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 simplified by using a suitable intravascular contrast agent. The proposed method, contrast-enhanced MR fluoroscopy, combines tracking and angiography into a single sequence and allows direct visualization of the magnetically prepared parts of catheters and guidewires with respect to the vasculature at a frame rate of about one image per 1.5 seconds. Contrast-enhanced MR fluoroscopy, although still limited in temporal resolution, thus obviates the need for subtraction and overlay techniques and eliminates the sensitivity of tracking to subject motion between acquisitions. Magn Reson Med 45:17-23, 2001.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Bakker CJ,Bos C,Weinmann HJdoi
10.1002/1522-2594(200101)45:1<17::aid-mrm1003>3.0.subject
Has Abstractpub_date
2001-01-01 00:00:00pages
17-23issue
1eissn
0740-3194issn
1522-2594pii
10.1002/1522-2594(200101)45:1<17::AID-MRM1003>3.0.journal_volume
45pub_type
杂志文章abstract::Compressed sensing has been of great interest to speed up the acquisition of MR images. The k-t group sparse (k-t GS) method has recently been introduced for dynamic MR images to exploit not just the sparsity, as in compressed sensing, but also the spatial group structure in the sparse representation. k-t GS achieves ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24333
更新日期:2013-04-01 00:00:00
abstract:PURPOSE:The optic nerve (ON) represents the sole pathway between the eyes and brain; consequently, diseases of the ON can have dramatic effects on vision. However, quantitative magnetization transfer (qMT) applications in the ON have been limited to ex vivo studies, in part because of the fatty connective tissue that s...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26164
更新日期:2017-02-01 00:00:00
abstract::Optimization of experimental settings of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), like the contrast administration protocol, is of great importance for reliable quantification of the microcirculatory properties, such as the volume transfer-constant K(trans). Using system identification theory an...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21575
更新日期:2008-05-01 00:00:00
abstract::Multichannel transmission has the potential to improve many aspects of MRI through a new paradigm in excitation. In this study, multichannel transmission is used to address the effects that variations in B(0) homogeneity have on fat-saturation preparation through the use of the frequency, phase, and amplitude degrees ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23238
更新日期:2012-08-01 00:00:00
abstract::Sequential albumin-Gd-DTPA and Gd-DTPA dynamic enhancement studies were performed in an animal tumor model for the comparison of regional vascularity and permeability parameters measured by these two different sizes of contrast agents. The early albumin-Gd-DTPA enhancement arises from the vascular compartment, and the...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910340318
更新日期:1995-09-01 00:00:00
abstract::A novel iterative k-space data-driven technique, namely parallel reconstruction using null operations (PRUNO), is presented for parallel imaging reconstruction. In PRUNO, both data calibration and image reconstruction are formulated into linear algebra problems based on a generalized system model. An optimal data cali...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22899
更新日期:2011-11-01 00:00:00
abstract:PURPOSE:Recently, natural d-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using d-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. METHODS:Mice were inoculated orthotopically with human U87-EGFRvIII gliom...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25995
更新日期:2015-12-01 00:00:00
abstract::The incoherent displacement of water in living tissues is of considerable interest because of the widespread use of diffusion-weighted MRI, for which image contrast is based on the water apparent diffusion coefficient (ADC). It has been hypothesized that the decrease in water ADC associated with brain injury is primar...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10181
更新日期:2002-07-01 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
pub_type: 杂志文章
doi:10.1002/mrm.25799
更新日期:2016-05-01 00:00:00
abstract::The complexity of biologic tissues, with multiple compartments each with its own diffusion and relaxation properties, requires complex formalisms to model water signal in most magnetic resonance imaging or magnetic resonance spectroscopy experiments. In this article, we describe a magnetic susceptibility-induced shift...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20565
更新日期:2005-07-01 00:00:00
abstract:PURPOSE:MRI-guided thermal ablations require reliable monitoring methods to ensure complete destruction of the diseased tissue while avoiding damage to the surrounding healthy tissue. Based on the fact that thermal ablations result in substantial changes in biomechanical properties, interventional MR elastography (MRE)...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25694
更新日期:2016-03-01 00:00:00
abstract::Trifluoroacetate and trifluoroacetamide, when added to a suspension of human red blood cells, give rise to separate 19F NMR signals from the intra- and extracellular species. This phenomenon has recently been exploited for measuring the membrane potential of erythrocytes. However, the separation of the peaks was incor...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910180119
更新日期:1991-03-01 00:00:00
abstract:PURPOSE:To develop a method to use information from multiple MRI contrasts to produce a composite angiogram with reduced sequence-specific artifacts and improved vessel depiction. METHODS:Bayesian posterior vessel probability was determined as a function of black blood (BB), contrast enhanced angiography (CE-MRA), and...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27966
更新日期:2020-03-01 00:00:00
