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Ulysse Gimenez, Hélène Lajous, Michèle El Atifi, Marie Bidart, Vincent Auboiroux, Pascal Henry Fries, François Berger, Hana Lahrech
Cellular MRI, which visualizes magnetically labelled cells (cells*), is an active research field for in vivo cell therapy and tracking. The simultaneous relaxation rate measurements (R2 *, R2 , R1 ) are the basis of a quantitative cellular MRI method proposed here. U937 cells were labelled with Molday ION Rhodamine B, a bi-functional superparamagnetic and fluorescent nanoparticle (U937*). U937* viability and proliferation were not affected in vitro. In vitro relaxometry was performed in a cell concentration range of [2...
October 21, 2016: Contrast Media & Molecular Imaging
Grzegorz Bauman, Francesco Santini, Orso Pusterla, Oliver Bieri
PURPOSE: To present a technique for simultaneous mapping of T1 , T2 , and relative spin density (M0 ) in human lung using inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) imaging. METHODS: Pulmonary relaxometry with IR-ufSSFP is based on an interleaved time series acquisition of 2D images acquired at 1.5T. The technique was tested in a phantom and in four healthy volunteers using breath-hold and electrocardiogram triggering. Typically, 30 transient state images were acquired in a single breath-hold within < 10 s...
October 19, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Samuel A Einstein, Bradley P Weegman, Meri T Firpo, Klearchos Papas, Michael Garwood
Techniques to monitor the oxygen partial pressure (pO<sub>2</sub>) within implanted tissue-engineered grafts (TEGs) are critically necessary for TEG development, but current methods are invasive and inaccurate. In this study, we investigated an accurate and noninvasive technique to monitor TEG pO<sub>2</sub> utilizing proton (<sup>1</sup>H) or fluorine (<sup>19</sup>F) magnetic resonance spectroscopy (MRS) relaxometry. The value of the spin-lattice relaxation rate constant (R<sub>1</sub>) of some biocompatible compounds is sensitive to dissolved oxygen (and temperature), while insensitive to other external factors...
October 19, 2016: Tissue Engineering. Part C, Methods
Martina F Callaghan, Siawoosh Mohammadi, Nikolaus Weiskopf
Quantitative MRI (qMRI) provides standardized measures of specific physical parameters that are sensitive to the underlying tissue microstructure and are a first step towards achieving maps of biologically relevant metrics through in vivo histology using MRI. Recently proposed models have described the interdependence of qMRI parameters. Combining such models with the concept of image synthesis points towards a novel approach to synthetic qMRI, in which maps of fundamentally different physical properties are constructed through the use of biophysical models...
October 18, 2016: NMR in Biomedicine
Ching-Yu Chou, Minglee Chu, Chi-Fon Chang, Tsunai Yu, Tai-Huang Huang, Dimitris Sakellariou
Field-dependent NMR studies of bio-molecular systems using a sample shuttling hardware operating on a high-field NMR apparatus have provided valuable structural and dynamic information. We have recently published a design of a compact sample transportation device, called "field-cycler", which was installed in a commercial spectrometer and which provided highly precise positioning and stability during high speed shuttling. In this communication, we demonstrate the first use of a sample shuttling device on a commercial high field standard bore NMR spectrometer, equipped with a commercial triple resonance cryogenically cooled NMR probe...
October 15, 2016: Journal of Biomolecular NMR
Sofya Kulikova, Lucie Hertz-Pannier, Ghislaine Dehaene-Lambertz, Cyril Poupon, Jessica Dubois
The volume fraction of water related to myelin (fmy) is a promising MRI index for in vivo assessment of brain myelination, that can be derived from multi-component analysis of T1 and T2 relaxometry signals. However, existing quantification methods require rather long acquisition and/or post-processing times, making implementation difficult both in research studies on healthy unsedated children and in clinical examinations. The goal of this work was to propose a novel strategy for fmy quantification within acceptable acquisition and post-processing times...
2016: PloS One
Gopal Nataraj, Jon-Fredrick Nielsen, Jeffrey Fessler
Rapid, reliable quantification of MR relaxation parameters T1 and T2 is desirable for many clinical applications. Steady-state sequences such as Spoiled Gradient-Recalled Echo (SPGR) and Dual-Echo Steady-State (DESS) are fast and wellsuited for relaxometry because the signals they produce are quite sensitive to T1 and T2 variation. However, T1, T2 estimation with these sequences typically requires multiple scans with varied sets of acquisition parameters. This paper describes a systematic framework for selecting scan types (e...
