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https://www.readbyqxmd.com/read/28097689/investigating-magnetic-susceptibility-of-human-knee-joint-at-7-tesla
#1
Hongjiang Wei, Russell Dibb, Kyle Decker, Nian Wang, Yuyao Zhang, Xiaopeng Zong, Weili Lin, Daniel B Nissman, Chunlei Liu
PURPOSE: To evaluate the magnetic susceptibility properties of different anatomical structures within the knee joint using quantitative susceptibility mapping (QSM). METHODS: A collagen tissue model was simulated and ex vivo animal cartilage experiments were conducted at 9.4 Tesla (T) to evaluate the B0 orientation-dependent magnetic susceptibility contrast observed in cartilage. Furthermore, nine volunteers (six healthy subjects without knee pain history and three patients with known knee injury, between 29 and 58 years old) were scanned using gradient-echo acquisitions on a high-field 7T MR scanner...
January 17, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28096435/regulation-of-aldosterone-secretion-by-mineralocorticoid-receptor-mediated-signaling
#2
Cherish Chong, Anis Hamid, Tham Yao, Amanda Garza, Luminita Pojoga, Gail K Adler, Jose R Romero, Gordon H Williams
We posit the existence of a paracrine/autocrine negative feedback loop, mediated by the mineralocorticoid receptor (MR), regulating aldosterone secretion. To assess this hypothesis we asked whether altering MR activity in zona glomerulosa (ZG) cells affects aldosterone production. To this end, we studied ex vivo ZG cells isolated from male Wistar rats fed chow containing either high (1.6% Na+ [HS]) or low (0.03% Na+ [LS]) amount of sodium. Western blot analyses demonstrated that MR was present in both the ZG and zona fasciculata/zona reticularis (ZF/ZR/ZR)...
January 17, 2017: Journal of Endocrinology
https://www.readbyqxmd.com/read/28096260/fgf21-mediates-the-thermogenic-and-insulin-sensitizing-effects-of-dietary-methionine-restriction-but-not-its-effects-on-hepatic-lipid-metabolism
#3
Desiree Wanders, Laura A Forney, Kirsten P Stone, David H Burk, Alicia Pierse, Thomas W Gettys
Dietary methionine restriction (MR) produces a rapid and persistent remodeling of white adipose tissue (WAT), increase in energy expenditure (EE), and enhancement of insulin sensitivity. Recent work established that hepatic expression of FGF21 is robustly increased by MR. Based on the known physiological effects of FGF21, Fgf21(-/-) mice were used to test whether FGF21 is an essential mediator of the physiological effects of dietary MR. The MR-induced increase in energy intake and EE, and activation of thermogenesis in WAT and BAT were lost in Fgf21(-/-) mice...
January 17, 2017: Diabetes
https://www.readbyqxmd.com/read/28093136/re-homogeneous-t1-hyperintense-renal-lesions-with-smooth-borders-is-contrast-enhanced-mr-imaging-needed
#4
Cary Siegel
No abstract text is available yet for this article.
February 2017: Journal of Urology
https://www.readbyqxmd.com/read/28092495/nonhypervascular-pancreatic-neuroendocrine-tumors-differential-diagnosis-from-pancreatic-ductal-adenocarcinomas-at-mr-imaging-retrospective-cross-sectional-study
#5
Sun Kyung Jeon, Jeong Min Lee, Ijin Joo, Eun Sun Lee, Hyun Jeong Park, Jin-Young Jang, Ji Kon Ryu, Kyung Bun Lee, Joon Koo Han
Purpose To determine useful magnetic resonance (MR) imaging features to differentiate nonhypervascular pancreatic neuroendocrine tumors (PNETs) from pancreatic ductal adenocarcinomas (PDACs). Materials and Methods The institutional review board approved this retrospective study and waived the informed consent requirement. Seventy-four patients with surgically confirmed PNETs and 82 patients with PDACs who underwent gadobutrol-enhanced MR imaging were included. Two radiologists independently evaluated the morphologic characteristics and temporal enhancement patterns of each tumor...
January 13, 2017: Radiology
https://www.readbyqxmd.com/read/28090600/learning-based-3t-brain-mri-segmentation-with-guidance-from-7t-mri-labeling
#6
Renping Yu, Minghui Deng, Pew-Thian Yap, Zhihui Wei, Li Wang, Dinggang Shen
Brain magnetic resonance image segmentation is one of the most important tasks in medical image analysis and has considerable importance to the effective use of medical imagery in clinical and surgical setting. In particular, the tissue segmentation of white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) is crucial for brain measurement and disease diagnosis. A variety of studies have shown that the learning-based techniques are efficient and effective in brain tissue segmentation. However, the learning-based segmentation methods depend largely on the availability of good training labels...
