Abstract:
PURPOSE:To achieve artifact-suppressed whole-brain pass-band-balanced steady-state free precession functional MRI from a single functional magnetic resonance imaging (fMRI) scan. METHODS:A complete and practical data acquisition sequence for alt-SSFP fMRI was developed. First, multishot flyback-echo-planar imaging (EPI) and echo-time shifting were used to achieve data acquisition that was robust against eddy currents, gradient delays, and ghosting artifacts. Second, a steady-state catalyzation scheme was implemented to reduce oscillations in the transient signal when catalyzing in and out of alternate steady states. Next, a short spatial-spectral radiofrequency (RF) pulse was designed to achieve excellent fat-suppression while maintaining a repetition time <15 ms to sensitize functional activation toward smaller vessels and capillaries. Lastly, parallel imaging was used to achieve whole-brain coverage and sufficiently high temporal resolution. RESULTS:Breath-hold experiments showed excellent fat-suppression and alt-SSFP's capability to recover functional sensitivity from signal dropout regions of conventional gradient-echo and banding artifacts from conventional pass-band-balanced steady-state free precession. Applying fat-suppression resulted in improved activation maps and increased temporal SNR. Visual stimulus functional studies verify the proposed method's excellent functional sensitivity to neuronal activation. CONCLUSION:Artifact-suppressed images are demonstrated, showing a practical pass-band-balanced steady-state free precession fMRI method that permits whole-brain imaging with excellent blood oxygen level-dependent sensitivity and fat suppression.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Jou T,Patterson S,Pauly JM,Bowen CVdoi
10.1002/mrm.25797subject
Has Abstractpub_date
2016-05-01 00:00:00pages
1978-88issue
5eissn
0740-3194issn
1522-2594journal_volume
75pub_type
杂志文章abstract:PURPOSE:To propose an explicit Balanced steady-state free precession (bSSFP) signal model that predicts eddy current-induced steady-state disruptions and to provide a prospective, practical, and general eddy current compensation method. THEORY AND METHODS:Gradient impulse response functions (GIRF) were used to simulat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28097
更新日期:2020-07-01 00:00:00
abstract::The use of phase correlation to detect rigid-body translational motion is reviewed and applied to individual echotrains in turbo-spin-echo data acquisition. It is shown that when the same echotrain is acquired twice, the subsampled correlation provides an array of delta-functions, from which the motion that occurred b...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21883
更新日期:2009-03-01 00:00:00
abstract:PURPOSE:Spiral-based trajectories for magnetic resonance imaging can be advantageous, but are often cumbersome to design or create. This work presents a flexible numerical algorithm for designing trajectories based on explicit definition of radial undersampling, and also gives several analytical expressions for charact...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24675
更新日期:2014-01-01 00:00:00
abstract:PURPOSE:To obtain whole-brain high-resolution T2 maps in 2 minutes by combining simultaneous multislice excitation and low-power PINS (power independent of number of slices) refocusing pulses with undersampling and a model-based reconstruction. METHODS:A multi-echo spin-echo sequence was modified to acquire multiple s...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27890
更新日期:2019-12-01 00:00:00
abstract:PURPOSE:The use of electromagnetic (EM) modeling is critical for specific absorption rate (SAR) characterization in parallel transmission MRI. Radiofrequency arrays that include decoupling networks can be difficult to characterize accurately in simulation. A practical method of simplifying modeling is to exclude the de...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25504
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abstract::A new contrast preparation based on modified driven equilibrium Fourier transfer is introduced and evaluated for generation of T1-weighted images for assessment of the myocardial perfusion with contrast agent first-pass kinetics. The new preparation scheme produces T1 contrast with insensitivity to arrhythmias in pros...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:1995-10-01 00:00:00
abstract:PURPOSE:Going to ultrahigh field MRI (e.g., 7 Tesla [T]), the nonuniformity of the B1+ field and the increased radiofrequency (RF) power deposition become challenging. While surface coils improve the power efficiency in B1+, its field remains nonuniform. In this work, an RF pulse was designed that uses the slab selecti...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25415
更新日期:2015-08-01 00:00:00
abstract::MRI after a constant infusion (CI) of Gd-DTPA has been used to identify the extent of myocardial infarction (MI). However, Gd-DTPA-enhanced "viability" imaging is more commonly performed with a bolus (for "delayed-enhancement" (DE) imaging). This study sought to determine how image delay time and time postinfarction i...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2004-11-01 00:00:00
abstract:PURPOSE:Investigation of the feasibility to perform high-resolution quantitative sodium imaging at 9.4 Tesla (T). METHODS:A proton patch antenna was combined with a sodium birdcage coil to provide a proton signal without compromising the efficiency of the X-nucleus coil. Sodium density weighted images with a nominal r...
