Abstract:
PURPOSE:To develop a fast and accurate method for 3D T2 mapping of prostate cancer using undersampled acquisition and dictionary-based fitting. METHODS:3D high-resolution T2 -weighted images (0.9 × 0.9 × 3 mm3 ) were obtained with a multishot T2 -prepared balanced steady-state free precession (T2 -prep-bSSFP) acquisition sequence using a 3D variable density undersampled Cartesian trajectory. Each T2 -weighted image was reconstructed using total variation regularized sensitivity encoding. A flexible simulation framework based on extended phase graphs generated a dictionary of magnetization signals, which was customized to the proposed sequence. The dictionary was matched to the acquired T2 -weighted images to retrieve quantitative T2 values, which were then compared to gold-standard spin echo acquisition values using monoexponential fitting. The proposed approach was validated in simulations and a T1 /T2 phantom, and feasibility was tested in 8 healthy subjects. RESULTS:The simulation analysis showed that the proposed T2 mapping approach is robust to noise and typically observed T1 variations. T2 values obtained in the phantom with T2 prep-bSSFP and the acquisition-specific, dictionary-based matching were highly correlated with the gold-standard spin echo method (r = 0.99). Furthermore, no differences were observed with the accelerated acquisition compared to the fully sampled acquisition (r = 0.99). T2 values obtained in prostate peripheral zone, central gland, and muscle in healthy subjects (age, 26 ± 6 years) were 97 ± 14, 76 ± 7, and 36 ± 3 ms, respectively. CONCLUSION:3D quantitative T2 mapping of the whole prostate can be achieved in 3 minutes.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Roccia E,Vidya Shankar R,Neji R,Cruz G,Munoz C,Botnar R,Goh V,Prieto C,Dregely Idoi
10.1002/mrm.27540subject
Has Abstractpub_date
2019-03-01 00:00:00pages
1795-1805issue
3eissn
0740-3194issn
1522-2594journal_volume
81pub_type
杂志文章abstract::Cerebral blood volume changes with arterial carbon dioxide were monitored by proton T1-weighted MR images following administration of the intravascular contrast agent Gd-DTPA labeled with human serum albumin. Without MR contrast, no significant image intensity changes were observed with PaCO2. Following contrast, regi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910230104
更新日期:1992-01-01 00:00:00
abstract::A number of techniques that recently have been used for fast NMR-imaging are based on a hybrid sequence of echo planar imaging (EPI) and FLASH imaging: after each NMR excitation several k-space lines are measured. The complete k-space is covered by performance of several excitations. It has been observed that there is...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910340328
更新日期:1995-09-01 00:00:00
abstract::Functional MRI (fMRI) was used to assess proprioceptive-associated cervical cord activity in 24 relapsing multiple sclerosis (MS) patients and 10 controls. Cord and brain conventional and diffusion tensor (DT) MRI were also acquired. fMRI was performed using a block design during a proprioceptive stimulation consistin...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21595
更新日期:2008-05-01 00:00:00
abstract::Whole-body NMR imaging antennas (probes) are strongly affected by the inevitable magnetic and controllable dielectric losses. Using a convenient parallelepiped model, the magnetic losses are evaluated. By introducing the "ideal power gain," the best possible antenna performance is delimited as a function of the freque...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910020403
更新日期:1985-08-01 00:00:00
abstract:PURPOSE:Application of phase rotation to the STRESS (=STEAM+PRESS) localization scheme, to shorten echo time, minimize J-coupling dephasing and estimate B1+ inhomogeneity. STRESS (=STEAM + PRESS) simultaneously refocuses and acquires the double spin echo (SE123 ) and stimulated echo (STE- ) pathways, combining PRESS-li...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26911
更新日期:2018-05-01 00:00:00
abstract::The previously observed improvement in spectral resolution of tissue proton NMR with high-resolution magic angle spinning (HRMAS) was speculated to be due largely to freeze-thawing artifacts resulting from tissue storage. In this study, 12 human prostate samples were analyzed on a 14.1T spectrometer at 3 degrees C, wi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10645
更新日期:2003-12-01 00:00:00
abstract:PURPOSE:Previous studies have associated low pH in intervertebral discs (IVDs) with discogenic back pain. The purpose of this study was to determine whether quantitative CEST (qCEST) MRI can be used to detect pH changes in IVDs in vivo. METHODS:The exchange rate ksw between glycosaminoglycan (GAG) protons and water pr...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26457