October 2016: Machine Learning in Medical Imaging
https://www.readbyqxmd.com/read/28090449/ultrashort-time-to-echo-magnetic-resonance-techniques-for-the-musculoskeletal-system
#7
REVIEW
Palanan Siriwanarangsun, Sheronda Statum, Reni Biswas, Won C Bae, Christine B Chung
Magnetic resonance (MR) imaging has been widely implemented as a non-invasive modality to investigate musculoskeletal (MSK) tissue disease, injury, and pathology. Advancements in MR sequences provide not only enhanced morphologic contrast for soft tissues, but also quantitative biochemical evaluation. Ultrashort time to echo (UTE) sequence, in particular, enables novel morphologic and quantitative evaluation of previously unseen MSK tissues. By using short minimum echo times (TE) below 1 msec, the UTE sequence can unveil short T2 properties of tissues including the deepest layers of the articular cartilage, cartilaginous endplate at the discovertebral junction, the meniscus, and the cortical bone...
December 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28089903/advances-in-mr-angiography-with-7t-mri-from-microvascular-imaging-to-functional-angiography
#8
Chan-A Park, Chang-Ki Kang, Young-Bo Kim, Zang-Hee Cho
Over the past few decades, vascular flow-dependent imaging techniques have proven to be effective for the visualization of large vessel diseases. However, these approaches are unlikely to be efficacious for small vessels because the affected small vessels cannot always be visualized directly, owing to a lack of detection sensitivity. Recently, many researchers have introduced state-of-the-art imaging techniques to visualize cerebral microvessels using ultra-high-field (UHF) magnetic resonance angiography (MRA)...
January 12, 2017: NeuroImage
https://www.readbyqxmd.com/read/28089181/dynamic-mr-defecography-of-the-posterior-compartment-comparison-with-conventional-x-ray-defecography
#9
E Poncelet, A Rock, J-F Quinton, M Cosson, N Ramdane, L Nicolas, A Feldmann, J Salleron
PURPOSE: The goal of this study was to compare conventional X-ray defecography and dynamic magnetic resonance (MR) defecography in the diagnosis of pelvic floor prolapse of the posterior compartment. MATERIAL AND METHODS: Fifty women with a mean age of 65.5 years (range: 53-72 years) who underwent X-ray defecography and MR defecography for clinical suspicion of posterior compartment dysfunction, were included in this retrospective study. X-ray defecography and dynamic MR defecography were reviewed separately for the presence of pelvic organ prolapse...
January 11, 2017: Diagnostic and Interventional Imaging
https://www.readbyqxmd.com/read/28088917/effects-of-heart-valve-prostheses-on-phase-contrast-flow-measurements-in-cardiovascular-magnetic-resonance-a-phantom-study
#10
Johanna Richau, Matthias A Dieringer, Julius Traber, Florian von Knobelsdorff-Brenkenhoff, Andreas Greiser, Carsten Schwenke, Jeanette Schulz-Menger
BACKGROUND: Cardiovascular Magnetic Resonance is often used to evaluate patients after heart valve replacement. This study systematically analyses the influence of heart valve prostheses on phase contrast measurements in a phantom trial. METHODS: Two biological and one mechanical aortic valve prostheses were integrated in a flow phantom. B0 maps and phase contrast measurements were acquired at a 1.5 T MR scanner using conventional gradient-echo sequences in predefined distances to the prostheses...
January 16, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28088078/genetically-tailored-magnetosomes-used-as-mri-probe-for-molecular-imaging-of-brain-tumor
#11
M Boucher, F Geffroy, S Prévéral, L Bellanger, E Selingue, G Adryanczyk-Perrier, M Péan, C T Lefèvre, D Pignol, N Ginet, S Mériaux
We investigate here the potential of single step production of genetically engineered magnetosomes, bacterial biogenic iron-oxide nanoparticles embedded in a lipid vesicle, as a new tailorable magnetic resonance molecular imaging probe. We demonstrate in vitro the specific binding and the significant internalization into U87 cells of magnetosomes decorated with RGD peptide. After injection at the tail vein of glioblastoma-bearing mice, we evidence in the first 2 h the rapid accumulation of both unlabeled and functionalized magnetosomes inside the tumor by Enhanced Permeability and Retention effects...
