abstract：:Formation of ternary complexes between Gd-DTPA, Gd-DTPA-BMA, and Gd-DOTA, used as contrast enhancement agents in MRI and the endogenously available carbonate and phosphate ions, has been demonstrated. The extent of ternary complex formation and its effect on the proton relaxation, measured at 9 MHz, rates is negligibl...

journal_title：Magnetic resonance in medicine

authors： Burai L,Hietapelto V,Király R,Tóth E,Brücher E

更新日期：1997-07-01 00:00:00

abstract：:The most widely-used functional magnetic resonance imaging (fMRI) technique is based on the blood oxygenation level dependent (BOLD) effect, which requires at least partial uncoupling between cerebral blood flow (CBF) and oxygen consumption changes during increased mental activity. To compare BOLD and CBF effects duri...

journal_title：Magnetic resonance in medicine

authors： Kim SG,Uğurbil K

更新日期：1997-07-01 00:00:00

abstract：:The guidance of minimally invasive procedures may become a very important future application of MRI. The guidance of interventions requires images of the anatomy as well as the information of the position of invasive devices used. This paper introduces continuous radial MRI for the simultaneous acquisition of the anat...

journal_title：Magnetic resonance in medicine

authors： Rasche V,Holz D,Köhler J,Proksa R,Röschmann P

更新日期：1997-06-01 00:00:00

abstract：:In vivo effective relaxation rates in normal rat liver were evaluated for four dextran coated iron oxide agents: monocrystalline iron oxide nanocolloid (MION) with a mean particle diameter of 3.9 nm, a polycrystalline agent (PION) with a larger mean diameter of 12 nm, and these two agents labeled with the asialofetuin...

journal_title：Magnetic resonance in medicine

authors： Mandeville JB,Moore J,Chesler DA,Garrido L,Weissleder R,Weisskoff RM

更新日期：1997-06-01 00:00:00

abstract：:A method for volume selective proton spectroscopy is presented based on a multiecho sequence with short refocusing interval tcp. It is demonstrated, that by appropriate choice of tcp on the order of 4-6 ms, signals from overlapping multiplets like the glutamine and glutamate (Glu/Gln) resonances in spectra of the huma...

journal_title：Magnetic resonance in medicine

authors： Hennig J,Thiel T,Speck O

更新日期：1997-06-01 00:00:00

abstract：:A current limitation of many myocardial tag acquisitions employing SPAMM encoding is the relatively rapid loss of tag contrast over the cardiac cycle. Acquisition schemes that apply line tags produce prolonged tag contrast compared with directly excited grid tags. However, a grid-tag series can be generated by combini...

journal_title：Magnetic resonance in medicine

authors： Doyle M,Walsh EG,Foster RE,Pohost GM

更新日期：1997-05-01 00:00:00

abstract：:A new model of compartmentalized relaxation--that which occurs for spins (protons) exchanging between compartments of different relaxation rates--is presented. This model generalizes previous ones by allowing spatially dependent relaxation within compartments. Solutions for the diffusion-Bloch equations are found via ...

journal_title：Magnetic resonance in medicine

authors： Barsky D,Pütz B,Schulten K

更新日期：1997-05-01 00:00:00

abstract：:Quantitative diffusion measurements were performed in tumors arising from inoculation of nude mice with two human breast cancer cell lines (MCF7 and T47D) to evaluate the specificity of this technique for characterizing solid tumors. ADC maps were compared to histology and correlated well with gross tumor morphology. ...

journal_title：Magnetic resonance in medicine

authors： Maier CF,Paran Y,Bendel P,Rutt BK,Degani H

更新日期：1997-04-01 00:00:00

abstract：:Measurements of the volume magnetic susceptibility of solids using the classical Gouy balance approach are hampered by variations in apparent density of the packed powder. In this paper a quantitative NMR measurement of the volume magnetic susceptibility of powdered solids is described and the volume susceptibility of...

journal_title：Magnetic resonance in medicine

authors： Hopkins JA,Wehrli FW

更新日期：1997-04-01 00:00:00

abstract：:Quantitative 1H MRS to determine cerebral metabolite patterns and MRI to determine CSF flow were applied to 12 patients with ventricular dilation-Group A, cortical atrophy (N = 5); or Group B, hydrocephalus (N = 7)- and in 9 normal controls. While mean brain water (Group A = 80% +/- 6; Group B = 86% +/- 5; normal = 85...

