Flexible and efficient optimization of quantitative sequences using automatic differentiation of Bloch simulations.

abstract：:Frequency-modulated (FM) pulses have practical advantages for spin-echo experiments, such as the ability to produce a broadband pi rotation, with an inhomogeneous radiofrequency (RF) field. However, such use leads to a nonlinear phase of the transverse magnetization, which is why FM pulses like the hyperbolic secant (...

journal_title：Magnetic resonance in medicine

authors： Park JY,Garwood M

更新日期：2009-01-01 00:00:00

abstract：:Sinusoidal capillarization induces microcirculatory changes in liver cirrhosis and fibrosis. The purpose of this study was to assess whether contrast-enhanced MRI can be used to demonstrate the effects of sinusoidal capillarization in liver fibrosis. Dynamic MRI after injection of a low-molecular-weight contrast agent...

journal_title：Magnetic resonance in medicine

authors： Van Beers BE,Materne R,Annet L,Hermoye L,Sempoux C,Peeters F,Smith AM,Jamart J,Horsmans Y

更新日期：2003-04-01 00:00:00

abstract：:Focused ultrasound heating of ex vivo bovine kidney and liver was monitored using magnetic resonance imaging (MRI) to investigate the quantitative relationship between time-dependent temperature elevations and altered contrast in MR images due to thermal coagulation. Proton resonance frequency shift MR thermometry was...

journal_title：Magnetic resonance in medicine

authors： Graham SJ,Chen L,Leitch M,Peters RD,Bronskill MJ,Foster FS,Henkelman RM,Plewes DB

更新日期：1999-02-01 00:00:00

abstract：:With standard spectroscopic imaging, high spatial resolution is achieved at the price of a large number of phase-encoding steps, leading to long acquisition times. Fast spatial encoding methods reduce the minimum total acquisition time. In this article, a k-space scanning scheme using a continuous series of growing an...

journal_title：Magnetic resonance in medicine

authors： Hiba B,Faure B,Lamalle L,Décorps M,Ziegler A

更新日期：2003-12-01 00:00:00

abstract：PURPOSE:To investigate whether saturation using existing methods developed for 3T imaging is feasible for clinical perfusion imaging at 7T, and to propose a new design of saturation pulse train for first-pass myocardial perfusion imaging at 7T. METHODS:The new design of saturation pulse train consists of four hyperbol...

journal_title：Magnetic resonance in medicine

authors： Tao Y,Hess AT,Keith GA,Rodgers CT,Liu A,Francis JM,Neubauer S,Robson MD

更新日期：2015-04-01 00:00:00

abstract：:Human intervertebral discs were investigated by 1H NMR in vitro. The measured parameters of samples differently located in discs give the "maps" of discs. The spin-lattice relaxation-time maps show similar structure to dry matter and bound water maps, which might mean the future possibility to detect certain disc proc...

journal_title：Magnetic resonance in medicine

authors： Furó I,Bobest M,Pócsik I,Tompa K

更新日期：1986-02-01 00:00:00

abstract：:Two-dimensional intersecting k-space trajectories have previously been demonstrated to allow fast multispectral imaging. Repeated sampling of k-space points leads to destructive interference of the signal coming from the off-resonance spectral peaks; on-resonance data reconstruction yields images of the on-resonance p...

journal_title：Magnetic resonance in medicine

authors： Bucholz EK,Song J,Johnson GA,Hancu I

更新日期：2008-03-01 00:00:00

abstract：:Among previous analyses of the steady-state free-precession (SSFP) signal in rapid MRI, one treatment resulted in equations that require the evaluation of infinite binomial series. Here, an analytical solution is derived by a transformation into the power series expansion of the derivative of the inverse sine function...

journal_title：Magnetic resonance in medicine

authors： Hänicke W,Vogel HU

更新日期：2003-04-01 00:00:00

abstract：PURPOSE:To facilitate assessment of RF power deposition and temperature rise within the breast, we present a method to seamlessly join heterogeneous breast models with standard whole-body models and demonstrate simulations at 7 T. METHODS:Finite-difference time-domain electromagnetic and bioheat simulations are perfor...