abstract::In vivo lactate detection using gradient enhanced double quantum coherence transfer (DQCT) was significantly improved by addition of short-time-inversion-recovery (STIR). Phantom studies demonstrated lipid suppression down to the background noise level with 33% loss of lactate signal. In vivo studies using a rabbit mo...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910400416
更新日期:1998-10-01 00:00:00
abstract::When developing new techniques for NMR imaging and in vivo spectroscopy it is a major advantage to be able to calculate the magnetization slice profiles, at any point during a pulse sequence in the presence of a field gradient. While this has frequently been done by treating the problem as a number of discrete resonan...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910050511
更新日期:1987-11-01 00:00:00
abstract:PURPOSE:Imaging of [2-13 C]lactate, a metabolic product of [2-13 C]pyruvate, is over considerable interest in hyperpolarized 13 C studies. However, artifact-free imaging of a J-coupled nuclear spin species can be challenging due to the peak-splitting induced by the spin-spin interactions. In this work, two new techniqu...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28532
更新日期:2021-03-01 00:00:00
abstract:PURPOSE:The clinical potential of the diffusion imaging-based analysis of fine brain structures such as fornix or cingulum is high due to the central role of these structures in psychiatric diseases. However, the quantification of diffusion parameters in fine structures is especially prone to partial volume effects (PV...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24774
更新日期:2014-03-01 00:00:00
abstract::For time-resolved background-subtracted contrast-enhanced magnetic resonance angiography, the bright and sparse arterial signal allows unique identification of contrast bolus arrival in the arteries. This article presents an automatic filtering algorithm using such arterial characterization for selecting arterial phas...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10358
更新日期:2002-12-01 00:00:00
abstract:PURPOSE:Structure-guided total variation is a recently introduced prior that allows reconstruction of images using knowledge of the location and orientation of edges in a reference image. In this work, we demonstrate the advantages of a variant of structure-guided total variation known as directional total variation (D...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28245
更新日期:2020-10-01 00:00:00
abstract::One-dimensional spectroscopic imaging of (13)C-4-glutamate turnover is performed in the human brain with a 6 cc nominal voxel resolution at 4T. Data were acquired with an indirect detection approach using a short spin echo single quantum (1)H-(13)C heteronuclear editing method and a 7 cm surface coil with quadrature (...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200011)44:5<673::aid-mrm3>3.0.co
更新日期:2000-11-01 00:00:00
abstract::Multiple-slice perfusion imaging by continuous arterial spin labeling (CASL) is made possible by amplitude modulation (AM) of the labeling RF pulse, but perfusion sensitivity is reduced relative to the single-slice technique. A computer model of the Bloch equations for velocity driven adiabatic fast passage was develo...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20604
更新日期:2005-09-01 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
pub_type: 杂志文章
doi:10.1002/mrm.25444
更新日期:2015-09-01 00:00:00
abstract:PURPOSE:To separate the spectrally overlapped lactate and lipid signals at 1.3 ppm using diffusion-weighted magnetic resonance spectroscopy (DW-MRS) based on their large diffusivity difference. METHODS:DW-MRS was applied to the gel phantoms containing lactate and lipid droplets, and to the rat brain tumors. Lactate an...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26144
更新日期:2017-02-01 00:00:00
abstract:PURPOSE:To demonstrate the feasibility of mapping gas exchange with single breath-hold hyperpolarized (HP) 129 Xe in humans, acquiring parametric maps of lung physiology. The potential benefit of acceleration using parallel imaging for this application is also explored. METHODS:Six healthy volunteers were scanned with...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27765
更新日期:2019-09-01 00:00:00
abstract::Metabolite signals with short T(1) or T(2) are difficult to localize with full sensitivity. This limitation was overcome with the development and implementation of a single-shot, complete three-dimensional "non-echo" localization method with reduced sensitivity to spatial B(1) variation, which is suitable for measurin...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200009)44:3<387::aid-mrm8>3.0.co
更新日期:2000-09-01 00:00:00
abstract:PURPOSE:To develop and test real-time MR elastography for viscoelastic parameter quantification in skeletal muscle during dynamic exercises. METHODS:In 15 healthy participants, 6 groups of lower-leg muscles (tibialis anterior, tibialis posterior, peroneus, extensor digitorum longus, soleus, gastrocnemius) were investi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28095
更新日期:2020-07-01 00:00:00
abstract:PURPOSE:Magnetic resonance imaging (MRI)-based techniques for assessing liver iron concentration (LIC) have been limited by single scanner calibration against biopsy. Here, the calibration of spin-density projection-assisted (SDPA) R2-MRI (FerriScan®) in iron-overloaded β-thalassemia patients treated with the iron chel...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章,多中心研究
doi:10.1002/mrm.24854
更新日期:2014-06-01 00:00:00
abstract::A multimodal MR study including relaxometry, diffusion tensor imaging (DTI), and MR spectroscopy was performed on patients with classical phenylketonuria (PKU) and matched controls, to improve our understanding of white matter (WM) lesions. Relaxometry yields information on myelin loss or malformation and may substant...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21422
更新日期:2007-12-01 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
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(199904)41:4<743::aid-mrm13
更新日期:1999-04-01 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
pub_type: 杂志文章
doi:10.1002/mrm.20977
更新日期:2006-09-01 00:00:00