October 4, 2016: IEEE Transactions on Medical Imaging
Abraham Colin-Molina, Salvador Pérez-Estrada, Arian E Roa, Alvin Villagrana-Garcia, Simón Hernández-Ortega, Mario Rodríguez, Stuart E Brown, Braulio Rodríguez-Molina
Liquid-like dynamics of a covalent 1,4-phenylene rotator have been unveiled in 1 with a brominated stator showing type-II halogen bonds. This singular rotation is favored by synergistic molecular changes in stacked molecules, according to VT solid state NMR, (1)H T1 relaxometry and VT X-ray experiments of this highly crystalline compound.
October 3, 2016: Chemical Communications: Chem Comm
Uchechukwuka D Monu, Caroline D Jordan, Bonnie L Samuelson, Brian A Hargreaves, Garry E Gold, Emily J McWalter
PURPOSE: To identify focal lesions of elevated MRI T2 and T1ρ relaxation times in articular cartilage of an ACL-injured group using a novel cluster analysis technique. MATERIALS AND METHODS: Eighteen ACL-injured patients underwent 3T MRI T2 and T1ρ relaxometry at baseline, six months and one year and six healthy volunteers at baseline, one day and one year. Clusters of contiguous pixels above or below T2 and T1ρ intensity and area thresholds were identified on a projection map of the 3D femoral cartilage surface...
October 5, 2016: Osteoarthritis and Cartilage
Yì-Xiáng J Wáng
No abstract text is available yet for this article.
August 2016: Quantitative Imaging in Medicine and Surgery
Rafael Menezes-Reis, Carlos E Garrido Salmon, Gustavo P Bonugli, Debora Mazoroski, Mauricio H Tamashiro, Leonor G Savarese, Marcello Henrique Nogueira-Barbosa
BACKGROUND: To investigate the detection of intervertebral disc (IVD) composition aging-related changes using T2 and T1ρ relaxometry in vivo in asymptomatic young adults. METHODS: We recruited ninety asymptomatic and young adults (42 men and 48 women) between 20 and 40 years old. T2 and T1ρ lumbar spine mappings were acquired using 1.5 T magnetic resonance imaging (MRI) scanner. Two independent observers manually segmented 450 lumbar discs in all slices. They also performed sub region segmentation of annulus fibrosus (AF) and nucleus pulposus (NP) at the central MRI sagittal slices...
August 2016: Quantitative Imaging in Medicine and Surgery
Douglas C Dean, Jitka Sojkova, Samuel Hurley, Steven Kecskemeti, Ozioma Okonkwo, Barbara B Bendlin, Frances Theisen, Sterling C Johnson, Andrew L Alexander, Catherine L Gallagher
Alterations to myelin may be a core pathological feature of neurodegenerative diseases. Although white matter microstructural differences have been described in Parkinson's disease (PD), it is unknown whether such differences include alterations of the brain's myelin content. Thus, the objective of the current study is to measure and compare brain myelin content between PD patients and age-matched controls. In this cross-sectional study, 63 participants from the Longitudinal MRI in Parkinson's Disease study underwent brain MRI, Unified Parkinson's Disease Rating Scale (UPDRS) scoring, and cognitive asessments...
2016: PloS One
Mark Drakesmith, Anirban Dutt, Leon Fonville, Stanley Zammit, Abraham Reichenberg, C John Evans, Philip McGuire, Glyn Lewis, Derek K Jones, Anthony S David
BACKGROUND: Grey matter (GM) abnormalities are robust features of schizophrenia and of people at ultra high-risk for psychosis. However the extent to which neuroanatomical alterations are evident in non-clinical subjects with isolated psychotic experiences is less clear. METHODS: Individuals (mean age 20 years) with (n = 123) or without (n = 125) psychotic experiences (PEs) were identified from a population-based cohort. All underwent T1-weighted structural, diffusion and quantitative T1 relaxometry MRI, to characterise GM macrostructure, microstructure and myelination respectively...