journal_title：Magnetic resonance in medicine

authors： Li X,Rispoli JV

更新日期：2019-02-01 00:00:00

abstract：:Passive MR tracking of catheters and guidewires is usually done by dynamically imaging a single thick slab, subtracting a baseline image, and combining the result with a previously acquired MR angiogram. In the in vitro and in vivo experiments reported here, it is demonstrated that this approach may be greatly simplif...

journal_title：Magnetic resonance in medicine

authors： Bakker CJ,Bos C,Weinmann HJ

更新日期：2001-01-01 00:00:00

abstract：PURPOSE:To quantify chemical exchange saturation transfer contrast in upper extremities of participants with lymphedema before and after standardized lymphatic mobilization therapy using correction procedures for B0 and B1 heterogeneity, and T1 relaxation. METHODS:Females with (n = 12) and without (n = 17) breast canc...

journal_title：Magnetic resonance in medicine

authors： Crescenzi R,Donahue PMC,Mahany H,Lants SK,Donahue MJ

更新日期：2020-05-01 00:00:00

abstract：:Functional magnetic resonance imaging (fMRI) has become the most widely used modality for visualizing regional brain activation in response to sensorimotor or cognitive tasks. While the majority of fMRI studies have used blood oxygenation level-dependent (BOLD) contrast as a marker for neural activation, baseline drif...

journal_title：Magnetic resonance in medicine

authors： Wang J,Aguirre GK,Kimberg DY,Roc AC,Li L,Detre JA

更新日期：2003-05-01 00:00:00

abstract：PURPOSE:To design low peak and integrated power simultaneous multislice excitation radiofrequency pulses with transmit field inhomogeneity compensation in high field MRI. THEORY AND METHODS:The "interleaved greedy and local optimization" algorithm for small-tip-angle spokes pulses is extended to design multiband (MB) ...

journal_title：Magnetic resonance in medicine

authors： Sharma A,Bammer R,Stenger VA,Grissom WA

更新日期：2015-09-01 00:00:00

abstract：PURPOSE:Quantitative myocardial perfusion mapping has advantages over qualitative assessment, including the ability to detect global flow reduction. However, it is not clinically available and remains a research tool. Building upon the previously described imaging sequence, this study presents algorithm and implementat...

journal_title：Magnetic resonance in medicine

authors： Xue H,Brown LAE,Nielles-Vallespin S,Plein S,Kellman P

更新日期：2020-02-01 00:00:00

abstract：:1H transverse nuclear magnetic relaxation times (T2) and self-diffusion coefficients (SDCs) of water were measured in isolated proteoglycan aggregates from pig articular cartilage. The influence of varying osmotic pressure, as well as of different calcium concentrations, on the samples was investigated. Due to a struc...

journal_title：Magnetic resonance in medicine

authors： Werner A,Gründer W

更新日期：1999-01-01 00:00:00

abstract：PURPOSE:To map brain metabolites and tissue magnetic susceptibility simultaneously using a single three-dimensional 1 H-MRSI acquisition without water suppression. METHODS:The proposed technique builds on a subspace imaging method called spectroscopic imaging by exploiting spatiospectral correlation (SPICE), which ena...

journal_title：Magnetic resonance in medicine

authors： Peng X,Lam F,Li Y,Clifford B,Liang ZP

更新日期：2018-01-01 00:00:00

abstract：:Techniques are described for the (31)P NMR analysis of glycerophospholipid (PL) headgroup and molecular species in brain. The (31)P NMR spectrum of PLs from human temporal cortex, solubilized in aqueous Na cholate, typically showed 3 major resonances, assigned to phosphatidylcholine (PC) molecular species containing 0...

journal_title：Magnetic resonance in medicine

authors： Pearce JM,Komoroski RA

更新日期：2000-08-01 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：: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：:Phase-contrast (PC) MRI is a noninvasive method for imaging blood and tissue velocity. PC experiments are typically segmented into many cardiac cycles in order to obtain sufficient spatial and temporal resolution, and thus require a gating signal to properly combine the data from multiple cardiac cycles. Although the ...

journal_title：Magnetic resonance in medicine

authors： Thompson RB,McVeigh ER

更新日期：2004-09-01 00:00:00

abstract：:Accurate and reproducible MRI R2 * relaxometry for tissue iron quantification is important in managing transfusion-dependent patients. MRI data are often acquired using array coils and reconstructed by the root-sum-square algorithm, and as such, measured signals follow the noncentral chi distribution. In this study, t...

