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https://www.readbyqxmd.com/read/28821875/convenient-and-effective-icgylation-of-magnetic-nanoparticles-for-biomedical-applications
#1
Hye Sun Park, Jongwoo Kim, Mi Young Cho, Hyunseung Lee, Sang Hwan Nam, Yung Doug Suh, Kwan Soo Hong
Nanoprobes used for biomedical applications usually require surface modifications with amphiphilic surfactants or inorganic coating materials to enhance their biocompatibility. We proposed a facile synthetic approach for the phase transfer of hydrophobic magnetic nanoparticles by the direct adherence of fluorescent probes, without any chemical modifications, for use as a magnetic resonance (MR)/near-infrared (NIR) fluorescence bimodal imaging contrast agent. Indocyanine green (ICG) was used not only as an optical component for NIR imaging, but also as a surfactant for phase transfer with no superfluous moiety: we therefore called the process "ICGylation"...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28820837/non-contrast-mr-lymphography-for-evaluation-of-lymph-node-transfer-for-secondary-upper-limb-lymphedema
#2
Lionel Arrivé, Sarah Derhy, Chrif Dlimi, Sanaa El Mouhadi, Laurence Monnier-Cholley, Corinne Becker
BACKGROUND: Our purpose was to evaluate the results of axillary lymph node transplantation (LNT) with non-contrast magnetic resonance (MR) lymphography in 15 patients with secondary upper limb lymphedema. METHODS: Fifteen female patients with lymphedema following breast cancer treatment underwent LNT. Non-contrast MR lymphography was obtained with a free-breathing 3D fast spin-echo sequence. Images analysis criteria included: (A) before surgery: a) severity of lymphedema graded as absent, mild, moderate, and severe; b) involvement of the muscular compartment; c) distal dilated lymphatic vessels; (B) after surgery: a) visualization of site of transplantation; b) visualization of transplanted lymph nodes; c) severity of lymphedema with regard to pretransplantation severity (i...
August 8, 2017: Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/28820653/fibrous-skeleton-of-the-heart-anatomic-overview-and-evaluation-of-pathologic-conditions-with-ct-and-mr-imaging
#3
Farhood Saremi, Damián Sánchez-Quintana, Shumpei Mori, Horia Muresian, Diane E Spicer, Cameron Hassani, Robert H Anderson
The fibrous skeleton is concentrated at the base of the ventricular mass. It provides electrical insulation at the atrioventricular level and fibrous continuity for the leaflets of the mitral, aortic, and tricuspid valves. Its components include the fibrous trigones, the fibrous area of aortic-mitral continuity, the subvalvar collar of the mitral valve, the membranous septum, the interleaflet triangles, the tendon of Todaro, and likely the conus ligament. The majority of the mitral annulus is fibrous, but the only true fibrous part of the tricuspid annulus is where the valvar leaflets are attached to the central fibrous body...
August 18, 2017: Radiographics: a Review Publication of the Radiological Society of North America, Inc
https://www.readbyqxmd.com/read/28819086/measurement-of-cerebrospinal-fluid-flow-dynamics-using-phase-contrast-mr-imaging-with-bilateral-jugular-vein-compression-a-feasibility-study-in-healthy-volunteers
#4
Shintaro Ichikawa, Utaroh Motosugi, Akihiro Okumura, Tatsuya Shimizu, Hiroshi Onishi
We measured the changes in the cerebrospinal fluid (CSF) flow dynamics after compression of the bilateral jugular veins using phase contrast-magnetic resonance imaging (PC-MRI). PC-MRI was performed in 10 healthy male volunteers using a 3T clinical scanner with a two-dimensional gradient echo sequence. We successfully measured the changes in CSF flow velocity using PC-MRI with and without compression of the bilateral jugular veins. The relative velocity range decreased by about 30% when the bilateral jugular veins were compressed...
August 16, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28817662/single-scan-rest-stress-imaging-with-99mtc-sestamibi-and-cadmium-zinc-telluride-based-spect-for-hyperemic-flow-quantification-a-feasibility-study-evaluated-with-cardiac-magnetic-resonance-imaging
#5
Yu-Hua Dean Fang, Yuan-Chang Liu, Kung-Chu Ho, Feng-Cheng Kuo, Ching-Fang Yang, Tzu-Chen Yen, I-Chang Hsieh
INTRODUCTION: We aimed to evaluate whether the hyperemic myocardial blood flow (MBF) can be estimated using cadmium zinc telluride (CZT)-based single-photon emission computed tomography (SPECT) cameras with a single, rapid rest/stress dynamic scan. Dynamic contrast-enhanced (DCE) cardiac magnetic resonance imaging (MRI) was used as a reference modality for flow measurement. MATERIALS AND METHODS: The proposed protocol included both the rest and stress acquisitions within a 24-min scan...
