Group sparse reconstruction using intensity-based clustering.

abstract：:We have developed a method for measuring the electrocardiogram (ECG) continuously during MR examinations. In contrast to ECG acquisition by wires, our new method is to amplify and convert the ECG into an optical signal directly above the patient's heart. The optical signal is transmitted out of the magnet bore by opti...

journal_title：Magnetic resonance in medicine

authors： Felblinger J,Lehmann C,Boesch C

更新日期：1994-10-01 00:00:00

abstract：PURPOSE:To develop a framework for respiratory motion-corrected 3D whole-heart water/fat coronary MR angiography (CMRA) at 3T with reduced and predictable scan time. METHODS:A 3D dual-echo acquisition and respiratory motion-corrected reconstruction framework for water/fat CMRA imaging was developed. The acquisition se...

journal_title：Magnetic resonance in medicine

authors： Munoz C,Cruz G,Neji R,Botnar RM,Prieto C

更新日期：2019-08-01 00:00:00

abstract：:T(2) quantification may augment diagnostic T(2)-weighted imaging; to improve cancer detection via auto-segmentation of multi-parametric acquisitions and to potentiate longitudinal studies of prostate cancer. However, robust quantitative techniques are not generally accessible or refined for clinical translation. This ...

journal_title：Magnetic resonance in medicine

authors： Foltz WD,Chopra S,Chung P,Bayley A,Catton C,Jaffray D,Wright GA,Haider MA,Ménard C

更新日期：2010-10-01 00:00:00

abstract：PURPOSE:Preclinical imaging of myocardial blood flow (MBF) can elucidate molecular mechanisms underlying cardiovascular disease. We compared the repeatability and variability of two methods, first-pass MRI and arterial spin labeling (ASL), for imaging MBF in mice. METHODS:Quantitative perfusion MRI in mice was perform...

journal_title：Magnetic resonance in medicine

authors： Naresh NK,Chen X,Moran E,Tian Y,French BA,Epstein FH

更新日期：2016-06-01 00:00:00

abstract：:The chemical shift of water and fat resonances in proton MRI allows separation of water and fat signal from chemical shift encoded data. This work describes an automatic method that produces separate water and fat images as well as quantitative maps of fat signal fraction and T2* from complex multiecho gradient-recall...

journal_title：Magnetic resonance in medicine

authors： Berglund J,Kullberg J

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:To improve signal-to-noise ratio (SNR) for high-resolution spectroscopic imaging using a subspace-based technique known as SPectroscopic Imaging by exploiting spatiospectral CorrElation (SPICE). METHODS:The proposed method is based on a union-of-subspaces model of MRSI signals, which exploits the partial separ...

journal_title：Magnetic resonance in medicine

authors： Ma C,Lam F,Ning Q,Johnson CL,Liang ZP

更新日期：2017-02-01 00:00:00

abstract：:Magnetic resonance imaging has achieved clinical importance and has become the primary tool in the investigation of head, spinal cord, pelvis, cancellous bone, pericardium (with gating), gallbladder, lymph node masses, and very soon, in the evaluation of joints. In many areas, particularly with respiratory and ECG gat...

journal_title：Magnetic resonance in medicine

authors： Margulis AR,Fisher MR

更新日期：1985-08-01 00:00:00

abstract：:For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition...

journal_title：Magnetic resonance in medicine

authors： Feng L,Srichai MB,Lim RP,Harrison A,King W,Adluru G,Dibella EV,Sodickson DK,Otazo R,Kim D

更新日期：2013-07-01 00:00:00

abstract：:Magnetic resonance images of the lungs of a guinea pig have been produced using hyperpolarized helium as the source of the MR signal. The resulting images are not yet sufficiently optimized to reveal fine structural detail within the lung, but the spectacular signal from this normally signal-deficient organ system off...

journal_title：Magnetic resonance in medicine

authors： Middleton H,Black RD,Saam B,Cates GD,Cofer GP,Guenther R,Happer W,Hedlund LW,Johnson GA,Juvan K

更新日期：1995-02-01 00:00:00

abstract：:A modified high-speed stimulated-echo acquisition mode (STEAM) diffusion sequence (90 degrees-TE/2-90 degrees-TM-[alpha-TE/2-STE]n) incorporating bipolar diffusion gradients that are less sensitive to macroscopic motion-induced artifacts is presented. Diffusion encoding was performed only during the first echo interva...

