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https://www.readbyqxmd.com/read/27920532/the-effect-of-magnetic-nanoparticles-on-neuronal-differentiation-of-induced-pluripotent-stem-cell-derived-neural-precursors
#1
Klára Jiráková, Monika Šeneklová, Daniel Jirák, Karolína Turnovcová, Magda Vosmanská, Michal Babič, Daniel Horák, Pavel Veverka, Pavla Jendelová
INTRODUCTION: Magnetic resonance (MR) imaging is suitable for noninvasive long-term tracking. We labeled human induced pluripotent stem cell-derived neural precursors (iPSC-NPs) with two types of iron-based nanoparticles, silica-coated cobalt zinc ferrite nanoparticles (CZF) and poly-l-lysine-coated iron oxide superparamagnetic nanoparticles (PLL-coated γ-Fe2O3) and studied their effect on proliferation and neuronal differentiation. MATERIALS AND METHODS: We investigated the effect of these two contrast agents on neural precursor cell proliferation and differentiation capability...
2016: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/27917112/reproducibility-and-reliability-of-quantitative-and-weighted-t1-and-t2-%C3%A2-mapping-for-myelin-based-cortical-parcellation-at-7-tesla
#2
Roy A M Haast, Dimo Ivanov, Elia Formisano, Kâmil Uludaǧ
Different magnetic resonance (MR) parameters, such as R1 (=1/T1) or T2(∗), have been used to visualize non-invasively the myelin distribution across the cortical sheet. Myelin contrast is consistently enhanced in the primary sensory and some higher order cortical areas (such as MT or the cingulate cortex), which renders it suitable for subject-specific anatomical cortical parcellation. However, no systematic comparison has been performed between the previously proposed MR parameters, i.e., the longitudinal and transversal relaxation values (or their ratios), for myelin mapping at 7 Tesla...
2016: Frontiers in Neuroanatomy
https://www.readbyqxmd.com/read/27915116/7t-mr-of-intracranial-pathology-preliminary-observations-and-comparisons-to-3t-and-1-5t
#3
Emmanuel C Obusez, Mark Lowe, Se-Hong Oh, Irene Wang, M S Jennifer Bullen, Paul Ruggieri, Virginia Hill, Daniel Lockwood, Todd Emch, Doksu Moon, Gareth Loy, Jonathan Lee, Matthew Kiczek, D O Manoj Massand, Volodymyr Statsevych, Todd Stultz, Stephen E Jones
PURPOSE: There have been an increasing number of studies involving ultra-high-field 7T of intracranial pathology, however, comprehensive clinical studies of neuropathology at 7T still remain limited. 7T has the advantage of a higher signal-to-noise ratio and a higher contrast-to-noise ratio, compared to current low field clinical MR scanners. We hypothesized 7T applied clinically, may improve detection and characterization of intracranial pathology. MATERIALS AND METHODS: We performed an IRB-approved 7T prospective study of patients with neurological disease who previously had lower field 3T and 1...
November 30, 2016: NeuroImage
https://www.readbyqxmd.com/read/27913827/intra-lesional-spatial-correlation-of-static-and-dynamic-fet-pet-parameters-with-mri-based-cerebral-blood-volume-in-patients-with-untreated-glioma
#4
Jens Göttler, Mathias Lukas, Anne Kluge, Stephan Kaczmarz, Jens Gempt, Florian Ringel, Mona Mustafa, Bernhard Meyer, Claus Zimmer, Markus Schwaiger, Stefan Förster, Christine Preibisch, Thomas Pyka
PURPOSE: (18)F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. METHODS: Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences...
December 2, 2016: European Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/27913362/learning-to-predict-eye-fixations-via-multiresolution-convolutional-neural-networks
#5
Nian Liu, Junwei Han, Tianming Liu, Xuelong Li
Eye movements in the case of freely viewing natural scenes are believed to be guided by local contrast, global contrast, and top-down visual factors. Although a lot of previous works have explored these three saliency cues for several years, there still exists much room for improvement on how to model them and integrate them effectively. This paper proposes a novel computation model to predict eye fixations, which adopts a multiresolution convolutional neural network (Mr-CNN) to infer these three types of saliency cues from raw image data simultaneously...
