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https://www.readbyqxmd.com/read/28748504/whole-brain-analyses-of-age-related-microstructural-changes-quantified-using-different-diffusional-magnetic-resonance-imaging-methods
#1
Miho Ota, Noriko Sato, Norihide Maikusa, Daichi Sone, Hiroshi Matsuda, Hiroshi Kunugi
PURPOSE: The new diffusional magnetic resonance imaging (dMRI) techniques, diffusional kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) have been developed to clarify the microstructural changes. To our knowledge, however, there is little information on the similarities and differences of these metrics evaluated by the image-by-image paired t test. MATERIALS AND METHODS: Twenty-three healthy subjects underwent dMRI. We estimated the relationships of these metrics evaluated by the image-by-image paired t-test and compared aging effects on each metric...
July 26, 2017: Japanese Journal of Radiology
https://www.readbyqxmd.com/read/28747882/comparison-of-it-neural-response-statistics-with-simulations
#2
Qiulei Dong, Bo Liu, Zhanyi Hu
Lehky et al. (2011) provided a statistical analysis on the responses of the recorded 674 neurons to 806 image stimuli in anterior inferotemporalm (AIT) cortex of two monkeys. In terms of kurtosis and Pareto tail index, they observed that the population sparseness of both unnormalized and normalized responses is always larger than their single-neuron selectivity, hence concluded that the critical features for individual neurons in primate AIT cortex are not very complex, but there is an indefinitely large number of them...
2017: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/28742373/utility-of-mri-to-differentiate-clear-cell-renal-cell-carcinoma-adrenal-metastases-from-adrenal-adenomas
#3
Nicola Schieda, Satheesh Krishna, Matthew D F McInnes, Bardia Moosavi, Abdulmohsen Alrashed, Robert Moreland, Evan S Siegelman
OBJECTIVE: The purpose of this study is to compare MRI features of clear cell renal cell carcinoma (RCC) adrenal metastases and adenomas. MATERIALS AND METHODS: Fifteen clear cell RCC adrenal metastases imaged with MRI were compared to 29 consecutive adenomas between 2006 and 2015. Two blinded radiologists assessed homogeneity (homogeneous vs heterogeneous), signal intensity (SI) decrease on chemical-shift MRI, and T2-weighted SI (isointense, mildly hyperintense, or markedly hyperintense) relative to muscle...
July 25, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28740446/diffusion-kurtosis-imaging-of-gliomas-grades-ii-and-iii-a-study-of-perilesional-tumor-infiltration-tumor-grades-and-subtypes-at-clinical-presentation
#4
Anna F Delgado, Markus Fahlström, Markus Nilsson, Shala G Berntsson, Maria Zetterling, Sylwia Libard, Irina Alafuzoff, Danielle van Westen, Jimmy Lätt, Anja Smits, Elna-Marie Larsson
BACKGROUND: Diffusion kurtosis imaging (DKI) allows for assessment of diffusion influenced by microcellular structures. We analyzed DKI in suspected low-grade gliomas prior to histopathological diagnosis. The aim was to investigate if diffusion parameters in the perilesional normal-appearing white matter (NAWM) differed from contralesional white matter, and to investigate differences between glioma malignancy grades II and III and glioma subtypes (astrocytomas and oligodendrogliomas)...
June 2017: Radiology and Oncology
https://www.readbyqxmd.com/read/28734955/predicting-the-nodal-status-in-gastric-cancers-the-role-of-apparent-diffusion-coefficient-histogram-characteristic-analysis
#5
Song Liu, Yujuan Zhang, Jie Xia, Ling Chen, Wenxian Guan, Yue Guan, Yun Ge, Jian He, Zhengyang Zhou
PURPOSE: To explore the application of histogram analysis in preoperative T and N staging of gastric cancers, with a focus on characteristic parameters of apparent diffusion coefficient (ADC) maps. MATERIALS AND METHODS: Eighty-seven patients with gastric cancers underwent diffusion weighted magnetic resonance imaging (b=0, 1000s/mm(2)), which generated ADC maps. Whole-volume histogram analysis was performed on ADC maps and 7 characteristic parameters were obtained...
