Analysis and correction of motion artifacts in diffusion weighted imaging.

abstract：:Diffusion-weighted MRI is a clinically useful technique, but its utility is compromised by high sensitivity to patient motion. Use of radial-scan data acquisition and projection reconstruction, rather than the conventional Fourier imaging method, can substantially reduce the sensitivity to global translational motion ...

journal_title：Magnetic resonance in medicine

authors： Gmitro AF,Alexander AL

更新日期：1993-06-01 00:00:00

abstract：:Activity-induced manganese-dependent contrast (AIM) MRI is a hemodynamic-independent functional MRI method that used manganese ion as an MR-detectable contrast agent. In AIM, MnCl(2) is infused intra-arterially after the blood-brain barrier (BBB) is opened with a hyperosmolar agent. Upon functional stimulation of the ...

journal_title：Magnetic resonance in medicine

authors： Aoki I,Tanaka C,Takegami T,Ebisu T,Umeda M,Fukunaga M,Fukuda K,Silva AC,Koretsky AP,Naruse S

更新日期：2002-12-01 00:00:00

abstract：PURPOSE:T2 -relaxation-under-spin-tagging (TRUST) is an MR technique for the non-invasive assessment of whole-brain cerebral oxygen extraction fraction (OEF), through measurement of the venous blood T2 relaxation time in the sagittal sinus. A key limitation of TRUST, however, is the lack of spatial specificity of the m...

journal_title：Magnetic resonance in medicine

authors： O'Brien C,Okell TW,Chiew M,Jezzard P

更新日期：2019-10-01 00:00:00

abstract：:With the advent of breath-hold MR cardiac imaging techniques, the minimization of TR and TE for oblique planes has become a critical issue. The slew rates and maximum currents of gradient amplifiers limit the minimum possible TR and TE by adding dead-periods to the pulse sequences. We propose a method of designing gra...

journal_title：Magnetic resonance in medicine

authors： Atalar E,McVeigh ER

更新日期：1994-12-01 00:00:00

abstract：:This study aims to assess whether an alternative method, that is based on volumetric surface detection (VoSD) without tracing and is totally free of geometric assumptions, can improve the reproducibility of right ventricular (RV) volume quantification from cardiac magnetic resonance (CMR) images, in comparison with a ...

journal_title：Magnetic resonance in medicine

authors： Catalano O,Corsi C,Antonaci S,Moro G,Mussida M,Frascaroli M,Baldi M,Caiani E,Lamberti C,Cobelli F

更新日期：2007-03-01 00:00:00

abstract：:The design of a piezoelectric-controlled trimmer capacitor and its use as a tuning element of an MRI surface coil at 63.8 MHz are described. It is found that image quality does not depend strongly on match of the coil to the transmission line but that tuning can be a significant factor. The work is intended to lead ev...

journal_title：Magnetic resonance in medicine

authors： Hyde JS,Rilling RJ,Jesmanowicz A,Kneeland JB

更新日期：1989-10-01 00:00:00

abstract：PURPOSE:To significantly reduce the background phase effects, especially at the air-tissue interface, and to enhance the desirable local structures of veins in susceptibility-weighted imaging. METHODS:In the proposed reconstruction method called Magnitude of Complex Filtering, a complex-valued magnetic resonance image...

journal_title：Magnetic resonance in medicine

authors： Lee Y,Han Y,Park H

更新日期：2014-03-01 00:00:00

abstract：:Radial MRI sequences are frequently used to obtain images with reduced sensitivity to motion. To decrease imaging time, multiple spin-echo acquisitions can be incorporated into radial sequences. In this case, different radial lines of Fourier data have different TE times and the resulting images can contain streaking ...

journal_title：Magnetic resonance in medicine

authors： Theilmann RJ,Gmitro AF,Altbach MI,Trouard TP

更新日期：2004-04-01 00:00:00

abstract：:Adipose tissue as well as other depots of fat (triglycerides) are increasingly being recognized as active contributors to the human function and metabolism. In addition to the fat concentration, also the fatty acid chemical composition (FAC) of the triglyceride molecules may play an important part in diseases such as ...

journal_title：Magnetic resonance in medicine

authors： Peterson P,Trinh L,Månsson S

更新日期：2021-01-01 00:00:00

abstract：PURPOSE:To improve the imaging quality of vessel walls with an endoesophageal Wireless Amplified NMR Detector (WAND). METHODS:A cylindrically shaped double-frequency resonator has been constructed with a single metal wire that is self-connected by a pair of nonlinear capacitors. The double-frequency resonator can conv...