November 29, 2016: IEEE Transactions on Neural Networks and Learning Systems
https://www.readbyqxmd.com/read/27910866/biomechanical-analysis-of-normal-brain-development-during-the-first-year-of-life-using-finite-strain-theory
#6
Jeong Chul Kim, Li Wang, Dinggang Shen, Weili Lin
The first year of life is the most critical time period for structural and functional development of the human brain. Combining longitudinal MR imaging and finite strain theory, this study aimed to provide new insights into normal brain development through a biomechanical framework. Thirty-three normal infants were longitudinally imaged using MRI from 2 weeks to 1 year of age. Voxel-wise Jacobian determinant was estimated to elucidate volumetric changes while Lagrange strains (both normal and shear strains) were measured to reveal directional growth information every 3 months during the first year of life...
December 2, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27910719/artifacts-in-multimodal-imaging-of-titanium-zirconium-and-binary-titanium-zirconium-alloy-dental-implants-an-in-vitro-study
#7
Ralf Smeets, Maximilian Schöllchen, Tobias Gauer, Gahzal Aarabi, Alexandre T Assaf, Carsten Rendenbach, Benedicta Beck-Broichsitter, Jan Semmusch, Jan Sedlacik, Max Heiland, Jens Fiehler, Susanne Siemonsen
OBJECTIVES: To analyze and evaluate imaging artifacts induced by zirconium, titanium and titanium-zirconium alloy dental implants. METHODS: Zirconium, titanium and titanium-zirconium alloy implants were embedded in gelatin and MRI, CT and CBCT were performed. Standard-protocols were used for each modality. For MRI, line-distance-profiles were plotted to quantify the accuracy of size-determination. For CT and CBCT, six shells surrounding the implant were defined every 0...
December 2, 2016: Dento Maxillo Facial Radiology
https://www.readbyqxmd.com/read/27908279/co-existing-intracranial-and-extracranial-carotid-artery-atherosclerotic-plaques-and-recurrent-stroke-risk-a-three-dimensional-multicontrast-cardiovascular-magnetic-resonance-study
#8
Yilan Xu, Chun Yuan, Zechen Zhou, Le He, Donghua Mi, Rui Li, Yuanyuan Cui, Yilong Wang, Yongjun Wang, Gaifen Liu, Zhuozhao Zheng, Xihai Zhao
BACKGROUND: As a systemic disease, atherosclerosis commonly affects intracranial and extracranial carotid arteries simultaneously which is defined as co-existing plaques. Previous studies demonstrated that co-existing atherosclerotic diseases are significantly associated with ischemic cerebrovascular events. The aim of this study was to investigate the characteristics of co-existing intracranial and extracranial carotid atherosclerotic plaques and their relationships with recurrent stroke by using 3D multi-contrast magnetic resonance (MR) vessel wall imaging...
December 2, 2016: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/27908174/respiratory-motion-compensation-for-simultaneous-pet-mr-based-on-highly-undersampled-mr-data
#9
Christopher M Rank, Thorsten Heußer, Andreas Wetscherek, Martin T Freitag, Oliver Sedlaczek, Heinz-Peter Schlemmer, Marc Kachelrieß
PURPOSE: Positron emission tomography (PET) of the thorax region is impaired by respiratory patient motion. To account for motion, the authors propose a new method for PET/magnetic resonance (MR) respiratory motion compensation (MoCo), which uses highly undersampled MR data with acquisition times as short as 1 min/bed. METHODS: The proposed PET/MR MoCo method (4D jMoCo PET) uses radial MR data to estimate the respiratory patient motion employing MR joint motion estimation and image reconstruction with temporal median filtering...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27908163/learning-based-3t-brain-mri-segmentation-with-guidance-from-7t-mri-labeling
#10
Minghui Deng, Renping Yu, Li Wang, Feng Shi, Pew-Thian Yap, Dinggang Shen
PURPOSE: Segmentation of brain magnetic resonance (MR) images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) is crucial for brain structural measurement and disease diagnosis. Learning-based segmentation methods depend largely on the availability of good training ground truth. However, the commonly used 3T MR images are of insufficient image quality and often exhibit poor intensity contrast between WM, GM, and CSF. Therefore, they are not ideal for providing good ground truth label data for training learning-based methods...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27905865/transient-bone-marrow-edema-syndrome-versus-osteonecrosis-perfusion-patterns-at-dynamic-contrast-enhanced-mr-imaging-with-high-temporal-resolution-can-allow-differentiation
#11
Tobias Geith, Thomas Niethammer, Stefan Milz, Olaf Dietrich, Maximilian Reiser, Andrea Baur-Melnyk
Purpose To prospectively evaluate the perfusion patterns at quantitative dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging of transient bone marrow edema syndrome (TBMES) and avascular osteonecrosis. Materials and Methods Institutional review board approval and written informed consent were obtained. Thirty-two patients (21 men, 11 women; mean age, 48 years; 26 hips, 10 knees) underwent conventional MR imaging and a dynamic contrast-enhanced three-dimensional spoiled gradient-echo sequence at 3 T...
