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 artifacts due to T(2) decay. The streaking is not only dependent on the T(2) of the object and the timing of the data acquisition, but also on the order in which radial lines are collected (view order). The view ordering can easily be controlled to minimize artifacts due to T(2) decay as well as motion. Four view-ordering techniques are presented and evaluated for the radial FSE sequence.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Theilmann RJ,Gmitro AF,Altbach MI,Trouard TPdoi
10.1002/mrm.20031subject
Has Abstractpub_date
2004-04-01 00:00:00pages
768-74issue
4eissn
0740-3194issn
1522-2594journal_volume
51pub_type
杂志文章abstract::Echo-planar spectroscopic imaging (EPSI) can be used for fast spectroscopic imaging of water and fat resonances at high resolution to improve structural and functional imaging. Because of the use of oscillating gradients during the free induction decay (FID), spectra obtained with EPSI are often degraded by Nyquist gh...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10485
更新日期:2003-06-01 00:00:00
abstract::The eigenimage filter was used to evaluate the results of a MRI study of cerebral ischemia in a rat model. This linear filter segments a desired feature in an image sequence from other features which may interfere with its observation. The animals were imaged temporally, after occlusion of the middle cerebral artery, ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910260207
更新日期:1992-08-01 00:00:00
abstract::Levo-tetrahydropalmatine (l-THP) has shown significant promise in preclinical and clinical studies to treat drug addiction. Pharmacological MRI methods can elucidate the regional cerebral effects of l-THP, but there are potential confounds from the use of general anesthesia. To investigate the possible anesthetic-drug...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23243
更新日期:2012-08-01 00:00:00
abstract::Vascular-space-occupancy (VASO) MRI exploits the difference between blood and tissue T1 to null blood signal and measure cerebral blood volume changes using the residual tissue signal. VASO imaging is more difficult at higher field because of sensitivity loss due to the convergence of tissue and blood T1 values and in...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24334
更新日期:2013-04-01 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
pub_type: 杂志文章
doi:10.1002/mrm.23188
更新日期:2012-06-01 00:00:00
abstract::Chemical shifts were extracted from in vivo 3-dimensional 31P NMR CSI data and pH images were constructed. The images could spatially resolve tissue pH ranging from 5.8 to 7.2 (with uncertainty of 0.11-0.17 pH unit) in an ischemia-reperfusion model of diabetic rat calf muscles. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290214
更新日期:1993-02-01 00:00:00
abstract:PURPOSE:To develop a wideband cardiac perfusion pulse sequence and test whether it is capable of suppressing image artifacts in patients with a cardiac implantable electronic device (CIED), while not exceeding the specific absorption rate (SAR) limit (2.0 W/kg). METHODS:A wideband perfusion pulse sequence was develope...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27458
更新日期:2019-02-01 00:00:00
abstract::The suppression of water signals in in vivo proton spectra by means of multiple-quantum filtering can be brought about in several ways. This communication exposes the shortcomings of using purely subtractive filtering techniques to observe signals from metabolites that contain proton couplings of the form AX3. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910110314
更新日期:1989-09-01 00:00:00
abstract::The purpose of this study was to determine the value of a blood-pool contrast media (NC100150, Nycomed Imaging (now Amersham Health) Oslo, Norway) for evaluation of venous thrombosis of the deep veins of the pelvis and lower extremities. Twelve patients were prospectively evaluated with conventional X-ray venography (...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1002/mrm.10607
更新日期:2003-11-01 00:00:00
abstract:PURPOSE:To develop and validate closed form mathematical expressions that predict the optimal contrast agent concentration for the maximum T1-weighted spoiled gradient echo (SGRE) signal. THEORY AND METHODS:Gadolinium and iron-based contrast agents can have significant transverse relaxivity that leads to signal dropou...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25744
更新日期:2016-04-01 00:00:00
abstract::Hyperpolarized noble gas ((3)He and (129)Xe) apparent diffusion coefficient (ADC) measurements have shown remarkable sensitivity to microstructural (i.e., alveolar) changes in the lung, particularly emphysema. The ADC of hyperpolarized noble gases depends strongly on the diffusion time (Δ), and (3)He ADC has been show...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24224
更新日期:2013-01-01 00:00:00
abstract:PURPOSE:To develop a novel technique for voxel-based mapping of lung microstructural parameters using hyperpolarized 129 Xe dissolved-phase MR imaging during saturation recovery. METHODS:A pulse sequence using a highly undersampled stack-of-stars trajectory was developed, and low-rank plus sparse matrix decomposition ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27559
更新日期:2019-04-01 00:00:00
abstract:PURPOSE:Diffusion-weighted magnetic resonance imaging suffers from physiological noise, such as artifacts caused by motion or system instabilities. Therefore, there is a need for robust diffusion parameter estimation techniques. In the past, several techniques have been proposed, including RESTORE and iRESTORE (Chang e...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25351
