keyword
MENU ▼
Read by QxMD icon Read
search

Skew deviation

keyword
https://www.readbyqxmd.com/read/28624925/liver-fibrosis-in-vivo-evaluation-using-intravoxel-incoherent-motion-derived-histogram-metrics-with-histopathologic-findings-at-3-0-t
#1
Fubi Hu, Ru Yang, Zixing Huang, Min Wang, Hanmei Zhang, Xu Yan, Bin Song
PURPOSE: To retrospectively determine the feasibility of intravoxel incoherent motion (IVIM) imaging based on histogram analysis for the staging of liver fibrosis (LF) using histopathologic findings as the reference standard. METHODS: 56 consecutive patients (14 men, 42 women; age range, 15-76, years) with chronic liver diseases (CLDs) were studied using IVIM-DWI with 9 b-values (0, 25, 50, 75, 100, 150, 200, 500, 800 s/mm(2)) at 3.0 T. Fibrosis stage was evaluated using the METAVIR scoring system...
June 17, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28592331/thyroid-nodule-recognition-in-computed-tomography-using-first-order-statistics
#2
Wenxian Peng, Chenbin Liu, Shunren Xia, Dangdang Shao, Yihong Chen, Rui Liu, Zhiping Zhang
BACKGROUND: Computed tomography (CT) is one of the popular tools for early detection of thyroid nodule. The pixel intensity of thyroid in CT image is very important information to distinguish nodule from normal thyroid tissue. The pixel intensity in normal thyroid tissues is homogeneous and smooth. In the benign or malignant nodules, the pixel intensity is heterogeneous. Several studies have shown that the first order features in ultrasound image can be used as imaging biomarkers in nodule recognition...
June 2, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28583627/resectable-pancreatic-adenocarcinoma-role-of-ct-quantitative-imaging-biomarkers-for-predicting-pathology-and-patient-outcomes
#3
Christophe Cassinotto, Jaron Chong, George Zogopoulos, Caroline Reinhold, Laurence Chiche, Jean-Pierre Lafourcade, Adeline Cuggia, Eric Terrebonne, Anthony Dohan, Benoît Gallix
BACKGROUNDS: Patients with a pancreatic cancer amenable to surgery still have a poor prognosis and high risk of post-operative recurrence. We aimed to assess the value of quantitative imaging biomarkers using computed-tomography (CT) texture analysis to evaluate the pathologic tumor aggressiveness and predict disease-free survival (DFS) in patients with resectable pancreatic adenocarcinoma. METHODS: We retrospectively performed attenuation measurements and texture analysis on the portal-venous phase of the pre-operative CT scan of 99 patients that underwent resection of a pancreatic ductal adenocarcinoma in two university hospitals...
May 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28575105/assessment-of-treatment-response-during-chemoradiation-therapy-for-pancreatic-cancer-based-on-quantitative-radiomic-analysis-of-daily-cts-an-exploratory-study
#4
Xiaojian Chen, Kiyoko Oshima, Diane Schott, Hui Wu, William Hall, Yingqiu Song, Yalan Tao, Dingjie Li, Cheng Zheng, Paul Knechtges, Beth Erickson, X Allen Li
PURPOSE: In an effort for early assessment of treatment response, we investigate radiation induced changes in quantitative CT features of tumor during the delivery of chemoradiation therapy (CRT) for pancreatic cancer. METHODS: Diagnostic-quality CT data acquired daily during routine CT-guided CRT using a CT-on-rails for 20 pancreatic head cancer patients were analyzed. On each daily CT, the pancreatic head, the spinal cord and the aorta were delineated and the histograms of CT number (CTN) in these contours were extracted...
2017: PloS One
https://www.readbyqxmd.com/read/28556277/distribution-of-blood-flow-velocity-in-the-normal-aorta-effect-of-age-and-gender
#5
Julio Garcia, Roel L F van der Palen, Emilie Bollache, Kelly Jarvis, Michael J Rose, Alex J Barker, Jeremy D Collins, James C Carr, Joshua Robinson, Cynthia K Rigsby, Michael Markl
PURPOSE: To apply flow distribution analysis in the entire aorta across a wide age range from pediatric to adult subjects. MATERIAL AND METHODS: In all, 98 healthy subjects (age 9-78 years, 41 women) underwent 4D flow MRI at 1.5T and 3T for the assessment of 3D blood flow in the thoracic aorta. Subjects were categorized into age groups: group 1 (n = 9, 5 women): 9-15 years; group 2 (n = 13, 8 women): 16-20 years; group 3 (n = 27, 14 women): 21-39 years; group 4 (n = 40, 11 women): 40-59 years; group 5 (n = 9, 3 women): >60 years...