更新日期:2016-12-01 00:00:00
abstract::Fucose is believed to be a marker for cancer that may be detectable by the 2D proton NMR (COSY) of human plasma. However, the COSY technique is time consuming and prone to error. These problems may be alleviated by using the SUPERCOSY pulse sequence; this technique shows that there are many other cross peaks in the re...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910150102
更新日期:1990-07-01 00:00:00
abstract::For diffusion-weighted magnetic resonance imaging and under circumstances where patient movement can be modeled as rigid body motion, it is shown both theoretically and experimentally that translations and rotations produce phase errors which are zero- and first-order, respectively, in position. While a navigator echo...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320313
更新日期:1994-09-01 00:00:00
abstract::A novel multiple quantum filtering method is proposed that uses a doubly selective pulse termed Delays Alternating with Nutations for Tailored Excitation (DANTE) for multiple quantum preparation. This method selectively prepares GABA-3 and GABA-4 into a multiple quantum state and suppresses all other resonances at 3.0...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10104
更新日期:2002-03-01 00:00:00
abstract::A new k-space direct matrix inversion (DMI) method is proposed here to accelerate non-Cartesian SENSE reconstructions. In this method a global k-space matrix equation is established on basic MRI principles, and the inverse of the global encoding matrix is found from a set of local matrix equations by taking advantage ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20974
更新日期:2006-08-01 00:00:00
abstract:PURPOSE:For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) has been shown to generate superior results compared with random sampling methods. However, due to its limited flexibility to incorporate additional constraints, PDS is not readily extendible to dynamic applications. Here, w...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25507
更新日期:2015-11-01 00:00:00
abstract:PURPOSE:To introduce and evaluate an image registration technique for robust quantification of CEST acquisitions corrupted by motion. METHODS:The proposed iterative algorithm exploits a low-rank approximation of the z-spectrum (LRAZ), to gradually separate the contrast variation due to saturation at different off-reso...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27206
更新日期:2018-11-01 00:00:00
abstract::Advances in modern magnetic resonance imaging (MRI) pulse sequences have enabled clinically practical cortical bone imaging. Human cortical bone is known to contain a distribution of T(1) and T(2) components attributed to bound and pore water, although clinical imaging approaches have yet to discriminate bound from po...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24186
更新日期:2012-12-01 00:00:00
abstract::Atherosclerosis initially develops predominantly at the aortic root and carotid origin, where effective visualization in mice requires efficient cardiac and respiratory gating. The present study sought to first compare the high-resolution MRI gating performance of two digital gating strategies using: 1) separate cardi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21308
更新日期:2007-12-01 00:00:00
abstract:PURPOSE:We sought to assess whether machine learning-based classification approaches can improve the classification of pancreatic tumor models relative to more simplistic analysis methods, using T1 relaxation, CEST, and DCE MRI. METHODS:The T1 relaxation time constants, % CEST at five saturation frequencies, and vascu...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27439
更新日期:2019-01-01 00:00:00
abstract::A novel method for detecting neural activity in functional magnetic resonance imaging (fMRI) data is introduced. It is based on canonical correlation analysis (CCA), which is a multivariate extension of the univariate correlation analysis widely used in fMRI. To detect homogeneous regions of activity, the method combi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200102)45:2<323::aid-mrm1041>3.0
更新日期:2001-02-01 00:00:00
abstract::Partially parallel imaging strategies such as SMASH, SENSE, and PILS rely on the sensitivity distribution of phased array RF coils to reduce MRI imaging time. Using an N-element phased array, these techniques allow maximum accelerations, L, such that L < or = N, with acceleration defined as the factor by which scan ti...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10113
更新日期:2002-04-01 00:00:00
