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diffusion kurtosis

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https://www.readbyqxmd.com/read/28295854/diffusion-kurtosis-imaging-for-differentiating-borderline-from-malignant-epithelial-ovarian-tumors-a-correlation-with-ki-67-expression
#1
Hai Ming Li, Shu Hui Zhao, Jin Wei Qiang, Guo Fu Zhang, Feng Feng, Feng Hua Ma, Yong Ai Li, Wei Yong Gu
PURPOSE: To investigate the use of diffusion kurtosis imaging (DKI) in differentiating borderline from malignant epithelial ovarian tumors (MEOTs) and to correlate DKI parameters with Ki-67 expression. MATERIALS AND METHODS: Fifty-two consecutive patients with epithelial ovarian tumors (17 borderline epithelial ovarian tumors, BEOTs; 35 MEOTs) were prospectively evaluated using DKI with b values of 0, 500, 1000, 1500, 2000, and 2500 s/mm(2) and standard diffusion-weighted imaging (DWI) with b values of 0 and 1000 s/mm(2) using a 1...
March 10, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28273747/histogram-analysis-of-volume-based-apparent-diffusion-coefficient-in-breast-cancer
#2
Ga Eun Park, Sung Hun Kim, Eun Jeong Kim, Bong Joo Kang, Mi Sun Park
Background Breast cancer is a heterogeneous disease. Recent studies showed that apparent diffusion coefficient (ADC) values have various association with tumor aggressiveness and prognosis. Purpose To evaluate the value of histogram analysis of ADC values obtained from the whole tumor volume in invasive ductal cancer (IDC) and ductal carcinoma in situ (DCIS). Material and Methods This retrospective study included 201 patients with confirmed DCIS (n = 37) and IDC (n = 164). The IDC group was divided into two groups based on the presence of a DCIS component: IDC-DCIS (n = 76) and pure IDC (n = 88)...
January 1, 2017: Acta Radiologica
https://www.readbyqxmd.com/read/28272771/sensitivity-of-diffusion-mri-to-perilesional-reactive-astrogliosis-in-focal-ischemia
#3
Rachel A Weber, Clifford H Chan, Xingju Nie, Emily Maggioncalda, Grace Valiulis, Abigail Lauer, Edward S Hui, Jens H Jensen, DeAnna L Adkins
Reactive astrogliosis is a response to injury in the central nervous system that plays an essential role in inflammation and tissue repair. It is characterized by hypertrophy of astrocytes, alterations in astrocyte gene expression and astrocyte proliferation. Reactive astrogliosis occurs in multiple neuropathologies, including stroke, traumatic brain injury and Alzheimer's disease, and it has been proposed as a possible source of the changes in diffusion magnetic resonance imaging (dMRI) metrics observed with these diseases...
March 8, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28265814/a-comparative-study-of-the-sensitivity-of-diffusion-related-parameters-obtained-from-diffusion-tensor-imaging-diffusional-kurtosis-imaging-q-space-analysis-and-bi-exponential-modelling-in-the-early-disease-course-24%C3%A2-h-of-hyperacute-6%C3%A2-h-ischemic-stroke-patients
#4
Gaëtan Duchêne, Frank Peeters, André Peeters, Thierry Duprez
OBJECTIVES: To compare the sensitivity and early temporal changes of diffusion parameters obtained from diffusion tensor imaging (DTI), diffusional kurtosis imaging (DKI), q-space analysis (QSA) and bi-exponential modelling in hyperacute stroke patients. MATERIALS AND METHODS: A single investigational acquisition allowing the four diffusion analyses was performed on seven hyperacute stroke patients with a 3T system. The percentage change between ipsi- and contralateral regions were compared at admission and 24 h later...
March 6, 2017: Magma
https://www.readbyqxmd.com/read/28264721/densitometric-and-local-histogram-based-analysis-of-computed-tomography-images-in-patients-with-idiopathic-pulmonary-fibrosis
#5
Samuel Y Ash, Rola Harmouche, Diego Lassala Lopez Vallejo, Julian A Villalba, Kris Ostridge, River Gunville, Carolyn E Come, Jorge Onieva Onieva, James C Ross, Gary M Hunninghake, Souheil Y El-Chemaly, Tracy J Doyle, Pietro Nardelli, Gonzalo V Sanchez-Ferrero, Hilary J Goldberg, Ivan O Rosas, Raul San Jose Estepar, George R Washko
BACKGROUND: Prior studies of clinical prognostication in idiopathic pulmonary fibrosis (IPF) using computed tomography (CT) have often used subjective analyses or have evaluated quantitative measures in isolation. This study examined associations between both densitometric and local histogram based quantitative CT measurements with pulmonary function test (PFT) parameters and mortality. In addition, this study sought to compare risk prediction scores that incorporate quantitative CT measures with previously described systems...
