Abstract:
:In this work, we report a case study of a stroke model in animals using two methods of quantification of the deviations from Gaussian behaviour: diffusion kurtosis imaging (DKI) and log-normal distribution function imaging (LNDFI). The affected regions were predominantly in grey rather than in white matter. The parameter maps were constructed for metrics quantifying the apparent diffusivity (evaluated from conventional diffusion tensor imaging, DKI and LNDFI) and for those quantifying the degree of deviations (mean kurtosis and a parameter σ characterising the width of the distribution). We showed that both DKI and LNDFI were able to dramatically enhance the visualisation of ischaemic lesions in comparison with conventional methods. The largest relative change in the affected versus healthy regions was observed in the mean kurtosis values. The average changes in the mean kurtosis and σ values in the lesions were a factor of two to three larger than the relative changes observed in the mean diffusivity. In conclusion, the applied methods promise valuable perspectives in the assessment of stroke.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Grinberg F,Ciobanu L,Farrher E,Shah NJdoi
10.1002/nbm.2802subject
Has Abstractpub_date
2012-11-01 00:00:00pages
1295-304issue
11eissn
0952-3480issn
1099-1492journal_volume
25pub_type
杂志文章abstract::The elimination of so-called background fields is an essential step in phase MRI and quantitative susceptibility mapping (QSM). Background fields, which are caused by sources outside the region of interest (ROI), are often one to two orders of magnitude stronger than tissue-related field variations from within the ROI...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.3604
更新日期:2017-04-01 00:00:00
abstract::Results of the evaluation of transrectal ultrasound (TRUS) guided needle biopsy of voxels identified as suspicious of malignancy on magnetic resonance spectroscopic imaging (MRSI) in a large cohort of men (n = 83) with abnormal digital rectal examination (DRE) [prostate specific antigen (PSA) 0-4 ng/ml] or PSA less th...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1083
更新日期:2007-02-01 00:00:00
abstract::The performance of multichannel transmit coil layouts and parallel transmission (pTx) RF pulse design was evaluated with respect to transmit B1 (B1 (+)) homogeneity and specific absorption rate (SAR) at 3 T for a whole body coil. Five specific coils were modeled and compared: a 32-rung birdcage body coil (driven eithe...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3378
更新日期:2015-10-01 00:00:00
abstract::The increased magnetic susceptibility effects at higher magnetic fields increase the demands for shimming of the B0 field for in vivo MRI and MRS. Both static and dynamic techniques have been developed to compensate for susceptibility-induced field inhomogeneities. In this study, we investigate the impact of and need ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3096
更新日期:2014-06-01 00:00:00
abstract::Renal urea handling is central to the urine concentrating mechanism, and as such the ability to image urea transport in the kidney is an important potential imaging biomarker for renal functional assessment. Glucagon levels associated with changes in dietary protein intake have been shown to influence renal urea handl...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4028
更新日期:2019-01-01 00:00:00
abstract::More than 50% of cancers fail to respond to any individual treatment and tumour follow-up after treatment plays a major role in routine therapy planning and pharmacological research. Today, MRS is the only technological approach providing non-invasive access to tumour biochemistry. Ten years ago, expectations were rai...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940060602
更新日期:1993-11-01 00:00:00
abstract::Free cytosolic [Mg2+] can be assessed in vivo by 31P MRS from the chemical shift of beta-ATP which in turn depends on the fraction of total ATP complexed to Mg2+ ions. The reliability of these in vivo measurements depends on the availability of an appropriate in vitro calibration to determine the limits of chemical sh...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(SICI)1099-1492(199602)9:1<24::AID-NBM392>
更新日期:1996-02-01 00:00:00
abstract::Proton NMR spectroscopy of biological fluids has produced interesting results lately. We used the technique to investigate the effects of cryopreservation on primary porcine hepatocytes as successful cryopreservation of primary porcine hepatocytes is of importance to the development of bioartificial liver support syst...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.765
