Off-resonance-dependent slice profile effects in balanced steady-state free precession imaging.

abstract：:A method is presented that improves the effectiveness of RF-spoiling whenever an image consists of the averaging of several identical single acquisitions. Using this method, it becomes possible to reduce the necessary moment of the spoiler gradient by a factor equal to the number of averages. The idea is to perform th...

journal_title：Magnetic resonance in medicine

authors： Leupold J,Hennig J

更新日期：2011-10-01 00:00:00

abstract：PURPOSE:Breath-holding is an established strategy for reducing motion artifacts in abdominal imaging. However, the breath-holding capabilities of patients are often overstrained by scans with large coverage and high resolution. In this work, a new strategy for coping with resulting incomplete breath-holds in abdominal ...

journal_title：Magnetic resonance in medicine

authors： Gdaniec N,Eggers H,Börnert P,Doneva M,Mertins A

更新日期：2014-05-01 00:00:00

abstract：:When deoxygenated, blood behaves as an effective susceptibility contrast agent. Changes in brain oxygenation can be monitored using gradient-echo echo-planar imaging. With this technique, difference images also demonstrate that blood oxygenation is increased during periods of recovery from respiratory challenge. ...

journal_title：Magnetic resonance in medicine

authors： Turner R,Le Bihan D,Moonen CT,Despres D,Frank J

更新日期：1991-11-01 00:00:00

abstract：:A partial saturation method is described for obtaining rapid images of tissue 1H spin-lattice relaxation rates following administration of the paramagnetic contrast agent gadolinium-diethylenetriaminepentaacetate. The paramagnetic contribution to the relaxation rates is proportional to the concentration of contrast ag...

journal_title：Magnetic resonance in medicine

authors： Kennedy SD,Szczepaniak LS,Gibson SL,Hilf R,Foster TH,Bryant RG

更新日期：1994-03-01 00:00:00

abstract：:Any number of coils can in principle be used simultaneously and independently in magnetic resonance imaging if the mutual inductances are sufficiently small. Surface coils and head or body coils have equal sensitivity at some crossover depth of the order of 6 to 10 cm. Using a 7.5-cm-diameter surface coil that was int...

journal_title：Magnetic resonance in medicine

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

更新日期：1988-02-01 00:00:00

abstract：:Metabolite signals with short T(1) or T(2) are difficult to localize with full sensitivity. This limitation was overcome with the development and implementation of a single-shot, complete three-dimensional "non-echo" localization method with reduced sensitivity to spatial B(1) variation, which is suitable for measurin...

journal_title：Magnetic resonance in medicine

authors： Choi IY,Tkác I,Gruetter R

更新日期：2000-09-01 00:00:00

abstract：:Healthy human brain diffusion anisotropy maps derived from standard spin echo diffusion tensor imaging (DTI) were compared with those using fluid-attenuated inversion recovery (FLAIR) preparation prior to DTI to null the signal from cerebrospinal fluid (CSF). Consistent comparisons entailed development of DTI postproc...

journal_title：Magnetic resonance in medicine

authors： Papadakis NG,Martin KM,Mustafa MH,Wilkinson ID,Griffiths PD,Huang CL,Woodruff PW

更新日期：2002-08-01 00:00:00

abstract：:Manganese is a useful contrast agent for MRI of animals. Previously, it has been shown that systemic doses of MnCl(2) provide unique contrast in the rodent brain, enabling visualization of neuroarchitecture. The present work investigates the dose and temporal dependence of brain enhancement after i.v. administration o...

journal_title：Magnetic resonance in medicine

authors： Lee JH,Silva AC,Merkle H,Koretsky AP

更新日期：2005-03-01 00:00:00

abstract：PURPOSE:To validate an automatic algorithm for offline T2* measurements, providing robust, vendor-independent T2*, and uncertainty estimates for iron load quantification in the heart and liver using clinically available imaging sequences. METHODS:A T2* region of interest (ROI)-based algorithm was developed for robustn...

journal_title：Magnetic resonance in medicine

authors： Bidhult S,Xanthis CG,Liljekvist LL,Greil G,Nagel E,Aletras AH,Heiberg E,Hedström E

更新日期：2016-04-01 00:00:00

abstract：PURPOSE:Magnetic resonance (MR) cholangiopancreatography (MRCP) is an established specialist method for imaging the upper abdomen and biliary/pancreatic ducts. Due to limitations of either MR image contrast or low through-plane resolution, patients may require further evaluation with contrast-enhanced computed tomograp...

journal_title：Magnetic resonance in medicine

authors： Ebner M,Patel PA,Atkinson D,Caselton L,Firmin L,Amin Z,Bainbridge A,De Coppi P,Taylor SA,Ourselin S,Chouhan MD,Vercauteren T