abstract::Pulsed arterial spin labeling (ASL) techniques provide a noninvasive method of obtaining qualitative and quantitative perfusion images with MRI. ASL techniques employ inversion recovery and/or saturation recovery to induce perfusion weighting, and thus the performance of these techniques is dependent on the slice prof...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1169
更新日期:2001-07-01 00:00:00
abstract::A new model of compartmentalized relaxation--that which occurs for spins (protons) exchanging between compartments of different relaxation rates--is presented. This model generalizes previous ones by allowing spatially dependent relaxation within compartments. Solutions for the diffusion-Bloch equations are found via ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910370507
更新日期:1997-05-01 00:00:00
abstract:PURPOSE:Quantitative evaluation of dynamic contrast enhanced MRI (DCE-MRI) allows for estimating perfusion, vessel permeability, and tissue volume fractions by fitting signal intensity curves to pharmacokinetic models. These compart mental models assume rapid equilibration of contrast agent within each voxel. However, ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26995
更新日期:2018-07-01 00:00:00
abstract::The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the m...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22169
更新日期:2010-01-01 00:00:00
abstract::A study was made of the in vivo detectability of a pH-sensitive, imidazolidine spin probe, and the efficacy of low-frequency electron spin resonance (ESR)-based techniques for pH measurement in vitro and in vivo in rats. The techniques used were longitudinally-detected ESR (LODESR) and field-cycled dynamic nuclear pol...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10392
更新日期:2003-03-01 00:00:00
abstract:PURPOSE:Cardiac T1 mapping has become an increasingly important imaging technique, contributing novel diagnostic options. However, currently utilized methods are often associated with accuracy problems because of heart rate variations and cardiac arrhythmia, limiting their value in clinical routine. This study aimed to...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27526
更新日期:2019-03-01 00:00:00
abstract::The purpose of this study was to determine the value of a blood-pool contrast media (NC100150, Nycomed Imaging (now Amersham Health) Oslo, Norway) for evaluation of venous thrombosis of the deep veins of the pelvis and lower extremities. Twelve patients were prospectively evaluated with conventional X-ray venography (...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1002/mrm.10607
更新日期:2003-11-01 00:00:00
abstract:PURPOSE:Intracranial and intraspinal compliance are parameters of interest in the diagnosis and prediction of treatment outcome in patients with normal pressure hydrocephalus and other forms of communicating hydrocephalus. A noninvasive method to estimate the spinal cerebrospinal fluid (CSF) pulse wave velocity (PWV) a...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28430
更新日期:2021-01-01 00:00:00
abstract::The analysis of abdominal and thoracic dynamic contrast-enhanced MRI is often impaired by artifacts and misregistration caused by physiological motion. Breath-hold is too short to cover long acquisitions. A novel multipurpose reconstruction technique, entitled dynamic contrast-enhanced generalized reconstruction by in...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22644
更新日期:2011-03-01 00:00:00
abstract:PURPOSE:The objective of this study was to determine whether a sodium phased array would improve sodium breast MRI at 3 T. The secondary objective was to create acceptable proton images with the sodium phased array in place. METHODS:A novel composite array for combined proton/sodium 3 T breast MRI is compared with a c...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24860
更新日期:2014-06-01 00:00:00
abstract:PURPOSE:To systematically evaluate the dependence of intravoxel-incoherent-motion (IVIM) parameters on the b-value threshold separating the perfusion and diffusion compartment, and to implement and test an algorithm for the standardized computation of this threshold. METHODS:Diffusion weighted images of the upper abdo...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25506
更新日期:2015-11-01 00:00:00
abstract::We studied the fluxes of a potassium congener (Rb(+)) in mouse hearts by (87)Rb MRS at 8.4T. The hearts were loaded with Rb(+) by perfusion with Krebs-Henseleit buffer, in which 50% of K(+) was substituted with Rb(+). We initiated Rb(+) efflux by changing the perfusion medium to Rb(+)-free buffer. Spectra were acquire...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20450
更新日期:2005-05-01 00:00:00