abstract：:The ultra-fast application of the RARE experiment is described in detail, with special emphasis on its multifarious applications with preparation experiments that produce transverse magnetization. The factors affecting the temporal evolution of the magnetization during the experiment are described, and the implication...

journal_title：Magnetic resonance in medicine

authors： Norris DG,Börnert P,Reese T,Leibfritz D

更新日期：1992-09-01 00:00:00

abstract：:The eigenimage filter was used to evaluate the results of a MRI study of cerebral ischemia in a rat model. This linear filter segments a desired feature in an image sequence from other features which may interfere with its observation. The animals were imaged temporally, after occlusion of the middle cerebral artery, ...

journal_title：Magnetic resonance in medicine

authors： Peck DJ,Spickler EM,Knight RA,Hearshen DO,Windham JP

更新日期：1992-08-01 00:00:00

abstract：:TOMROP is a multiple readout single inversion-recovery sequence which may potentially allow the measurement of multi-exponential T1 recoveries in vivo by NMR imaging. It is shown that several important modifications must be made to this sequence to permit T1 to be measured accurately and reliably. With these modificat...

journal_title：Magnetic resonance in medicine

authors： Gowland PA,Leach MO

更新日期：1992-07-01 00:00:00

abstract：:Velocity-encoded phase contrast imaging is being used increasingly in clinical imaging for quantization of blood flow. In this study, the accuracy and precision of ascending aorta flow measurements were found to depend on several subtle aspects of the scan prescription and image analysis. While the usual scan paramete...

journal_title：Magnetic resonance in medicine

authors： Buonocore MH,Bogren H

更新日期：1992-07-01 00:00:00

abstract：:31P NMR of superfused resting cartilage demonstrated the presence of phosphocreatine in chondrocytes. Changes in pH and in the NTP level were followed during carbon source starvation. From 31P spectra of perchloric acid extracts, phosphoethanolamine, phosphocholine, and the corresponding glycerol diesters were identif...

journal_title：Magnetic resonance in medicine

authors： Kvam BJ,Pollesello P,Vittur F,Paoletti S

更新日期：1992-06-01 00:00:00

abstract：:In order to determine if an increase in myocardial oxygen consumption is accompanied by changes in high energy phosphates in normal subjects and patients with dilated cardiomyopathy, phosphorus-31 spectra were acquired under resting conditions and during dobutamine infusion. In seven normal subjects, dobutamine raised...

journal_title：Magnetic resonance in medicine

authors： Schaefer S,Schwartz GG,Steinman SK,Meyerhoff DJ,Massie BM,Weiner MW

更新日期：1992-06-01 00:00:00

abstract：:The application of spectroscopy techniques to the study of normal and pathological tissue is currently limited by the difficulties of acquiring precisely localized spectra and analyzing the resulting, relatively low signal-to-noise data. Interpretation of multivoxel spectroscopy data is greatly facilitated by estimati...

journal_title：Magnetic resonance in medicine

authors： Nelson SJ,Vigneron DB,Brown TR

更新日期：1992-05-01 00:00:00

abstract：:Excitation by conventional B1 pulses in surface coil chemical-shift imaging experiments yields resonance intensities that vary greatly with position. B1-compensated semi-selective pulses overcome much of this problem. These pulses are employed for excitation and refocusing in 1H NMR spectroscopic localization in the i...

journal_title：Magnetic resonance in medicine

authors： Balschi JA,Hetherington HP,Pohost GM

更新日期：1992-05-01 00:00:00

abstract：:Transparent pulses are defined by the property of having no net effect on stationary spins, while selectively nutating and dephasing flowing spins. They are derived from the inverse scattering transform, a nonlinear extension of the inverse Fourier transform. They can be used as presaturation pulses to suppress select...

journal_title：Magnetic resonance in medicine

authors： Buonocore MH

更新日期：1992-04-01 00:00:00

abstract：:We developed a quantitative magnetic resonance imaging method to permit a rapid assessment of brain water content during osmotic brain edema produced by intraperitoneal (ip) injection of distilled water. Fifteen minutes after water injection, the normalized mean image intensity (MIn) from a spin-echo pulse sequence (T...

