Abstract:
PURPOSE:To design, evaluate, and apply a bow tie antenna transceiver radiofrequency (RF) coil array tailored for cardiac MRI at 7.0 Tesla (T). METHODS:The radiofrequency (RF) coil array comprises 16 building blocks each containing a bow tie shaped λ/2-dipole antenna. Numerical simulations were used for transmission field homogenization and RF safety validation. RF characteristics were examined in a phantom study. The array's suitability for high spatial resolution two-dimensional (2D) CINE imaging and for real time imaging of the heart was examined in a volunteer study. RESULTS:The arrays transmission fields and RF characteristics are suitable for cardiac MRI at 7.0T. The coil performance afforded a spatial resolution as good as (0.8 × 0.8 × 2.5) mm(3) for segmented 2D CINE MRI at 7.0T which is by a factor of 12 superior versus standardized protocols used in clinical practice at 1.5T. The proposed transceiver array supports 1D acceleration factors of up to R = 6 without impairing image quality significantly. CONCLUSION:The 16-channel bow tie antenna transceiver array supports accelerated and high spatial resolution cardiac MRI. The array is compatible with multichannel transmission and provides a technological basis for future clinical assessment of parallel transmission techniques at 7.0 Tesla. Magn Reson Med 75:2553-2565, 2016. © 2015 Wiley Periodicals, Inc.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Oezerdem C,Winter L,Graessl A,Paul K,Els A,Weinberger O,Rieger J,Kuehne A,Dieringer M,Hezel F,Voit D,Frahm J,Niendorf Tdoi
10.1002/mrm.25840subject
Has Abstractpub_date
2016-06-01 00:00:00pages
2553-65issue
6eissn
0740-3194issn
1522-2594journal_volume
75pub_type
杂志文章abstract:PURPOSE:To compare experimental transverse relaxivities of iron oxide nanocrystals (IONC) as a function of clustering and magnetic field strength with different theoretical model predictions. THEORY AND METHODS:Well-defined IONC clusters in nanoemulsions (NEs) of which both size and IONC loading could be judiciously t...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25465
更新日期:2015-09-01 00:00:00
abstract:PURPOSE:To enable accurate magnetic resonance (MR) parameter mapping with accelerated data acquisition, utilizing recent advances in constrained imaging with sparse sampling. THEORY AND METHODS:A new constrained reconstruction method based on low-rank and sparsity constraints is proposed to accelerate MR parameter map...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25421
更新日期:2015-08-01 00:00:00
abstract::Surgical specimens from 22 patients with infiltrating ductal carcinoma of the breast were analyzed by high-resolution 1H NMR spectroscopy at 80 and 300 MHz. Results were compared with those obtained from 9 benign (proliferative dysplasia without atypia) breast samples. NMR spectra at 80 MHz showed well-resolved water ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910080407
更新日期:1988-12-01 00:00:00
abstract:PURPOSE:Quantitative mapping of the native T1 of the heart using the modified look-locker inversion recovery (MOLLI) technique provides high quality diagnostic information without requiring contrast agents. Previous work has considered the effects of T2 relaxation on MOLLI T1 measurements, finding that the T1 measured ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24867
更新日期:2013-09-01 00:00:00
abstract::An in vitro study was performed to investigate the effects of B(o) inhomogeneity on magnetic resonance images of flow. Controlled inhomogeneity gradients (Gi) were applied and the magnitude of the artifacts produced was quantified for different echo delay times (TE). Both steady and pulsatile flows were examined. In t...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910350116
更新日期:1996-01-01 00:00:00
abstract::The protocol for delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) was adapted for the evaluation of transplanted osteochondral allograft cartilage. Eight patients with focal grade 4 cartilage defects of the femoral condyle were treated with single cylindrical osteochondral allografts. At 1 and 2 years, dGEMRIC i...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/mrm.24419
更新日期:2013-06-01 00:00:00
abstract::The aim of this work was to identify ventricular shape-based biomarkers in MR images to discriminate between patients with Alzheimer's disease (AD) and healthy elderly. Clinical MR images were collected for 58 patients and 28 age-matched healthy controls. After normalizing all the images the ventricular cerebrospinal ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21471
