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https://www.readbyqxmd.com/read/28227204/ultrasound-plane-wave-imaging-with-delay-multiply-and-sum-beamforming-and-coherent-compounding
#1
Giulia Matrone, Alessandro S Savoia, Giosue Caliano, Giovanni Magenes, Giulia Matrone, Alessandro S Savoia, Giosue Caliano, Giovanni Magenes, Giulia Matrone, Giovanni Magenes, Alessandro S Savoia, Giosue Caliano
Improving the frame rate is an important aspect in medical ultrasound imaging, particularly in 3D/4D cardiac applications. However, an accurate trade-off between the higher frame rate and image contrast and resolution should be performed. Plane-Wave Imaging (PWI) can potentially achieve frame rates in the order of 10 kHz, as it uses a single unfocused plane wave (and thus a single transmit event) to acquire the image of the entire region of interest. The lack of transmit focusing however causes a significant drop of image quality, which can be restored by coherently compounding several tilted plane-wave frames, at the expense of the frame rate...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226722/fast-analytical-spectral-filtering-methods-for-magnetic-resonance-perfusion-quantification
#2
Kasireddy V Reddy, Abhishek Mitra, Phaneendra K Yalavarthy, Kasireddy V Reddy, Abhishek Mitra, Phaneendra K Yalavarthy, Abhishek Mitra, Kasireddy V Reddy, Phaneendra K Yalavarthy
The deconvolution in the perfusion weighted imaging (PWI) plays an important role in quantifying the MR perfusion parameters. The PWI application to stroke and brain tumor studies has become a standard clinical practice. The standard approach for this deconvolution is oscillatory-limited singular value decomposition (oSVD) and frequency domain deconvolution (FDD). The FDD is widely recognized as the fastest approach currently available for deconvolution of MR perfusion data. In this work, two fast deconvolution methods (namely analytical fourier filtering and analytical showalter spectral filtering) are proposed...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28181054/an-evaluation-of-morphological-and-functional-multi-parametric-mri-sequences-in-classifying-non-muscle-and-muscle-invasive-bladder-cancer
#3
Valeria Panebianco, Ettore De Berardinis, Giovanni Barchetti, Giuseppe Simone, Constantino Leonardo, Marcello Domenico Grompone, Maurizio Del Monte, Davide Carano, Michele Gallucci, James Catto, Carlo Catalano
OBJECTIVES: Our goal is to determine the ability of multi-parametric magnetic resonance imaging (mpMRI) to differentiate muscle invasive bladder cancer (MIBC) from non-muscle invasive bladder cancer (NMIBC). METHODS: Patients underwent mpMRI before tumour resection. Four MRI sets, i.e. T2-weighted (T2W) + perfusion-weighted imaging (PWI), T2W plus diffusion-weighted imaging (DWI), T2W + DWI + PWI, and T2W + DWI + PWI + dif-fusion tensor imaging (DTI) were interpreted qualitatively by two radiologists, blinded to histology results...
February 8, 2017: European Radiology
https://www.readbyqxmd.com/read/28178170/use-of-susceptibility-weighted-imaging-in-assessing-ischemic-penumbra-a-case-report
#4
Xiujuan Wu, Song Luo, Ying Wang, Yang Chen, Jun Liu, Jing Bai, Jiachun Feng, Hongliang Zhang
RATIONALE: The ischemic penumbra assessment is essential for the subsequent therapy and prediction of evolution in patients with acute ischemic infraction. Although controversial as a perfect equivalence to penumbra, perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch may predict the response to thrombolysis. Due to the reliance of PWI on contrast agents, noninvasive alternatives remain an unmet need. PATIENT CONCERNS: We reported a 65-year-old man complained of paroxysmal hemiplegia of his right limbs and anepia for 2 days, whereas the symptoms lasted for about 12 hours when he admitted to the hospital...
February 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28176500/role-of-perfusion-weighted-imaging-in-a-diffusion-weighted-imaging-negative-transient-ischemic-attack
#5
Sang Hun Lee, Hyun Wook Nah, Bum Joon Kim, Sung Ho Ahn, Jong S Kim, Dong Wha Kang, Sun U Kwon
BACKGROUND AND PURPOSE: The absence of acute ischemic lesions in diffusion-weighted imaging (DWI) in transient ischemic attack (TIA) patients makes it difficult to diagnose the true vascular etiologies. Among patients with DWI-negative TIA, we investigated whether the presence of a perfusion-weighted imaging (PWI) abnormality implied a true vascular event by identifying new acute ischemic lesions in follow-up magnetic resonance imaging (MRI) in areas corresponding to the initial PWI abnormality...