2017: PloS One
https://www.readbyqxmd.com/read/28815766/preparation-of-robust-metal-free-magnetic-nanoemulsions-encapsulating-low-molecular-weight-nitroxide-radicals-and-hydrophobic-drugs-directed-toward-mri-visible-targeted-delivery
#6
Rui Tamura, Kota Nagura, Yusa Takemoto, Satori Moronaga, Yoshiaki Uchida, Satoshi Shimono, Akihiko Shiino, Kenji Tanigaki, Tsukuru Amano, Fumi Yoshino, Yohei Noda, Satoshi Koizumi, Naoki Komatsu, Tatsuhisa Kato, Jun Yamauchi
With a view to developing a theranostic nanomedicine for magnetic resonance (MR) imaging-visible targeted drug delivery system, robust metal-free magnetic nanoemulsions (mean particle sizes of less than 20 nm) consisting of the biocompatible surfactant 1 and the incorporated hydrophobic low-molecular-weight 2,2,5-trimethyl-5-(4-alkoxy)phenylpyrrolidine-N-oxyl radicals [(±)-2] have been prepared in pH 7.4 phosphate-buffered saline. The structure of the nanoemulsions has been characterized by electron paramagnetic resonance spectroscopy, and dynamic light scattering and small angle neutron scattering measurements...
August 16, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28814253/pet-mr-tomographs-a-review-with-technical-radiochemical-and-clinical-perspectives
#7
Giampiero Giovacchini, Elisabetta Giovannini, Mattia Riondato, Andrea Ciarmiello
In the last decade, an increasing number of positron emission tomography / magnetic resonance (PET/MR) tomographs have been installed and many clinical studies were performed in the neurological field. Although PET/MR has many favorable properties to support the application in brain imaging, attenuation correction, and therefore accurate quantification, is a problem that still requires optimal solution. In this review we have summarized the three main methods that are currently used to correct for attenuation in PET/MR, namely atlas- or template-based methods, segmentation-based methods, and reconstruction-based methods...
August 16, 2017: Current Radiopharmaceuticals
https://www.readbyqxmd.com/read/28813197/split-bolus-injection-producing-simultaneous-late-arterial-and-portal-venous-phases-in-ct-enterography-preliminary-results
#8
Johannes Boos, Jieming Fang, Christina M Chingkoe, Michele Perillo, Martin Smith, Vassilios Raptopoulos, Olga R Brook
OBJECTIVE: The purpose of this article is to evaluate the image quality and added value of split-bolus contrast agent injection combining late arterial and portal venous phases compared with single-bolus contrast agent injection late arterial phase CT enterography. MATERIALS AND METHODS: Consecutive patients who underwent CT enterography before and after implementation of a single-bolus CT enterography protocol were included. Attenuation and contrast-to-noise ratio (CNR) were assessed by ROI measurements of the bowel wall and arterial and venous structures...
August 16, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28812002/image-guided-thermal-ablation-with-mr-based-thermometry
#9
REVIEW
Mingming Zhu, Ziqi Sun, Chin K Ng
Thermal ablation techniques such as radiofrequency, microwave, high intensity focused ultrasound (HIFU) and laser have been used as minimally invasive strategies for the treatment of variety of cancers. MR thermometry methods are readily available for monitoring thermal distribution and deposition in real time, leading to decrease of incidents of normal tissue damage around targeted lesion. HIFU and laser-induced thermal therapy (LITT) are the two widely accepted tumor ablation techniques because of their compatibility with MR systems...