2016: NeuroImage: Clinical
Ana M Daugherty, Naftali Raz
Age-related declines in spatial navigation are associated with deficits in procedural and episodic memory and deterioration of their neural substrates. For the lack of longitudinal evidence, the pace and magnitude of these declines and their neural mediators remain unclear. Here we examined virtual navigation in healthy adults (N=213, age 18-77 years) tested twice, two years apart, with complementary indices of navigation performance (path length and complexity) measured over six learning trials at each occasion...
September 19, 2016: NeuroImage
Chiharu Yoshimoto, Junko Takahama, Takuya Iwabuchi, Masato Uchikoshi, Hiroshi Shigetomi, Hiroshi Kobayashi
PURPOSE: Heme and iron accumulation due to repeated hemorrhage in endometriosis may contribute to a pivotal role in carcinogenesis. We evaluate the clinical application of MR relaxometry in a series of ovarian endometriosis (OE) and endometriosis-associated ovarian cancer (EAOC). MATERIALS AND METHODS: A prospective study of diagnostic accuracy was conducted among 82 patients (67 OE and 15 EAOC) to compare MR relaxometry and biochemical measurement of cyst fluid total iron concentration...
September 16, 2016: Magnetic Resonance in Medical Sciences: MRMS
Valentina Pedoia, Matthew C Gallo, Richard B Souza, Sharmila Majumdar
PURPOSE: To study the local distribution of hip cartilage T1ρ and T2 relaxation times and their association with changes in patient reported outcome measures (PROMs) using a fully automatic, local, and unbiased method in subjects with and without hip osteoarthritis (OA). MATERIALS AND METHODS: The 3 Tesla MRI studies of the hip were obtained for 37 healthy controls and 16 subjects with radiographic hip OA. The imaging protocol included a three-dimensional (3D) SPGR sequence and a combined 3D T1ρ and T2 sequence...
September 14, 2016: Journal of Magnetic Resonance Imaging: JMRI
Chukwan Techakanon, Thomas M Gradziel, Diane M Barrett
Peach cultivars contribute to unique product characteristics and may affect the degree of browning after high-pressure processing (HPP). Nine peach cultivars were subjected to HPP at 0, 100, and 400 MPa for 10 min. Proton nuclear magnetic resonance ((1)H NMR) relaxometry, light microscopy, color, polyphenol oxidase (PPO) activity, and total phenols were evaluated. The development of enzymatic browning during refrigerated storage occurred because of damage during HPP that triggered loss of cell integrity, allowing substrates to interact with enzymes...
October 12, 2016: Journal of Agricultural and Food Chemistry
Masha M Rosenberg, Alfred G Redfield, Mary F Roberts, Lizbeth Hedstrom
Guanosine-5'-monophosphate reductase (GMPR) catalyzes the reduction of GMP to IMP and ammonia with concomitant oxidation of NADPH. Here we investigated the structure and dynamics of enzyme-bound substrates and cofactors by measuring (31)P relaxation rates over a large magnetic field range using high-resolution field cycling NMR relaxometry. Surprisingly, these experiments reveal differences in the low field relaxation profiles for the monophosphate of GMP compared to IMP in their respective NADP(+) complexes...
September 9, 2016: Journal of Biological Chemistry
Damien Nguyen, Oliver Bieri
PURPOSE: Triple echo steady state (TESS) uses the lowest steady state configuration modes for rapid relaxometry. Due to its unbalanced gradient scheme, however, TESS is inherently motion-sensitive. The purpose of this work is to merge TESS with a balanced acquisition scheme for motion-insensitive rapid configuration relaxometry, termed MIRACLE. METHODS: The lowest order steady state free precession (SSFP) configurations are retrieved by Fourier transformation of the frequency response of N frequency-shifted balanced SSFP (bSSFP) scans and subsequently processed for relaxometry, as proposed with TESS...
September 8, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Maryam Naseroleslami, Kazem Parivar, Samideh Khoei, Nahid Aboutaleb
OBJECTIVE: The label and detection of cells injected into target tissues is an area of focus for researchers. Iron oxide nanoparticles can be used to label cells as they have special characteristics. The purpose of this study is to examine the effects of iron oxide nanoparticles on human-derived amniotic membrane stem cell (hAMCs) survival and to investigate the magnetic properties of these nanoparticles with increased contrast in magnetic resonance imaging (MRI). MATERIALS AND METHODS: In this experimental study, we initially isolated mesenchymal stem cells from amniotic membranes and analyzed them by flow cytometry...
2016: Cell Journal
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