更新日期：2019-11-01 00:00:00

abstract：:Uncertainty regarding the intracellular/extracellular distribution of inorganic phosphate (P(i)) in tumors has raised concerns that pH calculated from the tumor P(i) chemical shift may not accurately represent the intracellular pH (pHin). This issue was addressed in subcutaneously transplanted murine radiation induced...

journal_title：Magnetic resonance in medicine

authors： Soto GE,Zhu Z,Evelhoch JL,Ackerman JJ

更新日期：1996-11-01 00:00:00

abstract：:Variations in T(1ρ) with locking-field strength (T(1ρ) dispersion) may be used to estimate proton exchange rates. We developed a novel approach utilizing the second derivative of the dispersion curve to measure exchange in a model system of cross-linked polyacrylamide gels. These gels were varied in relative compositi...

journal_title：Magnetic resonance in medicine

authors： Cobb JG,Xie J,Gore JC

更新日期：2011-12-01 00:00:00

abstract：:Hyperpolarized gases ((129)Xe and (3)He) are being used increasingly in both MRI and NMR spectroscopy studies. However, it has been shown that carrier agents are required to preserve the long relaxation times of gases in biological fluids. Optimized gas transport can be achieved through controlled T(1) and T(2) measur...

journal_title：Magnetic resonance in medicine

authors： Oregioni A,Parizel N,de Sousa PL,Grucker D

更新日期：2003-06-01 00:00:00

abstract：:In an effort to develop MRI methods for the evaluation of tumor angiogenesis (new blood vessel formation), MRI-derived cerebral blood volume (CBV) information has been compared to histologic measures of microvessel density (MVD). Although MVD is a standard marker of angiogenesis, it is not a direct correlate of the vo...

journal_title：Magnetic resonance in medicine

authors： Pathak AP,Schmainda KM,Ward BD,Linderman JR,Rebro KJ,Greene AS

更新日期：2001-10-01 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：PURPOSE:Previous studies have associated low pH in intervertebral discs (IVDs) with discogenic back pain. The purpose of this study was to determine whether quantitative CEST (qCEST) MRI can be used to detect pH changes in IVDs in vivo. METHODS:The exchange rate ksw between glycosaminoglycan (GAG) protons and water pr...

journal_title：Magnetic resonance in medicine

authors： Zhou Z,Bez M,Tawackoli W,Giaconi J,Sheyn D,de Mel S,Maya MM,Pressman BD,Gazit Z,Pelled G,Gazit D,Li D

更新日期：2016-12-01 00:00:00

abstract：PURPOSE:Anisotropic transverse R2 (1/T2 ) relaxation of water proton is sensitive to cartilage degenerative changes. The purpose is to develop an efficient method to extract this relaxation metric in clinical studies. METHODS:Anisotropic R2 can be measured inefficiently by standard R2 mapping after removing an isotrop...

journal_title：Magnetic resonance in medicine

authors： Pang Y,Palmieri-Smith RM,Malyarenko DI,Swanson SD,Chenevert TL

更新日期：2019-06-01 00:00:00

abstract：PURPOSE:The ultimate intrinsic signal-to-noise ratio (UISNR) is normally calculated using electrodynamic simulations with a complete basis of modes. Here, we provide an exact solution for the UISNR at the center of a dielectric sphere and assess how accurately this solution approximates UISNR away from the center. MET...

journal_title：Magnetic resonance in medicine

authors： Lee HH,Sodickson DK,Lattanzi R

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:The use of electromagnetic (EM) modeling is critical for specific absorption rate (SAR) characterization in parallel transmission MRI. Radiofrequency arrays that include decoupling networks can be difficult to characterize accurately in simulation. A practical method of simplifying modeling is to exclude the de...

journal_title：Magnetic resonance in medicine

authors： Beqiri A,Hand JW,Hajnal JV,Malik SJ

更新日期：2015-11-01 00:00:00

abstract：:A general analytical framework is presented for the design of birdcage radiofrequency resonators on cylindrical formers having arbitrary cross-sectional shape. The primary objective of such shapes would be to improve the sensitivity of the NMR experiment to noncircular regions of the human anatomy while maintaining fi...

journal_title：Magnetic resonance in medicine

authors： De Zanche N,Yahya A,Vermeulen FE,Allen PS

更新日期：2005-01-01 00:00:00

abstract：PURPOSE:We describe a 2 × 6 channel sodium/proton array for knee MRI at 3T. Multielement coil arrays are desirable because of well-known signal-to-noise ratio advantages over volume and single-element coils. However, low tissue-coil coupling that is characteristic of coils operating at low frequency can make the potent...