December 1, 2016: Radiology
https://www.readbyqxmd.com/read/27905543/rapid-functional-cardiac-imaging-after-gadolinium-injection-evaluation-of-a-highly-accelerated-sequence-with-sparse-data-sampling-and-iterative-reconstruction
#12
Johannes Budjan, Holger Haubenreisser, Thomas Henzler, Sonja Sudarski, Michaela Schmidt, Christina Doesch, Ibrahim Akin, Martin Borggrefe, Nadja M Meßner, Stefan O Schoenberg, Ulrike I Attenberger, Theano Papavassiliu
To generate a patient-friendly, time-efficient cardiac MRI examination protocol, a highly accelerated real-time CINE MR sequence (SSIR) was acquired in the idle time in between contrast injection and late gadolinium enhancement phase. 20 consecutive patients underwent a cardiac MRI examination including a multi-breath-hold sequence as gold standard (Ref) as well as SSIR sequences with (SSIR-BH) and without breath-hold (SSIR-nonBH). SSIR sequences were acquired 4 minutes after gadolinium injection. Right- (RV) and left-ventricular (LV) volumetric functional parameters were evaluated and compared between Ref and SSIR sequences...
December 1, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27904246/noninvasive-imaging-of-the-biliary-system-relevant-to-percutaneous-interventions
#13
REVIEW
Stephen Thomas, Kayleen Jahangir
Clinical data such as history, physical examination, and laboratory tests are useful in identifying patients with biliary obstruction and biliary sources of infection. However, if intervention is planned, noninvasive imaging is needed to confirm the presence, location, and extent of the disease process. Currently, the most commonly available and used noninvasive modalities are ultrasound (US), computed tomography (CT), magnetic resonance (MR), and nuclear medicine hepatobiliary scintigraphy (HIDA). US is quick, portable, readily available, and is commonly the first imaging modality used when biliary pathology is suspected...
December 2016: Seminars in Interventional Radiology
https://www.readbyqxmd.com/read/27900508/temperature-dependence-of-viscosity-relaxation-times-t1-t2-and-simulated-contrast-for-potential-perfusates-in-post-mortem-mr-angiography-pmmra
#14
Bridgette Webb, Thomas Widek, Bernhard Neumayer, Christine Bruguier, Sylvia Scheicher, Hanna Sprenger, Silke Grabherr, Thorsten Schwark, Rudolf Stollberger
Developments in post-mortem imaging increasingly focus on addressing recognised diagnostic weaknesses, especially with regard to suspected natural deaths. Post-mortem MR angiography (PMMRA) may offer additional diagnostic information to help address such weaknesses, specifically in the context of sudden cardiac death. Complete filling of the coronary arteries and acceptable contrast with surrounding tissue are essential for a successful approach to PMMRA. In this work, the suitability of different liquids for inclusion in a targeted PMMRA protocol was evaluated...
November 29, 2016: International Journal of Legal Medicine
https://www.readbyqxmd.com/read/27900204/preoperative-mr-staging-of-cervical-carcinoma-are-oblique-and-contrast-enhanced-sequences-necessary
#15
Susanne Fridsten, Ann-Cathrin Hellström, Kristina Hellman, Anders Sundin, Boel Söderén, Lennart Blomqvist
BACKGROUND: As the choice of treatment in patients with cervical carcinoma depends on cancer stage at diagnosis, accurate staging is essential. PURPOSE: To compare three different combinations of magnetic resonance (MR) sequences for preoperative staging. MATERIAL AND METHODS: Fifty-seven consecutive patients with biopsy proven cervical carcinoma underwent MR imaging (MRI) staging followed by primary surgical treatment. Thirty-two of 57 patients had had a cone biopsy prior to MRI...