June 2017: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28811630/solid-state-31-p-and-1-h-chemical-mr-micro-imaging-of-hard-tissues-and-biomaterials-with-magic-angle-spinning-at-very-high-magnetic-field
#10
Maxime Yon, Vincent Sarou-Kanian, Ulrich Scheler, Jean-Michel Bouler, Bruno Bujoli, Dominique Massiot, Franck Fayon
In this work, we show that it is possible to overcome the limitations of solid-state MRI for rigid tissues due to large line broadening and short dephasing times by combining Magic Angle Spinning (MAS) with rotating pulsed field gradients. This allows recording ex vivo (31)P 3D and 2D slice-selected images of rigid tissues and related biomaterials at very high magnetic field, with greatly improved signal to noise ratio and spatial resolution when compared to static conditions. Cross-polarization is employed to enhance contrast and to further depict spatially localized chemical variations in reduced experimental time...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28809859/do-regional-brain-volumes-and-major-depressive-disorder-share-genetic-architecture-a-study-of-generation-scotland-n-19%C3%A2-762-uk-biobank-n-24%C3%A2-048-and-the-english-longitudinal-study-of-ageing-n-5766
#11
E M Wigmore, T-K Clarke, D M Howard, M J Adams, L S Hall, Y Zeng, J Gibson, G Davies, A M Fernandez-Pujals, P A Thomson, C Hayward, B H Smith, L J Hocking, S Padmanabhan, I J Deary, D J Porteous, K K Nicodemus, A M McIntosh
Major depressive disorder (MDD) is a heritable and highly debilitating condition. It is commonly associated with subcortical volumetric abnormalities, the most replicated of these being reduced hippocampal volume. Using the most recent published data from Enhancing Neuroimaging Genetics through Meta-analysis (ENIGMA) consortium's genome-wide association study of regional brain volume, we sought to test whether there is shared genetic architecture between seven subcortical brain volumes and intracranial volume (ICV) and MDD...
August 15, 2017: Translational Psychiatry
https://www.readbyqxmd.com/read/28808701/osteosarcoma-of-the-mandible-a-case-report-with-ct-mri-and-scintigraphy
#12
Mikiko Sue, Takaaki Oda, Yoshihiko Sasaki, Ayako Kameta, Yasuo Okada, Ichiro Ogura
Osteosarcomas are especially rare in the mandible and maxilla, representing 1.6% of all bony malignant tumours. In this article, we described a case of osteosarcoma of the mandible. Computed tomography (CT) image showed a well-circumscribed homogeneous mass, with nonhomogeneous contrast enhancement. T1-weighted magnetic resonance imaging (MR) image showed intermediate signal intensity on, and after administration the lesion showed signal intensity lower than muscle. T2-weighted MR image showed heterogeneous high signal intensity...
2017: Chinese Journal of Dental Research
https://www.readbyqxmd.com/read/28807363/deducing-magnetic-resonance-neuroimages-based-on-knowledge-from-samples
#13
Yuwei Jiang, Feng Liu, Mingxia Fan, Xuzhou Li, Zhiyong Zhao, Zhaoling Zeng, Yi Wang, Dongrong Xu
PURPOSE: Because individual variance always exists, using the same set of predetermined parameters for magnetic resonance imaging (MRI) may not be exactly suitable for each participant. We propose a knowledge-based method that can repair MRI data of undesired contrast as if a new scan were acquired using imaging parameters that had been individually optimized. METHODS: The method employed a strategy called analogical reasoning to deduce voxel-wise relaxation properties using morphological and biological similarity...
July 29, 2017: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
https://www.readbyqxmd.com/read/28805936/characterizing-hypoxia-in-human-glioma-a-simultaneous-multimodal-mri-and-pet-study
#14
Christine Preibisch, Kuangyu Shi, Anne Kluge, Mathias Lukas, Benedikt Wiestler, Jens Göttler, Jens Gempt, Florian Ringel, Mohamed Al Jaberi, Jürgen Schlegel, Bernhard Meyer, Claus Zimmer, Thomas Pyka, Stefan Förster
Hypoxia plays an important role for the prognosis and therapy response of cancer. Thus, hypoxia imaging would be a valuable tool for pre-therapeutic assessment of tumor malignancy. However, there is no standard validated technique for clinical application available yet. Therefore, we performed a study in 12 patients with high-grade glioma, where we directly compared the two currently most promising techniques, namely the MR-based relative oxygen extraction fraction (MR-rOEF) and the PET hypoxia marker H-1-(3-[(18) F]-fluoro-2-hydroxypropyl)-2-nitroimidazole ([(18) F]-FMISO)...
August 14, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28803447/registration-free-automatic-identification-of-gold-fiducial-markers-in-mri-target-delineation-images-for-prostate-radiotherapy
#15
Christian Gustafsson, Juha Korhonen, Emilia Persson, Adalsteinn Gunnlaugsson, Tufve Nyholm, Lars E Olsson
PURPOSE: The superior soft tissue contrast of magnetic resonance imaging (MRI) compared to computed tomography (CT) has urged the integration of MRI and elimination of CT in radiotherapy treatment (RT) for prostate. An intraprostatic gold fiducial marker (GFM) appear hyperintense on CT. On T2 weighted (T2w) MRI target delineation images the GFM appear as a small signal void similar to calcifications and post biopsy fibrosis. It can therefore be difficult to identify the markers without CT...
