Iterative projection onto convex sets for quantitative susceptibility mapping.

abstract：:High-order radiofrequency transmitter coils are described that permit, in the context of NMR imaging, a knowledgeable trade-off between coil complexity and the degree of inhomogeneity over a specified volume of space. A mathematical formulation of high-order coils is developed for an axially symmetric polarizing dc fi...

journal_title：Magnetic resonance in medicine

authors： Sotgiu A,Hyde JS

更新日期：1986-02-01 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：:Simulations of dynamic susceptibility contrast (DSC) MRI are frequently performed by assuming a certain shape for the input function and the microvascular response function. However, to investigate the influence of parameters that will affect the shape of the input function, a more complex model of the human vasculatu...

journal_title：Magnetic resonance in medicine

authors： van Osch MJ,Vonken EJ,Wu O,Viergever MA,van der Grond J,Bakker CJ

更新日期：2003-09-01 00:00:00

abstract：:To achieve optimal image quality and highest spatial resolution for inner ear imaging with a 3D gradient echo sequence, it is necessary to minimize susceptibility dephasing effects by using very short TE. Fractional RF pulses and echoes can yield short TE for moderate spatial resolution; however, for voxel size of les...

journal_title：Magnetic resonance in medicine

authors： Ying K,Schmalbrock P,Clymer B

更新日期：1995-01-01 00:00:00

abstract：PURPOSE:To use quantitative susceptibility mapping (QSM) to investigate changes in cartilage canals in the distal femur of juvenile goats after their surgical transection. METHODS:Chondronecrosis was surgically induced in the right medial femoral condyles of four 4-day-old goats. Both the operated and control knees we...

journal_title：Magnetic resonance in medicine

authors： Wang L,Nissi MJ,Toth F,Johnson CP,Garwood M,Carlson CS,Ellermann J

更新日期：2017-03-01 00:00:00

abstract：:Nanostructured hydrogels have been developed as synthetic tissues and scaffolds for cell and drug delivery, and as guides for tissue regeneration. A fundamental problem in the development of synthetic hydrogels is that implanted gel structure is difficult to monitor noninvasively. This work demonstrates that the aggre...

journal_title：Magnetic resonance in medicine

authors： Colomb J,Louie K,Massia SP,Bennett KM

更新日期：2010-12-01 00:00:00

abstract：PURPOSE:To investigate Shift Undersampling improves Parametric mapping Efficiency and Resolution (SUPER), a novel blockwise curve-fitting method for accelerating parametric mapping with very fast reconstruction. METHODS:SUPER uses interleaved k-space undersampling, which enables a blockwise decomposition of the otherw...

journal_title：Magnetic resonance in medicine

authors： Hu C,Peters DC

更新日期：2019-06-01 00:00:00

abstract：:The authors addressed the hypothesis that interactions with creatine kinase (CK) play a role in the off-resonance magnetization transfer (MT) effect of creatine in skeletal muscle. Toward that aim, (1)H MT studies were done on hindleg muscle in wild-type mice and in transgenic mice, lacking cytoplasmic CK and/or mitoc...

journal_title：Magnetic resonance in medicine

authors： Kruiskamp MJ,van Vliet G,Nicolay K

更新日期：2000-05-01 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：:Perfusion imaging by arterial spin labeling (ASL) can be highly sensitive to the transit time from the labeling site to the tissue. We report the results of a study designed to separate the transit time and perfusion contributions to activation in ASL images accompanying motor and visual stimulation. Fractional transi...

journal_title：Magnetic resonance in medicine

authors： Gonzalez-At JB,Alsop DC,Detre JA

更新日期：2000-05-01 00:00:00

abstract：:The incorporation of RF coils into the tips of intravascular devices has been shown to enable the localization of catheters and guidewires under MR guidance. Furthermore, such coils can be used for endoluminal imaging. The long cable required to connect the coil with the scanner input inadvertently acts as a dipole an...

journal_title：Magnetic resonance in medicine

authors： Ladd ME,Quick HH

更新日期：2000-04-01 00:00:00

abstract：:Several methods have been proposed for overcoming the effects of radiofrequency (RF) magnetic field inhomogeneity in high-field MRI. Some of these methods rely at least in part on the ability to independently control magnitude and phase of different drives in either one multielement RF coil or in different RF coils in...

journal_title：Magnetic resonance in medicine

authors： Mao W,Smith MB,Collins CM

更新日期：2006-10-01 00:00:00

abstract：PURPOSE:Head motion continues to be a major source of artifacts and data quality degradation in MRI. The goal of this work was to develop and demonstrate a novel technique for prospective, 6 degrees of freedom (6DOF) rigid body motion estimation and real-time motion correction using inductively coupled wireless nuclear...

journal_title：Magnetic resonance in medicine

authors： Sengupta S,Tadanki S,Gore JC,Welch EB

更新日期：2014-10-01 00:00:00

abstract：:Recovery of the cerebral cortex after 10 min of cardiac arrest was studied in rat using noninvasive MRI techniques. The apparent diffusion coefficient (ADC) of brain water was imaged to document reversal of the metabolic impairment. Perfusion-weighted imaging and blood oxygen level dependent (BOLD) imaging were perfor...

journal_title：Magnetic resonance in medicine

authors： Schmitz B,Bock C,Hoehn-Berlage M,Kerskens CM,Böttiger BW,Hossmann KA

更新日期：1998-05-01 00:00:00

abstract：:Parallel imaging presents a promising approach for MRI of hyperpolarized nuclei, as the penalty in signal-to-noise ratio typically encountered with (1)H MRI due to a reduction in acquisition time can be offset by an increase in flip angle. The signal-to-noise ratio of hyperpolarized MRI generally exhibits a strong dep...

