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Su Myat Phyu, Chih-Chung Tseng, Tim Andrew Davies Smith
PURPOSE: Glycogen synthase kinase 3 (GSK3) is a key controlling element of many cellular processes including cell-cycle progression and recent studies suggest that GSK3 is a potential anticancer target. Changes in glucose metabolism associated with GSK3 inhibition may impact on lipid synthesis, whilst lipid metabolites can act as molecular response markers. METHODS: Here, SKBr3 breast and HCT8 colorectal cancer cells were treated with the GSK3 inhibitor SB216763, and [14 C (U)] glucose and [3 H] choline incorporation into lipids was determined...
November 16, 2018: Magma
Sonia Waiczies, Jens T Rosenberg, Andre Kuehne, Ludger Starke, Paula Ramos Delgado, Jason M Millward, Christian Prinz, Joao Dos Santos Periquito, Andreas Pohlmann, Helmar Waiczies, Thoralf Niendorf
OBJECTIVE: Fluorine MR would benefit greatly from enhancements in signal-to-noise ratio (SNR). This study examines the sensitivity gain of 19 F MR that can be practically achieved when moving from 9.4 to 21.1 T. MATERIALS AND METHODS: We studied perfluoro-15-crown-5-ether (PFCE) at both field strengths (B0 ), as a pure compound, in the form of nanoparticles (NP) as employed to study inflammation in vivo, as well as in inflamed tissue. Brains, lymph nodes (LNs) and spleens were obtained from mice with experimental autoimmune encephalomyelitis (EAE) that had been administered PFCE NPs...
November 12, 2018: Magma
Ahmed A Khalil, Susanne Mueller, Marco Foddis, Larissa Mosch, Janet Lips, Ingo Przesdzing, Sebastian Temme, Ulrich Flögel, Ulrich Dirnagl, Philipp Boehm-Sturm
INTRODUCTION: We explored the use of a perfluoro-15-crown-5 ether nanoemulsion (PFC) for measuring tissue oxygenation using a mouse model of vascular cognitive impairment. METHODS: Seventeen C57BL/6 mice underwent stereotactic injection of PFC coupled to a fluorophore into the striatum and corpus callosum. Combined 1H/19F magnetic resonance imaging (MRI) to localize the PFC and R1 mapping to assess pO2 were performed. The effect of gas challenges on measured R1 was investigated...
November 12, 2018: Magma
Maik Rothe, Annika Jahn, Kilian Weiss, Jong-Hee Hwang, Julia Szendroedi, Malte Kelm, Jürgen Schrader, Michael Roden, Ulrich Flögel, Florian Bönner
OBJECTIVES: Fluorine-19 (19 F) MRI with intravenously applied perfluorocarbons allows the in vivo monitoring of infiltrating immune cells as demonstrated in small animal models at high field. Here, we aimed to transfer this approach to a clinical scanner for detection of inflammatory processes in the heart after acute myocardial infarction (AMI) in a large animal model. MATERIALS AND METHODS: Optimization of coil and sequence performance was carried out on phantoms and in vivo at a 3 T Philips Achieva...
November 12, 2018: Magma
Ashley V Makela, Paula J Foster
PURPOSE: To develop methods for fluorine-19 (19 F) MRI cell tracking in mice on a 3 Tesla clinical scanner. Compared to iron-based cell tracking, 19 F MRI has lower sensitivity and, consequently, preclinical 19 F cell tracking has only been performed at relatively high magnetic field strengths (> 3 T). Here, we focus on using 19 F MRI to detect macrophages in tumors; macrophage density is an indication of tumor aggressiveness and, therefore, 19 F MRI could be used as an imaging biomarker...
November 12, 2018: Magma
Jean-Pierre Raufman, Melissa Metry, Jessica Felton, Kunrong Cheng, Su Xu, James Polli
In up to 50% of people diagnosed with a common ailment, diarrhea-predominant irritable bowel syndrome, diarrhea results from excess spillage of bile acids into the colon-data emerging over the past decade identified deficient release of a gut hormone, fibroblast growth factor 19 (FGF19), and a consequent lack of feedback suppression of bile acid synthesis as the most common cause. 75 Selenium homotaurocholic acid (SeHCAT) testing, considered the most sensitive and specific means of identifying individuals with bile acid diarrhea, is unavailable in many countries, including the United States...
