Characterization of white matter alterations in phenylketonuria by magnetic resonance relaxometry and diffusion tensor imaging.

abstract：:A modified inversion-recovery sequence is introduced which performs subtraction angiography by varying time-of-flight effects of blood flowing into an imaged slab. The selective 180 degrees excitation inverts different regions between measurements to isolate arterial and/or venous blood. On normal human subjects, high...

journal_title：Magnetic resonance in medicine

authors： Nishimura DG,Macovski A,Pauly JM,Conolly SM

更新日期：1987-02-01 00:00:00

abstract：:Some of the important features of how pulsatile flow generates artifacts in three-dimensional magnetic resonance imaging are analyzed and demonstrated. Time variations in the magnetic resonance signal during the heart cycle lead to more complex patterns of artifacts in 3D imaging than in 2D imaging. The appearance and...

journal_title：Magnetic resonance in medicine

authors： Frank LR,Buxton RB,Kerber CW

更新日期：1993-09-01 00:00:00

abstract：:The experiments reported herein are the first MRI investigations of the orientational dependence of T(2) relaxation in articular cartilage at microscopic resolution over the 360 degrees angular space. For each of six canine cartilage specimens, 48 independent T(2)-weighted proton images were acquired for 12 different ...

journal_title：Magnetic resonance in medicine

authors： Xia Y,Moody JB,Alhadlaq H

更新日期：2002-09-01 00:00:00

abstract：:Current implementations of coronary artery magnetic resonance angiography (MRA) suffer from limited coverage of the coronary arterial system. Whole-heart coronary MRA was implemented based on a free-breathing steady-state free-precession (SSFP) technique with magnetization preparation. The technique was compared to a ...

journal_title：Magnetic resonance in medicine

authors： Weber OM,Martin AJ,Higgins CB

更新日期：2003-12-01 00:00:00

abstract：:Imaging of stable paramagnetic spin probes in phantom objects and in vivo was evaluated using a RF time domain EPR spectrometer/imager operating at 300 MHz. Projections were collected using static magnetic field gradients and images were reconstructed using filtered back-projection techniques. Results from phantom obj...

journal_title：Magnetic resonance in medicine

authors： Afeworki M,van Dam GM,Devasahayam N,Murugesan R,Cook J,Coffin D,Larsen JH,Mitchell JB,Subramanian S,Krishna MC

更新日期：2000-03-01 00:00:00

abstract：PURPOSE:Magnetically labeled cells and tissue iron deposits provide qualitative means to detect and monitor cardiovascular and cerebrovascular diseases with magnetic resonance imaging. However, to quantitatively examine the extent of pathological micromorphological changes, detailed knowledge about microstructural para...

journal_title：Magnetic resonance in medicine

authors： Kurz FT,Kampf T,Heiland S,Bendszus M,Schlemmer HP,Ziener CH

更新日期：2014-05-01 00:00:00

abstract：:A type of local coil (or surface coil) for magnetic resonance imaging and spectroscopy is described in which two circular loops of the same diameter are disposed axially with respect to each other and in which counter rotating currents (CRC) are supported in the two loops. This type of coil has been used for localized...

journal_title：Magnetic resonance in medicine

authors： Froncisz W,Jesmanowicz A,Kneeland JB,Hyde JS

更新日期：1986-08-01 00:00:00

abstract：:We have noninvasively produced low-resolution, quantitative nuclear magnetic resonance images of cerebral blood flow in 2-ml voxels in eight cats. Typical signal-to-noise of 4 to 1 was obtained in cerebral voxels in 16.5-s epochs. Mean flow during normocapnia (paCO2 = 39 +/- 4 mm Hg) and hypercapnia (paCO2 = 62 +/- 4 ...

journal_title：Magnetic resonance in medicine

authors： Branch CA,Ewing JR,Helpern JA,Ordidge RJ,Butt S,Welch KM

更新日期：1992-11-01 00:00:00

abstract：:MR imaging experiments were conducted to investigate the feasibility of estimating vascular pulse pressure waveforms from measurements of blood flow rates and vessel cross-sectional area. Blood flow waveforms were measured in the aorta's of three 25-30-kg pigs at multiple imaging sections using phase-contrast velocity...

journal_title：Magnetic resonance in medicine

authors： Urchuk SN,Fremes SE,Plewes DB

更新日期：1997-08-01 00:00:00

abstract：:The use of phase correlation to detect rigid-body translational motion is reviewed and applied to individual echotrains in turbo-spin-echo data acquisition. It is shown that when the same echotrain is acquired twice, the subsampled correlation provides an array of delta-functions, from which the motion that occurred b...