journal_title：Magnetic resonance in medicine

authors： Feng Y,He T,Gatehouse PD,Li X,Harith Alam M,Pennell DJ,Chen W,Firmin DN

更新日期：2013-12-01 00:00:00

abstract：:A method is described for multislice imaging by means of rf pulses which contain a multifrequency excitation spectrum. These pulses label each slice by an individual signal phase and allow the separation of the signals from all the slices by subsequent add/subtract procedures. The image sensitivity corresponds to the ...

journal_title：Magnetic resonance in medicine

authors： Müller S

更新日期：1988-03-01 00:00:00

abstract：PURPOSE:To investigate the feasibility of estimating calibration constants (K and T2o ) in vivo for converting whole-blood T2 to blood hemoglobin oxygen saturation (HbO2 ) according to the Luz-Meiboom model, 1/T2=1/T2o+K(1-HbO2)2, where K and T2o are relaxivity and transverse relaxation time of fully saturated blood, r...

journal_title：Magnetic resonance in medicine

authors： Langham MC,Rodríguez-Soto AE,Schwartz N,Wehrli FW

更新日期：2018-04-01 00:00:00

abstract：PURPOSE:To develop a fast three-dimensional (3D) k-space encoding method based on spiral projection imaging (SPI) with an interleaved golden-angle approach and to validate this novel sequence on small animal models. METHODS:A disk-like trajectory, in which each disk contained spirals, was developed. The 3D encoding wa...

journal_title：Magnetic resonance in medicine

authors： Castets CR,Lefrançois W,Wecker D,Ribot EJ,Trotier AJ,Thiaudière E,Franconi JM,Miraux S

更新日期：2017-05-01 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

abstract：:Tumor pH is physiologically important since it influences a number of processes relevant to tumorigenesis and therapy. Hence, knowledge of localized pH within tumors would contribute to understanding these processes. The destructiveness, poor spatial resolution, and poor signal-to-noise ratio (SNR) of current technolo...

journal_title：Magnetic resonance in medicine

authors： van Sluis R,Bhujwalla ZM,Raghunand N,Ballesteros P,Alvarez J,Cerdán S,Galons JP,Gillies RJ

更新日期：1999-04-01 00:00:00

abstract：:We developed a live high-field multiple-mouse magnetic resonance imaging method to increase the throughput of imaging studies involving large numbers of mice. Phantom experiments were performed in 7 shielded radiofrequency (RF) coils for concurrent imaging on a 7 Tesla MRI scanner outfitted with multiple transmit and ...

journal_title：Magnetic resonance in medicine

authors： Bock NA,Nieman BJ,Bishop JB,Mark Henkelman R

更新日期：2005-11-01 00:00:00

abstract：:Chemical exchange saturation transfer (CEST) and spin-locking (SL) experiments were both able to probe the exchange process between protons of nonequivalent chemical environments. To compare the characteristics of the CEST and SL approaches in the study of chemical exchange effects, we performed CEST and SL experiment...

journal_title：Magnetic resonance in medicine

authors： Jin T,Autio J,Obata T,Kim SG

更新日期：2011-05-01 00:00:00

abstract：:Segmented interleaved echo planar imaging offers a fast and efficient approach to magnetic resonance angiography. Unfortunately, this technique is particularly sensitive to oblique flow in the imaging plane. In this work, a mathematical analysis of oblique flow effects for several types of k-space coverage is presente...

journal_title：Magnetic resonance in medicine

authors： Beck G,Li D,Haacke EM,Noll TG,Schad LR

更新日期：2001-04-01 00:00:00

abstract：:Longitudinal and transverse relaxation rates for the 11B resonances in sodium borocaptate (BSH) at varying concentrations were measured in undiluted horse serum in a 4.7 Tesla field. The results could be fit by a model that assumes fast exchange of the BSH molecule between a free and a bound state, using values of 0.7...

journal_title：Magnetic resonance in medicine

authors： Bendel P,Frantz A,Zilberstein J,Kabalka GW,Salomon Y

更新日期：1998-03-01 00:00:00