Abstract：
:A four-channel Tic-Tac-Toe (TTT) transmit RF coil was designed and constructed for foot and ankle imaging at 7T MRI. Numerical simulations using an in-house developed FDTD package and experimental analyses using a homogenous phantom show an excellent agreement in terms of B1+ field distribution and s-parameters. Simulations performed on an anatomically detailed human lower leg model demonstrated an B1+ field distribution with a coefficient of variation (CV) of 23.9%/15.6%/28.8% and average B1+ of 0.33μT/0.56μT/0.43μT for 1W input power (i.e., 0.25W per channel) in the ankle/calcaneus/mid foot respectively. In-vivo B1+ mapping shows an average B1+ of 0.29μT over the entire foot/ankle. This newly developed RF coil also presents acceptable levels of average SAR (0.07W/kg for 10g per 1W of input power) and peak SAR (0.34W/kg for 10g per 1W of input power) over the whole lower leg. Preliminary in-vivo images in the foot/ankle were acquired using the T2-DESS MRI sequence without the use of a dedicated receive-only array.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Santini T,Kim J,Wood S,Krishnamurthy N,Farhat N,Maciel C,Raval SB,Zhao T,Ibrahim TSdoi
10.1016/j.mri.2017.09.005subject
Has Abstractpub_date
2018-01-01 00:00:00pages
1-6eissn
0730-725Xissn
1873-5894pii
S0730-725X(17)30179-0journal_volume
45pub_type
杂志文章abstract：:The functional value of TurboFLASH MR imaging in the assessment of dynamic contrast enhancement and renal perfusion anomalies was evaluated in seven patients, who also underwent renal scintigraphy in baseline conditions. The basal renograms obtained from MAG-3 scintigraphy (mercapto acetyl triglycine, MAG3-S) and from...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(94)92534-8
更新日期：1994-01-01 00:00:00
abstract：:NMR imaging and localized 1H spectroscopy of a variety of aquatic organisms in vivo is described for the first time. The practical consideration of life support, water volume, salinity, and anesthesia are discussed and solutions presented. Such animal studies shape our understanding of physiology, biochemistry, and bi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(90)90253-x
更新日期：1990-01-01 00:00:00
abstract：:A numerical method is applied to calculate an optimal distribution of currents in air which generate the magnetic field gradients required to spatially encode the radiofrequency signal in a NMR tomographic experiment. We compare the performances of the gradient circuits for the whole body air-core electromagnet descri...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(90)90242-t
更新日期：1990-01-01 00:00:00
abstract：:Localized high-resolution diffusion tensor images (DTI) from the midbrain were obtained using reduced field-of-view (rFOV) methods combined with SENSE parallel imaging and single-shot echo planar (EPI) acquisitions at 7T. This combination aimed to diminish sensitivities of DTI to motion, susceptibility variations, and...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2013.01.013
更新日期：2013-07-01 00:00:00
abstract：BACKGROUND:Since the advent of magnetic resonance imaging, metal artifacts have posed an important diagnostic problem in different fields of medicine. However, this has not been systematically studied in patients undergoing surgery for brain tumors. OBJECTIVE:This study was planned to assess whether metal artifacts ca...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2012.11.001
更新日期：2013-06-01 00:00:00
abstract：:Brain asymmetry is a phenomenon well known for handedness and has been studied in motor cortices. However, few quantitative studies on asymmetrical cortical activity in motor areas have been conducted. In this study, we systematically investigated asymmetrical cortical activity in motor areas during sequential finger ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2007.03.024
更新日期：2007-12-01 00:00:00
abstract：:We assessed the magnetic resonance (MR) imaging characteristics of two categories of epileptogenic substrates, neoplasms, and vascular malformations, to determine MR sensitivity and typical imaging features. A blinded retrospective analysis was performed on MR scans from 41 patients who had a neoplasm or vascular malf...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(95)02026-p
更新日期：1995-01-01 00:00:00
abstract：UNLABELLED:The conventional diagnostic work-up of a patient suspected of having a vascular cause for stridor, or dysphagia, includes esophagography and bronchoscopy to delineate the abnormal structure without imaging the structure itself. Cine-angiography is regarded as the golden standard, but is not routinely perform...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(97)00245-2
更新日期：1998-01-01 00:00:00
abstract：:It is a big challenge to segment magnetic resonance (MR) images with intensity inhomogeneity. The widely used segmentation algorithms are region based, which mostly rely on the intensity homogeneity, and could bring inaccurate results. In this paper, we propose a novel region-based active contour model in a variationa...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2012.10.010
更新日期：2013-05-01 00:00:00
abstract：:High density barium sulphate suspension was investigated as an oral contrast on MRI. On 30 consecutive subjects, the stomach (in all cases) and the two first portions of the duodenum (in 21 cases) were filled with the suspension. This oral contrast behaved as a negative contrast, being hypointense on all pulse sequenc...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(91)90019-i
更新日期：1991-01-01 00:00:00
abstract：:Geometric distortion in MR imaging predominantly arises from the inhomogeneity of the static field and the nonlinearity of the gradients. It is the purpose of this paper to analyse the object and machine related contributions to geometric distortion in order to determine which corrections are necessary for attaining a...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(92)90011-n
更新日期：1992-01-01 00:00:00
abstract：PURPOSE:Intramuscular fat infiltration is a dynamic process, in response to exercise and muscle health, which can be quantified by estimating fat fraction (FF) from Dixon MRI. Healthy hip abductor muscles are a good indicator of a healthy hip and an active lifestyle as they have a fundamental role in walking. The autom...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.06.019
更新日期：2020-10-01 00:00:00
abstract：PURPOSE:Rapid regional fluctuations in GABA may result in inhomogeneous concentrations throughout the brain parenchyma. The goal of this study is to provide further insight into the natural distribution of GABA throughout the brain and thus determine if a surrogate site may be used for spectroscopy when evaluating moto...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.02.015
