Abstract:
:In this manuscript, fast and clinically feasible model-based bootstrapping algorithms using a geometrically constrained two-tensor diffusion model are employed for estimating uncertainty in fiber orientation. A Monte-Carlo-based tensor morphology voxel classification algorithm is initially applied using single-tensor bootstrap samples before the use of a two-tensor model-based bootstrapping algorithm. Classification of tensor morphologies allows the tensor morphology to be considered when selecting the most appropriate bootstrap procedure. A constrained two-tensor model approach can greatly reduce data acquisition and computational times for whole bootstrap data volume generation compared to other multifiber model techniques, facilitating widespread clinical use. For comparison, we propose a new repetition-bootstrap algorithm based on classified voxels and the constrained two-tensor model. Tractography with these bootstrapping algorithms is also developed to estimate the connection probabilities between brain regions, especially regions with complex fiber configurations. Experimental results on synthetic data, a hardware phantom and human brain data demonstrate the superior performance of our algorithms compared to conventional approaches.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Ratnarajah N,Simmons A,Bertoni M,Hojjatoleslami Adoi
10.1016/j.mri.2012.07.004subject
Has Abstractpub_date
2013-02-01 00:00:00pages
296-312issue
2eissn
0730-725Xissn
1873-5894pii
S0730-725X(12)00280-9journal_volume
31pub_type
杂志文章abstract::More than a dozen Nuclear Magnetic Resonance (NMR) imaging methods have been described using different radio-frequency pulse sequences, magnetic field gradient variations, and data processing. In order to have a theoretical understanding in the most general case, we have conceived a computer program for the simulation...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(84)90065-1
更新日期:1984-01-01 00:00:00
abstract::Magic-angle sample spinning is one of the cornerstones in high-resolution NMR of solid and semisolid materials. The technique enhances spectral resolution by averaging away rank 2 anisotropic spin interactions, thereby producing isotropic-like spectra with resolved chemical shifts and scalar couplings. In principle, i...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.11.067
更新日期:2005-02-01 00:00:00
abstract::In-plane flow quantification in MRI offers the potential for assessing vessel patency, and both volume flow rate and flow velocity. These techniques will have definite future impact on MR angiography. The method used in this paper employs motion artifact suppression technique (MAST) gradients to refocus spins travelli...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90409-2
更新日期:1988-05-01 00:00:00
abstract::We report the MR appearance of undifferentiated (embryonal) sarcoma of the liver (USL) in a 13-year-old female who presented with a 1-year history of intermittent abdominal pain, weight loss, and fatigue. The tumor was a large, solitary, well-defined focal mass lesion with multiple cystic spaces, septations, and subst...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.02.003
更新日期:2004-07-01 00:00:00
abstract::Metabolic imaging of hyperpolarized [1-(13)C] pyruvate co-polarized with [(13)C]urea by dynamic nuclear polarization with rapid dissolution is a promising new method for assessing tumor metabolism and perfusion simultaneously in vivo. Novel pulse sequences are required to enable dynamic imaging of multiple (13)C spect...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.06.037
更新日期:2013-02-01 00:00:00
abstract::In this study, in order to differentiate cavernous hemangioma and hepatic metastases, rapid acquisition relaxation enhanced (RARE) sequence was used. First, in vivo measurements of T1, T2 relaxation times and proton density were obtained using T1, T2 calculation protocol (TOMIKON S50, 0.5T) and multipoint techniques. ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(99)00008-9
更新日期:1999-06-01 00:00:00
abstract::The goal of this study was to develop and evaluate high-resolution magnetic resonance spectroscopic imaging (MRSI) utilizing the gains in signal-to-noise ratio (SNR) provided by combining higher magnetic field with high-sensitivity phased-array (PA) coils. We investigated the maximum improvement in spatial resolution ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2005.10.019
更新日期:2006-01-01 00:00:00
abstract::Functional magnetic resonance imaging (fMRI) has found widespread clinical interest. Difficulties in clinical use of the fMRI technique arise, considering the lack of knowledge about activation task performance. This accounts especially for sensorimotor activation studies, in which performance of the sensorimotor acti...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(95)02052-u
更新日期:1996-01-01 00:00:00