journal_title：Magnetic resonance in medicine

authors： Bluml S,McComb JG,Ross BD

更新日期：1997-03-01 00:00:00

abstract：:Short image acquisition times and sensitivity to magnetic susceptibility favor the use of gradient echo imaging methods in functional MRI (fMRI). However, magnetic susceptibility effects attributed to air-tissue interfaces also lead to severe signal loss in images of the large inferior frontal and lateral temporal cor...

journal_title：Magnetic resonance in medicine

authors： Yang QX,Dardzinski BJ,Li S,Eslinger PJ,Smith MB

更新日期：1997-03-01 00:00:00

abstract：:Three-dimensional magnetization-prepared (MP) MR angiography (MRA) was applied to the carotid and vertebral arteries by using ECG triggering, a slab selective RF inversion pulse, centric phase encoding and acquisition during diastole. Both theoretically and experimentally, the MP MRA sequence was shown to perform well...

journal_title：Magnetic resonance in medicine

authors： Wilman AH,Huston J 3rd,Riederer SJ

更新日期：1997-02-01 00:00:00

abstract：:It is demonstrated that the stability of the Carr-Purcell-Meiboom-Gill (CPMG) sequence reflects the existence of a steady state solution to the Bloch equations in the absence of T2 and T1 decay. The steady state theory is then used to evaluate the performance of low flip angle RARE imaging sequences with both constant...

journal_title：Magnetic resonance in medicine

authors： Alsop DC

更新日期：1997-02-01 00:00:00

abstract：:A cerebrospinal fluid (CSF)-suppressed flow-attenuated inversion recovery (FLAIR) double-shot diffusion echo-planar imaging (EPI) sequence was developed and used, along with a non-CSF-suppressed version of the sequence, to determine the extent of the contribution of CSF partial-volume averaging to the apparent diffusi...

journal_title：Magnetic resonance in medicine

authors： Falconer JC,Narayana PA

更新日期：1997-01-01 00:00:00

abstract：:Using a 32-echo imaging pulse sequence, T2 relaxation decay curves were acquired from five white- and six gray-matter brain structures outlined in 12 normal volunteers. The water contents of white and gray matter were 0.71 (0.01) and 0.83 (0.03) g/ml, respectively. All white-matter structures had significantly higher ...

journal_title：Magnetic resonance in medicine

authors： Whittall KP,MacKay AL,Graeb DA,Nugent RA,Li DK,Paty DW

更新日期：1997-01-01 00:00:00

abstract：:Magnetic resonance imaging allows numerous k-space sampling schemes such as cartesian, polar, spherical, and other non-rectilinear trajectories. Non-rectilinear MR acquisitions permit fast scan times and can suppress motion artifacts. Still, these sampling schemes may adversely affect the image characteristics due to ...

journal_title：Magnetic resonance in medicine

authors： Lauzon ML,Rutt BK

更新日期：1996-12-01 00:00:00

abstract：:Diffusion-weighted single voxel experiments conducted at b-values up to 1 x 10(4) smm-2 yielded biexponential signal attenuation curves for both normal and ischemic brain. The relative fractions of the rapidly and slowly decaying components (f1, f2) are f1 = 0.80 +/- 0.02, f2 = 0.17 +/- 0.02 in healthy adult rat brain...

journal_title：Magnetic resonance in medicine

authors： Niendorf T,Dijkhuizen RM,Norris DG,van Lookeren Campagne M,Nicolay K

更新日期：1996-12-01 00:00:00

abstract：:A robust postprocessing method to detect regions of magnetic field change is presented. High resolution gradient echo data is acquired to create a complex baseline image. From this image, two low resolution images are obtained by applying a low pass filter on the magnitude image and the complex image, respectively. Su...

journal_title：Magnetic resonance in medicine

authors： Lai S,Reichenbach JR,Haacke EM

更新日期：1996-11-01 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：:Functional MR imaging (fMRI) of activation in the brain is one of the more demanding applications required of an NMR imaging instrument. Since the signal changes in activation imaging are quite small, any instrumental variations can easily compromise the fMRI contrast. The authors describe a simple method for measurin...

journal_title：Magnetic resonance in medicine

authors： Weisskoff RM

更新日期：1996-10-01 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：:The accurate assessment of pulmonary perfusion is especially important in the evaluation of patients with suspected pulmonary embolism, a common and potentially lethal disorder that can be treated by aggressive anticoagulation. In this study, we demonstrate for the first time the use of MR to image pulmonary perfusion...

