Motion-adaptive spatio-temporal regularization for accelerated dynamic MRI.

abstract：:The radial trajectory has found applications in cardiac imaging because of its resilience to undersampling and motion artifacts. Recent work has shown that interleaved and weighted radial imaging can produce images with multiple contrasts from a single data set. This feature was investigated for inversion recovery ima...

journal_title：Magnetic resonance in medicine

authors： Peters DC,Botnar RM,Kissinger KV,Yeon SB,Appelbaum EA,Manning WJ

更新日期：2006-05-01 00:00:00

abstract：:A restricted field of view (rFOV) approach for imaging a dynamic time series of volumes of limited spatial extent within a larger subject is described. The shorter readout with rFOV-MRI can be exploited to either limit image artifacts or increase spatial resolution. To accomplish rFOV imaging of a multislice volume fo...

journal_title：Magnetic resonance in medicine

authors： Pisani L,Bammer R,Glover G

更新日期：2007-02-01 00:00:00

abstract：:Parallel magnetic resonance imaging in k-space such as generalized auto-calibrating partially parallel acquisition exploits spatial correlation among neighboring signals over multiple coils in calibration to estimate missing signals in reconstruction. It is often challenging to achieve accurate calibration information...

journal_title：Magnetic resonance in medicine

authors： Park S,Park J

更新日期：2012-06-01 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：PURPOSE:High angular resolution diffusion imaging (HARDI) is a well-established method to help reveal the architecture of nerve bundles, but long scan times and geometric distortions inherent to echo planar imaging (EPI) have limited its integration into clinical protocols. METHODS:A fast imaging method is proposed he...

journal_title：Magnetic resonance in medicine

authors： Chao TC,Chiou JG,Maier SE,Madore B

更新日期：2017-02-01 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：:Minimally invasive cardiac surgery requires arresting and emptying of the heart, which compromises visualization of the surgical field. In this feasibility study a novel surgical procedure is demonstrated in which real-time MRI is used to guide the placement of a prosthetic aortic valve in the beating heart via direct...

journal_title：Magnetic resonance in medicine

authors： McVeigh ER,Guttman MA,Lederman RJ,Li M,Kocaturk O,Hunt T,Kozlov S,Horvath KA

更新日期：2006-11-01 00:00:00

abstract：PURPOSE:Spectrally selective "prewinding" radiofrequency pulses can counteract B0 inhomogeneity in steady-state sequences, but can only prephase a limited range of off-resonance. We propose spectral-spatial small-tip angle prewinding pulses that increase the off-resonance bandwidth that can be successfully prephased by...

journal_title：Magnetic resonance in medicine

authors： Williams SN,Nielsen JF,Fessler JA,Noll DC

更新日期：2018-03-01 00:00:00

abstract：:Signal-to-noise ratio (SNR) is a major challenge to sodium magnetic resonance imaging. Phased array coils have been shown significantly improving SNR in proton imaging over volume coils. This study investigates SNR advantage of a 15-channel array head coil (birdcage volume coil for transmit/receive and 15-channel arra...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Zhao T,Wiggins GC,Wald LL,Zheng H,Weimer J,Boada FE

更新日期：2012-12-01 00:00:00

abstract：:This study demonstrates the feasibility of applying free-breathing, cardiac-gated, susceptibility-weighted fast spin-echo imaging together with black blood preparation and navigator-gated respiratory motion compensation for anatomically accurate T2* mapping of the heart. First, T2* maps are presented for oil phantoms ...

journal_title：Magnetic resonance in medicine

authors： Heinrichs U,Utting JF,Frauenrath T,Hezel F,Krombach GA,Hodenius MA,Kozerke S,Niendorf T

更新日期：2009-09-01 00:00:00

abstract：PURPOSE:Currently, the time required for image reconstruction is prohibitively long if data are acquired using multidimensional imaging trajectories that make use of multichannel systems equipped with nonlinear gradients. Methods are presented that reduce the computational complexity of the iterative time-domain recons...

journal_title：Magnetic resonance in medicine

authors： Schultz G,Gallichan D,Reisert M,Hennig J,Zaitsev M

更新日期：2014-08-01 00:00:00

abstract：:The shells trajectory is a 3D data acquisition method with improved efficiency compared to Cartesian sampling. It is a true center-out trajectory that does not repeatedly resample the center of k-space, and also offers advantages for motion correction. This work demonstrates that k-space undersampling can be combined ...

journal_title：Magnetic resonance in medicine

authors： Shu Y,Riederer SJ,Bernstein MA

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:Diabetic nephropathy (DN) is the leading cause of renal failure; however, current clinical tests are insufficient for assessing this disease. DN is associated with changes in renal metabolites, so we evaluated the utility of chemical exchange saturation transfer (CEST) imaging to detect changes characteristic o...

journal_title：Magnetic resonance in medicine

authors： Wang F,Kopylov D,Zu Z,Takahashi K,Wang S,Quarles CC,Gore JC,Harris RC,Takahashi T

更新日期：2016-11-01 00:00:00

abstract：:The rotationally invariant trace/3 apparent diffusion coefficients (ADC) of N-acetyl aspartate (NAA), creatine and phosphocreatine (tCr), and choline (Cho) were determined using a diffusion-weighted stimulated echo acquisition mode sequence at 3 T in three separate human brain regions, namely the subcortical white mat...

