Abstract：
:Noise estimation is a challenging task in magnetic resonance imaging (MRI), with applications in quality assessment, filtering or diffusion tensor estimation. Main noise estimators based on the Rician model are revisited and classified in this article, and new useful methods are proposed. Additionally, all the surveyed estimators are extended to the noncentral chi model, which applies to multiple-coil MRI and some important parallel imaging algorithms for accelerated acquisitions. The proposed new noise estimation procedures, based on the distribution of local moments, show better performance in terms of smaller variance and unbiased estimation over a wide range of experiments, with the additional advantage of not needing to explicitly segment the background of the image.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Aja-Fernández S,Tristán-Vega A,Alberola-López Cdoi
10.1016/j.mri.2009.05.025subject
Has Abstractpub_date
2009-12-01 00:00:00pages
1397-409issue
10eissn
0730-725Xissn
1873-5894pii
S0730-725X(09)00140-4journal_volume
27pub_type
杂志文章abstract：:This paper describes a geometrically small NMR imaging system which has been developed and assembled within a university medical center environment. Consideration is given to the technical specifications and basic economics for the magnet system, NMR spectrometer, and computer configuration. Initial research objective...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(82)90268-5
更新日期：1982-01-01 00:00:00
abstract：AIM:To assess imaging findings and characteristics of the lymphatic system in patients affected by lipedema and lipolymphedema of the lower extremities on Non-Contrast MR Lymphography (NCMRL). MATERIALS AND METHODS:44 lower extremities in 11 consecutive female patients affected by lipedema, and 11 patients with lipoly...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.06.010
更新日期：2020-09-01 00:00:00
abstract：:The hippocampal formation is a brain system that is implicated in learning and memory. The major input to the hippocampus arrives from the entorhinal cortex (EC) to the dentate gyrus (DG) through the perforant path. In the present work, we have investigated the functional properties of this connection by concomitantly...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2008.02.018
更新日期：2008-09-01 00:00:00
abstract：:The purpose of this study was to develop a method to determine time discrepancies between input and myocardial time-signal intensity (TSI) curves for accurate estimation of myocardial perfusion with first-pass contrast-enhanced MRI. Estimation of myocardial perfusion with contrast-enhanced MRI using kinetic models req...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.06.015
更新日期：2015-11-01 00:00:00
abstract：:We report on experiments to characterize internal magnetic field gradients that are caused by magnetic susceptibility differences between the solid phase and the fluids filling the pore space. Our measurements focus on low-field relaxometry of brine and oil in sandstones from various reservoirs around the world. Our r...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(01)00287-9
更新日期：2001-04-01 00:00:00
abstract：:Use of conjugated equine estrogens (CEE) has been linked to smaller regional brain volumes in women aged ≥65 years; however, it is unknown whether this results in a broad-based characteristic pattern of effects. Structural magnetic resonance imaging was used to assess regional volumes of normal tissue and ischemic les...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章,随机对照试验
doi：10.1016/j.mri.2010.12.001
更新日期：2011-05-01 00:00:00
abstract：:Magnetic resonance imaging (MRI) is a completely noninvasive modality that has shown significant promise for the evaluation of the cardiovascular system. Our imaging technique employed electrocardiographic (ECG) gating, which resulted in well-resolved images of the cardiac structures. Patients and animals with a varie...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(84)90002-x
更新日期：1984-01-01 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：:Thirty patients with Chiari I malformation were examined by MRI over 2-year period. All patients underwent MRI scan before and after surgical decompression of the posterior fossa. Images of the craniocervical junction confirmed tonsillar herniation in all cases and allowed the definition of two anatomically distinct t...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00383-9
更新日期：1997-01-01 00:00:00
abstract：:Functional magnetic resonance imaging (fMRI) was performed on a conventional 1.5 T scanner by means of a modified FLASH-technique at temporal resolutions of 80 and 320 ms. The method's stability was assessed by phantom measurements and by investigation of three volunteers resulting in a low amplitude (3%) periodic (4 ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(96)00021-5
更新日期：1996-01-01 00:00:00
abstract：:In this paper, a new reaction-diffusion model with viscous stress tensor is proposed for modeling the diffusion and invasion of brain glioma cells, which is based on the model in Yuan J.J., Liu L., Hu Q.M. Mathematical modeling of brain glioma growth using modified reaction-diffusion equation on brain MR images. Compu...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.10.012
更新日期：2016-02-01 00:00:00
abstract：:Radio frequency magnetic fields from 5 to 100 kHz off resonance reduce longitudinal magnetization of water in some tissues without affecting the magnetization of simple solutions (Wolff, S.D.; Balaban, R.S. Magnetization transfer contrast (MTC) and tissue water proton relaxation in vivo. Magn. Reson. Med. 10:135-144; ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(90)90050-c
更新日期：1990-01-01 00:00:00
abstract：:The medical specialty radiology has experienced a number of extremely important and influential technical developments in the past that have affected how medical imaging is deployed. Artificial intelligence (AI) is potentially another such development that will introduce fundamental changes into the practice of radiol...