更新日期:2002-05-01 00:00:00
abstract::In this study, Blood Oxygenation Level Dependent (BOLD) contrast in the detection of human brain activation was compared between spin-echo and gradient-echo echo-planar sequences at 1.5 T. Time course series of spin-echo and gradient-echo images containing the primary motor cortex were collected during rest (no finger...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940070104
更新日期:1994-03-01 00:00:00
abstract::Exercise studies investigating the metabolic response of calf muscles using 31 P MRS are usually performed with a single knee angle. However, during natural movement, the distribution of workload between the main contributors to force, gastrocnemius and soleus is influenced by the knee angle. Hence, it is of interest ...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.3905
更新日期:2018-06-01 00:00:00
abstract::A quantitative magnetization transfer (qMT) technique was employed to quantify the ratio of the sizes of the bound and free water proton pools in ex vivo mouse brains. The goal was to determine the pool size ratio sensitivity to myelin. Fixed brains from both shiverer mice and control littermates were imaged. The pool...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1358
更新日期:2009-06-01 00:00:00
abstract::The goal of this study was to validate metabolite quantification at short TE, with particular focus on how to best account for the macromolecular signal contribution. A robust, short-TE PRESS protocol is presented, which allows reliable quantification, in vivo, of metabolite signals at 3 T in human brain. Water suppre...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1219
更新日期:2008-06-01 00:00:00
abstract::In recent years, quantitative nuclear magnetic resonance imaging and spectroscopy (NMRI and NMRS) have been used more systematically as outcome measures in natural history and clinical trial studies for Duchenne muscular dystrophy (DMD). Whereas most of these studies have emphasized the evaluation of the fat fraction ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3839
更新日期:2018-01-01 00:00:00
abstract::A review of the theory, technology, and use of radio frequency (RF) coils for small-animal MRI is presented. It includes a brief overview of MR signal-to-noise (S/N) analysis and discussions of the various coils commonly used in small-animal MR: surface coils, linear volume coils, birdcages, and their derivatives. The...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1149
更新日期:2007-05-01 00:00:00
abstract::The intrinsic nonuniformities in the transmit radiofrequency field from standard quadrature volume resonators at high field are particularly problematic for localized MRS in areas such as the temporal lobe, where a low signal-to-noise ratio and poor metabolite quantification result from destructive B₁⁺ field interfere...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1638
更新日期:2011-08-01 00:00:00
abstract::A method to extract shapes of bubble polyhedra from three-dimensional nuclear magnetic resonance image data of foam has been developed. The method consists of four steps: first, to compute series of maximum intensity projection images from the three-dimensional NMR image data of foam to visualize the network structure...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199701)10:1<13::aid-nbm443
更新日期:1997-01-01 00:00:00
abstract::Spontaneous fluctuations in the blood oxygenation level-dependent (BOLD) MRI signal during the resting state are increasingly being studied in healthy and diseased brain in humans and animal models. Yet, the relationship between functional brain status and the characteristics of spontaneous BOLD fluctuations remains p...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1556
更新日期:2011-01-01 00:00:00
abstract::1H MR spectroscopy was used to correlate the metabolite signals in 66 untreated metastatic brain tumors with the results of Gd-DTPA enhanced MRI. Cubic volumes containing brain metastases of lung cancer (n = 17), mammary carcinoma (n = 24), melanoma (n = 12) and those originating from other tumors (n = 13) were examin...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(SICI)1099-1492(199604)9:2<65::AID-NBM397>
更新日期:1996-04-01 00:00:00
abstract::The aim of this study was to evaluate the change of breast density in the normal breast of patients receiving neoadjuvant chemotherapy (NAC). Forty-four breast cancer patients were studied. MRI acquisition was performed before treatment (baseline), and 4 and 12 weeks after treatment. A computer-algorithm-based program...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3006