May 26, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28552959/multiparametric-quantification-of-thermal-heterogeneity-within-aqueous-materials-by-water-1h-nmr-spectroscopy-paradigms-and-algorithms
#6
Norbert W Lutz, Monique Bernard
Processes involving heat generation and dissipation play an important role in the performance of numerous materials. The behavior of (semi-)aqueous materials such as hydrogels during production and application, but also properties of biological tissue in disease and therapy (e.g., hyperthermia) critically depend on heat regulation. However, currently available thermometry methods do not provide quantitative parameters characterizing the overall temperature distribution within a volume of soft matter. To this end, we present here a new paradigm enabling accurate, contactless quantification of thermal heterogeneity based on the line shape of a water proton nuclear magnetic resonance (1H NMR) spectrum...
2017: PloS One
https://www.readbyqxmd.com/read/28550313/quantification-of-hepatocellular-carcinoma-heterogeneity-with-multiparametric-magnetic-resonance-imaging
#7
Stefanie J Hectors, Mathilde Wagner, Octavia Bane, Cecilia Besa, Sara Lewis, Romain Remark, Nelson Chen, M Isabel Fiel, Hongfa Zhu, Sacha Gnjatic, Miriam Merad, Yujin Hoshida, Bachir Taouli
Tumour heterogeneity poses a significant challenge for treatment stratification. The goals of this study were to quantify heterogeneity in hepatocellular carcinoma (HCC) using multiparametric magnetic resonance imaging (mpMRI), and to report preliminary data correlating quantitative MRI parameters with advanced histopathology and gene expression in a patient subset. Thirty-two HCC patients with 39 HCC lesions underwent mpMRI including diffusion-weighted imaging (DWI), blood-oxygenation-level-dependent (BOLD), tissue-oxygenation-level-dependent (TOLD) and dynamic contrast-enhanced (DCE)-MRI...
May 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28538408/precision-of-quantitative-computed-tomography-texture-analysis-using-image-filtering-a-phantom-study-for-scanner-variability
#8
Koichiro Yasaka, Hiroyuki Akai, Dennis Mackin, Laurence Court, Eduardo Moros, Kuni Ohtomo, Shigeru Kiryu
Quantitative computed tomography (CT) texture analyses for images with and without filtration are gaining attention to capture the heterogeneity of tumors. The aim of this study was to investigate how quantitative texture parameters using image filtering vary among different computed tomography (CT) scanners using a phantom developed for radiomics studies.A phantom, consisting of 10 different cartridges with various textures, was scanned under 6 different scanning protocols using four CT scanners from four different vendors...
May 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28523469/system-for-automatic-heart-rate-calculation-in-epileptic-seizures
#9
Marcin Kołodziej, Andrzej Majkowski, Remigiusz J Rak, Bartosz Świderski, Andrzej Rysz
This article presents a comprehensive system for automatic heart rate (HR) detection. The system is robust and resistant to disturbances (noise, interferences, artifacts) occurring mainly during epileptic seizures. ECG signal filtration (IIR) and normalization due to skewness and standard deviation were used as preprocessing steps. A key element of the system is a reference QRS complex pattern calculated individually for each ECG recording. Next, a cross-correlation of the reference QRS pattern with short, normalized ECG windows is calculated and the maxima of the correlation are found (R-wave locations)...
May 18, 2017: Australasian Physical & Engineering Sciences in Medicine
https://www.readbyqxmd.com/read/28513853/association-between-textural-and-morphological-tumor-indices-on-baseline-pet-ct-and-early-metabolic-response-on-interim-pet-ct-in-bulky-malignant-lymphomas
#10
Fayçal Ben Bouallègue, Yassine Al Tabaa, Marilyne Kafrouni, Guillaume Cartron, Fabien Vauchot, Denis Mariano-Goulart
PURPOSE: We investigated whether metabolic, textural and morphological tumoral indices evaluated on baseline PET-CT were predictive of early metabolic response on interim PET-CT in a cohort of patients with bulky Hodgkin and non-Hodgkin malignant lymphomas. METHODS: This retrospective study included 57 patients referred for initial PET-CT examination. In-house dedicated software was used to delineate tumor contours using a fixed 30% threshold of SUV max and then to compute tumoral metabolic parameters (SUV max, mean, peak, standard deviation, skewness and kurtosis, metabolic tumoral volume (MTV), total lesion glycolysis, and area under the curve of the cumulative histogram), textural parameters (Moran's and Geary's indices, energy, entropy, contrast, correlation derived from the gray-level co-occurrence matrix, area under the curve of the power spectral density, auto-correlation distance, and granularity), and shape parameters (surface, asphericity, convexity, surfacic extension, and 2D and 3D fractal dimensions)...
