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https://www.readbyqxmd.com/read/28109537/clinical-factors-associated-with-cerebral-metabolism-in-term-neonates-with-congenital-heart-disease
#1
Anna Lonyai Harbison, Jodie K Votava-Smith, Sylvia Del Castillo, S Ram Kumar, Vince Lee, Vincent Schmithorst, Hollie A Lai, Sharon O'Neil, Stefan Bluml, Lisa Paquette, Ashok Panigrahy
OBJECTIVE: To determine associations between patient and clinical factors with postnatal brain metabolism in term neonates with congenital heart disease (CHD) via the use of quantitative magnetic resonance spectroscopy. STUDY DESIGN: Neonates with CHD were enrolled prospectively to undergo pre- and postoperative 3T brain magnetic resonance imaging. Short-echo single-voxel magnetic resonance spectroscopy of parietal white matter was used to quantify metabolites related to brain maturation (n-acetyl aspartate, choline, myo- inositol), neurotransmitters (glutamate and gamma-aminobutyric acid), energy metabolism (glutamine, citrate, glucose, and phosphocreatine), and injury/apoptosis (lactate and lipids)...
January 19, 2017: Journal of Pediatrics
https://www.readbyqxmd.com/read/28097371/high-resolution-diffusion-weighted-imaging-for-solitary-orbital-tumors-3d-turbo-field-echo-with-diffusion-sensitized-driven-equilibrium-dsde-tfe-preparation-technique
#2
Akio Hiwatashi, Osamu Togao, Koji Yamashita, Kazufumi Kikuchi, Hiroshi Yoshikawa, Makoto Obara, Hiroshi Honda
PURPOSE: To differentiate cystic from solid solitary intraorbital tumors using 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation without contrast material. MATERIALS AND METHODS: This retrospective study was approved by our institutional review boards, and written informed consent was waived. A total of 26 patients with intraorbital tumors were studied. Motion probing gradients were conducted at one direction with b‑values of 0 and 500 s/mm(2)...
January 17, 2017: Clinical Neuroradiology
https://www.readbyqxmd.com/read/28096732/estimation-of-t2-relaxation-time-of-breast-cancer-correlation-with-clinical-imaging-and-pathological-features
#3
Mirinae Seo, Jung Kyu Ryu, Geon-Ho Jahng, Yu-Mee Sohn, Sun Jung Rhee, Jang-Hoon Oh, Kyu-Yeoun Won
OBJECTIVE: The purpose of this study was to estimate the T2* relaxation time in breast cancer, and to evaluate the association between the T2* value with clinical-imaging-pathological features of breast cancer. MATERIALS AND METHODS: Between January 2011 and July 2013, 107 consecutive women with 107 breast cancers underwent multi-echo T2*-weighted imaging on a 3T clinical magnetic resonance imaging system. The Student's t test and one-way analysis of variance were used to compare the T2* values of cancer for different groups, based on the clinical-imaging-pathological features...
January 2017: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
https://www.readbyqxmd.com/read/28092533/linear-system-models-for-ultrasonic-imaging-intensity-signal-statistics
#4
Craig Abbey, Yang Zhu, Sara Bahramian, Michael Insana
Despite a great deal of work characterizing the statistical properties of radio-frequency backscattered ultrasound signals, less is known about the statistical properties of demodulated intensity signals. Analysis of intensity is made more difficult by a strong nonlinearity that arises in the process of demodulation. This limits our ability to characterize the spatial resolution and noise properties of B-mode ultrasound images. In this work, we generalize earlier results on two-point intensity covariance using a multivariate systems approach...