journal_title：Magnetic resonance in medicine

authors： Ellegood J,Hanstock CC,Beaulieu C

更新日期：2005-05-01 00:00:00

abstract：PURPOSE:To present a time-efficient technique for banding reduction in balanced steady-state free precession (bSSFP) imaging using phase-cycled simultaneous multislice (SMS) acquisition with CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration). THEORY:The proposed technique exploits the ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Shao X,Martin T,Moeller S,Yacoub E,Wang DJ

更新日期：2016-12-01 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：:In the pulsed arterial spin labeling (ASL) techniques EPISTAR, PICORE, and FAIR, subtraction of two images in which inflowing blood is first tagged and then not tagged yields a qualitative map of perfusion. An important reason this map is not quantitative is that there is a spatially varying delay in the transit of bl...

journal_title：Magnetic resonance in medicine

authors： Wong EC,Buxton RB,Frank LR

更新日期：1998-05-01 00:00:00

abstract：:A method of post-processing to enhance the image resolution of the distribution of free radical molecules obtained with continuous-wave electron paramagnetic resonance (CW-EPR) imaging is reported. The low spatial resolution of EPR imaging, which has created difficulties in biomedical applications, was overcome by the...

journal_title：Magnetic resonance in medicine

authors： Ikebata Y,Sato-Akaba H,Aoyama T,Fujii H,Itoh K,Hirata H

更新日期：2009-09-01 00:00:00

abstract：PURPOSE:A new approach to design parallel transmit (pTx) head arrays is proposed that integrates transmit radiofrequency pulse designs with electromagnetic modeling of array coil elements. THEORY AND METHODS:An approach to design pTx head arrays is proposed that finds optimal groupings of a large number of coils into ...

journal_title：Magnetic resonance in medicine

authors： Cao Z,Yan X,Gore JC,Grissom WA

更新日期：2020-06-01 00:00:00

abstract：:Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-...

journal_title：Magnetic resonance in medicine

authors： Lin W,Paczynski RP,Celik A,Hsu CY,Powers WJ

更新日期：1998-12-01 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：: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：: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：:High-resolution magic-angle spinning has become a valuable tool to study biologic samples; however, there are only a few high-resolution magic-angle spinning methodologies that have been explored specifically to deal with small semisolid biomaterials such as tissues. Here, we report a novel high-resolution (1)H NMR sp...

journal_title：Magnetic resonance in medicine

authors： Wong A,Aguiar PM,Sakellariou D

更新日期：2010-02-01 00:00:00

abstract：PURPOSE:To develop and evaluate a novel 2D phase-unwrapping method that works robustly in the presence of severe noise, rapid phase changes, and disconnected regions. THEORY AND METHODS:The MR phase map usually varies rapidly in regions adjacent to wraps. In contrast, the phasors can vary slowly, especially in regions...

journal_title：Magnetic resonance in medicine

authors： Cheng J,Mei Y,Liu B,Guan J,Liu X,Wu EX,Feng Q,Chen W,Feng Y

更新日期：2018-01-01 00:00:00

abstract：:The manufacturing of intravascular imaging coils poses several challenges. Due to their size, it can be difficult to incorporate local matching networks and signal amplifiers. The goal of this study is to investigate tuning and amplification strategies for intravascular coils and to assess the signal-to-noise benefits...

journal_title：Magnetic resonance in medicine

authors： Yak N,Anderson KJ,Wright GA

更新日期：2012-11-01 00:00:00

abstract：:The ability to generate in vivo maps of lactate may have significant diagnostic utility in staging and treatment planning of a wide variety of cancers. The double selective multiple quantum filter technique (SelMQC) has been shown to be effective for nonlocalized detection of lactate with little or no interference fro...

journal_title：Magnetic resonance in medicine

authors： Pickup S,Lee SC,Mancuso A,Glickson JD

更新日期：2008-08-01 00:00:00

abstract：PURPOSE:We incorporate simultaneous multislice (SMS) acquisition into MR fingerprinting (MRF) to accelerate the MRF acquisition. METHODS:The t-Blipped SMS-MRF method is achieved by adding a Gz blip before each data acquisition window and balancing it with a Gz blip of opposing polarity at the end of each TR. Thus the ...

journal_title：Magnetic resonance in medicine

authors： Ye H,Ma D,Jiang Y,Cauley SF,Du Y,Wald LL,Griswold MA,Setsompop K

更新日期：2016-05-01 00:00:00

abstract：:The success in utilizing in vivo NMR to identify and/or monitor metabolic abnormalities will be determined in large part on the reliability with which the spectral parameters of the metabolites present can be measured. For these reasons it is clear that there is a need for the development of algorithms with which to o...

journal_title：Magnetic resonance in medicine

authors： Lenkinski RE,Allman T,Scheiner JD,Deming SN

更新日期：1989-06-01 00:00:00

abstract：PURPOSE:To investigate the use of shielded-coaxial-cable (SCC) coils as elements for multi-channel receive-only and transceive arrays for 7T human MRI and to compare their performance with equivalently sized conventional loop coils. METHODS:The SCC coil element consists of a coaxial loop with interrupted central condu...

journal_title：Magnetic resonance in medicine

authors： Ruytenberg T,Webb A,Zivkovic I

更新日期：2020-03-01 00:00:00