journal_title：Magnetic resonance in medicine

authors： Brown R,Lakshmanan K,Madelin G,Alon L,Chang G,Sodickson DK,Regatte RR,Wiggins GC

更新日期：2016-10-01 00:00:00

abstract：PURPOSE:Phosphorus spectroscopy (31 P-MRS) is a proven method to probe cardiac energetics. Studies typically report the phosphocreatine (PCr) to adenosine triphosphate (ATP) ratio. We focus on another 31 P signal: inorganic phosphate (Pi), whose chemical shift allows computation of myocardial pH, with Pi/PCr providing ...

journal_title：Magnetic resonance in medicine

authors： Apps A,Valkovič L,Peterzan M,Lau JYC,Hundertmark M,Clarke W,Tunnicliffe EM,Ellis J,Tyler DJ,Neubauer S,Rider OJ,Rodgers CT,Schmid AI

更新日期：2021-03-01 00:00:00

abstract：:Manganese-enhanced MRI has previously been used for visualization of brain architecture and functional mapping of neural pathways. The present work investigated the potential of manganese-enhanced MRI for noninvasive imaging of salivary glands in living subjects. Marked shortening of T(1) was observed in salivary glan...

journal_title：Magnetic resonance in medicine

authors： Seshadri M,Hoy A

更新日期：2010-09-01 00:00:00

abstract：:Continuously moving table (CMT) MRI is a new method that is capable of generating 3D, seamless, large field-of-view (FOV) images by acquiring readouts along the patient superior-inferior axis as the subject is translated through the scanner. For applications that require artifact-free images, such as arterial-phase co...

journal_title：Magnetic resonance in medicine

authors： Sabati M,Lauzon ML,Mahallati H,Frayne R

更新日期：2006-05-01 00:00:00

abstract：:A 3.0 Tesla, 0.80-m bore magnet replaced our previous 1.9 Tesla, 0.76-m magnet. The 3.0 Tesla replacement magnet had a dipole moment of 1.7 with respect to that of the 1.9 Tesla magnet. The pre-existing cylindrically symmetric passive steel shielding was modified to confine the fringe fields of the replacement magnet ...

journal_title：Magnetic resonance in medicine

authors： Ewing JR,Warner R,Helpern JA

更新日期：1993-03-01 00:00:00

abstract：:Cerebral blood volume changes with arterial carbon dioxide were monitored by proton T1-weighted MR images following administration of the intravascular contrast agent Gd-DTPA labeled with human serum albumin. Without MR contrast, no significant image intensity changes were observed with PaCO2. Following contrast, regi...

journal_title：Magnetic resonance in medicine

authors： Moseley ME,Chew WM,White DL,Kucharczyk J,Litt L,Derugin N,Dupon J,Brasch RC,Norman D

更新日期：1992-01-01 00:00:00

abstract：PURPOSE:Spatio-temporal encoding (SPEN) experiments can deliver single-scan MR images without folding complications and with robustness to chemical shift and susceptibility artifacts. Further resolution improvements are shown to arise by relying on multiple receivers, to interpolate the sampled data along the low-bandw...

journal_title：Magnetic resonance in medicine

authors： Liberman G,Solomon E,Lustig M,Frydman L

更新日期：2018-02-01 00:00:00

abstract：:A receive-only phased-array coil was designed to image the lower extremities. The array consists of four volume coils placed on two cylindrical formers. The coil array has the ability to image both legs simultaneously over a 40 cm longitudinal field of view (FOV). Experiments using phantoms show an increase in signal-...

journal_title：Magnetic resonance in medicine

authors： Brown R,Mareyam A,Reid E,Wang Y

更新日期：2004-03-01 00:00:00

abstract：:This paper describes a technique for characterizing the gradient subsystem of a magnetic resonance (MR) system. The technique uses a Fourier-transform analysis to directly measure the k-space trajectory produced by an arbitrary gradient waveform. In addition, the method can be easily extended to multiple dimensions an...

journal_title：Magnetic resonance in medicine

authors： Alley MT,Glover GH,Pelc NJ

更新日期：1998-04-01 00:00:00

abstract：:The role of relative cerebral blood volume (rCBV) in the early response of blood oxygenation level-dependent (BOLD) signal following sensory stimulation was assessed. Magnetic resonance imaging (MRI) measurements of rCBV and BOLD signal as a function of time (t) were compared with relative cerebral blood flow (rCBF) o...

journal_title：Magnetic resonance in medicine

authors： Marota JJ,Ayata C,Moskowitz MA,Weisskoff RM,Rosen BR,Mandeville JB

更新日期：1999-02-01 00:00:00