March 7, 2017: Respiratory Research
https://www.readbyqxmd.com/read/28244188/model-based-denoising-in-diffusion-weighted-imaging-using-generalized-spherical-deconvolution
#6
Jonathan I Sperl, Tim Sprenger, Ek T Tan, Marion I Menzel, Christopher J Hardy, Luca Marinelli
PURPOSE: Diffusion MRI often suffers from low signal-to-noise ratio, especially for high b-values. This work proposes a model-based denoising technique to address this limitation. METHODS: A generalization of the multi-shell spherical deconvolution model using a Richardson-Lucy algorithm is applied to noisy data. The reconstructed coefficients are then used in the forward model to compute denoised diffusion-weighted images (DWIs). The proposed method operates in the diffusion space and thus is complementary to image-based denoising methods...
February 28, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28214960/axonal-disruption-in-white-matter-underlying-cortical-sulcus-tau-pathology-in-chronic-traumatic-encephalopathy
#7
Laurena Holleran, Joong Hee Kim, Mihika Gangolli, Thor Stein, Victor Alvarez, Ann McKee, David L Brody
Chronic traumatic encephalopathy (CTE) is a progressive degenerative disorder associated with repetitive traumatic brain injury. One of the primary defining neuropathological lesions in CTE, based on the first consensus conference, is the accumulation of hyperphosphorylated tau in gray matter sulcal depths. Post-mortem CTE studies have also reported myelin loss, axonal injury and white matter degeneration. Currently, the diagnosis of CTE is restricted to post-mortem neuropathological analysis. We hypothesized that high spatial resolution advanced diffusion MRI might be useful for detecting white matter microstructural changes directly adjacent to gray matter tau pathology...
March 2017: Acta Neuropathologica
https://www.readbyqxmd.com/read/28208489/prediction-of-the-moments-in-advection-diffusion-lattice-boltzmann-method-ii-attenuation-of-the-boundary-layers-via-double-%C3%AE-bounce-back-flux-scheme
#8
Irina Ginzburg
Impact of the unphysical tangential advective-diffusion constraint of the bounce-back (BB) reflection on the impermeable solid surface is examined for the first four moments of concentration. Despite the number of recent improvements for the Neumann condition in the lattice Boltzmann method-advection-diffusion equation, the BB rule remains the only known local mass-conserving no-flux condition suitable for staircase porous geometry. We examine the closure relation of the BB rule in straight channel and cylindrical capillary analytically, and show that it excites the Knudsen-type boundary layers in the nonequilibrium solution for full-weight equilibrium stencil...
January 2017: Physical Review. E
https://www.readbyqxmd.com/read/28208379/prediction-of-the-moments-in-advection-diffusion-lattice-boltzmann-method-i-truncation-dispersion-skewness-and-kurtosis
#9
Irina Ginzburg
The effect of the heterogeneity in the soil structure or the nonuniformity of the velocity field on the modeled resident time distribution (RTD) and breakthrough curves is quantified by their moments. While the first moment provides the effective velocity, the second moment is related to the longitudinal dispersion coefficient (k_{T}) in the developed Taylor regime; the third and fourth moments are characterized by their normalized values skewness (Sk) and kurtosis (Ku), respectively. The purpose of this investigation is to examine the role of the truncation corrections of the numerical scheme in k_{T}, Sk, and Ku because of their interference with the second moment, in the form of the numerical dispersion, and in the higher-order moments, by their definition...
January 2017: Physical Review. E
https://www.readbyqxmd.com/read/28207858/non-small-cell-lung-cancer-whole-lesion-histogram-analysis-of-the-apparent-diffusion-coefficient-for-assessment-of-tumor-grade-lymphovascular-invasion-and-pleural-invasion
#10
Naoko Tsuchiya, Mariko Doai, Katsuo Usuda, Hidetaka Uramoto, Hisao Tonami
PURPOSE: Investigating the diagnostic accuracy of histogram analyses of apparent diffusion coefficient (ADC) values for determining non-small cell lung cancer (NSCLC) tumor grades, lymphovascular invasion, and pleural invasion. MATERIALS AND METHODS: We studied 60 surgically diagnosed NSCLC patients. Diffusion-weighted imaging (DWI) was performed in the axial plane using a navigator-triggered single-shot, echo-planar imaging sequence with prospective acquisition correction...