journal_title：Magnetic resonance in medicine

authors： Zeng X,Barbic M,Chen L,Qian C

更新日期：2017-11-01 00:00:00

abstract：:Endogenous glucose production (EGP), gluconeogenic and glycogenolytic fluxes by analysis of a single (2)H-NMR spectrum is demonstrated with 6-hr and 24-hr fasted rats. Animals were administered [1-(2)H, 1-(13)C]glucose, a novel tracer of glucose turnover, and (2)H(2)O. Plasma glucose enrichment from both tracers was q...

journal_title：Magnetic resonance in medicine

authors： Nunes PM,Jones JG

更新日期：2009-09-01 00:00:00

abstract：:Designing multidimensional radiofrequency pulses for clinical application must take into account the local specific absorption rate (SAR) as controlling the global SAR does not guarantee suppression of hot spots. The maximum peak SAR, averaged over an N grams cube (local NgSAR), must be kept under certain safety limit...

journal_title：Magnetic resonance in medicine

authors： Sbrizzi A,Hoogduin H,Lagendijk JJ,Luijten P,Sleijpen GL,van den Berg CA

更新日期：2012-03-01 00:00:00

abstract：:In this study, the precision and accuracy of a new method for measuring axial rotations of the lumbar vertebrae, which are thought to be increased in patients with degenerative spinal instability, were estimated. A standard image registration algorithm involving a user-selected center of rotation was adapted for this ...

journal_title：Magnetic resonance in medicine

authors： Rogers BP,Haughton VM,Arfanakis K,Meyerand ME

更新日期：2002-12-01 00:00:00

abstract：PURPOSE:Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. THEORY AND METHODS:Two d...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Sadeghi A,Atalar E

更新日期：2018-07-01 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：PURPOSE:To design hyperbolic secant (HS) excitation pulses to reduce signal dropout in the orbitofrontal and inferior temporal regions in gradient-echo echo-planar imaging (GE-EPI) for functional MRI (fMRI) applications. METHODS:An algorithm based on Bloch simulations optimizes the HS pulse parameters needed to give t...

journal_title：Magnetic resonance in medicine

authors： Wastling SJ,Barker GJ

更新日期：2015-09-01 00:00:00

abstract：:Myocardial MR first-pass perfusion time courses are contaminated by signals from the ventricles (spillover) as a consequence of partial volume effects and motion. An early increase in the signal intensity from the myocardium is an indicator of contamination. This contamination leads to under- or overestimation of perf...

journal_title：Magnetic resonance in medicine

authors： Köstler H,Ritter C,Reiss-Zimmermann M,Beer M,Hahn D,Sandstede J

更新日期：2004-04-01 00:00:00

abstract：:The concept of temporal echo multiplexing is defined and used to develop rapid biphasic spin-echo sequences for imaging the heart. Three imaging sequences, based on four-echo and two-echo multiplexing and rapid single echo (i.e., conventional spin-echo imaging), are compared. Preliminary results indicate that two-echo...

journal_title：Magnetic resonance in medicine

authors： Parker DL,Caputo GR,Frederick PR

更新日期：1989-07-01 00:00:00

abstract：PURPOSE:To present and validate a new method that formalizes a direct link between k-space and wavelet domains to apply separate undersampling and reconstruction for high- and low-spatial-frequency k-space data. THEORY AND METHODS:High- and low-spatial-frequency regions are defined in k-space based on the separation o...

journal_title：Magnetic resonance in medicine

authors： Sung K,Hargreaves BA

更新日期：2013-11-01 00:00:00

abstract：PURPOSE:To accelerate dynamic MR applications using infimal convolution of total generalized variation functionals (ICTGV) as spatio-temporal regularization for image reconstruction. THEORY AND METHODS:ICTGV comprises a new image prior tailored to dynamic data that achieves regularization via optimal local balancing b...

journal_title：Magnetic resonance in medicine

authors： Schloegl M,Holler M,Schwarzl A,Bredies K,Stollberger R

更新日期：2017-07-01 00:00:00

abstract：PURPOSE:The goal of this work was to detect disease-related microstructural changes to the liver using magnetic resonance imaging. Chronic liver disease can cause microstructural changes in the liver that reduce plasma access to the perisinusoidal space--the site of exchange between the blood plasma and the hepatic par...