journal_title：Magnetic resonance in medicine

authors： Olson JE,Katz-Stein A,Reo NV,Jolesz FA

更新日期：1992-03-01 00:00:00

abstract：:Saline solutions of manganese ions (Mn2+) were used as articular contrast agents in magnetic resonance microscopy (9.4 T) of cartilage of chicken femoral condyles and pig temporomandibular joints. The diffusion of Mn2+ from the articular surface into the cartilage matrix led to a strong contrast enhancement in the car...

journal_title：Magnetic resonance in medicine

authors： Kusaka Y,Gründer W,Rumpel H,Dannhauer KH,Gersonde K

更新日期：1992-03-01 00:00:00

abstract：:A double-tuned single coil probe for high field metabolic NMR studies has been designed and tested. The resonant coil is a single-turn of copper foil wound on a quartz cylinder. It is fed by a short length of parallel strip line made of the same material; the feeder is also used as a tuning capacitance. Electrical par...

journal_title：Magnetic resonance in medicine

authors： Najim E,Grivet JP

更新日期：1992-02-01 00:00:00

abstract：:This paper describes a method for correcting the chemical-shift artifacts in 19F NMR imaging of perfluoroctylbromide emulsion (PFOB) by utilizing the two spectral peaks of PFOB which have a long T2 value in conjunction with the Dixon method. Corrected images are obtained from the magnitude of the measured images using...

journal_title：Magnetic resonance in medicine

authors： Lee HK,Nalcioglu O,Buxton RB

更新日期：1992-02-01 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：:A high frequency solution of the electromagnetic field produced by a circular surface coil adjacent to a homogeneous conducting, dielectric sphere is used to predict the attainable signal to noise ratio (S/N) and specific absorption rate (SAR) for in vivo 1H NMR spectroscopy experiments from 200 to 430 MHz (4.7-10 T)....

journal_title：Magnetic resonance in medicine

authors： Keltner JR,Carlson JW,Roos MS,Wong ST,Wong TL,Budinger TF

更新日期：1991-12-01 00:00:00

abstract：:Magnetic resonance (MR) can offer a unique window on the structure/function relationships in the brain, by utilizing the established link between tissue function, metabolism, and hemodynamics. This report focuses on recent applications of MR-based cerebral blood volume (CBV) imaging in humans. Our methodology uses hig...

journal_title：Magnetic resonance in medicine

authors： Rosen BR,Belliveau JW,Aronen HJ,Kennedy D,Buchbinder BR,Fischman A,Gruber M,Glas J,Weisskoff RM,Cohen MS

更新日期：1991-12-01 00:00:00

abstract：:This review reports data on the general and renal tolerance of the paramagnetic contrast agent Gd-DTPA after intravenous administration. Gd-DTPA was administered usually at a dose level of 0.1-0.2 mmol/kg body wt (range: 0.005-0.25 mmol/kg body wt) in cranial, spinal and body MR indications. In phase I-IIIa studies a ...

journal_title：Magnetic resonance in medicine

authors： Niendorf HP,Haustein J,Cornelius I,Alhassan A,Clauss W

更新日期：1991-12-01 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：:Introduction of a Gaussian weighting function into the phase encoding of the spin-echo imaging method via variable tip angle excitation, with concomitant optimization of the recycle delay, is shown to increase the sensitivity of T2-weighted imaging by up to 40%. In addition, the Gibbs artifact associated with sharp bo...

journal_title：Magnetic resonance in medicine

authors： Webb AG,Clarkson RB

更新日期：1991-10-01 00:00:00

abstract：:Fitting a model to an experimental spectrum is a difficult nonlinear estimation problem. The solution presented here is to start an iterative search procedure sufficiently close to the optimal model parameter set. This is achieved by providing tissue-dependent a priori peak information and by a novel correlation metho...

journal_title：Magnetic resonance in medicine

authors： Burger C,McKinnon G,Buchli R,Boesiger P

更新日期：1991-10-01 00:00:00

abstract：:In rapidly acquired gradient echo images, lipid regions usually appear as areas of high signal intensity. In 2D inflow angiograms processed by the maximum intensity projection algorithm, this high lipid signal may prevent angiographic visualization of some blood vessels. We present a new approach to suppress the lipid...

journal_title：Magnetic resonance in medicine

authors： Doyle M,Matsuda T,Pohost GM

更新日期：1991-09-01 00:00:00

abstract：:We applied diffusion-sensitive echo planar (Instascan) imaging to study thermal changes caused by a Nd:YAG laser. Images of phantom materials and normal rabbit brain tissue in vivo, acquired in 150 ms, every 2s, clearly showed the dynamics of temperature-related signal intensity changes in the regions irradiated by th...