abstract::Increasing scientific interest in the zebrafish as a model organism across a range of biomedical and biological research areas raises the need for the development of in vivo imaging tools appropriate to this subject. Development of the embryonic and early stage forms of the subject can currently be assessed using opti...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.10.013
更新日期:2017-04-01 00:00:00
abstract::Quantitative MRI of neuromelanin (NM) containing structures (referred to as NM-MRI) in the brainstem, namely the locus coeruleus (LC) and substantia nigra (SN), may assist with the early detection of Parkinson's disease (PD) and Alzheimer's disease (AD) as well as differential diagnosis in the early disease stages. In...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.07.003
更新日期:2014-12-01 00:00:00
abstract:PURPOSE:To provide a comprehensive understanding of multi-shot EPI diffusion imaging methods by comparing Readout segmented EPI (RS-EPI) and interleaved EPI (iEPI). MATERIALS AND METHODS:RS-EPI and iEPI were compared on the same 3T scanner. A 2D navigator was used for both RS-EPI and iEPI for phase correction. Signal ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2017.11.011
更新日期:2018-04-01 00:00:00
abstract:PURPOSE:To develop a method for estimating metabolite concentrations using phased-array coils and sensitivity-encoded (SENSE) magnetic resonance spectroscopic images (MRSI) of the human brain. MATERIALS AND METHODS:The method is based on the phantom replacement technique and uses receive coil sensitivity maps and body...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2009.11.003
更新日期:2010-04-01 00:00:00
abstract::Although there is ample evidence in the literature for structural, functional and physiological asymmetries in the two hemispheres of human brain, direct evidence of a similar asymmetry in the in vivo distribution of brain metabolites has been lacking. In this study, the existence of chemical asymmetries in six differ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00342-6
更新日期:1997-01-01 00:00:00
abstract::In this contribution, we report results from MRI studies of the propagation of heavy metal ions through columns packed with sandy aquifer materials. Both sorption of low concentrations of heavy metal ions from water flowing through the column and the formation of sorption traces produced from initially localized highe...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(03)00166-8
更新日期:2003-04-01 00:00:00
abstract::Microscopic magnetic resonance elastography is a high-resolution method for visualizing shear waves and assessing the biomechanical viscoelastic properties of small biological samples. In this work, we used error propagation to develop a simple analytical model that relates the signal-to-noise ratio of MR magnitude im...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.09.040
更新日期:2007-01-01 00:00:00
abstract:PURPOSE:To assess the sensitivity and specificity of intra-plaque hemorrhage (IPH), large lipid-rich necrotic core (LR-NC) and ulceration or cap rupture (UCR) for symptomatic carotid plaque characterization and to evaluate a new imaging score [Hemorrhage, Ulceration or cap rupture, Lipid-rich necrotic Core (HULC) score...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.04.024
更新日期:2012-12-01 00:00:00
abstract::Pulsed arterial spin labeling (PASL) is an increasingly common technique for noninvasively measuring cerebral blood flow (CBF) and has previously been shown to have good repeatability. It is likely to find a place in clinical trials and in particular the investigation of pharmaceutical agents active in the central ner...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2011.02.030
更新日期:2011-12-01 00:00:00
abstract::T2-weighted images are considered the most sensitive for lesion detection at high field; however, long imaging time is problematic. Accordingly, the authors compared four breath-hold T2 or T2* weighted sequences comprising T2*-weighted FLASH, T2*-weighted PSIF, T2-weighted rapid spin echo (RASE), and T2-weighted Turbo...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(92)90371-6
更新日期:1992-01-01 00:00:00
abstract::Glioblastoma Multiforme is the most common and most aggressive type of brain tumors. Although accurate prediction of Glioblastoma borders and shape is absolutely essential for neurosurgeons, there are not many in silico platforms that can make such predictions. In the current study, an automatic patient-specific simul...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.12.012
更新日期:2020-05-01 00:00:00
abstract::Echo planar imaging (EPI) was extended for the acquisition of both, the spin-echo (SE) and the stimulated echo in a stimulated echo sequence after one excitation from thermal equilibrium. The two independent EPI images reflect different states of the transverse magnetization excited and measured almost simultaneously....
