the development of hypertension (HT). This study aimed to determine the connection between pancreatic fat and atherosclerosis in overweight and obese people without HT.Patients and methods: We included 128 patients who were non-hypertensive and overweight or obese in a study between December 2019 and November 2022. Medical history was collected, and all participants underwent a physical examination and blood tests. Pancreatic fat content was measured by magnetic resonance imaging (MRI) and was grouped into quartiles based on pancreatic fat fraction (PFF). The upper three quartiles (PFFā‰„ 10.33%) were defined as non-alcoholic fatty pancreas disease (NAFPD) and the first quartile (PFF< 10.33%) as non-NAFPD. High baPWV (H-baPWV) and low baPWV (L-baPWV) were classified according to the median baPWV (1159 cm/s). The effect of NAFPD on baPWV was examined using binary logistic regression. The study population consisted of 96 NAFPD and 32 non-NAFPD cases.Results: Participants with NAFPD had significantly higher levels of baPWV than people without. The rates of NAFPD and the PFF values varied significantly in the L-baPWV and H-baPWV groups. Logistic regression analysis suggested that the presence of NAFPD was independently correlated with increased baPWV after adjusting for age, smoking, body mass index, blood pressure, lipid profiles, and glycemic index.Conclusion: NAFPD is an independent risk factor for increased baPWV in individuals with overweight and obesity but no HT, suggesting that the presence of NAFPD may be a warning signal of early atherosclerosis.Keywords: obesity, non-alcoholic fatty pancreas disease, overweight, arterial stiffness, brachial-ankle pulse wave velocit

    Cultivate Quantitative Magnetic Resonance Imaging Methods to Measure Markers of Health and Translate to Large Scale Cohort Studies

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    Magnetic Resonance Imaging (MRI) is an indispensable tool in healthcare and research, with a growing demand for its services. The appeal of MRI stems from its non-ionizing radiation nature, ability to generate high-resolution images of internal organs and structures without invasive procedures, and capacity to provide quantitative assessments of tissue properties such as ectopic fat, body composition, and organ volume. All without long term side effects. Nine published papers are submitted which show the cultivation of quantitative measures of ectopic fat within the liver and pancreas using MRI, and the process of validating whole-body composition and organ volume measurements. All these techniques have been translated into large-scale studies to improve health measurements in large population cohorts. Translating this work into large-scale studies, including the use of artificial intelligence, is included. Additionally, an evaluation accompanies these published studies, appraising the evolution of these quantitative MRI techniques from the conception to their application in large cohort studies. Finally, this appraisal provides a summary of future work on crowdsourcing of ground truth training data to facilitate its use in wider applications of artificial intelligence.In conclusion, this body of work presents a portfolio of evidence to fulfil the requirements of a PhD by published works at the University of Salford

    Preclinical MRI of the kidney : methods and protocols

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    This Open Access volume provides readers with an open access protocol collection and wide-ranging recommendations for preclinical renal MRI used in translational research. The chapters in this book are interdisciplinary in nature and bridge the gaps between physics, physiology, and medicine. They are designed to enhance training in renal MRI sciences and improve the reproducibility of renal imaging research. Chapters provide guidance for exploring, using and developing small animal renal MRI in your laboratory as a unique tool for advanced in vivo phenotyping, diagnostic imaging, and research into potential new therapies. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Cutting-edge and thorough, Preclinical MRI of the Kidney: Methods and Protocols is a valuable resource and will be of importance to anyone interested in the preclinical aspect of renal and cardiorenal diseases in the fields of physiology, nephrology, radiology, and cardiology. This publication is based upon work from COST Action PARENCHIMA, supported by European Cooperation in Science and Technology (COST). COST (www.cost.eu) is a funding agency for research and innovation networks. COST Actions help connect research initiatives across Europe and enable scientists to grow their ideas by sharing them with their peers. This boosts their research, career and innovation. PARENCHIMA (renalmri.org) is a community-driven Action in the COST program of the European Union, which unites more than 200 experts in renal MRI from 30 countries with the aim to improve the reproducibility and standardization of renal MRI biomarkers

    Preclinical MRI of the Kidney

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    This Open Access volume provides readers with an open access protocol collection and wide-ranging recommendations for preclinical renal MRI used in translational research. The chapters in this book are interdisciplinary in nature and bridge the gaps between physics, physiology, and medicine. They are designed to enhance training in renal MRI sciences and improve the reproducibility of renal imaging research. Chapters provide guidance for exploring, using and developing small animal renal MRI in your laboratory as a unique tool for advanced in vivo phenotyping, diagnostic imaging, and research into potential new therapies. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Cutting-edge and thorough, Preclinical MRI of the Kidney: Methods and Protocols is a valuable resource and will be of importance to anyone interested in the preclinical aspect of renal and cardiorenal diseases in the fields of physiology, nephrology, radiology, and cardiology. This publication is based upon work from COST Action PARENCHIMA, supported by European Cooperation in Science and Technology (COST). COST (www.cost.eu) is a funding agency for research and innovation networks. COST Actions help connect research initiatives across Europe and enable scientists to grow their ideas by sharing them with their peers. This boosts their research, career and innovation. PARENCHIMA (renalmri.org) is a community-driven Action in the COST program of the European Union, which unites more than 200 experts in renal MRI from 30 countries with the aim to improve the reproducibility and standardization of renal MRI biomarkers

    Nutrient-based strategies to enhance docosahexaenoic acid (DHA) utilization in the piglet brain