更新日期:2008-02-01 00:00:00
abstract:PURPOSE:The purpose of this study is to increase the robustness of MR fingerprinting (MRF) toward subject motion. METHODS:A novel reconstruction algorithm, MOtion insensitive MRF (MORF), was developed, which uses an iterative reconstruction based retrospective motion correction approach. Each iteration loops through t...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27227
更新日期:2018-12-01 00:00:00
abstract::Volume-localized proton NMR spectroscopy was used to estimate bone marrow cellularity in the posterior iliac crests of patients undergoing treatment with hematopoietic growth factors for a variety of hematologic and neoplastic disorders. Twelve patients were accrued, six of whom were studied more than once, yielding a...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910190108
更新日期:1991-05-01 00:00:00
abstract:PURPOSE:To determine the feasibility of employing the prior knowledge of well-separated chemical exchange saturation transfer (CEST) signals in the 9.4 T Z-spectrum to separate overlapping CEST signals acquired at 3 T, using a deep learning approach trained with 3 T and 9.4 T CEST spectral data from brains of the same ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27690
更新日期:2019-06-01 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
pub_type: 杂志文章
doi:10.1002/mrm.28560
更新日期:2021-04-01 00:00:00
abstract::To detect perfusion abnormalities in areas of high magnetic susceptibility in the brain, an arterial spin-labeling MRI technique utilizing flow-sensitive alternating inversion recovery (FAIR) and half-Fourier single shot turbo spin-echo (HASTE) for spin preparation and image acquisition, respectively, was developed. I...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200103)45:3<431::aid-mrm1056>3.0
更新日期:2001-03-01 00:00:00
abstract::Noninvasive investigation of aldose reductase activities in rat testis was performed using 3-fluoro-3-deoxy-D-glucose (3-FDG) and nuclear magnetic resonance (NMR) spectroscopy/imaging. Quantitative determination of testis aldose reductase activities, expressed as the sorbitol index, showed a value similar to that of b...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290417
更新日期:1993-04-01 00:00:00
abstract::A new volume selection/spectral editing pulse sequence (VOSING) is presented. The features specific to the technique are that the volume selection and the editing intervals coincide and that no decoupling is necessary. The pulse sequence can be applied under both homo- and heteronuclear conditions. Phantom experiments...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910080108
更新日期:1988-09-01 00:00:00
abstract::MR acoustic, or sound, noise due to gradient pulsing has been one of the problems in MRI, both in patient scanning as well as in many areas of psychiatric and neuroscience research, such as brain fMRI. Especially in brain fMRI, sound noise is one of the serious noise sources that obscures the small signals obtainable ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910390224
更新日期:1998-02-01 00:00:00
abstract::A transrectal probe for 1H imaging and 31P MR spectroscopy of the prostate gland is described. The probe is covered with plastic and consists of an insectional portion containing an rf coil and a handle containing a tuning and matching circuit. Using this transrectal probe, 1H MR images and the first 31P MR spectra of...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章,评审
doi:10.1002/mrm.1910110209
更新日期:1989-08-01 00:00:00
abstract::Subject motion during scan is a major source of artifacts in MR examinations. Prospective motion correction is a promising technique that tracks subject motion and adjusts the imaging volume in real time; however, additional retrospective correction may be necessary to achieve robust image quality and compatibility wi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24269
更新日期:2013-02-01 00:00:00
abstract::The combination of cardiac viability and functional information enhances the identification of different heart tissues in the setting of ischemic heart disease. A method has recently been proposed for obtaining black-blood delayed-enhancement (DE) viability images using the stimulated-echo acquisition mode (STEAM) MRI...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21390
更新日期:2007-10-01 00:00:00