更新日期:2015-06-01 00:00:00
abstract::Imaging delayed hyperenhancement of myocardial infarction is most commonly performed using an inversion recovery (IR) prepared 2D breathhold segmented k-space gradient echo (FGRE) sequence. Since only one slice is acquired per breathhold in this technique, 12-16 successive breathholds are required for complete anatomi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20061
更新日期:2004-05-01 00:00:00
abstract::A modified Look-Locker acquisition using saturation recovery (MLLSR) for breath-held myocardial T(1) mapping is presented. Despite its reduced dynamic range, saturation recovery enables substantially higher imaging efficiency than conventional inversion recovery T(1) mapping because it does not require time for magnet...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24137
更新日期:2012-03-01 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
pub_type: 杂志文章
doi:10.1002/mrm.1910350520
更新日期:1996-05-01 00:00:00
abstract::Alternate methods to quantify mitochondrial activity or function have been extensively used for studying insulin resistance and type 2 diabetes mellitus, namely saturation transfer and phosphocreatine (PCr) recovery. As these methods are in fact determining different parameters, this study aimed to compare saturation ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23095
更新日期:2012-04-01 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
pub_type: 杂志文章
doi:10.1002/mrm.26794
更新日期:2018-03-01 00:00:00
abstract::Using a material that already is in widespread use in humans, India ink, the first EPR measurements in a human have been made, using the India ink in a pre-existing tattoo. The EPR spectra of India ink are very sensitive to the partial pressure of oxygen (pO2), thereby making it feasible to use this approach to measur...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910310218
更新日期:1994-02-01 00:00:00
abstract:PURPOSE:To develop a strategy for training a physics-guided MRI reconstruction neural network without a database of fully sampled data sets. METHODS:Self-supervised learning via data undersampling (SSDU) for physics-guided deep learning reconstruction partitions available measurements into two disjoint sets, one of wh...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28378
更新日期:2020-12-01 00:00:00
abstract::An effective shield for the dc fringing fields produced by a large-bore, high field magnet intended for imaging and in vivo spectroscopy is presented. While limiting the extent of fringe fields, the shield has little effect on the homogeneity of the central field of the magnet. The effect of institutional safety polic...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910020506
更新日期:1985-10-01 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
pub_type: 杂志文章
doi:10.1002/mrm.10410
更新日期:2003-04-01 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
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(200004)43:4<615::aid-mrm19
更新日期:2000-04-01 00:00:00
abstract:PURPOSE:To integrate markerless head motion tracking with prospectively corrected neuroanatomical MRI sequences and to investigate high-frequency motion correction during imaging echo trains. METHODS:A commercial 3D surface tracking system, which estimates head motion by registering point cloud reconstructions of the ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27705
更新日期:2019-07-01 00:00:00
abstract:PURPOSE:To test the feasibility of using the SPICE (SPectroscopic Imaging by exploiting spatiospectral CorrElation) technique, which uses the partial separability of spectroscopic data, for high resolution hyperpolarized (HP) 13 C spectroscopic imaging. METHODS:Numerical simulations were performed to investigate the i...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27061
更新日期:2018-08-01 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
pub_type: 杂志文章
doi:10.1002/mrm.1910370206
更新日期:1997-02-01 00:00:00
abstract::A new k-space direct matrix inversion (DMI) method is proposed here to accelerate non-Cartesian SENSE reconstructions. In this method a global k-space matrix equation is established on basic MRI principles, and the inverse of the global encoding matrix is found from a set of local matrix equations by taking advantage ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20974
更新日期:2006-08-01 00:00:00
abstract::A methodology is presented for estimating T(1) using a two-point technique with a standard multislice gradient echo sequence. The method explicitly corrects for the shape of the RF pulse and for spatial variations in transmitted RF field intensity. Including these factors in the calculation of T(1) gives a substantial...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1112
更新日期:2001-05-01 00:00:00
abstract:PURPOSE:To compare fitting methods and sampling strategies, including the implementation of an optimized b-value selection for improved estimation of intravoxel incoherent motion (IVIM) parameters in breast cancer. METHODS:Fourteen patients (age, 48.4 ± 14.27 years) with cancerous lesions underwent 3 Tesla breast MRI ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25484
更新日期:2015-10-01 00:00:00
abstract::This communication describes the design and application of a receiver coil operating at liquid nitrogen temperature and intended as a surface coil in a whole-body imager. Its particular application is seen as the external receiver for parasitic internal or implanted detectors. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910070211
更新日期:1988-06-01 00:00:00