January 12, 2017: Journal of Clinical Neurology
https://www.readbyqxmd.com/read/28139701/the-value-of-resting-state-functional-mri-in-subacute-ischemic-stroke-comparison-with-dynamic-susceptibility-contrast-enhanced-perfusion-mri
#6
Ling Ni, Jingwei Li, Weiping Li, Fei Zhou, Fangfang Wang, Christopher G Schwarz, Renyuan Liu, Hui Zhao, Wenbo Wu, Xin Zhang, Ming Li, Haiping Yu, Bin Zhu, Arno Villringer, Yufeng Zang, Bing Zhang, Yating Lv, Yun Xu
To evaluate the potential clinical value of the time-shift analysis (TSA) approach for resting-state fMRI (rs-fMRI) blood oxygenation level-dependent (BOLD) data in detecting hypoperfusion of subacute stroke patients through comparison with dynamic susceptibility contrast perfusion weighted imaging (DSC-PWI). Forty patients with subacute stroke (3-14 days after neurological symptom onset) underwent MRI examination. Cohort A: 31 patients had MRA, DSC-PWI and BOLD data. Cohort B: 9 patients had BOLD and MRA data...
January 31, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28111420/a-follow-up-study-of-the-association-between-mobile-phone-use-and-symptoms-of-ill-health
#7
Yong Min Cho, Hee Jin Lim, Hoon Jang, Kyunghee Kim, Jae Wook Choi, Chol Shin, Seung Ku Lee, Jong Hwa Kwon, Nam Kim
The duration and frequency of mobile phone calls, and their relationship with various health effects, have been investigated in our previous cross-sectional study. This 2-year period follow-up study aimed to assess the changes in these variables of same subjects. The study population comprised 532 non-patient adult subjects sampled from the Korean Genome Epidemiology Study. The subjects underwent a medical examination at a hospital in 2012/2013 and revisited the same hospital in 2014/2015 to have the same examination for the characteristics of mobile phone use performed...
2016: Environmental Health and Toxicology
https://www.readbyqxmd.com/read/28095183/total-mercury-concentrations-in-white-and-striped-mullet-mugil-curema-and-m-cephalus-from-a-coastal-lagoon-in-the-se-gulf-of-california
#8
Jorge Ruelas-Inzunza, Cinthia K Kohen-Sandoval, Mauricio A Ramos-Osuna, Karla G Sánchez-Osuna, Pamela Spanopoulos-Zarco, Carolina G Delgado-Alvarez, Felipe Amezcua-Martínez
The White and Striped mullets (Mugil curema and M. cephalus) are highly abundant and commercially important estuarine fish in northwest (NW) Mexico. Because of their feeding habits and habitat, they are likely to accumulate mercury (Hg) in their muscle and liver. The objectives of this study were to determine total Hg distribution in the tissues of interest, to correlate Hg levels between tissues and with length and weight of fish, to estimate the percentage weekly intake (PWI) of total Hg and methyl Hg (MeHg) through consumption of both mullet species, and to compare total Hg levels with mullets from other areas...
January 17, 2017: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
https://www.readbyqxmd.com/read/28065234/quantitative-measurement-of-cerebral-blood-flow-in-enhanced-psedo-continuous-arterial-spin-labeling-perfusion-imaging-in-patients-with-intracranial-atherosclerotic-stenosis
#9
Yang Xu, Jin-Hao Lü, Lin Ma, Wei-Jun Chen, Xin Lou
<strong>Objective</strong> To acquire cerebral blood flow (CBF) in patients with severe intracranial atherosclerotic stenosis with enhanced pseudo-continuous arterial spin labeling (e-pCASL) and compare it with the findings of dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC PWI) and pseudo-continuous arterial spin labeling (pCASL). <strong>Methods</strong> A total of 39 consecutive patients with severe intracranial atherosclerotic stenosis were enrolled in this study...
December 20, 2016: Zhongguo Yi Xue Ke Xue Yuan Xue Bao. Acta Academiae Medicinae Sinicae
https://www.readbyqxmd.com/read/28043217/modulation-of-carotid-strain-by-statin-therapy-in-atherosclerosis-patients
#10
Christian Alexander Schaefer, Anna Katharina Blatzheim, Sebastian Gorgonius Passon, Kristin Solveig Pausewang, Nadjib Schahab, Georg Nickenig, Dirk Skowasch, Robert Schueler, Christoph Hammerstingl, Simon Pingel
BACKGROUND: The beneficial effect of statin therapy on the progress of atherosclerotic disease has been demonstrated by numerous studies. Vascular strain imaging is an arising method to evaluate arterial stiffness. Our study examined whether an influence of statin therapy on the vessel wall could be detected by vascular strain imaging. PATIENTS AND METHODS: 88 patients with recently detected atherosclerosis underwent an angiological examination including ankle-brachial index (ABI), pulse wave index (PWI), central puls ewave velocity and duplex ultrasound...