January 16, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28091836/assessment-of-edema-using-stir-via-3d-cardiovascular-magnetic-resonance-imaging-in-patients-with-suspected-myocarditis
#5
Michael Jeserich, Bela Merkely, Pascal Schlosser, Simone Kimmel, Gabor Pavlik, Stephan Achenbach
OBJECTIVE: To evaluate three-dimensional T2-weighted fast spin echo triple inversion recovery sequences (STIR+) for the diagnosis of myocardial edema in patients with suspected early myocarditis after respiratory or gastrointestinal tract viral infection and at follow-up. MATERIALS AND METHODS: We prospectively examined 28 patients with suspected myocarditis and 37 controls matched for gender and age. An ECG-triggered STIR+ was used to cover the entire left ventricle in short-axis images with 10-mm slice thickness and no interslice gap...
January 16, 2017: Magma
https://www.readbyqxmd.com/read/28090656/real-time-monitoring-of-tissue-displacement-and-temperature-changes-during-mr-guided-high-intensity-focused-ultrasound
#6
Pierre Bour, Fabrice Marquet, Valéry Ozenne, Solenn Toupin, Erik Dumont, Jean-François Aubry, Matthieu Lepetit-Coiffe, Bruno Quesson
PURPOSE: The therapy endpoint most commonly used in MR-guided high intensity focused ultrasound is the thermal dose. Although namely correlated with nonviable tissue, it does not account for changes in mechanical properties of tissue during ablation. This study presents a new acquisition sequence for multislice, subsecond and simultaneous imaging of tissue temperature and displacement during ablation. METHODS: A single-shot echo planar imaging sequence was implemented using a pair of motion-encoding gradients, with alternated polarities...
January 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28088148/lithium-ion-micrometer-diffusion-in-a-garnet-type-cubic-li7la3zr2o12-llzo-studied-using-7-li-nmr-spectroscopy
#7
Kikuko Hayamizu, Shiro Seki, Tomoyuki Haishi
Mobile lithium ions in a cubic garnet Li7La3Zr2O12 (Al-stabilized) were studied using (7)Li NMR spectroscopy for membrane and powder samples, the latter of which was ground from the membrane. Lithium diffusion in a micrometer space was measured using the pulsed-gradient spin-echo (7)Li NMR method between 70 and 130 °C. When the observation time (Δ) was shorter than 20 ms, the echo attenuation showed diffusive diffraction patterns, indicating that the Li(+) diffusing space is not free but restricted. For longer Δ, the values of apparent diffusion constant (Dapparent) became gradually smaller to approach an equilibrated value (close to a tracer diffusion constant)...
January 14, 2017: Journal of Chemical Physics
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
#8
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/28072576/ultrasonic-computed-tomography-imaging-of-iron-oxide-nanoparticles
#9
Or Perlman, Haim Azhari
Iron oxide nanoparticles (IONPs) are becoming increasingly used and intensively investigated in the field of medical imaging. They are currently FDA approved for magnetic resonance imaging (MRI), and it would be highly desirable to visualize them by ultrasound as well. Previous reports using the conventional ultrasound B-scan (pulse-echo) imaging technique have shown very limited detectability of these particles. The aim of this study is to explore the feasibility of imaging IONPs using the through-transmission ultrasound methodology and demonstrate their detectability using ultrasonic computed tomography (UCT)...
February 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28058747/towards-a-neurochemical-profile-of-the-amygdala-using-short-te-1-h-magnetic-resonance-spectroscopy-at-3%C3%A2-t
#10
Florian Schubert, Simone Kühn, Jürgen Gallinat, Ralf Mekle, Bernd Ittermann
The amygdala plays a key role in emotional learning and in the processing of emotions. As disturbed amygdala function has been linked to several psychiatric conditions, a knowledge of its biochemistry, especially neurotransmitter levels, is highly desirable. The spin echo full intensity acquired localized (SPECIAL) sequence, together with a transmit/receive coil, was used to perform very short-TE magnetic resonance spectroscopy at 3 T to determine the neurochemical profile in a spectroscopic voxel containing the amygdala in 21 healthy adult subjects...