July 19, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28734056/in-vivo-placental-mri-shape-and-textural-features-predict-fetal-growth-restriction-and-postnatal-outcome
#6
Sonia Dahdouh, Nickie Andescavage, Sayali Yewale, Alexa Yarish, Diane Lanham, Dorothy Bulas, Adre J du Plessis, Catherine Limperopoulos
PURPOSE: To investigate the ability of three-dimensional (3D) MRI placental shape and textural features to predict fetal growth restriction (FGR) and birth weight (BW) for both healthy and FGR fetuses. MATERIALS AND METHODS: We recruited two groups of pregnant volunteers between 18 and 39 weeks of gestation; 46 healthy subjects and 34 FGR. Both groups underwent fetal MR imaging on a 1.5 Tesla GE scanner using an eight-channel receiver coil. We acquired T2-weighted images on either the coronal or the axial plane to obtain MR volumes with a slice thickness of either 4 or 8 mm covering the full placenta...
July 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28728757/value-of-whole-lesion-apparent-diffusion-coefficient-adc-first-order-statistics-and-texture-features-in-clinical-staging-of-cervical-cancers
#7
Y Guan, W Li, Z Jiang, B Zhang, Y Chen, X Huang, J Zhang, S Liu, J He, Z Zhou, Y Ge
AIM: To explore the value of whole-lesion apparent diffusion coefficient (ADC) first-order statistics and texture features in clinical staging of cervical cancers. MATERIALS AND METHODS: Fifty-six women (mean age, 51 years) with histopathologically confirmed cervical cancers underwent 3 T pelvic magnetic resonance imaging including diffusion-weighted imaging (b=0, 800 s/mm(2)) prospectively. The ADC first-order statistics and texture features derived from the whole volume of cervical cancers were correlated with International Federation of Gynecology and Obstetrics (FIGO) stages (i...
July 18, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/28727556/effective-screening-and-classification-of-cervical-precancer-biopsy-imagery
#8
Jaidip Jagtap, Nishigandha Patil, Abdul K Parchur, Chayanika Pantola, Asha Agarwal, Kiran Pandey, Asima Pradhan
Microscope images of biopsy samples of cervical precancers conventionally discriminated by histopathology, the current "gold standard" for cancer detection, showed that their correlation properties are segregated into different classes. The correlation domains clearly indicate increasing cellular clustering in different grades of precancer compared to their normal counterparts. This trend indicates the probability of pixel distribution of the corresponding tissue images. Because the cell density is not uniform in the higher grades, the skewness (asymmetry of a distribution), kurtosis (sharpness of a distribution), entropy (randomness), and standard deviation are affected...
July 18, 2017: IEEE Transactions on Nanobioscience
https://www.readbyqxmd.com/read/28725591/diffusion-weighted-imaging-of-the-prostate-principles-application-and-advances
#9
REVIEW
Martin H Maurer, Johannes T Heverhagen
This review article aims to provide an overview on the principles of diffusion-weighted magnetic resonance imaging (DW-MRI) and its applications in the imaging of the prostate. DW-MRI with regards to different applications for prostate cancer (PCa) detection and characterization, local staging as well as for active surveillance (AS) and tumor recurrence after radical prostatectomy (RP) will be discussed. Furthermore, advances in DW-MRI techniques like diffusion kurtosis imaging (DKI) will be presented.
June 2017: Translational Andrology and Urology
https://www.readbyqxmd.com/read/28718517/evaluation-of-fitting-models-for-prostate-tissue-characterization-using-extended-range-b-factor-diffusion-weighted-imaging
#10
Fredrik Langkilde, Thiele Kobus, Andriy Fedorov, Ruth Dunne, Clare Tempany, Robert V Mulkern, Stephan E Maier
PURPOSE: To compare the fitting and tissue discrimination performance of biexponential, kurtosis, stretched exponential, and gamma distribution models for high b-factor diffusion-weighted images in prostate cancer. METHODS: Diffusion-weighted images with 15 b-factors ranging from b = 0 to 3500 s/mm(2) were obtained in 62 prostate cancer patients. Pixel-wise signal decay fits for each model were evaluated with the Akaike Information Criterion (AIC). Parameter values for each model were determined within normal prostate and the index lesion...