August 13, 2017: Medical Physics
https://www.readbyqxmd.com/read/28803358/prospective-head-to-head-comparison-of-11-c-choline-pet-mr-and-11-c-choline-pet-ct-for-restaging-of-biochemical-recurrent-prostate-cancer
#16
Matthias Eiber, Isabel Rauscher, Michael Souvatzoglou, Tobias Maurer, Markus Schwaiger, Konstantin Holzapfel, Ambros J Beer
PURPOSE: Whole-body integrated (11)C-choline PET/MR might provide advantages compared to (11)C-choline PET/CT for restaging of prostate cancer (PC) due to the high soft-tissue contrast and the use of multiparametric MRI, especially for detection of local recurrence and bone metastases. MATERIALS AND METHODS: Ninety-four patients with recurrent PC underwent a single-injection/dual-imaging protocol with contrast-enhanced PET/CT followed by fully diagnostic PET/MR...
August 12, 2017: European Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/28803217/accurate-model-based-segmentation-of-gynecologic-brachytherapy-catheter-collections-in-mri-images
#17
Andre Mastmeyer, Guillaume Pernelle, Ruibin Ma, Lauren Barber, Tina Kapur
The gynecological cancer mortality rate, including cervical, ovarian, vaginal and vulvar cancers, is more than 20,000 annually in the US alone. In many countries, including the US, external-beam radiotherapy followed by high dose rate brachytherapy is the standard-of-care. The superior ability of MR to visualize soft tissue has led to an increase in its usage in planning and delivering brachytherapy treatment. A technical challenge associated with the use of MRI imaging for brachytherapy, in contrast to that of CT imaging, is the visualization of catheters that are used to place radiation sources into cancerous tissue...
July 18, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28801826/brain-activity-changes-in-somatosensory-and-emotion-related-areas-with-medial-patellofemoral-ligament-deficiency
#18
Masaru Kadowaki, Taku Tadenuma, Nobuyuki Kumahashi, Yuji Uchio
BACKGROUND: Patellar instability with medial patellofemoral ligament (MPFL) deficiency is a common sports injury among young people. Although nonoperative and surgical treatment can provide stability of the patella, patients often have anxiety related to the knee. We speculate that neural dysfunction may be related to anxiety in these patients; however, the mechanism in the brain that generates this anxiety remains unknown. QUESTIONS/PURPOSES: (1) How does brain activity in patients with MPFL deficiency change in the areas related to somatic sensation against lateral shift of the patella? (2) How does patella instability, which can lead to continuous fear or apprehension for dislocation, influence brain activity in the areas related to emotion? METHODS: Nineteen patients with MPFL deficiency underwent surgical reconstruction in our hospital from April 2012 to March 2014...
August 11, 2017: Clinical Orthopaedics and related Research
https://www.readbyqxmd.com/read/28800546/mr-based-respiratory-and-cardiac-motion-correction-for-pet-imaging
#19
Thomas Küstner, Martin Schwartz, Petros Martirosian, Sergios Gatidis, Ferdinand Seith, Christopher Gilliam, Thierry Blu, Hadi Fayad, Dimitris Visvikis, F Schick, B Yang, H Schmidt, N F Schwenzer
PURPOSE: To develop a motion correction for Positron-Emission-Tomography (PET) using simultaneously acquired magnetic-resonance (MR) images within 90 s. METHODS: A 90 s MR acquisition allows the generation of a cardiac and respiratory motion model of the body trunk. Thereafter, further diagnostic MR sequences can be recorded during the PET examination without any limitation. To provide full PET scan time coverage, a sensor fusion approach maps external motion signals (respiratory belt, ECG-derived respiration signal) to a complete surrogate signal on which the retrospective data binning is performed...
August 3, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28799210/whole-brain-arteriography-and-venography-using-improved-velocity-selective-saturation-pulse-trains
#20
Wenbo Li, Feng Xu, Michael Schär, Jing Liu, Taehoon Shin, Yansong Zhao, Peter C M van Zijl, Bruce A Wasserman, Ye Qiao, Qin Qin
PURPOSE: To develop velocity-selective (VS) MR angiography (MRA) protocols for arteriography and venography with whole-brain coverage. METHODS: Tissue suppression using velocity-selective saturation (VSS) pulse trains is sensitive to radiofrequency field (B1 +) inhomogeneity. To reduce its sensitivity, we replaced the low-flip-angle hard pulses in the VSS pulse train with optimal composite (OCP) pulses. Additionally, new pulse sequences for arteriography and venography were developed by placing spatially selective inversion pulses with a delay to null signals from either venous or arterial blood...
August 10, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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