January 6, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28058428/incorporation-of-aspirin-modulates-the-dynamical-and-phase-behavior-of-the-phospholipid-membrane
#11
V K Sharma, E Mamontov, M Ohl, M Tyagi
Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most widely used medications in the world for their analgesic, antipyretic, and anti-inflammatory actions, despite a well-known incidence of a wide spectrum of their adverse effects. To a great extent, beneficial action and side effects of NSAIDs are associated with the interaction of these drugs at the cell membrane level. Here, we use neutron scattering to combine elastic intensity scans, quasielastic and neutron spin echo (NSE) measurements to understand the effect of aspirin, a commonly used NSAID, on the dynamical and phase behavior of the membrane of dimyristoylphosphatidylcholine (DMPC), a prominent representative of phospholipids residing in the outer leaflet of the human erythrocyte membrane...
January 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28055818/time-domain-nuclear-magnetic-resonance-td-nmr-and-chemometrics-for-determination-of-fat-content-in-commercial-products-of-milk-powder
#12
Paloma Andrade Martins Nascimento, Paulo Lopes Barsanelli, Ana Paula Rebellato, Juliana Azevedo Lima Pallone, Luiz Alberto Colnago, Fabíola Manhas Verbi Pereira
This study shows the use of time-domain (TD)-NMR transverse relaxation (<italic>T</italic><sub>2</sub>) data and chemometrics in the nondestructive determination of fat content for powdered food samples such as commercial dried milk products. Most proposed NMR spectroscopy methods for measuring fat content correlate free induction decay or echo intensities with the sample&#x2019;s mass. The need for the sample&#x2019;s mass limits the analytical frequency of NMR determination, because weighing the samples is an additional step in this procedure...
January 5, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28048894/su-f-i-58-image-quality-comparisons-of-different-motion-magnitudes-and-tr-values-in-mr-pet
#13
J Patrick, M Tavallaei, R Thompson, R Stodilka, M Drangova, S Gaede
PURPOSE: The aim of this work is to evaluate the accuracy and sensitivity of a respiratory-triggered MR-PET protocol in detecting four different sized lesions at two different magnitudes of motion, with two different TR values, using a novel PET-MR-CT compatible respiratory motion phantom. METHODS: The eight-compartment torso phantom was setup adjacent to the motion stage, which moved four spherical compartments (28, 22, 17, 10 mm diameter) in two separate (1 and 2 cm) linear motion profiles, simulating a 3...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048261/su-g-jep2-11-polymer-gels-as-3d-qa-devices-in-magnetic-resonance-guided-radiation-therapy
#14
Y Roed, M Kadbi, J Wang, L Pinsky, G Ibbott
PURPOSE: To demonstrate the potential of polymer gels to serve as 3D QA devices in MR-guided radiotherapy. METHODS: Custom-designed polymer gel dosimeters (MGS Research, Madison, CT) were centered on the penumbras of a radiation field, parallel to the magnetic field lines inside a 1.5 T MR scanner integrated with a 7 MV linac (MR-Linac). 15 Gy were delivered perpendicular to the magnetic field. Coronal MR images were acquired with a 2D balanced-Fast Field Echo (b-FFE) sequence in real-time during irradiation and with a 2D spin echo sequence at different times after irradiation...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047200/tu-h-206-07-assessment-of-geometric-distortion-in-epi-with-a-spamm-tagged-acquisition
#15
K Hwang, J Meier, J Yung, R Stafford
PURPOSE: Echo planar imaging (EPI) is known to exhibit gross geometric distortion caused by multiple factors, including B0 inhomgeneity and transient eddy currents. However, diffusion weighted (DW) EPI has become indispensable for diagnosis and therapy assessment. We propose a methodology for quantifying distortion in EPI sequences that does not require the use of dedicated spatial accuracy phantoms, enabling flexibility in phantom design for QA of distortion effects in EPI protocols...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046948/su-f-j-159-influence-of-the-elevated-posterior-position-by-using-the-customized-vacuum-bag-on-the-abdominal-mr-image-quality-a-quantitative-phantom-study