journal_title：Magnetic resonance in medicine

authors： Hatabu H,Gaa J,Kim D,Li W,Prasad PV,Edelman RR

更新日期：1996-10-01 00:00:00

abstract：:For clinical 31P MR spectroscopic imaging (MRSI) studies, where signal averaging is necessary, some improvement of sensitivity and spatial response function may be achieved by acquiring data over a spherical k-space volume and varying the number of averages acquired in proportion to the desired spatial filter. Eight d...

journal_title：Magnetic resonance in medicine

authors： Hugg JW,Maudsley AA,Weiner MW,Matson GB

更新日期：1996-09-01 00:00:00

abstract：:Optimal control theory has been applied in the past for the design of RF pulses for selective excitation. This was the outcome of having established the controllability of the MR spin system for the selective excitation problem. "Minimum distance" was the main formulation used for the solution. Because of their robust...

journal_title：Magnetic resonance in medicine

authors： Rosenfeld D,Zur Y

更新日期：1996-09-01 00:00:00

abstract：:The objective of this article was to analyze the accuracy and precision with which the quantitative distribution of articular cartilage can be determined in the knee joint using MRI. A three-dimensional (3D) technique that accounts for the out-of-plane deviation of the interface normal in strongly curved joint surface...

journal_title：Magnetic resonance in medicine

authors： Eckstein F,Gavazzeni A,Sittek H,Haubner M,Lösch A,Milz S,Englmeier KH,Schulte E,Putz R,Reiser M

更新日期：1996-08-01 00:00:00

abstract：:Hyperpolarized 129Xe has been used to obtain gas phase images of mouse lung in vivo, showing distinct ventilation variation as a function of the breathing cycle. Spectra of 129Xe in the thorax show complex structure in both the gas phase (-4 to 3 ppm) and tissue-dissolved (190-205 ppm) regions. The alveolar gas peak s...

journal_title：Magnetic resonance in medicine

authors： Wagshul ME,Button TM,Li HF,Liang Z,Springer CS,Zhong K,Wishnia A

更新日期：1996-08-01 00:00:00

abstract：:Algorithms to reliably detect motion in navigator echoes are crucial to many MRI motion suppression techniques. The accuracy of these algorithms is affected by noise and deformation of navigator echo profile caused by physiologic motion. This study compared the performance of algorithms based on correlation and least ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Grimm RC,Felmlee JP,Riederer SJ,Ehman RL

更新日期：1996-07-01 00:00:00

abstract：:To obtain a better understanding of the mechanisms underlying early changes in the brain water apparent diffusion coefficient (ADC) observed in cerebral ischemia, dynamic changes in the ADC of water and in the energy status were measured at postnatal day 8 or 9 in neonatal rat brains after cardiac arrest using 1H MRS/...

journal_title：Magnetic resonance in medicine

authors： van der Toorn A,Syková E,Dijkhuizen RM,Vorísek I,Vargová L,Skobisová E,van Lookeren Campagne M,Reese T,Nicolay K

更新日期：1996-07-01 00:00:00

abstract：:A modified high-speed stimulated-echo acquisition mode (STEAM) diffusion sequence (90 degrees-TE/2-90 degrees-TM-[alpha-TE/2-STE]n) incorporating bipolar diffusion gradients that are less sensitive to macroscopic motion-induced artifacts is presented. Diffusion encoding was performed only during the first echo interva...

journal_title：Magnetic resonance in medicine

authors： Yongbi MN,Ding S,Dunn JF

更新日期：1996-06-01 00:00:00

abstract：:If magnetic resonance spectroscopy (MRS) is to become a useful tool in clinical medicine, it will be necessary to find reliable methods for analyzing and classifying MRS data. Automated methods are desirable because they can remove user bias and can deal with large amounts of data, allowing the use of all the availabl...

journal_title：Magnetic resonance in medicine

authors： Tate AR,Watson D,Eglen S,Arvanitis TN,Thomas EL,Bell JD

更新日期：1996-06-01 00:00:00

abstract：:The application of T1 rho an an alternative contrast parameter in high-field magnetic resonance histology (MRH) has been investigated. Spectroscopic measurements of T1 rho were performed on 5.75% agar and 1.0 mM MnCI2 phantoms at 9.4 T to validate the accuracy of the imaging measurements. Image studies were performed ...