journal_title：Magnetic resonance in medicine

authors： Beeman SC,Mandarino LJ,Georges JF,Bennett KM

更新日期：2013-12-01 00:00:00

abstract：:Motion-sensitive phase contrast magnetic resonance imaging and magnetic resonance elastography are applied for the measurement of volumetric strain and tissue compressibility in human brain. Volumetric strain calculated by the divergence operator using a biphasic effective-medium model is related to dilatation and com...

journal_title：Magnetic resonance in medicine

authors： Hirsch S,Klatt D,Freimann F,Scheel M,Braun J,Sack I

更新日期：2013-09-01 00:00:00

abstract：:The accuracy of the outcome in a diffusion tensor imaging (DTI) experiment depends on the acquisition scheme as well as the postprocessing methods used. In the present study, the DTI results acquired after applying different combinations of diffusion-weighted (DW) gradient orientations were initially compared. Then, s...

journal_title：Magnetic resonance in medicine

authors： Arfanakis K,Cordes D,Haughton VM,Carew JD,Meyerand ME

更新日期：2002-02-01 00:00:00

abstract：:A multimodal MR study including relaxometry, diffusion tensor imaging (DTI), and MR spectroscopy was performed on patients with classical phenylketonuria (PKU) and matched controls, to improve our understanding of white matter (WM) lesions. Relaxometry yields information on myelin loss or malformation and may substant...

journal_title：Magnetic resonance in medicine

authors： Vermathen P,Robert-Tissot L,Pietz J,Lutz T,Boesch C,Kreis R

更新日期：2007-12-01 00:00:00

abstract：:Diffusion tensor imaging is gaining increasing importance for anatomical imaging of the developing mouse brain. However, the application of diffusion tensor imaging to mouse brain imaging at microscopic levels is hindered by the limitation on achievable spatial resolution. In this study, fast diffusion tensor microima...

journal_title：Magnetic resonance in medicine

authors： Aggarwal M,Mori S,Shimogori T,Blackshaw S,Zhang J

更新日期：2010-07-01 00:00:00

abstract：:A reproducibility study of proton MR spectroscopic imaging ((1)H-MRSI) of the human brain was conducted to evaluate the reliability of an automated 3D in vivo spectroscopic imaging acquisition and associated quantification algorithm. A PRESS-based pulse sequence was implemented using dualband spectral-spatial RF pulse...

journal_title：Magnetic resonance in medicine

authors： Gu M,Kim DH,Mayer D,Sullivan EV,Pfefferbaum A,Spielman DM

更新日期：2008-09-01 00:00:00

abstract：PURPOSE:We aim to leverage the power of deep-learning with high-fidelity training data to improve the reliability and processing speed of hemodynamic mapping with MR fingerprinting (MRF) arterial spin labeling (ASL). METHODS:A total of 15 healthy subjects were studied on a 3T MRI. Each subject underwent 10 runs of a m...

journal_title：Magnetic resonance in medicine

authors： Fan H,Su P,Huang J,Liu P,Lu H

更新日期：2021-04-01 00:00:00

abstract：PURPOSE:The purpose of this project was to construct a physical brain phantom for MRI, mimicking structure and T1 relaxation properties of white matter (WM) and gray matter (GM). METHODS:The phantom design comprised 2 compartments, 1 resembling the WM and 1 resembling the GM. Their T1 relaxation times, as assessed usi...

journal_title：Magnetic resonance in medicine

authors： Altermatt A,Santini F,Deligianni X,Magon S,Sprenger T,Kappos L,Cattin P,Wuerfel J,Gaetano L

更新日期：2019-02-01 00:00:00

abstract：:Although promising for visualizing the structure of ordered tissues, MR diffusion tensor imaging (DTI) has been hampered by long acquisition time and low spatial resolution associated with its inherently low signal-to-noise ratio (SNR). Moreover, the uncertainty in the DTI measurements has a direct impact on the accur...

journal_title：Magnetic resonance in medicine

authors： Chen B,Hsu EW

更新日期：2005-08-01 00:00:00

abstract：:Chemical shift imaging benefits from signal-to-noise ratio (SNR) and chemical shift dispersion increases at stronger main field such as 7 Tesla, but the associated shorter radiofrequency (RF) wavelengths encountered require B1+ mitigation over both the spatial field of view (FOV) and a specified spectral bandwidth. Th...

journal_title：Magnetic resonance in medicine

authors： Setsompop K,Alagappan V,Gagoski BA,Potthast A,Hebrank F,Fontius U,Schmitt F,Wald LL,Adalsteinsson E

更新日期：2009-02-01 00:00:00