#16
O Wong, J Yuan, M Law, A Ding, S Yu, K Cheung
PURPOSE: Signal-to-noise ratio(SNR) of MR abdominal imaging in diagnostic radiology is maximized by minimizing the coil-to-patient distance. However, for radiotherapy applications, customized vacuum-bag is needed for abdominal immobilization at the cost of the increasing distance to the posterior spine coil. This sub-optimized coil setting for RT applications may compromise image quality, such as SNR and homogeneity, thus potentially affect tissue delineation. In this study, we quantitatively evaluate the effect of the vertical position change on SNR and image quality change using an ACR MR phantom...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046341/th-ef-bra-11-feasibility-of-super-resolution-time-resolved-4dmri-for-multi-breath-volumetric-motion-simulation-in-radiotherapy-planning
#17
G Li, J Wei, K Zakian, M Hunt, J Deasy
PURPOSE: To develop a novel super-resolution time-resolved 4DMRI technique to evaluate multi-breath, irregular and complex organ motion without respiratory surrogate for radiotherapy planning. METHODS: The super-resolution time-resolved (TR) 4DMRI approach combines a series of low-resolution 3D cine MRI images acquired during free breathing (FB) with a high-resolution breath-hold (BH) 3DMRI via deformable image registration (DIR). Five volunteers participated in the study under an IRB-approved protocol...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046306/su-g-jep2-14-mri-based-hdr-prostate-brachytherapy-a-phantom-study-for-interstitial-catheter-reconstruction-with-0-35t-mri-images
#18
S Park, M Kamrava, Y Yang
PURPOSE: To evaluate the accuracy of interstitial catheter reconstruction with 0.35T MRI images for MRI-based HDR prostate brachytherapy. METHODS: Recently, a real-time MRI-guided radiotherapy system combining a 0.35T MRI system and three cobalt 60 heads (MRIdian System, ViewRay, Cleveland, OH, USA) was installed in our department. A TrueFISP sequence for MRI acquisition at lower field on Viewray was chosen due to its fast speed and high signal-to-noise efficiency...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28027765/selective-visualization-of-pelvic-splanchnic-nerve-and-pelvic-plexus-using-readout-segmented-echo-planar-diffusion-weighted-magnetic-resonance-neurography-a-preliminary-study-in-healthy-male-volunteers
#19
Rikiya Yamashita, Hiroyoshi Isoda, Shigeki Arizono, Akihiro Furuta, Tsuyoshi Ohno, Ayako Ono, Katsutoshi Murata, Kaori Togashi
PURPOSE: To evaluate the potential of readout-segmented echo-planar diffusion-weighted magnetic resonance neurography (RS-EPI DW-MRN) for the selective visualization of pelvic splanchnic nerve and pelvic plexus in healthy male volunteers. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. RS-EPI DW-MRN images were acquired from thirteen healthy male volunteers aged 25-48 years between September 2013 and December 2013...
January 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28027757/free-breathing-dynamic-liver-examination-using-a-radial-3d-t1-weighted-gradient-echo-sequence-with-moderate-undersampling-for-patients-with-limited-breath-holding-capacity
#20
Benjamin Kaltenbach, Andrei Roman, Christoph Polkowski, Tatjana Gruber-Rouh, Ralf W Bauer, Renate Hammerstingl, Thomas J Vogl, Stephan Zangos
PURPOSE: To compare free-breathing radial VIBE with moderate undersampling (us-radial-VIBE) with a standard breathhold T1-weighted volumetric interpolated sequence (3D GRE VIBE) in patients unable to suspend respiration during dynamic liver examination. MATERIAL AND METHODS: 23 consecutive patients underwent dynamic liver MR examination using the free-breathing us-radial-VIBE sequence as part of their oncologic follow-up. All patients were eligible for the free-breathing protocol due to severe respiratory artifacts at the planning or precontrast sequences...
January 2017: European Journal of Radiology
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