journal_title：Magnetic resonance in medicine

authors： Mendes J,Kholmovski E,Parker DL

更新日期：2009-03-01 00:00:00

abstract：:Cerebral metabolite concentrations and water content were measured by means of localized proton magnetic resonance spectroscopy in 50 children, while metabolite peak ratios in short echo time spectra were evaluated in 173 examinations. Normative curves for normal development were established for two cerebral locations...

journal_title：Magnetic resonance in medicine

authors： Kreis R,Ernst T,Ross BD

更新日期：1993-10-01 00:00:00

abstract：:In this study, we report the use of a novel ultrashort echo time T(1)rhoT(1) sequence that combines a spin-lock preparation pulse with a two-dimensional ultrashort echo time sequence of a nominal echo time 8 microsec. The ultrashort echo time-T(1)rho sequence was employed to quantify T(1)rho in short T(2) tissues incl...

journal_title：Magnetic resonance in medicine

authors： Du J,Carl M,Diaz E,Takahashi A,Han E,Szeverenyi NM,Chung CB,Bydder GM

更新日期：2010-09-01 00:00:00

abstract：:The exponential clearance rate constant, (kappa), and filtration fraction (FF) have been measured for dialysis of Gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) (Magnevist, Berlex, Wayne, NJ) solutions by using a Look-Locker imaging technique under conditions of flow. The measured values of kappa for the Baxt...

journal_title：Magnetic resonance in medicine

authors： Niendorf ER,Santyr GE,Brazy PC,Grist TM

更新日期：1996-10-01 00:00:00

abstract：:Applications of fMRI in functional brain imaging are mainly confined to single subject designs, prohibiting the assessment of subject or group by condition interactions (i.e., differential activations) or areas of conjoint activation. In this paper a framework for fMRI group designs, using statistical parametric mappi...

journal_title：Magnetic resonance in medicine

authors： Büchel C,Turner R,Friston K

更新日期：1997-11-01 00:00:00

abstract：:Proton-electron double-resonance imaging (PEDRI) was used to assess renal function by monitoring the flow of the exogenous nitroxide free radical proxyl carboxylic acid (PCA) through normal and injured kidneys in the living rat. Kidney damage was induced by treatment with 2-bromoethylamine (BEA), which provides a well...

journal_title：Magnetic resonance in medicine

authors： Seimenis I,Foster MA,Lurie DJ,Hutchison JM,Whiting PH,Payne S

更新日期：1998-08-01 00:00:00

abstract：PURPOSE:A new method, called Transmit and Receive Patterns from Low-Tip-angle gradient-Echo Images (TRIPLET), is described which simultaneously maps the B1+ and B1- fields of a transmit/receive radiofrequency coil array. The input data are low-tip-angle gradient-echo images, which can be acquired in a relatively short ...

journal_title：Magnetic resonance in medicine

authors： Sbrizzi A,Raaijmakers AJ,Hoogduin H,Lagendijk JJ,Luijten PR,van den Berg CA

更新日期：2014-07-01 00:00:00

abstract：:Proteoglycan (PG) depletion-induced changes in T1rho (spin-lattice relaxation in rotating frame) relaxation and dispersion in articular cartilage were studied at 4T. Using a spin-lock cluster pre-encoded fast spin echo sequence, T1rho maps of healthy bovine specimens and specimens that were subjected to PG depletion w...

journal_title：Magnetic resonance in medicine

authors： Akella SV,Regatte RR,Gougoutas AJ,Borthakur A,Shapiro EM,Kneeland JB,Leigh JS,Reddy R

更新日期：2001-09-01 00:00:00

abstract：:Previous theoretical reports described the dependence of interpretation of the observed phase of the NMR signal on the time origin(s) of moment calculations and position's Taylor series expansion. This work provides experimental confirmation of predictions derived from that theory. For accelerative motion, experimenta...

journal_title：Magnetic resonance in medicine

authors： Duerk JL,Simonetti OP,Hurst GC,Finelli DA

更新日期：1994-07-01 00:00:00

abstract：:The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the m...

journal_title：Magnetic resonance in medicine

authors： Zheng S,Xia Y

更新日期：2010-01-01 00:00:00

abstract：:The equal-phase line (EPL) algorithm is proposed as a means of allowing rapid Fourier transform (FT) reconstruction of MR image data acquired on a non-Cartesian grid. The pixels on the image are grouped according to their positions. The pixels in a group have the same phase in the complex exponential function -exp[j2p...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Lin J,Jin D