更新日期:2013-12-01 00:00:00
abstract::The possibility of quantifying the superimposed signal of glutamate and glutamine (Glx) and its components by ¹H magnetic resonance spectroscopy (MRS) in the spinal cord is an exciting challenge with important clinical applications in neurological conditions. The spinal cord is a particularly difficult region of inter...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2867
更新日期:2013-03-01 00:00:00
abstract::We describe the optimal high-level postprocessing of single-voxel (1)H magnetic resonance spectra and assess the benefits and limitations of automated methods as diagnostic aids in the detection of recurrent brain tumor. In a previous clinical study, 90 long-echo-time single-voxel spectra were obtained from 52 patient...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1041
更新日期:2006-08-01 00:00:00
abstract::Quantitative magnetisation transfer imaging (qMTI) is an extension of conventional MT techniques and allows the measurement of parameters that reflect tissue ultrastructure through the properties of macromolecule-bound protons; these include the bound proton fraction and the relaxation times of free and bound proton p...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1614
更新日期:2011-06-01 00:00:00
abstract::In recent years considerable effort has been devoted to applying pattern recognition techniques to the complex task of data analysis in magnetic resonance spectroscopy. It may be argued that such techniques will facilitate putting MRS technology to practical clinical use. This paper reviews approaches of pattern recog...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(199705)10:3<99::aid-nbm461
更新日期:1997-05-01 00:00:00
abstract::While phase imaging with a gradient echo (GRE) sequence is popular, phase imaging with balanced steady-state free precession (bSSFP) has been underexplored. The purpose of this study was to investigate anatomical and functional phase imaging with multiple phase-cycled bSSFP, in expectation of increasing spatial covera...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3699
更新日期:2017-06-01 00:00:00
abstract::We propose a very high-resolution, three-dimensional (3D) gradient-echo technique with a twofold parallel imaging acceleration using a specialized occipital receiver coil at 3 T to perform functional MRI (fMRI) of the visual cortex. This configuration makes it possible to acquire 3D fMRI data within a timescale compat...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1158
更新日期:2007-08-01 00:00:00
abstract::One of the most commonly used methods for in vivo MRS detection of γ-aminobutyric acid (GABA) is the MEGA-point-resolved spectroscopy (MEGA-PRESS) technique. However, accurate quantification of GABA using MEGA-PRESS is complicated by spectral co-editing of macromolecular resonances. In this article, a new pulse sequen...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1688
更新日期:2011-12-01 00:00:00
abstract::In this study we aimed to assess the effects of continuous formalin fixation on diffusion and relaxation metrics of the ex vivo porcine heart at 7 T. Magnetic resonance imaging was performed on eight piglet hearts using a 7 T whole body system. Hearts were measured fresh within 3 hours of cardiac arrest followed by im...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4298
更新日期:2020-07-01 00:00:00
abstract::In vitro (1)H MRS of human bile has shown potential in the diagnosis of various hepatopancreatobiliary (HPB) diseases. Previously, in vivo (1)H MRS of human bile in gallbladder using a 1.5 T scanner demonstrated the possibility of quantification of choline-containing phospholipids (chol-PLs). However, other lipid comp...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3173
更新日期:2014-10-01 00:00:00
abstract::The purpose of this work was to carry out diffusion tensor imaging (DTI) at multiple diffusion times Td in skeletal muscle in normal subjects and chronic exertional compartment syndrome (CECS) patients and analyze the data with the random permeable barrier model (RPBM) for biophysical specificity. Using an institution...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.3087
更新日期:2014-05-01 00:00:00
abstract::Detailed (1)H and (13)C NMR spectroscopy of lipid extracts from 12 human intracranial tuberculomas and two control brain tissue samples was performed to assess the role of lipids in the disease process. One-dimensional and two-dimensional NMR techniques were used to resolve the mixture of lipid components and make res...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1191
更新日期:2008-03-01 00:00:00