December 19, 2016: Biomaterials
https://www.readbyqxmd.com/read/28086840/evidence-of-multiple-insecticide-resistance-mechanisms-in-anopheles-gambiae-populations-in-bangui-central-african-republic
#12
Marina Lidwine Olé Sangba, Aboubakar Sidick, Renaud Govoetchan, Christian Dide-Agossou, Razaki A Ossè, Martin Akogbeto, Mamadou Ousmane Ndiath
BACKGROUND: Knowledge of insecticide resistance status in the main malaria vectors is an essential component of effective malaria vector control. This study presents the first evaluation of the status of insecticide resistance in Anopheles gambiae populations from Bangui, the Central African Republic. METHODS: Anopheles mosquitoes were reared from larvae collected in seven districts of Bangui between September to November 2014. The World Health Organisation's bioassay susceptibility tests to lambda-cyhalothrin (0...
January 13, 2017: Parasites & Vectors
https://www.readbyqxmd.com/read/28079361/controllable-synthesis-of-smart-multifunctional-nanoscal-metal-organic-framework-for-magnetic-resonance-optical-imaging-and-targeted-drug-delivery
#13
Xuechuan Gao, Manjue Zhai, Weihua Guan, Jingjuan Liu, Zhiliang Liu, Alatangaole Damirin
As a result of their extraordinarily large surfaces and well-defined pores, the design of multifunctional metal-organic framework (MOF) is crucial for drug delivery while has been rarely reported. In this paper, a novel drug delivery system (DDS) based on nanoscale metal-organic framework (MOF) was developed for using in cancer diagnosis and therapy. This MOF based tumour targeting DDS was fabricated by a simple post-synthetic surface modification process. Firstly, magnetic mesoporous nanomaterial Fe-MIL-53-NH2 was devoted for encapsulating the drug and served as a magnetic resonance (MR) contrast agent...
January 12, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28078511/intra-individual-comparison-of-different-gadolinium-based-contrast-agents-in-the-quantitative-evaluation-of-c6-glioma-with-dynamic-contrast-enhanced-magnetic-resonance-imaging
#14
Ying Li, Gang Liu, Xin Lou, Zhiye Chen, Lin Ma
This experiment aimed to compare the ionic (Gadodiamide, Gd-DTPA-BMA) and non-ionic (Gadopentetate dimeglumine, Gd-DTPA) gadolinium-based contrast agents (GBCA) in the quantitative evaluation of C6 glioma with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). A C6 glioma model was established in 12 Wistar rats, and magnetic resonance (MR) scans were performed six days after tumor implantation. Imaging was performed using a 3.0-T MR scanner with a 7-inch handmade circular coil. Pre-contrast T1 mapping and dynamic contrast-enhanced T1WI after a bolus injection (0...
January 4, 2017: Science China. Life Sciences
https://www.readbyqxmd.com/read/28078116/pretreatment-tumor-volume-as-a-prognostic-factor-in-metastatic-colorectal-cancer-treated-with-selective-internal-radiation-to-the-liver-using-yttrium-90-resin-microspheres
#15
Neha Bhooshan, Navesh K Sharma, Shahed Badiyan, Adeel Kaiser, Fred M Moeslein, Young Kwok, Pradip P Amin, Svetlana Kudryasheva, Michael D Chuong
BACKGROUND: Yttrium-90 ((90)Y)-resin microspheres can prolong intrahepatic disease control and improve overall survival (OS) in patients with metastatic colorectal cancer (CRC). Prognostic factors for improved outcomes in patients undergoing selective internal radiation therapy (SIRT) have been studied, but the relationship between pre-SIRT liver tumor volume and outcomes has not well described. METHODS: We retrospectively reviewed the records of patients with metastatic CRC who were treated at our institution with (90)Y-resin microspheres...
December 2016: Journal of Gastrointestinal Oncology
https://www.readbyqxmd.com/read/28077908/magnetic-resonance-imaging-of-a-case-of-central-neurocytoma
#16
Kreshnike Dedushi, Serbeze Kabashi, Mehmet Sahin Ugurel, Naser Ramadani, Sefedin Mucaj, Kamber Zeqiraj
BACKGROUND: The purpose of this study is to investigate the MRI features of central neurocytoma. CASE REPORT: A 45 year old man with 3 months of worsening daily headaches. These headaches were diffuse, lasted for several hours, and mostly occurred in the morning. She was initially diagnosed and treated for migraines but later he had epileptic attack and diplopia and neurolog recomaded MRI. METHODS: precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D-Hi-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W and Flash/T2W oblique coronal plane (perpendicular to temporal lobes) GRE/T2W axial plane for detection of heme products...