journal_title：Magnetic resonance in medicine

authors： Bleier AR,Jolesz FA,Cohen MS,Weisskoff RM,Dalcanton JJ,Higuchi N,Feinberg DA,Rosen BR,McKinstry RC,Hushek SG

更新日期：1991-09-01 00:00:00

abstract：:A planar YBa2Cu3Ox (YBCO) coil has been used as a pick-up coil in a nuclear magnetic resonance imager. It was found that the quality factor (Q) of the YBCO coil was greater than its copper counterpart by approaching 50% even in a field of 0.15 T. The Q of the copper coil at 77 K and in a field of 0.15 T was 1200 while...

journal_title：Magnetic resonance in medicine

authors： Hall AS,Alford NM,Button TW,Gilderdale DJ,Gehring KA,Young IR

更新日期：1991-08-01 00:00:00

abstract：:The behavior of the lithium (Li) ion in normal human erythrocytes has been studied by 7Li NMR. The uptake of Li into the cells was followed as a function of solution conditions, temperature, hematocrit, and blood age using dysprosium tripolyphosphate shift reagent. Under our conditions the uptake of Li increases with ...

journal_title：Magnetic resonance in medicine

authors： Gullapalli RP,Hawk RM,Komoroski RA

更新日期：1991-08-01 00:00:00

abstract：:Calculations and experiments that provide support for our previously stated theorem are presented: If two coils simultaneously receiving magnetic resonance signals from the same anatomic region exhibit zero mutual inductance, there can be no correlation of the noise. It is shown that correlation does not exist even in...

journal_title：Magnetic resonance in medicine

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

更新日期：1991-07-01 00:00:00

abstract：:This contribution reports the first direct and noninvasive observation of cerebral glucose in normal anesthetized rats (n = 16) using short-echo-time localized proton NMR spectroscopy (2.35 T, STEAM, TR = 6000 ms, TE = 20 ms, 125 microliters). In addition to resonances from N-acetyl aspartate (NAA), glutamate, total c...

journal_title：Magnetic resonance in medicine

authors： Gyngell ML,Michaelis T,Hörstermann D,Bruhn H,Hänicke W,Merboldt KD,Frahm J

更新日期：1991-06-01 00:00:00

abstract：:The differential effects of high temperature on 9L rat gliosarcoma cells cultured in two distinctive forms, namely, anchored monolayer cells and multicellular spheroids, were investigated using 31P nuclear magnetic resonance spectroscopy. The critical temperatures resulting in irreversible changes in cellular energeti...

journal_title：Magnetic resonance in medicine

authors： Suzuki N,Kwee IL,Tamas LB,Nakada T

更新日期：1991-06-01 00:00:00

abstract：:In vivo echo-planar MR imaging was used to measure apparent diffusion coefficients (ADC) of cerebral tissues in a comprehensive noninvasive evaluation of early ischemic brain damage induced by occlusion of the middle cerebral artery (MCA) in a cat model of acute regional stroke. Within 10 min after arterial occlusion,...

journal_title：Magnetic resonance in medicine

authors： Kucharczyk J,Mintorovitch J,Asgari HS,Moseley M

更新日期：1991-06-01 00:00:00

abstract：:Assuming that the SSFP magnetization response maintains a steady state which is periodic in the presence of diffusion, we can solve for the diffusion effect in such sequences. Formulating a Fourier series decomposition solution to the Bloch-Torrey equation and imposing the steady-state condition, analytical expression...

journal_title：Magnetic resonance in medicine

authors： Carney CE,Wong ST,Patz S

更新日期：1991-06-01 00:00:00

abstract：:Volume-localized proton NMR spectroscopy was used to estimate bone marrow cellularity in the posterior iliac crests of patients undergoing treatment with hematopoietic growth factors for a variety of hematologic and neoplastic disorders. Twelve patients were accrued, six of whom were studied more than once, yielding a...

journal_title：Magnetic resonance in medicine

authors： Ballon D,Jakubowski A,Gabrilove J,Graham MC,Zakowski M,Sheridan C,Koutcher JA

更新日期：1991-05-01 00:00:00

abstract：:The properties of the image noise for selective averaging of phase-encoding lines have been investigated. For a given acquisition time, selective averaging results in a signal-to-noise ratio penalty compared to averaging all lines equally. In addition, selective averaging yields a non uniform distribution of noise cha...