November 2016: Acta Radiologica Open
https://www.readbyqxmd.com/read/27899518/variable-mr-and-pathologic-patterns-of-hemorrhage-after-iodinated-contrast-infusion-in-mca-occlusion-reperfusion-model
#16
Humberto Morales, Aigang Lu, Yuko Kurosawa, Joseph F Clark, Thomas Tomsick
OBJECTIVE: To examine the hypothesis that IA reperfusion with iso-osmolar iodixanol, low-osmolar iopamidol, or saline causes different effects on MR signal changes and pathologic cut-brain section related to hemorrhagic transformation (HT) or iodinated radiographic contrast media (IRCM) deposition. METHODS: Infarct was induced in 30 rats by middle cerebral artery suture occlusion. Reperfusion was performed after 5 hours with iso-osmolar iodixanol (n=9), low-osmolar iopamidol (n=12) or saline (n=9)...
November 29, 2016: Journal of Neurointerventional Surgery
https://www.readbyqxmd.com/read/27899435/imaging-oxygen-metabolism-with-hyperpolarized-magnetic-resonance-a-novel-approach-for-cardiac-and-renal-function%C3%A2-assessement
#17
Marie Schroeder, Christoffer Lausten
Every tissue in the body critically depends on meeting its energetic demands with sufficient oxygen supply. Oxygen supply/demand imbalances underlie the diseases that inflict the greatest socioeconomic burden globally. The purpose of this review is to examine how hyperpolarized contrast media, used in combination with MR data acquisition methods, may advance our ability to assess oxygen metabolism non-invasively and thus improve management of clinical disease. We first introduce the concept of hyperpolarization and how hyperpolarized contrast media have been practically implemented to achieve translational and clinical research...
November 29, 2016: Bioscience Reports
https://www.readbyqxmd.com/read/27896520/early-perfusion-mri-predicts-survival-outcome-in-patients-with-recurrent-glioblastoma-treated-with-bevacizumab-and-carboplatin
#18
Iwan E Bennett, Kathryn M Field, Christopher M Hovens, Bradford A Moffat, Mark A Rosenthal, Katharine Drummond, Andrew H Kaye, Andrew P Morokoff
Bevacizumab, an anti-angiogenic agent, is FDA-approved for use in patients with recurrent glioblastoma multiforme (rGBM). The radiologic evaluation of tumor response to bevacizumab is complex and there is no validated method of monitoring tumor vascularity during therapy. We evaluated perfusion-weighted MR imaging (PWI) in our cohort of patients enrolled in the CABARET trial, which examined the effectiveness of bevacizumab with or without carboplatin in patients with rGBM. Pre-treatment and early follow-up (4- and 8-week) PWI were used to calculate relative cerebral blood volume (rCBV) histogram statistics of the contrast-enhancing and FLAIR hyperintense tumor volumes...
November 28, 2016: Journal of Neuro-oncology
https://www.readbyqxmd.com/read/27895875/takeaways-from-pre-contrast-t1-and-t2-breast-magnetic-resonance-imaging-in-women-with-recently-diagnosed-breast-cancer
#19
Seung Hee Han, Yeong Yi An, Bong Joo Kang, Sung Hun Kim, Eun Jae Lee
BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE - MRI) has been widely used in the management of breast cancer, and its diagnostic value in breast imaging has been demonstrated. There have only been a few reports regarding the usefulness of pre-contrast imaging. Knowledge about clinically significant findings of preoperative, pre-contrast T1 and T2 MR images will allow more accurate decisions regarding patient treatment and management. OBJECTIVES: The aim of this study was to evaluate the clinically significant findings of preoperative, pre-contrast T1 and T2 MR images in recently diagnosed breast cancer patients...
October 2016: Iranian Journal of Radiology: a Quarterly Journal Published By the Iranian Radiological Society
https://www.readbyqxmd.com/read/27894786/mr-angiography-can-guide-ed-management-of-suspected-acute-aortic-dissection
#20
Gary X Wang, Sandeep S Hedgire, Thang Q Le, Jonathan D Sonis, Brian J Yun, Michael H Lev, Ali S Raja, Anand M Prabhakar
BACKGROUND: Aortic dissection is typically evaluated with computed tomography angiography (CTA). However, the feasibility of using magnetic resonance angiography (MRA) in the ED is unclear. This study examined the indications and outcomes of MRA in suspected aortic dissection evaluation in the ED. METHODS: An IRB approved review identified patients who underwent MRA in the ED for acute thoracic aortic dissection from January 2010 to June 2016. Demographics, clinical assessment, CTA contraindications, outcomes, and ED disposition were analyzed...
November 17, 2016: American Journal of Emergency Medicine
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