journal_title：Magnetic resonance in medicine

authors： Yongbi MN,Ding S,Dunn JF

更新日期：1996-06-01 00:00:00

abstract：PURPOSE:Define criteria for selection of optimal flip angle sets for T1 estimation and evaluate effects on T1 mapping. THEORY AND METHODS:Flip angle sets for spoiled gradient echo-based T1 mapping were selected by minimizing T1 estimate variance weighted by the joint density of M0 and T1 in an initial acquisition. The...

journal_title：Magnetic resonance in medicine

authors： Lewis CM,Hurley SA,Meyerand ME,Koay CG

更新日期：2016-09-01 00:00:00

abstract：PURPOSE:Sensitivity encoding (SENSE) reconstruction of multiband echo planar imaging (EPI) may cause artifacts when simultaneously excited slices require different phase correction to remove the EPI-specific ghost shifted by half of the matrix size (N). We propose a simplified solution of this problem that combines SEN...

journal_title：Magnetic resonance in medicine

authors： Hennel F,Buehrer M,von Deuster C,Seuven A,Pruessmann KP

更新日期：2016-09-01 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：:A 3.0 Tesla, 0.80-m bore magnet replaced our previous 1.9 Tesla, 0.76-m magnet. The 3.0 Tesla replacement magnet had a dipole moment of 1.7 with respect to that of the 1.9 Tesla magnet. The pre-existing cylindrically symmetric passive steel shielding was modified to confine the fringe fields of the replacement magnet ...

journal_title：Magnetic resonance in medicine

authors： Ewing JR,Warner R,Helpern JA

更新日期：1993-03-01 00:00:00

abstract：PURPOSE:MR safety at 7 Tesla relies on accurate numerical simulations of transmit electromagnetic fields to fully assess local specific absorption rate (SAR) safety. Numerical simulations for SAR safety are currently performed using models of healthy patients. These simulations might not be useful for estimating SAR in...

journal_title：Magnetic resonance in medicine

authors： Restivo MC,van den Berg CA,van Lier AL,Polders DL,Raaijmakers AJ,Luijten PR,Hoogduin H

更新日期：2016-01-01 00:00:00

abstract：:Orientational anisotropy of T2 and T1 relaxation times, diffusion, and magnetization transfer has been investigated for six different tissues: tendon, cartilage, kidney, muscle, white matter, and optic nerve. Relaxation anisotropy was observed for tendon and cartilage, and diffusional anisotropy was measured in kidney...

journal_title：Magnetic resonance in medicine

authors： Henkelman RM,Stanisz GJ,Kim JK,Bronskill MJ

更新日期：1994-11-01 00:00:00

abstract：:Intraplaque hemorrhage in atherosclerotic plaques has been associated with accelerated plaque growth as well as exacerbation of clinical symptoms. The identification of intraplaque hemorrhage using magnetic resonance imaging primarily relies on the detection of methemoglobin on T(1) weighted images. Current techniques...

journal_title：Magnetic resonance in medicine

authors： Wang J,Ferguson MS,Balu N,Yuan C,Hatsukami TS,Börnert P

更新日期：2010-11-01 00:00:00

abstract：:We present preliminary results for a 3D finite element calculation to evaluate RF penetration in conducting dielectric materials at high field strengths. A tetrahedral mesh is used along with a Coulomb gauge constraint in a finite element method that yields excellent numerical stability at high frequencies. Accuracy i...

journal_title：Magnetic resonance in medicine

authors： Petropoulos LS,Haacke EM,Brown RW,Boerner E

更新日期：1993-09-01 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

authors： Boudreau M,Xu X,Santyr GE

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

authors： Kern AL,Gutberlet M,Voskrebenzev A,Klimeš F,Rotärmel A,Wacker F,Hohlfeld JM,Vogel-Claussen J

更新日期：2019-04-01 00:00:00

abstract：PURPOSE:To model and correct the dephasing effects in the gradient-echo signal for arbitrary RF excitation pulses with large flip angles in the presence of macroscopic field variations. METHODS:The dephasing of the spoiled 2D gradient-echo signal was modeled using a numerical solution of the Bloch equations to calcula...