May 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28484820/-vertigo-and-dizziness-in-the-emergency-room
#11
REVIEW
A Zwergal, K Möhwald, M Dieterich
Vertigo and dizziness are among the most common chief complaints in the emergency department. Etiologies can be categorized into three subgroups: neurootological (vestibular), medical (especially cardiovascular, metabolic), and psychiatric disorders. The diagnostic approach in the emergency department is based on a systematic analysis of case history (type, time course of symptoms, modulating factors, associated symptoms), clinical examination of the vestibular, ocular motor, and cerebellar systems (head impulse test, nystagmus, skew deviation, positioning maneuver, test of gait and stance), as well as a basal monitoring (vital signs, 12-lead ECG, blood tests)...
June 2017: Der Nervenarzt
https://www.readbyqxmd.com/read/28474892/current-phase-relation-of-ballistic-graphene-josephson-junctions
#12
G Nanda, J L Aguilera-Servin, P Rakyta, A Kormányos, R Kleiner, D Koelle, K Watanabe, T Taniguchi, L M K Vandersypen, S Goswami
The current-phase relation (CPR) of a Josephson junction (JJ) determines how the supercurrent evolves with the superconducting phase difference across the junction. Knowledge of the CPR is essential in order to understand the response of a JJ to various external parameters. Despite the rising interest in ultraclean encapsulated graphene JJs, the CPR of such junctions remains unknown. Here, we use a fully gate-tunable graphene superconducting quantum intereference device (SQUID) to determine the CPR of ballistic graphene JJs...
June 14, 2017: Nano Letters
https://www.readbyqxmd.com/read/28441749/using-wavelet-packet-transform-for-surface-roughness-evaluation-and-texture-extraction
#13
Xiao Wang, Tielin Shi, Guanglan Liao, Yichun Zhang, Yuan Hong, Kepeng Chen
Surface characterization plays a significant role in evaluating surface functional performance. In this paper, we introduce wavelet packet transform for surface roughness characterization and surface texture extraction. Surface topography is acquired by a confocal laser scanning microscope. Smooth border padding and de-noise process are implemented to generate a roughness surface precisely. By analyzing the high frequency components of a simulated profile, surface textures are separated by using wavelet packet transform, and the reconstructed roughness and waviness coincide well with the original ones...
April 23, 2017: Sensors
https://www.readbyqxmd.com/read/28429801/the-dizzy-patient-don-t-forget-disorders-of-the-central-vestibular-system
#14
REVIEW
Thomas Brandt, Marianne Dieterich
Vertigo and dizziness are among the most common complaints in neurology clinics, and they account for about 13% of the patients entering emergency units. In this Review, we focus on central vestibular disorders, which are mostly attributable to acute unilateral lesions of the bilateral vestibular circuitry in the brain. In a tertiary interdisciplinary outpatient dizziness unit, central vestibular disorders, including vestibular migraine, comprise about 25% of the established diagnoses. The signs and symptoms of these disorders can mimic those of peripheral vestibular disorders with sustained rotational vertigo...
June 2017: Nature Reviews. Neurology
https://www.readbyqxmd.com/read/28419171/ultrasound-texture-analysis-association-with-lymph-node-metastasis-of-papillary-thyroid-microcarcinoma
#15
Soo-Yeon Kim, Eunjung Lee, Se Jin Nam, Eun-Kyung Kim, Hee Jung Moon, Jung Hyun Yoon, Kyung Hwa Han, Jin Young Kwak
This retrospective study aimed to evaluate whether ultrasound texture analysis is useful to predict lymph node metastasis in patients with papillary thyroid microcarcinoma (PTMC). This study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. Between May and July 2013, 361 patients (mean age, 43.8 ± 11.3 years; range, 16-72 years) who underwent staging ultrasound (US) and subsequent thyroidectomy for conventional PTMC ≤ 10 mm between May and July 2013 were included...