journal_title：Magnetic resonance in medicine

authors： Mugler JP 3rd

更新日期：1991-05-01 00:00:00

abstract：:To enhance contrast between flow and static tissue, NMR projective angiographic methods usually require data subtraction, or alternatively the application of special data processing routines such as the "maximum intensity projection" algorithm. We have successfully developed a direct projection method which yields suf...

journal_title：Magnetic resonance in medicine

authors： Matsuda T,Doyle M,Pohost GM

更新日期：1991-04-01 00:00:00

abstract：:Paramagnetic ions complexed to proteins may lose, retain, or enhance solvent paramagnetic relaxation (SPR) relative to free solution. We measured T1 and T2 of three mouse cancers, their normal counterparts, and six additional tissues. Long T1 of cancers was not caused by necrosis or by different contents of water, fat...

journal_title：Magnetic resonance in medicine

authors： Negendank W,Corbett T,Crowley M,Kellogg C

更新日期：1991-04-01 00:00:00

abstract：:The sensitivity of diffusion-weighted MRI was compared to that of T2-weighted MRI following temporary middle cerebral artery occlusion (MCA-O) for 33 min followed by 4 h of reperfusion in rats. Diffusion-weighted spin-echo images using strong gradients (b value of 1413 s/mm2) demonstrated a significant increase in sig...

journal_title：Magnetic resonance in medicine

authors： Mintorovitch J,Moseley ME,Chileuitt L,Shimizu H,Cohen Y,Weinstein PR

更新日期：1991-03-01 00:00:00

abstract：:Trifluoroacetate and trifluoroacetamide, when added to a suspension of human red blood cells, give rise to separate 19F NMR signals from the intra- and extracellular species. This phenomenon has recently been exploited for measuring the membrane potential of erythrocytes. However, the separation of the peaks was incor...

journal_title：Magnetic resonance in medicine

authors： Xu AS,Potts JR,Kuchel PW

更新日期：1991-03-01 00:00:00

abstract：:Phosphorus NMR can measure myocardial tissue pH from the chemical shift of inorganic phosphate (Pi) in isolated buffer-perfused hearts, but in vivo the Pi peak originating from the myocardium is obscured by the resonance of 2,3-diphosphoglycerate (DPG) in the blood, making pH difficult to determine. Taking advantage o...

journal_title：Magnetic resonance in medicine

authors： Zahler R,Majumdar S,Frederick B,Laughlin M,Barrett E,Gore JC

更新日期：1991-02-01 00:00:00

abstract：:At TE values of 136 ms, it has recently been shown that the lactate methyl signal, when obtained with a stimulated-echo (STE) sequence, is modulated at the zero-quantum (ZQ) frequency when TM is varied. Here we describe an additional modulation of the ZQ lactate signal, due to spin-spin coupling, that results in a 10-...

journal_title：Magnetic resonance in medicine

authors： Sotak CH,Alger JR

更新日期：1991-02-01 00:00:00

abstract：:Leakage of Gd-DTPA through a defective blood-brain barrier is measured quantitatively using dynamic MRI scanning, in which repeated scans are made after a bolus injection. Image registration artifacts are minimized; a dose of 0.1 mM/kg and an IR sequence enable enhancement to be measured quantitatively. The triexponen...

journal_title：Magnetic resonance in medicine

authors： Tofts PS,Kermode AG

更新日期：1991-02-01 00:00:00

abstract：:Specialized receiver coils having a small sensitive region can provide an improvement in SNR for MR imaging and spectroscopy, at the expense of limiting the usable field of view. This work presents a technique for designing coil arrays that allows the size and location of the sensitive region to be selected remotely. ...

journal_title：Magnetic resonance in medicine

authors： Wright SM,Magin RL,Kelton JR

更新日期：1991-01-01 00:00:00

abstract：:NMRD profiles, the magnetic field dependence of the water proton longitudinal relaxation rates, have been acquired for two new diphosphonate-modified GdDTPA complexes currently under evaluation as relaxation agents for the MRI detection of soft-tissue calcifications. Fresh dilute solutions show profiles identical to t...

journal_title：Magnetic resonance in medicine

authors： Adzamli IK,Blau M

更新日期：1991-01-01 00:00:00