journal_title：Magnetic resonance in medicine

authors： Deppe MH,Parra-Robles J,Marshall H,Lanz T,Wild JM

更新日期：2011-12-01 00:00:00

abstract：PURPOSE:To investigate the heating induced by (pseudo)-continuous arterial spin labeling ((p)CASL) sequences in vivo at 9.4T and to evaluate the benefit of a dedicated labeling coil. METHODS:Temperature was measured continuously in the brain, neck, and rectum of 9 rats with fiber-optic temperature probes while running...

journal_title：Magnetic resonance in medicine

authors： Hirschler L,Collomb N,Voiron J,Köhler S,Barbier EL,Warnking JM

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:Continuously moving table (CMT) MRI is a high throughput technique that has multiple applications in whole-body imaging. In this work, CMT MRI based on golden angle (GA, 111.246° azimuthal step) radial sampling is developed at 3 Tesla (T), with the goal of increased flexibility in image reconstruction using arb...

journal_title：Magnetic resonance in medicine

authors： Sengupta S,Smith DS,Welch EB

更新日期：2015-12-01 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：:High-resolution turbo spin echo (TSE) images have demonstrated important details of carotid artery morphology; however, it is evident that pulsatile blood and wall motion related to the cardiac cycle are still significant sources of image degradation. Although ECG gating can reduce artifacts due to cardiac-induced pul...

journal_title：Magnetic resonance in medicine

authors： Mendes J,Parker DL,Hulet J,Treiman GS,Kim SE

更新日期：2011-11-01 00:00:00

abstract：PURPOSE:Intracranial and intraspinal compliance are parameters of interest in the diagnosis and prediction of treatment outcome in patients with normal pressure hydrocephalus and other forms of communicating hydrocephalus. A noninvasive method to estimate the spinal cerebrospinal fluid (CSF) pulse wave velocity (PWV) a...

journal_title：Magnetic resonance in medicine

authors： Sonnabend K,Brinker G,Maintz D,Bunck AC,Weiss K

更新日期：2021-01-01 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：:In some dynamic applications of MRI, only a part of the field-of-view (FOV) actually undergoes dynamic changes. A class of methods, called reduced-FOV (rFOV) methods, convert the knowledge that some part of the FOV is static or not very dynamic into an increase in temporal resolution for the dynamic part, or into a re...

journal_title：Magnetic resonance in medicine

authors： Madore B,Fredrickson JO,Alley MT,Pelc NJ

更新日期：2000-04-01 00:00:00

abstract：:Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstruct...

journal_title：Magnetic resonance in medicine

authors： Lin FH

更新日期：2013-07-01 00:00:00

abstract：PURPOSE:Dynamic glucose-enhanced (DGE)-MRI based on chemical exchange-sensitive MRI, that is, glucoCEST and gluco-chemical exchange-sensitive spin-lock (glucoCESL), is intrinsically prone to motion-induced artifacts because the final DGE contrast relies on the difference of images, which were acquired with a time gap o...

journal_title：Magnetic resonance in medicine

authors： Boyd PS,Breitling J,Zimmermann F,Korzowski A,Zaiss M,Schuenke P,Weinfurtner N,Schlemmer HP,Ladd ME,Bachert P,Paech D,Goerke S

更新日期：2020-07-01 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：:Certain kinds of artifacts have been reported when projection reconstruction (PR) techniques are used in magnetic resonance imaging (MRI). These will occur if the spacing between samples in k-space is too large. It has been suggested that PR requires finer k-space sampling than does two-dimensional Fourier reconstruct...

journal_title：Magnetic resonance in medicine

authors： Joseph PM

更新日期：1998-09-01 00:00:00

abstract：PURPOSE:To perform quantitative susceptibility mapping (QSM) in negligible acquisition time and apply it to measuring iron-rich subcortical gray matter. METHODS:Whole brain QSM was performed using single-shot gradient echo-planar imaging (EPI) in under 7 seconds on a standard 1.5 T system for imaging brain iron in sub...

journal_title：Magnetic resonance in medicine

authors： Sun H,Wilman AH

更新日期：2015-05-01 00:00:00

abstract：:Dynamic contrast-enhanced (DCE-) MRI is often used to evaluate the response to experimental antiangiogenic therapies in small animal models of cancer. Unfortunately, DCE-MRI studies often require a substantial investment of both time and money to achieve the desired level of statistical significance. Multiple-mouse MR...

journal_title：Magnetic resonance in medicine

authors： Ramirez MS,Ragan DK,Kundra V,Bankson JA

更新日期：2007-09-01 00:00:00

abstract：:A stimulated echo sequence was used to obtain 19F NMR spectra from within a 4-ml voxel in a cat brain. The time dependence of the 19F NMR signal from an inert gas (CHF3) was used to calculate the blood flow in the voxel. The position of the voxel was selected using a 1H MR image. ...

journal_title：Magnetic resonance in medicine

authors： van Zijl PC,Ligeti L,Sinnwell T,Alger JR,Chesnick AS,Moonen CT,McLaughlin AC

更新日期：1990-12-01 00:00:00

abstract：:The goal of this work was to develop and evaluate a numerically optimized inversion pulse to be used with a homonuclear editing sequence to measure human cerebral GABA in vivo at 4.1 T in the occipital lobe. The optimized pulse was constructed using pallindromic symmetry with 30 pulses and 29 delays. The optimized pul...

journal_title：Magnetic resonance in medicine

authors： Hetherington HP,Newcomer BR,Pan JW

更新日期：1998-01-01 00:00:00