2017: PloS One
https://www.readbyqxmd.com/read/28416644/evaluation-of-different-estimation-methods-for-accuracy-and-precision-in-biological-assay-validation
#16
Binbing Yu, Harry Yang
Biological assays (bioassays) are procedures to estimate the potency of a substance by studying its effects on living organisms, tissues, and cells. Bioassays are essential tools for gaining insight into biologic systems and processes including, for example, the development of new drugs and monitoring environmental pollutants. Two of the most important parameters of bioassay performance are relative accuracy (bias) and precision. Although general strategies and formulas are provided in USP 〈1033〉, a comprehensive understanding of the definitions of bias and precision remain elusive...
April 17, 2017: PDA Journal of Pharmaceutical Science and Technology
https://www.readbyqxmd.com/read/28399805/tno1-a-tgn-localized-snare-interacting-protein-modulates-root-skewing-in-arabidopsis-thaliana
#17
Rahul Roy, Diane C Bassham
BACKGROUND: The movement of plant roots within the soil is key to their ability to interact with the environment and maximize anchorage and nutrient acquisition. Directional growth of roots occurs by a combination of sensing external cues, hormonal signaling and cytoskeletal changes in the root cells. Roots growing on slanted, impenetrable growth medium display a characteristic waving and skewing, and mutants with deviations in these phenotypes assist in identifying genes required for root movement...
April 11, 2017: BMC Plant Biology
https://www.readbyqxmd.com/read/28397569/analysis-of-an-ordinal-endpoint-for-use-in-evaluating-treatments-for-severe-influenza-requiring-hospitalization
#18
Ross L Peterson, David M Vock, John H Powers, Sean Emery, Eduardo Fernandez Cruz, Sally Hunsberger, Mamta K Jain, Sarah Pett, James D Neaton
Background/Aims A single best endpoint for evaluating treatments of severe influenza requiring hospitalization has not been identified. A novel six-category ordinal endpoint of patient status is being used in a randomized controlled trial (FLU-Intravenous Immunoglobulin - FLU-IVIG) of intravenous immunoglobulin. We systematically examine four factors regarding the use of this ordinal endpoint that may affect power from fitting a proportional odds model: (1) deviations from the proportional odds assumption which result in the same overall treatment effect as specified in the FLU-IVIG protocol and which result in a diminished overall treatment effect, (2) deviations from the distribution of the placebo group assumed in the FLU-IVIG design, (3) the effect of patient misclassification among the six categories, and (4) the number of categories of the ordinal endpoint...
March 1, 2017: Clinical Trials: Journal of the Society for Clinical Trials
https://www.readbyqxmd.com/read/28388315/a-simulation-based-sample-size-calculation-method-for-pre-clinical-tumor-xenograft-experiments
#19
Jianrong Wu, Shengping Yang
Pre-clinical tumor xenograft experiments usually require a small sample size that is rarely greater than 20, and data generated from such experiments very often do not have censored observations. Many statistical tests can be used for analyzing such data, but most of them were developed based on large sample approximation. We demonstrate that the type-I error rates of these tests can substantially deviate from the designated rate, especially when the data to be analyzed has a skewed distribution. Consequently, the sample size calculated based on these tests can be erroneous...
April 7, 2017: Journal of Biopharmaceutical Statistics
https://www.readbyqxmd.com/read/28384860/fungal-opportunistic-pneumonias-in-hiv-aids-patients-an-indian-tertiary-care-experience
#20
Ravinder Kaur, Bhanu Mehra, Megh Singh Dhakad, Ritu Goyal, Preena Bhalla, Richa Dewan
INTRODUCTION: Opportunistic pneumonias are a major cause of mortality and morbidity in Human Immunodeficiency Virus (HIV) reactive patients. Despite the significant role that fungi play in causation of this opportunistic mycoses, very few Indian studies have attempted to investigate the burden and aetiological spectrum of HIV/AIDS-associated fungal pneumonias. AIM: To document the prevalence of fungal aetiology in HIV/AIDS-related opportunistic pneumonias in an Indian setting; and to elucidate the various fungal opportunists responsible for the same...
February 2017: Journal of Clinical and Diagnostic Research: JCDR
keyword
keyword
61301
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"