November 1, 2018: Magma
Mareike Gastl, Sophie M Peereboom, Maximilian Fuetterer, Florian Boenner, Malte Kelm, Robert Manka, Sebastian Kozerke
OBJECTIVES: To study inter-individual differences of the relation between diaphragm and heart motion, the objective of the present study was to implement respiratory navigation on the heart and compare it against the established method of navigator gating on the diaphragm for single-voxel cardiac 1 H-MRS. MATERIALS AND METHODS: 1 H-MRS was performed on a 1.5T system in 19 healthy volunteers of mixed age (range 24-75 years). Spectra were recorded in a 6-8 ml voxel in the ventricular septum using a PRESS (point-resolved spectroscopy) sequence and ECG gating...
October 30, 2018: Magma
Matthew C Restivo, Adrienne E Campbell-Washburn, Peter Kellman, Hui Xue, Rajiv Ramasawmy, Michael S Hansen
INTRODUCTION: Computationally intensive image reconstruction algorithms can be used online during MRI exams by streaming data to remote high-performance computers. However, data acquisition rates often exceed the bandwidth of the available network resources creating a bottleneck. Data compression is, therefore, desired to ensure fast data transmission. METHODS: The added noise variance due to compression was determined through statistical analysis for two compression libraries (one custom and one generic) that were implemented in this framework...
October 25, 2018: Magma
Chressen Catharina Remus, Emilia Solano, Thomas Ernst, Rene Thieme, Kurt Hecher, Gerhard Adam, Petra Arck
OBJECTIVES: The purpose of our study was to evaluate MRI as a tool to examine placental morphology in a murine model in comparison to classical histology techniques. METHODS: Assessment of placental samples (n = 24) from C57Bl/6 J mice was performed using MR imaging and histomorphological analyses. To optimize image contrast for MRI, a protocol for gadolinium-mediated enhancement of placental tissue was established. To test method sensitivity, placental zone assessment with MRI and histology was applied to a model of prenatal stress exposure known to affect placental morphology (n = 10)...
October 19, 2018: Magma
Giovanna Nordio, Aurélien Bustin, Markus Henningsson, Imran Rashid, Amedeo Chiribiri, Tevfik Ismail, Freddy Odille, Claudia Prieto, René Michael Botnar
The original version of this article unfortunately contained a mistake. The presentation of Equation was incorrect. The corrected equation is given below.
October 8, 2018: Magma
Xin Liu, Zhong-Xing Jiang, Bruce Y Yu, Eun-Kee Jeong
PURPOSE: To use 19 F imaging tracer (19 FIT-27) to evaluate kinetics in major organs. INTRODUCTION: Kinetics studies using proton MRI are difficult because of low concentration of 19 FIT-27 protons relative to background water protons. Because there is no background source of 19 F NMR in a biological body, 19 F may be an ideal nucleus to directly trace 19 FIT-27. However, there are several challenges for reliable 19 F MR imaging and spectroscopy, particularly with clinical whole-body MRI systems, which include low concentrations and long 19 F T1 ...
October 5, 2018: Magma
Céline Marie Desmet, Ly Binh An Tran, Pierre Danhier, Bernard Gallez
OBJECTIVES: Electron paramagnetic resonance (EPR) oximetry using particulate materials allows repeatable measurements of oxygen in tissues. However, the materials identified so far are not medical devices, thus precluding their immediate use in clinical studies. The aim of this study was to assess the magnetic properties of Carbo-Rep® , a charcoal suspension used as a liquid marker for preoperative tumor localization. MATERIALS AND METHODS: Calibration curves (EPR linewidth as a function of pO2 ) were built using 9-GHz EPR spectrometry...
September 12, 2018: Magma
Giovanna Nordio, Aurélien Bustin, Markus Henningsson, Imran Rashid, Amedeo Chiribiri, Tevfik Ismail, Freddy Odille, Claudia Prieto, René Michael Botnar
PURPOSE: To improve the precision of a free-breathing 3D saturation-recovery-based myocardial T1 mapping sequence using a post-processing 3D denoising technique. METHODS: A T1 phantom and 15 healthy subjects were scanned on a 1.5 T MRI scanner using 3D saturation-recovery single-shot acquisition (SASHA) for myocardial T1 mapping. A 3D denoising technique was applied to the native T1-weighted images before pixel-wise T1 fitting. The denoising technique imposes edge-preserving regularity and exploits the co-occurrence of 3D spatial gradients in the native T1-weighted images by incorporating a multi-contrast Beltrami regularization...