journal_title：Magnetic resonance imaging
pub_type： 社论
doi：10.1016/j.mri.2019.12.006
更新日期：2020-05-01 00:00:00
abstract：:Contrast-enhanced 3D MR voiding urethrography (CE 3D MRVU) was performed on 5 healthy volunteers and 18 patients with urethral disease. After intravenous injection of 0.3 ml/kg gadolinium, the images of the three consecutive acquisitions of the 3D MRVU technique were obtained during voiding. The raw data were reconstr...
journal_title：Magnetic resonance imaging
pub_type： 临床试验,杂志文章
doi：10.1016/j.mri.2004.09.008
更新日期：2004-11-01 00:00:00
abstract：PURPOSE:To determine the diagnostic performance of diffusion-weighted MRI and MR volumetry for the assessment of tumor response after preoperative chemoradiotherapy (CRT) in patients with locally advanced rectal cancer. MATERIALS AND METHODS:Forty-three patients with rectal cancer who underwent preoperative CRT were p...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2014.08.041
更新日期：2015-02-01 00:00:00
abstract：:Dynamic contrast-enhanced MRI (DCE-MRI) was used to noninvasively evaluate the effects of AG-03736, a novel inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, on tumor microvasculature in a breast cancer model. First, a dose response study was undertaken to determine the responsiveness o...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2006.09.041
更新日期：2007-04-01 00:00:00
abstract：:It has been shown recently that quantitative T2-maps may be measured by acquisition of a series of at least eight T2-weighted SNAPSHOT FLASH images. These measurements require a relaxation delay of 10-15 s after each T2-weighted image for the complete relaxation of the spin system. This results in long measuring times...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(95)00004-z
更新日期：1995-01-01 00:00:00
abstract：:We report a geographic area of prominent hypointensity in T2-weighted images vs. normal adjacent liver parenchyma in a patient with cholangiocarcinoma and lymphangitic metastasis of the liver after superparamagnetic iron oxide (SPIO) administration. The area showing this prominent signal drop showed Kupffer cell proli...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2007.10.012
更新日期：2008-05-01 00:00:00
abstract：:A new approach to solid-state imaging (SSI) is presented. The method relies on narrowing the resonance line using the Lee-Goldburg sequence. The technique is easy to implement in practice and may find widespread applications in materials science. ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(92)90409-s
更新日期：1992-01-01 00:00:00
abstract：BACKGROUND:Doppler based mitral annular velocities are an integral part of echocardiographic left ventricular diastolic function assessment. Although these measurements can be obtained by phase contrast cardiac magnetic resonance imaging (PC-CMR), this approach has limitations. The aims of this study were to assess the...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2018.08.018
更新日期：2019-01-01 00:00:00
abstract：:Prostate MRI is an important tool to diagnose and characterize cancer. High local sensitivity and good parallel imaging performance are of paramount importance for diagnostic quality and efficiency. The purpose of this work was to evaluate stacked resonators as part of a surface receiver array for prostate MRI at 3 Te...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2018.07.010
更新日期：2018-11-01 00:00:00
abstract：OBJECTIVE:The pathological changes in Parkinson disease begin in the brainstem; reach the limbic system and ultimately spread to the cerebral cortex. In Parkinson disease (PD) patients, we evaluated the alteration of cingulate fibers, which comprise part of the limbic system, by using diffusional kurtosis imaging (DKI)...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2013.06.009
更新日期：2013-11-01 00:00:00
abstract：:Susceptibility differences are common causes for artifacts in magnetic resonance (MR); therefore, it is important to choose phantom materials in a way that these artifacts are kept at a minimum. In this study, a previously proposed MR imaging (MRI) method [Beuf O, Briguet A, Lissac M, Davis R. Magnetic resonance imagi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2006.07.005
更新日期：2006-11-01 00:00:00
abstract：:Within the magnetic resonance imaging (MRI) community the trend is going to higher and higher magnetic fields, ranging from 1.5 T to 7 T, corresponding to Larmor frequencies of 63.8-298 MHz. Since for high-field MRI the magnetization increases with the applied magnetic field, the signal-to-noise-ratio increases as wel...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2012.06.014
更新日期：2013-02-01 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：: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：:Diffraction ideas were first introduced to NMR by Mansfield and Grannell. Here we compare "Mansfield (k-space) diffraction" with the "diffusive (q-space) diffraction," noting their similarities and differences. The diffusive-diffraction concept is extremely helpful in elucidating the Pulsed Gradient Spin Echo NMR expe...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00152-x
更新日期：1996-01-01 00:00:00
abstract：:Spiral acquisition schemes offer unique advantages such as flow compensation, efficient k-space sampling and robustness against motion that make this option a viable choice among other non-Cartesian sampling schemes. For this reason, the main applications of spiral imaging lie in dynamic magnetic resonance imaging suc...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章,评审
doi：10.1016/j.mri.2010.03.036
更新日期：2010-07-01 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：:In this paper the effects of reducing the flip angle of the 90-degree observation pulse in inversion recovery imaging are described and analyzed. When incorporated in an IR sequence with a short inversion time (STIR), reduction to the 90-degree pulse allows a significant shortening of the repetition time without loss ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(91)90418-l
更新日期：1991-01-01 00:00:00