更新日期：2002-06-01 00:00:00

abstract：PURPOSE:To determine the feasibility of employing the prior knowledge of well-separated chemical exchange saturation transfer (CEST) signals in the 9.4 T Z-spectrum to separate overlapping CEST signals acquired at 3 T, using a deep learning approach trained with 3 T and 9.4 T CEST spectral data from brains of the same ...

journal_title：Magnetic resonance in medicine

authors： Zaiss M,Deshmane A,Schuppert M,Herz K,Glang F,Ehses P,Lindig T,Bender B,Ernemann U,Scheffler K

更新日期：2019-06-01 00:00:00

abstract：:Human cardiac 31P nuclear magnetic resonance (NMR) spectra are usually quantified in relative terms, i.e., the ratio of metabolite signals is calculated. If 31P NMR spectroscopy of the heart is to emerge as a clinically relevant diagnostic modality, reliable quantification of absolute concentrations of 31P metabolites...

journal_title：Magnetic resonance in medicine

authors： Meininger M,Landschütz W,Beer M,Seyfarth T,Horn M,Pabst T,Haase A,Hahn D,Neubauer S,von Kienlin M

更新日期：1999-04-01 00:00:00

abstract：:A comparison between contrast and signal-to-noise ratio (SNR), as obtained by both maximum entropy (ME) and 2DFT reconstruction, is reported for NMR images. Our results show that in the ME elaboration the contrast and SNR are generally increased with respect to the 2DFT elaboration. The magnitude of such an increase d...

journal_title：Magnetic resonance in medicine

authors： De Simone BC,De Luca F,Maraviglia B

更新日期：1988-11-01 00:00:00

abstract：:Gliomas are the most common primary brain tumors and the majority are highly malignant, with one of the worst prognoses for patients. Gliomas are characterized by invasive growth into normal brain tissue that makes complete surgical resection and accurate radiotherapy planning extremely difficult. We have performed in...

journal_title：Magnetic resonance in medicine

authors： Wright AJ,Fellows G,Byrnes TJ,Opstad KS,McIntyre DJ,Griffiths JR,Bell BA,Clark CA,Barrick TR,Howe FA

更新日期：2009-12-01 00:00:00

abstract：PURPOSE:Magnetization transfer in white matter (WM) causes biexponential relaxation, but most quantitative T1 measurements fit data assuming monoexponential relaxation. The resulting monoexponential T1 estimate varies based on scan parameters and represents a source of variation between studies, especially at high fiel...

journal_title：Magnetic resonance in medicine

authors： Rioux JA,Levesque IR,Rutt BK

更新日期：2016-06-01 00:00:00

abstract：PURPOSE:Recent MRI studies have suggested that the magnetic susceptibility of white matter (WM) in the human brain is anisotropic, providing a new contrast mechanism for the visualization of fiber bundles and allowing the extraction of cellular compartment-specific information. This study provides an independent confir...

journal_title：Magnetic resonance in medicine

authors： van Gelderen P,Mandelkow H,de Zwart JA,Duyn JH

更新日期：2015-11-01 00:00:00

abstract：:Breathing motion is one of the main sources of artifacts in MRI acquisitions that can severely impair diagnosis. In MRI with continuously moving table, the application of common motion compensation approaches such as breath holding or the synchronization of the measurement with the breathing motion can be problematic....

journal_title：Magnetic resonance in medicine

authors： Honal M,Leupold J,Huff S,Baumann T,Ludwig U

更新日期：2010-03-01 00:00:00

abstract：:Dynamic susceptibility contrast (DSC) MRI is now increasingly used for measuring perfusion in many different applications. The quantification of DSC data requires the measurement of the arterial input function (AIF) and the deconvolution of the tissue concentration time curve. One of the most accepted deconvolution me...

journal_title：Magnetic resonance in medicine

authors： Calamante F,Gadian DG,Connelly A

更新日期：2000-09-01 00:00:00

abstract：PURPOSE:Conventional fat/water separation techniques require that patients hold breath during abdominal acquisitions, which often fails and limits the achievable spatial resolution and anatomic coverage. This work presents a novel approach for free-breathing volumetric fat/water separation. METHODS:Multiecho data are ...

journal_title：Magnetic resonance in medicine

authors： Benkert T,Feng L,Sodickson DK,Chandarana H,Block KT

更新日期：2017-08-01 00:00:00

abstract：:Coronary artery data acquisition with steady-state free precession (SSFP) is typically performed in a single frame in mid-diastole with a spectrally selective pulse to suppress epicardial fat signal. Data are acquired while the signal approaches steady state, which may lead to artifacts from the SSFP transient respons...

journal_title：Magnetic resonance in medicine

authors： Park J,Larson AC,Zhang Q,Simonetti O,Li D

更新日期：2005-10-01 00:00:00