更新日期：2015-06-01 00:00:00
abstract：:The present study examined initial changes in non-traumatic osteonecrosis of the femoral head (ONF) on T1- and T2-weighted MR images, and fat suppression images. The subjects were 57 renal transplant recipients (37 males and 20 females), whose median age at the time of transplantation was 31.5 years old (range, 10 to ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(01)00424-6
更新日期：2001-09-01 00:00:00
abstract：:Fifteen patients with liver cirrhosis and two control groups were examined. The first control group consisted of 7 healthy volunteers, and the second group of 17 patients with nonfocal liver diseases. The T1 and T2 relaxation times were calculated from signal intensities read out from a region of interest centrally lo...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章,评审
doi：10.1016/0730-725x(90)90137-q
更新日期：1990-01-01 00:00:00
abstract：:Obstructive sleep apnea syndrome (OSAS) is caused by multi-level upper airway obstruction. Anatomic changes at the sites of obstruction may modify the physical or acoustic properties of snores. The surgical success of OSA depends upon precise localization of obstructed levels. We present a case of OSAS who received si...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.08.004
更新日期：2015-12-01 00:00:00
abstract：:Diffusion tensor imaging (DTI) is potentially sensitive to collagen degeneration in cartilage. In this study, DTI was measured on human cartilage samples with interventions of trypsin and collagenase. The measured preferred diffusion direction was consistent with the zonal structure of collagen network. The glycosamin...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2006.10.015
更新日期：2007-02-01 00:00:00
abstract：:An NMR technique is described which allows the observation of ionic charge carriers moving in the electric field within a porous system saturated with electrolyte solution. This method, which was recently developed in our laboratory, gives experimental access to the study of electric transport in disordered media on a...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(01)00267-3
更新日期：2001-04-01 00:00:00
abstract：PURPOSE:The state-of-the-art method to quantify sodium concentrations in vivo consists in a fully relaxed 3D spin-density (SD) weighted acquisition. Nevertheless, most sodium MRI clinical studies use short-TR SD acquisitions to reduce acquisition durations. We present a clinically viable implementation of the Variable ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2019.01.015
更新日期：2019-05-01 00:00:00
abstract：AIM:The study aimed to validate magnetic resonance microscopy (MRM) studies of forensic tissue specimens (skin samples with electric injury patterns) against the results from routine histology. METHODS AND RESULTS:Computed tomography and magnetic resonance imaging are fast becoming important tools in clinical and fore...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2004.08.019
更新日期：2004-10-01 00:00:00
abstract：:Magnetic resonance imaging (MRI) has been used to characterize tissues in morphological studies. Here, 23Na NMR imaging was used to study the distribution in muscle of brine (5 M NaCl), injected before onset of rigor mortis. First, the distribution of brine was monitored in excised muscle from rabbits for 6 hr followi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(94)92360-4
更新日期：1994-01-01 00:00:00
abstract：:We retrospectively compared the diagnostic accuracy of abdominal ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) studies performed on the same individual to determine the relative performance of these modalities in the evaluation of disease processes, arising from different intra-abdomi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2003.01.001
更新日期：2004-01-01 00:00:00
abstract：:Multi-contrast magnetic resonance imaging (MRI) is a useful technique to aid clinical diagnosis. This paper proposes an efficient algorithm to jointly reconstruct multiple T1/T2-weighted images of the same anatomical cross section from partially sampled k-space data. The joint reconstruction problem is formulated as m...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2014.08.025
更新日期：2014-12-01 00:00:00
abstract：:Quantification of magnetic resonance (MR)-based relaxation parameters of tendons and ligaments is challenging due to their very short transverse relaxation times, requiring application of ultra-short echo-time (UTE) imaging sequences. We quantify both T1 and T2* in the quadriceps and patellar tendons of healthy volunt...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2019.07.015
更新日期：2019-11-01 00:00:00
abstract：:The radiologic findings from 60 patients with 86 internally deranged temporomandibular joints (TMJ) upon whom sequential imaging procedures had been performed over a period of two months to ten years were analyzed and correlated with clinical, surgical (72 joints), and pathological observations. Internal derangement o...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(89)90404-9
更新日期：1989-09-01 00:00:00
abstract：:Parallel excitation using multiple transmit channels has emerged as an effective method to shorten multidimensional spatially selective radiofrequency (RF) pulses, which have a number of important applications, including B1 field inhomogeneity correction in high-field MRI. The specific absorption rate (SAR) is a prima...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2008.02.003
更新日期：2008-10-01 00:00:00
abstract：:The advantages of the application of NMR imaging to the studies of enhanced oil recovery methods that include polymer slug flooding, combination slug flooding, and thermal soaking are described. ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00192-0
更新日期：1996-01-01 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：BACKGROUND:Ultra-high spatial resolution imaging of whole, ex vivo brains provides new opportunities to understand neurological disease. Recent work has demonstrated that 100 μm isotropic resolution can reveal anatomical details that are otherwise difficult to appreciate, but relied on fabrication facilities, fabricati...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.11.002
更新日期：2021-02-01 00:00:00
abstract：:This summary attempts to provide forward-looking concepts regarding gadolinium related toxicity, as discussed in further detail in this issue. ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章,评审
doi：10.1016/j.mri.2016.09.002
更新日期：2016-12-01 00:00:00