journal_title：Magnetic resonance in medicine

authors： Soellradl M,Lesch A,Strasser J,Pirpamer L,Stollberger R,Ropele S,Langkammer C

更新日期：2020-08-01 00:00:00

abstract：PURPOSE:A new T1 mapping method is proposed that is accurate, rapid, and robust to motion. Considering these features, the method is dubbed "T-One with Enhanced Robustness and Speed (TOWERS)." METHODS:TOWERS is composed of inversion recovery (IR) and saturation recovery (SR) acquisitions. In the IR acquisitions, a sli...

journal_title：Magnetic resonance in medicine

authors： Eldeniz C,Finsterbusch J,Lin W,An H

更新日期：2016-07-01 00:00:00

abstract：PURPOSE:To test and implement a motion-robust and respiratory-resolved 3D Radial Flow framework that addresses the need for rapid, high resolution imaging in neonatal patients with congenital heart disease. METHODS:A 4-point velocity encoding and 3D radial trajectory with double-golden angle ordering was combined with...

journal_title：Magnetic resonance in medicine

authors： Schrauben EM,Lim JM,Goolaub DS,Marini D,Seed M,Macgowan CK

更新日期：2020-02-01 00:00:00

abstract：:Comparative NMR studies of normal and pathologically altered human stomach tissues were performed on the basis of proton T1 relaxation time measurements in the presence of high external concentrations of relaxation (contrast) agents manganese ethylenediaminetetraacetic acid (Mn-EDTA) and gadolinium diethylenetriaminep...

journal_title：Magnetic resonance in medicine

authors： Srejić R,Popov DV,Boricić I,Zuvela M

更新日期：1990-09-01 00:00:00

abstract：:Knowledge about the triglyceride (fat) (1)H spectrum enables quantitative determination of several triglyceride characteristics. This work describes a model-based chemical shift imaging method that separates water and fat signal and provides maps of three triglyceride quantities: fatty acid carbon chain length, unsatu...

journal_title：Magnetic resonance in medicine

authors： Berglund J,Ahlström H,Kullberg J

更新日期：2012-12-01 00:00:00

abstract：PURPOSE:The T(1) of tissue has a strong dependence on the measurement magnetic field strength. T(1) -dispersion could be a useful contrast parameter, but is unavailable to clinical MR systems which operate at fixed magnetic field strength. The purpose of this work was to implement a removable insert magnet coil for fie...

journal_title：Magnetic resonance in medicine

authors： Pine KJ,Goldie F,Lurie DJ

更新日期：2014-11-01 00:00:00

abstract：PURPOSE:Undiagnosed dehydration compromises health outcomes across many populations. Existing dehydration diagnostics require invasive bodily fluid sampling or are easily confounded by fluid and electrolyte intake, environment, and physical activity limiting widespread adoption. We present a portable MR sensor designed...

journal_title：Magnetic resonance in medicine

authors： Bashyam A,Frangieh CJ,Li M,Cima MJ

更新日期：2020-04-01 00:00:00

abstract：:This work presents a method applied to the design of short self-shielded gradient coils of cylindrical geometry. The method uses a hybrid technique that combines the simulated annealing and target field methods to optimize the standard stream functions. The optimized stream functions were parameterized using a few deg...

journal_title：Magnetic resonance in medicine

authors： Tomasi D

更新日期：2001-03-01 00:00:00

abstract：:Breathing motion is one of the main sources of artifacts in MRI acquisitions that can severely impair diagnosis. In MRI with continuously moving table, the application of common motion compensation approaches such as breath holding or the synchronization of the measurement with the breathing motion can be problematic....

journal_title：Magnetic resonance in medicine

authors： Honal M,Leupold J,Huff S,Baumann T,Ludwig U

更新日期：2010-03-01 00:00:00

abstract：:For MR applications such as contrast-enhanced MR angiography, it is desirable to achieve simultaneously high spatial and temporal resolution. The current clinical standard uses view-sharing methods combined with parallel imaging; however, this approach still provides limited spatial and temporal resolution. To improve...

journal_title：Magnetic resonance in medicine

authors： Wang K,Busse RF,Holmes JH,Beatty PJ,Brittain JH,Francois CJ,Reeder SB,Du J,Korosec FR

更新日期：2011-08-01 00:00:00