journal_title：Magnetic resonance in medicine

authors： Engelhardt RT,Johnson GA

更新日期：1996-05-01 00:00:00

abstract：:Proton spin relaxation rate constants in normal and hyponatremic rat brain were measured to determine the sensitivity of metabolite relaxation properties to cytotoxic edema and to quantify metabolite concentration in normal and edematous brain. Relaxation rate constants for protons of water and spectral regions with d...

journal_title：Magnetic resonance in medicine

authors： Rooney WD,Ebisu T,Mancuso A,Graham S,Weiner MW,Maudsley AA

更新日期：1996-05-01 00:00:00

abstract：:Phased-array coils distribute the high signal-to-noise ratio (SNR) performance of their small component surface coils over the larger area covered by the entire array. The inhomogeneous sensitivity profiles of the component surface coils result in images with very high signal near the phased-array and decreased signal...

journal_title：Magnetic resonance in medicine

authors： Murakami JW,Hayes CE,Weinberger E

更新日期：1996-04-01 00:00:00

abstract：:It is well known that when compared to conventional spin-echo (CSE) imaging for equivalent effective echo times, fast spin-echo (FSE) imaging experiments yield higher signal intensities for coupled spin systems, such as that for lipid. One hypothesis put forth for this phenomenon is the removal of scalar coupling-base...

journal_title：Magnetic resonance in medicine

authors： Williamson DS,Mulken RV,Jakab PD,Jolesz FA

更新日期：1996-04-01 00:00:00

abstract：:The magnetization subtraction technique (MS), which is equivalent to the inversion recovery technique in strong magnetic fields, has been implemented in dynamic nuclear polarization-enhanced magnetic resonance imaging (DNPI). The general theoretical basis of the MS method, which can be applied to DNPI or to prepolariz...

journal_title：Magnetic resonance in medicine

authors： Planinsic G,Grucker D,Stepisnik J

更新日期：1996-03-01 00:00:00

abstract：:Image contrast with gradient-recalled echo sequences (GRE) used for fMRI can have both blood oxygen level-dependent (BOLD) and inflow components, and the latter is often undesirable. A dual-echo technique can be used to differentiate these mechanisms, because modulation of signal from inflow is common to both echoes, ...

journal_title：Magnetic resonance in medicine

authors： Glover GH,Lemieux SK,Drangova M,Pauly JM

更新日期：1996-03-01 00:00:00

abstract：:The authors describe a method for accurate in vivo multislice imaging of the active component of the B1 field which is based on a previously proposed method, which uses the signal intensity ratio of two images measured with different excitation angles, and a repetition time TR 5 > or = 5 T1. The new method essentially...

journal_title：Magnetic resonance in medicine

authors： Stollberger R,Wach P

更新日期：1996-02-01 00:00:00

abstract：:The utility of a noninvasive steady state susceptibility-contrast MRI technique for continuous measurement of relative cerebral blood volume (rCBV) during global transient ischemia and subsequent hyperemia in a feline ischemia model is demonstrated. The measurements were obtained during a 10-min period of occlusion an...

journal_title：Magnetic resonance in medicine

authors： Hamberg LM,Boccalini P,Stranjalis G,Hunter GJ,Huang Z,Halpern E,Weisskoff RM,Moskowitz MA,Rosen BR

更新日期：1996-02-01 00:00:00

abstract：:An in vitro study was performed to investigate the effects of B(o) inhomogeneity on magnetic resonance images of flow. Controlled inhomogeneity gradients (Gi) were applied and the magnitude of the artifacts produced was quantified for different echo delay times (TE). Both steady and pulsatile flows were examined. In t...

journal_title：Magnetic resonance in medicine

authors： Drangova M,Pelc NJ

更新日期：1996-01-01 00:00:00

abstract：:The proton exchange rates between water and the hydroxyl protons of threonine, serine, tyrosine, the amino protons of lysine, and the guanidinium protons of arginine were measured in the pH range 0.5 to 8.5 and for the temperatures 4 degrees C, 10 degrees C, 20 degrees C, 30 degrees C, and 36 degrees C. The intrinsic ...

journal_title：Magnetic resonance in medicine

authors： Liepinsh E,Otting G

更新日期：1996-01-01 00:00:00