2017: PloS One
https://www.readbyqxmd.com/read/28205277/preliminary-evaluation-of-altered-brain-microstructure-in-the-emotion-cognition-region-in-children-with-haemophilia-a-a-diffusional-kurtosis-imaging-study
#11
D Hu, H Kang, Y Lv, N Zhang, L Tang, J Zhang, K Shi, R Wu, Y Peng
AIM: Using diffusional kurtosis imaging (DKI) to assess the impact of emotional disorders on microstructural changes of the brain in children with haemophilia A. MATERIALS AND METHODS: Diffusional kurtosis imaging was acquired from haemophilia A (n = 22) and controls (n = 22) using a 3T scanner. A regression analysis of frontal, cingulate, hippocampus, insula and amygdala regions of interest (ROIs) was conducted. Clinical data and results of psychological tests were collected...
February 15, 2017: Haemophilia: the Official Journal of the World Federation of Hemophilia
https://www.readbyqxmd.com/read/28199367/evaluation-of-different-mathematical-models-and-different-b-value-ranges-of-diffusion-weighted-imaging-in-peripheral-zone-prostate-cancer-detection-using-b-value-up-to-4500-s-mm2
#12
Zhaoyan Feng, Xiangde Min, Daniel J A Margolis, Caohui Duan, Yuping Chen, Vivek Kumar Sah, Nabin Chaudhary, Basen Li, Zan Ke, Peipei Zhang, Liang Wang
OBJECTIVES: To evaluate the diagnostic performance of different mathematical models and different b-value ranges of diffusion-weighted imaging (DWI) in peripheral zone prostate cancer (PZ PCa) detection. METHODS: Fifty-six patients with histologically proven PZ PCa who underwent DWI-magnetic resonance imaging (MRI) using 21 b-values (0-4500 s/mm2) were included. The mean signal intensities of the regions of interest (ROIs) placed in benign PZs and cancerous tissues on DWI images were fitted using mono-exponential, bi-exponential, stretched-exponential, and kurtosis models...
2017: PloS One
https://www.readbyqxmd.com/read/28194415/diffusion-kurtosis-imaging-detects-microstructural-changes-in-the-brain-after-acute-alcohol-intoxication-in-rats
#13
Xi-Ran Chen, Jie-Ying Zeng, Zhi-Wei Shen, Ling-Mei Kong, Wen-Bin Zheng
The aim of this study was to test the technical feasibility of diffusion kurtosis imaging (DKI) in the brain after acute alcohol intoxication. Diffusion tensor imaging (DTI) and DKI during 7.0 T MRI were performed in the frontal lobe and thalamus before and 30 min, 2 h, and 6 h after ethyl alcohol administration. Compared with controls, mean kurtosis values of the frontal lobe and thalamus first decreased by 44% and 38% within 30 min (p < 0.01 all) and then increased by 14% and 46% at 2 h (frontal lobe, p > 0...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28176436/differential-microstructural-and-morphological-abnormalities-in-mild-cognitive-impairment-and-alzheimer-s-disease-evidence-from-cortical-and-deep-gray-matter
#14
Nan-Jie Gong, Chun-Chung Chan, Lam-Ming Leung, Chun-Sing Wong, Russell Dibb, Chunlei Liu
One aim of this study is to use non-Gaussian diffusion kurtosis imaging (DKI) for capturing microstructural abnormalities in gray matter of Alzheimer's disease (AD). The other aim is to compare DKI metrics against thickness of cortical gray matter and volume of deep gray matter, respectively. A cohort of 18 patients with AD, 18 patients with amnestic mild cognitive impairment (MCI), and 18 normal controls underwent morphological and DKI MR imaging. Images were investigated using regions-of-interest-based analyses for deep gray matter and vertex-wise analyses for cortical gray matter...
February 8, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28160039/measuring-the-apparent-diffusion-coefficient-in-primary-rectal-tumors-is-there-a-benefit-in-performing-histogram-analyses
#15
Miriam M van Heeswijk, Doenja M J Lambregts, Monique Maas, Max J Lahaye, Z Ayas, Jos M G M Slenter, Geerard L Beets, Frans C H Bakers, Regina G H Beets-Tan
PURPOSE: The apparent diffusion coefficient (ADC) is a potential prognostic imaging marker in rectal cancer. Typically, mean ADC values are used, derived from precise manual whole-volume tumor delineations by experts. The aim was first to explore whether non-precise circular delineation combined with histogram analysis can be a less cumbersome alternative to acquire similar ADC measurements and second to explore whether histogram analyses provide additional prognostic information. METHODS: Thirty-seven patients who underwent a primary staging MRI including diffusion-weighted imaging (DWI; b0, 25, 50, 100, 500, 1000; 1...