abstract::It is well known that when compared to conventional spin-echo (CSE) imaging for equivalent effective echo times, fast spin-echo (FSE) imaging experiments yield higher signal intensities for coupled spin systems, such as that for lipid. One hypothesis put forth for this phenomenon is the removal of scalar coupling-base...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910350409
更新日期:1996-04-01 00:00:00
abstract:PURPOSE:This study evaluates biochemical imbalances in a rat model that reflects dysfunctional pathways in migraine. The high sensitivity and spectral dispersion available to 1 H MRS at 21.1 T expands metabolic profiling in this migraine model to include lactate (Lac), taurine (Tau), aspartate, and Gly-a mixture of gly...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26811
更新日期:2018-03-01 00:00:00
abstract::In active catheter tracking, small RF coils are attached to the catheter for localization. For interactive catheter steering at vessel branchings, it is necessary to visualize not only a single point near the catheter tip but also the entire shape and orientation of the catheter's distal end. Therefore, a 35-mm-long t...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20108
更新日期:2004-07-01 00:00:00
abstract:PURPOSE:To test the hypothesis that a noninvasive dynamic contrast enhanced MRI (DCE-MRI) derived interstitial volume fraction (ve ) and/or distribution volume (VD ) were correlated with tumor cellularity in cerebral tumor. METHODS:T1 -weighted DCE-MRI studies were performed in 18 athymic rats implanted with U251 xeno...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24873
更新日期:2014-06-01 00:00:00
abstract::Strong, extensive magnetic fringe fields are a significant problem with magnetic resonance imaging magnets. This is particularly acute with 4-T, whole-body research magnets. To date this problem has been addressed by restricting an extensive zone around the unshielded magnet or by placing external unsaturated iron shi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290107
更新日期:1993-01-01 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
pub_type: 杂志文章
doi:10.1002/mrm.1910030122
更新日期:1986-02-01 00:00:00
abstract::Fast proton magnetic resonance spectroscopic imaging (MRSI) using a multi-element head-coil array is examined with respect to three aspects: the coil design, the use of an appropriate signal combination method, and the design of the MRSI pulse sequence itself. An eight-element head-coil array has been developed to inc...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910400204
更新日期:1998-08-01 00:00:00
abstract:PURPOSE:Endothelial nitric oxide synthase (eNOS) plays a central role in regulating vascular tone, blood flow, and microvascular permeability. Endothelial dysfunction, including eNOS dysfunction, is an early biomarker of vascular disease. This study aimed to show that myocardial T1 mapping during nitric oxide synthase ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26870
更新日期:2018-04-01 00:00:00
abstract::Accelerated magnetic resonance imaging techniques reduce signal acquisition time by undersampling k-space. A fundamental problem in accelerated magnetic resonance imaging is the recovery of quality images from undersampled k-space data. Current state-of-the-art recovery algorithms exploit the spatial and temporal stru...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24524
更新日期:2013-09-01 00:00:00
abstract::A simple (2)H NMR method for quantifying absolute (2)H-enrichments in all seven aliphatic positions of glucose following its derivatization to monoacetone glucose is presented. The method is based on the addition of a small quantity of (2)H-enriched formate to the NMR sample. When the method was applied to [2-(2)H]mon...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10234
更新日期:2002-09-01 00:00:00
abstract::The absolute partial pressure of oxygen (pO(2)) in the mammary gland pad and femoral muscle of female mice was measured using EPR oximetry at 700 MHz. A small quantity of lithium phthalocyanine (LiPc) crystals was implanted in both mammary and femoral muscle tissue of female C3H mice. Subsequent EPR measurements were ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20714
更新日期:2005-12-01 00:00:00
abstract:PURPOSE:To design short parallel transmission (pTx) pulses for excitation of arbitrary three-dimensional (3D) magnetization patterns. METHODS:We propose a joint optimization of the pTx radiofrequency (RF) and gradient waveforms for excitation of arbitrary 3D magnetization patterns. Our optimization of the gradient wav...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26021
更新日期:2016-10-01 00:00:00