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更新日期:2018-07-01 00:00:00
abstract:PURPOSE:To characterize and optimize 19 F MRI for different perfluorocarbons (PFCs) at 3T and quantify the loss of acquisition efficiency as a function of different temperature and cellular conditions. METHODS:The T1 and T2 relaxation times of the commonly used PFCs perfluoropolyether (PFPE), perfluoro-15-crown-5-ethe...
journal_title:Magnetic resonance in medicine
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abstract::A new ultrafast MR imaging method is proposed and tested, which enables whole-brain fMRI with a true temporal resolution of 1 sec. The method combines a 3D PRESTO pulse sequence with the concept of sensitivity-encoding with multiple receiver coils (SENSE). The so-called PRESTO-SENSE technique is demonstrated on a set ...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/1522-2594(200006)43:6<779::aid-mrm1>3.0.co
更新日期:2000-06-01 00:00:00
abstract::To enhance contrast between flow and static tissue, NMR projective angiographic methods usually require data subtraction, or alternatively the application of special data processing routines such as the "maximum intensity projection" algorithm. We have successfully developed a direct projection method which yields suf...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910180213
更新日期:1991-04-01 00:00:00
abstract::Quantitative magnetization transfer imaging yields indices describing the interactions between free water protons and immobile, macromolecular protons-including the macromolecular to free pool size ratio (PSR) and the rate of magnetization transfer between pools k(mf) . This study describes the first implementation of...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.22928
更新日期:2011-11-01 00:00:00
abstract:PURPOSE:To optimize and investigate the influence of bipolar gradients for flow suppression in metabolic quantification of hyperpolarized 13 C chemical shift imaging (CSI) of mouse liver at 9.4 T. METHODS:The trade-off between the amount of flow suppression using bipolar gradients and T2* effect from static spins was ...
journal_title:Magnetic resonance in medicine
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更新日期:2017-11-01 00:00:00
abstract:PURPOSE:To study the feasibility of black-blood contrast in native T1 mapping for reduction of partial voluming at the blood-myocardium interface. METHODS:A saturation pulse prepared heart-rate-independent inversion recovery (SAPPHIRE) T1 mapping sequence was combined with motion-sensitized driven-equilibrium (MSDE) b...
journal_title:Magnetic resonance in medicine
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更新日期:2017-08-01 00:00:00
abstract::In past decades, much effort has been invested in developing therapies for spinal injuries. Lack of standardization of clinical read-out measures, however, makes direct comparison of experimental therapies difficult. Damage and therapeutic effects in vivo are routinely evaluated using rather subjective behavioral test...
journal_title:Magnetic resonance in medicine
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更新日期:2006-05-01 00:00:00
abstract:PURPOSE:Multi-echo spin-echo (MSE) transverse relaxometry mapping using multi-component models is used to study disease activity in neuromuscular disease by assessing the T2 of the myocytic component (T2water ). Current extended phase graph algorithms are not optimized for fat fractions above 50% and the effects of ina...
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更新日期:2016-02-01 00:00:00
abstract:PURPOSE:Classification of pediatric brain tumors from 1 H-magnetic resonance spectroscopy (MRS) can aid diagnosis and management of brain tumors. However, varied incidence of the different tumor types leads to imbalanced class sizes and introduces difficulties in classifying rare tumor groups. This study assessed diffe...
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更新日期:2017-06-01 00:00:00
abstract::Patient motion and image distortion induced by eddy currents cause artifacts in maps of diffusion parameters computed from diffusion-weighted (DW) images. A novel and comprehensive approach to correct for spatial misalignment of DW imaging (DWI) volumes acquired with different strengths and orientations of the diffusi...
journal_title:Magnetic resonance in medicine
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更新日期:2004-01-01 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...
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更新日期:2017-02-01 00:00:00
abstract:PURPOSE:To develop a method based on fat-water transition region extraction (TREE) for robust fat-water separation and quantification in challenging scenarios, including low signal-to-noise ratio (SNR), fast changing B0 field, and disjointed anatomies. THEORY AND METHODS:In TREE method, the phasor solutions of each pi...
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更新日期:2019-07-01 00:00:00
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journal_title:Magnetic resonance in medicine
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更新日期:1989-09-01 00:00:00
abstract:PURPOSE:To assess the impact of a different distortion correction (DC) method and patient geometry (sagittal balance) on the quality of spinal cord tractography rendering according to different tractography approaches. METHODS:Forty-four adults free of spinal cord diseases underwent cervical diffusion-weighted imaging...
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更新日期:2021-01-21 00:00:00
abstract:PURPOSE:MR elastography (MRE) of the brain is being explored as a biomarker of neurodegenerative disease such as dementia. However, MRE measures for healthy brain have varied widely. Differing wave delivery methodologies may have influenced this, hence finite element-based simulations were performed to explore this pos...
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pub_type: 杂志文章
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更新日期:2017-07-01 00:00:00
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更新日期:2015-08-01 00:00:00
abstract::Magnetoferritin nanoparticles have been developed as high-relaxivity, functional contrast agents for MRI. Several previous techniques have relied on unloading native ferritin and re-incorporation of iron into the core, often resulting in a polydisperse sample. Here, a simplified technique is developed using commercial...
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更新日期:2010-11-01 00:00:00
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更新日期:2016-11-01 00:00:00