July 17, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28716688/influence-of-thoracic-fluid-compartments-on-pulmonary-congestion-in-chronic-heart-failure
#11
Steven C Chase, Bryan J Taylor, Troy J Cross, Kirsten E Coffman, Lyle J Olson, Bruce D Johnson
INTRODUCTION: Pulmonary congestion is a common finding of heart failure (HF), but it remains unclear how pulmonary and heart blood volumes (Vp and Vh) and extravascular lung water (EVLW) change in stable HF and impact lung function. METHODS: Fourteen patients with HF (age: 68±11 y; LVEF: 33±8%) and 12 controls (age: 65±9 y) were recruited. A pulmonary function test, thoracic CT scan, and contrast perfusion scan were performed. From the thoracic scan, a histogram of CT attenuation of lung tissue was generated and skew, kurtosis, and full-width half-max were calculated as surrogates of EVLW...
July 14, 2017: Journal of Cardiac Failure
https://www.readbyqxmd.com/read/28714551/influence-of-the-mode-of-administration-on-the-results-of-medication-adherence-questionnaires
#12
Ana C Cabral, Mariana Moura-Ramos, Margarida Castel-Branco, Margarida Caramona, Fernando Fernandez-Llimos, Isabel V Figueiredo
INTRODUCTION AND OBJECTIVES: Adherence to medication regimen is commonly assessed through questionnaires, some of which are validated via self-administration. The inadequate health literacy of elderly people pushes researchers to the use of interviews as a method of administration. The aims of this study were to compare the results obtained with an interviewer-administered and a self-administered medication adherence questionnaire and to evaluate the consequences of the adherence status classification of individuals...
July 17, 2017: Journal of Evaluation in Clinical Practice
https://www.readbyqxmd.com/read/28712716/differentiation-of-glioma-malignancy-grade-using-diffusion-mri
#13
Ivan I Maximov, Aram S Tonoyan, Igor N Pronin
Modern diffusion MR protocols allow one to acquire the multi-shell diffusion data with high diffusion weightings in a clinically feasible time. In the present work we assessed three diffusion approaches based on diffusion and kurtosis tensor imaging (DTI, DKI), and neurite orientation dispersion and density imaging (NODDI) as possible biomarkers for human brain glioma grade differentiation based on the one diffusion protocol. We used three diffusion weightings (so called b-values) equal to 0, 1000, and 2500s/mm(2) with 60 non-coplanar diffusion directions in the case of non-zero b-values...
July 13, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28708850/tumor-spatial-heterogeneity-in-myxoid-containing-soft-tissue-using-texture-analysis-of-diffusion-weighted-mri
#14
Hyun Su Kim, Jae-Hun Kim, Young Cheol Yoon, Bong Keun Choe
The objective of this study was to examine the tumor spatial heterogeneity in myxoid-containing soft-tissue tumors (STTs) using texture analysis of diffusion-weighted imaging (DWI). A total of 40 patients with myxoid-containing STTs (23 benign and 17 malignant) were included in this study. The region of interest (ROI) was manually drawn on the apparent diffusion coefficient (ADC) map. For texture analysis, the global (mean, standard deviation, skewness, and kurtosis), regional (intensity variability and size-zone variability), and local features (energy, entropy, correlation, contrast, homogeneity, variance, and maximum probability) were extracted from the ADC map...
2017: PloS One
https://www.readbyqxmd.com/read/28702832/effect-of-perfusion-on-diffusion-kurtosis-imaging-estimates-for-in-vivo-assessment-of-integrated-2016-who-glioma-grades-a%C3%A2-cross-sectional-observational-study
#15
Johann-Martin Hempel, Jens Schittenhelm, Cornelia Brendle, Benjamin Bender, Georg Bier, Marco Skardelly, Ghazaleh Tabatabai, Salvador Castaneda Vega, Ulrike Ernemann, Uwe Klose
PURPOSE: To assess the role of perfusion-related signal decay on diffusion kurtosis imaging (DKI) estimates for in vivo stratification of glioma according to the integrated approach of the 2016 World Health Organization classification of tumors of the central nervous system (2016 CNS WHO). METHODS: In this study 77 patients with histopathologically confirmed glioma were retrospectively assessed between January 2013 and February 2017 in a prospective trial. Mean kurtosis (MK) and mean diffusivity (MD) metrics from DKI were assessed by two physicians blinded to the study from a volume of interest around the entire solid tumor...