February 3, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28151889/early-white-matter-injuries-in-patients-with-acute-carbon-monoxide-intoxication-a-tract-specific-diffusion-kurtosis-imaging-study-and-strobe-compliant-article
#16
Ping-Huei Tsai, Ming-Chung Chou, Shih-Wei Chiang, Hsiao-Wen Chung, Hua-Shan Liu, Hung-Wen Kao, Cheng-Yu Chen
Evaluation of acute white matter injuries caused by carbon monoxide (CO) poisoning can be limited by conventional magnetic resonance (MR) imaging. We aim to evaluate the feasibility of diffusion kurtosis imaging (DKI) for early detection of white matter alterations in patients with acute CO intoxication.A total of 30 subjects including 15 acute CO patients and 15 age- and sex-matched healthy volunteers were enrolled in this study. MR examinations were performed on a 3T MR scanner within 8 days after CO intoxication...
February 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28139225/toward-ideal-separation-by-size-exclusion-chromatography
#17
Miloš Netopilík
In analyses of polystyrene standards by size-exclusion chromatography for polymers of molecular weight about thirty thousand and higher, the separation improved with decreasing flow-rate is in accord with Giddings observation of transversal diffusion as a factor decreasing the broadening of the band broadening function. The variance of the elution curves is larger than it corresponds to dispersity M¯w/M¯n and the shape of the elution curves depends on the experimental conditions which suggests that it reflects properties of the band broadening function...
March 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28139036/multiparametric-diffusion-weighted-imaging-in-breast-lesions-association-with-pathologic-diagnosis-and-prognostic-factors
#18
Shiteng Suo, Fang Cheng, Mengqiu Cao, Jiwen Kang, Mingyao Wang, Jia Hua, Xiaolan Hua, Lan Li, Qing Lu, Jialin Liu, Jianrong Xu
PURPOSE: To determine the utility of multiparametric diffusion-weighted imaging (DWI) including monoexponential (apparent diffusion coefficient [ADC]), biexponential (Df , Ds , and f), stretched-exponential (distributed diffusion coefficient [DDC] and α), and kurtosis (mean diffusivity [MD] and mean kurtosis [MK]) models in the differentiation and characterization of breast lesions, and assess their associations with prognostic factors in invasive breast cancer. MATERIALS AND METHODS: This study included 101 patients (44 benign and 57 malignant lesions) who underwent 3T breast multi-b-value DWI...
January 31, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28111394/comparison-of-analytical-values-in-diffusion-kurtosis-imaging-among-different-mri-units
#19
Shogo Tan, Koichi Ujita, Yasuhiro Fukushima, Takayuki Suto
Diffusion kurtosis imaging (DKI) is a method of analyzing restricted diffusion. Mean kurtosis (MK) is obtained from DKI. It is not known how different MRI scanners and coil systems will change MK when the same imaging parameters are used. The purpose of this study is to identify tendencies in MK when using various MRI scanners and coil systems. A total of 27 healthy volunteers were enrolled in this study. DKI was performed on the brain for each volunteer on five MRI scanner/coil system combinations using the same scan parameters...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28090658/analysis-of-the-effects-of-noise-dwi-sampling-and-value-of-assumed-parameters-in-diffusion-mri-models
#20
Elizabeth B Hutchinson, Alexandru V Avram, M Okan Irfanoglu, C Guan Koay, Alan S Barnett, Michal E Komlosh, Evren Özarslan, Susan C Schwerin, Sharon L Juliano, Carlo Pierpaoli
PURPOSE: This study was a systematic evaluation across different and prominent diffusion MRI models to better understand the ways in which scalar metrics are influenced by experimental factors, including experimental design (diffusion-weighted imaging [DWI] sampling) and noise. METHODS: Four diffusion MRI models-diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), mean apparent propagator MRI (MAP-MRI), and neurite orientation dispersion and density imaging (NODDI)-were evaluated by comparing maps and histogram values of the scalar metrics generated using DWI datasets obtained in fixed mouse brain with different noise levels and DWI sampling complexity...
January 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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