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)91234-n
更新日期:1994-01-01 00:00:00
abstract::Magnetic resonance imaging (MRI) and spectroscopy (MRS) have contributed considerably to clinical radiology, and a variety of MR techniques have been developed to evaluate pathological processes as well as normal tissue biology at the cellular and molecular level. However, in comparison to nuclear imaging, MRI has rel...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.12.008
更新日期:2017-05-01 00:00:00
abstract::Functional T1ρ mapping has been proposed as a method to assess pH and metabolism dynamics in the brain with high spatial and temporal resolution. The purpose of this work is to describe and evaluate a variant of the spin-locked echo-planar imaging sequence for functional T1ρ mapping at 3T. The proposed sequence rapidl...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.07.010
更新日期:2014-11-01 00:00:00
abstract::Poly(L-glutamic acid) (PGA)-cystamine-[gadolinium (Gd)-DO3A] was prepared in high yield with a high Gd-DO3A conjugation efficiency. Approximately 55% of the carboxylic groups in PGA were loaded with Gd-DO3A via cystamine as the spacer. Cystamine can be readily cleaved by endogenous thiols to release the Gd(III) chelat...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.03.009
更新日期:2006-09-01 00:00:00
abstract:PURPOSE:The purpose was to validate diffusion-weighted imaging (DWI) in the assessment of hepatic metastases compared with superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging. MATERIALS AND METHODS:For 21 consecutive patients with 160 metastases from extrahepatic malignancy and 25 benign focal lesi...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2011.12.007
更新日期:2012-05-01 00:00:00
abstract::Magnetic field gradients play a fundamental role in MR imaging and localized spectroscopy. The MRI experiment, in particular fast MRI, relies on precise gradient switching, which has become more demanding with the constantly growing number of fast imaging techniques. Here we present a simple MR method to measure the b...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.02.002
更新日期:2007-11-01 00:00:00
abstract::The discrimination of tumor boundaries from normal tissue, as well as the evaluation of tissue heterogeneity and tumor grading often continue to pose a challenge in MRI. Although yielding promising results in various fields of medical imaging, two- dimensional (2D) texture analysis in MRI has, until now, demonstrated ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(03)00201-7
更新日期:2003-11-01 00:00:00
abstract::Gd-DOTA contrast enhancement of MR images was evaluated on induced mammary tumors in female rats. A single intravenous injection of the carcinogenic N-nitrosourea ENU was administered to Wistar rats; this simple treatment led to a high percentage of mammary tumors without causing death. All the induced tumors were ade...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(90)90215-n
更新日期:1990-01-01 00:00:00
abstract:OBJECTIVES:To compare the accuracy of contrast-enhanced ultrasound (CEUS) and Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for the assessment of changes in tissue vascularization as result of sorafenib treatment in a rat model of hepatocellular carcinoma (HCC). METHODS:Male Buffalo rats with orthot...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.11.012
更新日期:2019-04-01 00:00:00
abstract::Acetaminophen (APAP) toxicity is responsible for approximately half of all cases of acute liver failure in the United States. The mouse model of APAP toxicity is widely used to examine mechanisms of APAP toxicity. Noninvasive approaches would allow for serial measurements in a single animal to study the effects of exp...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2011.09.023
更新日期:2012-02-01 00:00:00
abstract::Twenty-seven patients with soft-tissue tumors were examined with a Picker 0.15-tesla resistive magnet and by computed tomography (CT). In all but one patient, MRI was better than or equal to CT in defining the anatomic extent of the tumor. We could determine whether major vascular structures were engulfed by the tumor...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(85)90398-4
更新日期:1985-01-01 00:00:00