September 6, 2018: Magma
Da Xie, Lauren E Ohman, Emily L Que
OBJECTIVES: Our aim was to demonstrate the potential of exploiting simultaneous changes in coordination geometry and spin state in fluorinated Ni(II) complexes as an avenue for 19 F magnetic-resonance (MR)-based pH sensing. MATERIALS AND METHODS: Crystal structures were studied using an Agilent Technologies SuperNova Dual Source diffractometer. Solution magnetic moment was determined using Evan's method. MR images were collected on a 7.0-T MR scanner equipped with a quadrature 19 F volume coil...
September 3, 2018: Magma
Raluca G Chelu, Michael Horowitz, Dominica Sucha, Isabella Kardys, Delphine Ingremeau, Shreyas Vasanawala, Koen Nieman, Jean-Francois Paul, Albert Hsiao
PURPOSE: With the hypothesis that 4D flow can be used in evaluation of cardiac shunts, we seek to evaluate the multilevel and interreader reproducibility of measurements of the blood flow, shunt fraction and shunt volume in patients with atrial septum defect (ASD) in practice at multiple clinical sites. MATERIALS AND METHODS: Four-dimensional flow MRI examinations were performed at four institutions across Europe and the US. Twenty-nine patients (mean age, 43 years; 11 male) were included in the study...
August 31, 2018: Magma
Ralf Lützkendorf, Robin M Heidemann, Thorsten Feiweier, Michael Luchtmann, Sebastian Baecke, Jörn Kaufmann, Jörg Stadler, Eike Budinger, Johannes Bernarding
OBJECTIVES: We assessed the use of high-resolution ultra-high-field diffusion magnetic resonance imaging (dMRI) to determine neuronal fiber orientation density functions (fODFs) throughout the human brain, including gray matter (GM), white matter (WM), and small intertwined structures in the cerebellopontine region. MATERIALS AND METHODS: We acquired 7-T whole-brain dMRI data of 23 volunteers with 1.4-mm isotropic resolution; fODFs were estimated using constrained spherical deconvolution...
December 2018: Magma
Andreas Reichert, Michael Bock, Simon Reiss, Christiaan G Overduin, Jurgen J Fütterer, Axel Joachim Krafft
OBJECTIVE: To accelerate a passive tracking sequence based on phase-only cross correlation (POCC) using simultaneous slice excitation. METHODS: For magnetic resonance (MR)-guided biopsy procedures, passive markers have been proposed that can be automatically localized online using a POCC-based tracking sequence. To accelerate the sequence, a phase-offset multiplanar (POMP) excitation technique was implemented to acquire tracking images. In a phantom experiment, the POMP-POCC sequence was tested and compared with the sequential non-accelerated version in terms of duration and accuracy...
December 2018: Magma
Conor J MacDonald, Stephen Gandy, Eilidh C M Avison, Shona Matthew, Rose Ross, John G Houston
OBJECTIVE: To compare non-contrast enhanced MRI with ultrasound (US) for measurement of arm blood vessel geometries and flow velocities in volunteers and patients with end-stage renal disease. MATERIALS AND METHODS: Subjects were scanned using US (reference standard), and MRI 2D time-of-flight (ToF), 2D phase contrast (PC), and 3D multi-echo data image combination (MEDIC). Patients were also scanned after arteriovenous fistula (AVF) surgery. RESULTS: For mean vessel diameters (radial and brachial arteries; cephalic vein) MEDIC measurements were similar to US (p > 0...
December 2018: Magma
Juha I Peltonen, Teemu Mäkelä, Eero Salli
OBJECTIVE: Quality assurance (QA) of magnetic resonance imaging (MRI) often relies on imaging phantoms with suitable structures and uniform regions. However, the connection between phantom measurements and actual clinical image quality is ambiguous. Thus, it is desirable to measure objective image quality directly from clinical images. MATERIALS AND METHODS: In this work, four measurements suitable for clinical image QA were presented: image resolution, contrast-to-noise ratio, quality index and bias index...
December 2018: Magma
Oscar Jalnefjord, Mats Andersson, Mikael Montelius, Göran Starck, Anna-Karin Elf, Viktor Johanson, Johanna Svensson, Maria Ljungberg
OBJECTIVE: Intravoxel incoherent motion (IVIM) shows great potential in many applications, e.g., tumor tissue characterization. To reduce image-quality demands, various IVIM analysis approaches restricted to the diffusion coefficient (D) and the perfusion fraction (f) are increasingly being employed. In this work, the impact of estimation approach for D and f is studied. MATERIALS AND METHODS: Four approaches for estimating D and f were studied: segmented IVIM fitting, least-squares fitting of a simplified IVIM model (sIVIM), and Bayesian fitting of the sIVIM model using marginal posterior modes or posterior means...
December 2018: Magma
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