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    Using the piglet as a model for the human infant, the goal of this study was to compare dietary lipid matrices found in infant formula and maternal milk on post-natal neurodevelopmental patterns. Over a 25-day feeding study, piglets (n=9-10 per treatment, 1.5 Ā± 0.2 kg initial BW) were either sow-reared (SR) with ad libitum intake, or artificially-reared (AR) receiving 1 of 3 milk replacers modified to mimic the nutritional profile and intake pattern of sowā€™s milk. Our AR treatments included: T1, artificially-reared (AR) control formula; T2, T1 + 45% total dietary fat replaced with pre-digested fat (PDF); T3, T2 + 10% lecithin + 0.4% cholesterol. Sow-reared animals were used as a positive control for study outcomes. Piglets were weighed daily, serum samples were collected at d 0, d 14, and d 25 of study, and fecal samples were collected, and pooled from d 13-27. At 3 weeks of age, piglets were subjected to a standardized set of magnetic resonance imaging (MRI) procedures to identify macro- and micro-structural characteristics of the brain. At study conclusion, piglets were euthanized and tissues were collected for further analysis. For the duration of the study, SR piglets exhibited higher BW gain and heavier extracted whole brain weights compared with AR piglets. Analysis of fecal fat suggested greater (P < 0.05) excretion of dietary fat with addition of PDF along with lecithin and cholesterol. Serum lipid profiling at d 14 and d 25 of study revealed serum triglycerides (TAG) concentrations to be higher (P = 0.176, P = 0.164) in T3-fed piglets when compared with T1- and T2-fed piglets. Furthermore, serum cholesterol concentrations were higher (P < 0.05) in T3-fed piglets when compared with T1- and T2-fed piglets on d 25 of study. Furthermore, hippocampal tissue analysis revealed neutral lipid (NL) docosahexaenoic acid (DHA) concentrations were greater (P < 0.05) in T3-fed pigs compared with T1-fed and SR pigs. Hippocampal phospholipid (PL) DHA concentrations of T2- or T3-fed pigs were intermediate to T1-fed and SR piglets. Diffusion tensor imaging, a MRI sequence that characterizes brain microstructure, revealed that SR piglets had greater (P < 0.05) average whole-brain fractional anisotropy (FA) values compared with AR piglets, suggesting differences in white matter organization. Although global analysis did not reveal differences within AR treatments for DTI outcomes, FA values of the internal capsule were not different between SR and T3-fed piglets, suggesting a modulatory effect of PDF + lecithin + cholesterol fat system on white matter maturation. Higher fecal fat excretion, partnered with higher serum TAG concentrations in T3-fed piglets as compared with other AR treatments, suggested higher bioavailability of the PDF when supplemented with lecithin and cholesterol. Elevated serum cholesterol at d 25 of study, partnered with elevated hippocampal DHA concentrations of T3-fed animals suggested higher bioavailability of the PDF, especially when supplemented with lecithin and cholesterol. Higher FA values in the internal capsule of T3-fed piglets indicate higher myelination of this early maturing white matter rich region as compared with other AR treatments, and may be impacted by elevated serum cholesterol concentrations. As the animal matures in age, the 2-fold elevation of hippocampal DHA seen in T3-fed piglets, as compared with control or SR animals, may produce similar elevations white matter maturation in the hippocampus as seen in the IC. Overall, our results indicate differential patterns of white matter development between AR and SR animals, and replacing part of formula TAG with PDF, and addition of lecithin and cholesterol, may elicit preferential accretion of brain DHA due to compositional manipulations of the dietary lipid matrix

    Newborn feeding and infant phenotype

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    Breastfeeding in infancy, when compared with formula feeding, is associated with a reduced incidence of components of the metabolic syndrome later in life. One potential mechanism is via an effect on lipid metabolism and storage, manifesting as altered adiposity and ectopic lipid deposition. I have examined the null hypothesis: no association is detectable between infant feeding and adiposity or ectopic lipid in infancy, through a meta-analysis of published studies and a prospective cohort study of healthy infants employing gold standard direct measurement techniques (magnetic resonance imaging and spectroscopy). Eleven studies were identified for meta-analysis: in formula-fed compared to breastfed infants, fat mass was lower at 3-4 months [mean difference (95% confidence interval)]: [-0.09 kg (-0.18, -0.01 kg)] and 6 months [-0.18 kg (- 0.34, -0.01 kg)]. Conversely, at 12 months, fat mass was higher in formula-fed infants [0.29 kg (-0.03, 0.61 kg)] than in breastfed infants. Eighty-seven infants were included in a prospective cohort, of which 73 were investigated at two time points. In healthy, term, breastfed infants adipose tissue accretion between birth and 2-3 months ages was predominantly within subcutaneous rather than internal adipose tissue compartments, and a significant increase in intrahepatocellular lipid was detected: median [interquartile range] 0.653 [0.367-1.900] after birth and 1.837 [1.408-2.429] at 2-3 months. Comparing breastfed with formula fed infants within this cohort no significant differences were detected in total adipose tissue, adipose tissue distribution or intrahepatocellular lipid between birth and 2-3 months. Significant associations were detected between maternal BMI, rate of weight gain in early infancy and gender, and adipose tissue partitioning at 2-3 months. While method of feeding is associated with altered infant fat mass up to 6 months, no association is detectable with adipose tissue partitioning or ectopic hepatic lipid at 2-3 months.Open Acces

    The radiological investigation of musculoskeletal tumours : chairperson's introduction

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