December 2016: Acta Informatica Medica: AIM
https://www.readbyqxmd.com/read/28076722/is-there-long-term-signal-intensity-increase-in-the-central-nervous-system-on-t1-weighted-images-after-mr-imaging-with-the-hepatospecific-contrast-agent-gadoxetic-acid-a-cross-sectional-study-in-91-patients
#17
Johannes Kahn, Helena Posch, Ingo G Steffen, Dominik Geisel, Christian Bauknecht, Thomas Liebig, Timm Denecke
Purpose To evaluate whether there is T1-weighted signal intensity (SI) increase in the dentate nucleus (DN) and globus pallidus (GP) in relation to the middle cerebellar peduncle (MCP), pons, and thalamus after repeated administration of the liver-specific contrast agent gadoxetic acid. Materials and Methods This was an institutional review board-approved, prospectively conducted (written informed consent acquired), cross-sectional study performed in a consecutively selected patient group (n = 91; patients received one to 37 doses of gadoxetic acid) and a control group (n = 52; subjects had never received injections of gadolinium-based contrast agent) examined with a standard T1-weighted two-dimensional spin-echo pulse sequence of the brain at 1...
January 11, 2017: Radiology
https://www.readbyqxmd.com/read/28076003/reducing-functional-mr-imaging-acquisition-times-by-optimizing-workflow
#18
Wilson B Chwang, Michael Iv, Jason Smith, Aleksandrs Kalnins, Jake Mickelsen, Roland Bammer, Dominik Fleischmann, David B Larson, Max Wintermark, Michael Zeineh
Functional magnetic resonance (MR) imaging is a complex, specialized examination that is able to noninvasively measure information critical to patient care such as hemispheric language lateralization ( 1 ). Diagnostic functional MR imaging requires extensive patient interaction as well as the coordinated efforts of the entire health care team. We observed in our practice at an academic center that the times to perform functional MR imaging examinations were excessively lengthy, making scheduling of the examination difficult...
January 2017: Radiographics: a Review Publication of the Radiological Society of North America, Inc
https://www.readbyqxmd.com/read/28075625/unenhanced-and-contrast-enhanced-mr-angiography-and-perfusion-imaging-for-suspected-pulmonary-thromboembolism
#19
Yoshiharu Ohno, Takeshi Yoshikawa, Yuji Kishida, Shinichiro Seki, Nevzat Karabulut
OBJECTIVE: This article discusses the basics of unenhanced MR angiography (MRA) and MR venography (MRV), time-resolved contrast-enhanced (CE) MRA and dynamic first-pass CE perfusion MRI, and unenhanced and CE MRV, in addition to assessing the clinical relevance of these techniques for evaluating patients with suspected pulmonary thromboembolism and deep venous thrombosis. CONCLUSION: Since the 1990s, the efficacy of MRA or MRV and dynamic perfusion MRI for patients with suspected pulmonary thromboembolism and deep venous thrombosis has been evaluated...
January 11, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28074323/changes-in-cerebral-metabolism-during-ketogenic-diet-in-patients-with-primary-brain-tumors-1-h-mrs-study
#20
Moran Artzi, Gilad Liberman, Nachum Vaisman, Felix Bokstein, Faina Vitinshtein, Orna Aizenstein, Dafna Ben Bashat
Normal brain cells depend on glucose metabolism, yet they have the flexibility to switch to the usage of ketone bodies during caloric restriction. In contrast, tumor cells lack genomic and metabolic flexibility and are largely dependent on glucose. Ketogenic-diet (KD) was suggested as a therapeutic option for malignant brain cancer. This study aimed to detect metabolic brain changes in patients with malignant brain gliomas on KD using proton magnetic-resonance-spectroscopy ((1)H-MRS). Fifty MR scans were performed longitudinally in nine patients: four patients with recurrent glioblastoma (GB) treated with KD in addition to bevacizumab; one patient with gliomatosis-cerebri treated with KD only; and four patients with recurrent GB who did not receive KD...
January 10, 2017: Journal of Neuro-oncology
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