July 12, 2017: Clinical Neuroradiology
https://www.readbyqxmd.com/read/28692997/automated-classification-and-removal-of-eeg-artifacts-with-svm-and-wavelet-ica
#16
Chong Yeh Sai, Norrima Mokhtar, Hamzah Arof, Paul Cumming, Masahiro Iwahashi
Brain electrical activity recordings by electroencephalography (EEG) are often contaminated with signal artifacts. Procedures for automated removal of EEG artifacts are frequently sought for clinical diagnostics and brain computer interface (BCI) applications. In recent years, a combination of independent component analysis (ICA) and discrete wavelet transform (DWT) has been introduced as standard technique for EEG artifact removal. However, in performing the wavelet-ICA procedure, visual inspection or arbitrary thresholding may be required for identifying artifactual components in the EEG signal...
July 4, 2017: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/28689259/differential-diagnosis-of-parkinsonism-by-a-combined-use-of-diffusion-kurtosis-imaging-and-quantitative-susceptibility-mapping
#17
Kenji Ito, Chigumi Ohtsuka, Kunihiro Yoshioka, Hiroyuki Kameda, Suguru Yokosawa, Ryota Sato, Yasuo Terayama, Makoto Sasaki
PURPOSE: We investigated whether diffusion kurtosis imaging (DKI) and quantitative susceptibility mapping (QSM) could detect pathological changes that occur in Parkinson's disease (PD), multiple system atrophy with predominant parkinsonism (MSA-P) or predominant cerebellar ataxia (MSA-C), and progressive supranuclear palsy syndrome (PSPS) and thus be used for differential diagnosis that is often difficult. METHODS: Seventy patients (41 with PD, 6 with MSA-P, 7 with MSA-C, 16 with PSPS) and 20 healthy controls were examined using a 3...
July 8, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28688982/the-effects-of-striatal-silent-lacunar-infarction-on-the-substantia-nigra-and-movement-disorders-in-parkinson-s-disease-a-follow-up-study
#18
Guohua Zhang, Chengguo Zhang, Yuhu Zhang, Yukai Wang, Kun Nie, Bin Zhang, Haiqun Xie, Jiancong Lu, Lijuan Wang
OBJECTIVE: Striatal silent lacunar infarction (SSLI) is associated with structural changes to the substantia nigra (SN), detectable by diffusion kurtosis imaging (DKI). In this follow-up study, we investigated the effects of SSLI on the SN and movement disorders in patients with Parkinson's disease (PD). METHODS: A total of 60 untreated patients with early-stage PD, divided into control and SSLI groups, were enrolled in this study. All participants underwent conventional MRI and DKI twice; at baseline and after a 1-year period...
June 27, 2017: Parkinsonism & related Disorders
https://www.readbyqxmd.com/read/28676888/spinal-cord-microstructure-integrating-phase-sensitive-inversion-recovery-and-diffusional-kurtosis-imaging
#19
V Panara, R Navarra, P A Mattei, E Piccirilli, A R Cotroneo, N Papinutto, R G Henry, A Uncini, M Caulo
PURPOSE: The aim of this prospective study was to determine the feasibility in terms of repeatability and reproducibility of diffusional kurtosis imaging (DKI) for microstructural assessment of the normal cervical spinal cord (cSC) using a phase-sensitive inversion recovery (PSIR) sequence as the anatomical reference for accurately defining white-matter (WM) and gray-matter (GM) regions of interests (ROIs). METHODS: Thirteen young healthy subjects were enrolled to undergo DKI and PSIR sequences in the cSC...
July 4, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28675748/a-preliminary-study-for-the-assessment-of-hypertension-using-static-and-dynamic-ir-thermograms
#20
Jayanthi Thiruvengadam, Anburajan Mariamichael
Structural changes in blood vessels occur due to prolonged hypertension. Early detection of blood pressure (mm Hg) is essential for disease prevention. The aim of this work is to propose a computer-aided diagnostic (CADx) model for the diagnosis of hypertension using variables derived from non-contact static and dynamic thermal imaging in comparison with the pulse wave velocity (PWV)-derived parameters. Static and dynamic infrared (IR) thermograms of selected skin areas of the body from known hypertensive (n=14) and age- and sex-matched normal subjects were captured...
July 4, 2017: Biomedizinische Technik. Biomedical Engineering
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