January 3, 2017: VASA. Zeitschrift Für Gefässkrankheiten
https://www.readbyqxmd.com/read/28029273/mri-based-mismatch-detection-in-acute-ischemic-stroke-optimal-pwi-maps-and-thresholds-validated-with-pet
#11
Olivier Zaro-Weber, Walter Moeller-Hartmann, Dora Siegmund, Alexandra Kandziora, Alexander Schuster, Wolf-Dieter Heiss, Jan Sobesky
Perfusion-weighted (PW) magnetic resonance imaging (MRI) is used to detect penumbral tissue in acute stroke, but the selection of optimal PW-maps and thresholds for tissue at risk detection remains a matter of debate. We validated the performance of PW-maps with 15O-water-positron emission tomography (PET) in a large comparative PET-MR cohort of acute stroke patients. In acute and subacute stroke patients with back-to-back MRI and PET imaging, PW-maps were validated with 15O-water-PET. We pooled two different cerebral blood flow (CBF) PET-maps to define the critical flow (CF) threshold, (i) quantitative (q)CBF-PET with the CF threshold <20 ml/100 g/min and (ii) normalized non-quantitative (nq)CBF-PET with a CF threshold of <70% (corresponding to <20 ml/100 g/min according to a previously published normogram)...
January 1, 2016: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28002039/pulse-wave-imaging-using-coherent-compounding-in-a-phantom-and-in-vivo
#12
Iason Zacharias Apostolakis, Matthew D J McGarry, Ethan A Bunting, Elisa E Konofagou
Pulse wave velocity (PWV) is a surrogate marker of arterial stiffness linked to cardiovascular morbidity. Pulse wave imaging (PWI) is a technique developed by our group for imaging the pulse wave propagation in vivo. PWI requires high temporal and spatial resolution, which conventional ultrasonic imaging is unable to simultaneously provide. Coherent compounding is known to address this tradeoff and provides full aperture images at high frame rates. This study aims to implement PWI using coherent compounding within a GPU-accelerated framework...
March 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27927085/increased-vascular-occlusion-in-patients-with-pseudoxanthoma-elasticum
#13
Simon Pingel, Kristin Solveig Pausewang, Sebastian Gorgonius Passon, Anna Katharina Blatzheim, Martin Gliem, Peter Charbel Issa, Doris Hendig, Fritz Horlbeck, Izabela Tuleta, Georg Nickenig, Nadjib Schahab, Dirk Skowasch, Christian Alexander Schaefer
BACKGROUND: Pseudoxanthoma elasticum (PXE) is an autosomal recessive inherited multisystem disorder of the connective tissue caused by a loss-of-function mutation of the ABCC6 gene. It can affect the cardiovascular system, presumably leading to a high prevalence of atherosclerosis. PATIENTS AND METHODS: 46 PXE patients and 18 controls underwent an angiological examination consisting of measurement of ankle-brachial index (ABI), strain-gauge arterial reserve (SGAR), arterial resting perfusion, pulse wave index (PWI), central pulse wave velocity, and ultrasound examination...
December 8, 2016: VASA. Zeitschrift Für Gefässkrankheiten
https://www.readbyqxmd.com/read/27896520/early-perfusion-mri-predicts-survival-outcome-in-patients-with-recurrent-glioblastoma-treated-with-bevacizumab-and-carboplatin
#14
Iwan E Bennett, Kathryn M Field, Christopher M Hovens, Bradford A Moffat, Mark A Rosenthal, Katharine Drummond, Andrew H Kaye, Andrew P Morokoff
Bevacizumab, an anti-angiogenic agent, is FDA-approved for use in patients with recurrent glioblastoma multiforme (rGBM). The radiologic evaluation of tumor response to bevacizumab is complex and there is no validated method of monitoring tumor vascularity during therapy. We evaluated perfusion-weighted MR imaging (PWI) in our cohort of patients enrolled in the CABARET trial, which examined the effectiveness of bevacizumab with or without carboplatin in patients with rGBM. Pre-treatment and early follow-up (4- and 8-week) PWI were used to calculate relative cerebral blood volume (rCBV) histogram statistics of the contrast-enhancing and FLAIR hyperintense tumor volumes...
January 2017: Journal of Neuro-oncology
https://www.readbyqxmd.com/read/27895495/predictive-values-of-diffusion-weighted-imaging-and-perfusion-weighted-imaging-in-evaluating-the-efficacy-of-transcatheter-arterial-chemoembolization-for-hepatocellular-carcinoma
#15
Min Lin, Man-Man Tian, Wei-Ping Zhang, Li Xu, Ping Jin
This study explored the predictive values of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) in evaluating the efficacy of transcatheter arterial chemoembolization (TACE) for patients with hepatocellular carcinoma (HCC). A total of 118 HCC patients treated with TACE were selected from April 2013 to November 2015. T1-weighted imaging (T1WI)/T2-weighted imaging (T2WI), DWI, and PWI were performed on all patients before and after TACE. Efficacy was evaluated according to modified Response Evaluation Criteria in Solid Tumors 1...
2016: OncoTargets and Therapy
https://www.readbyqxmd.com/read/27857749/erythropoietin-reduces-apoptosis-of-brain-tissue-cells-in-rats-after-cerebral-ischemia-reperfusion-injury-a-characteristic-analysis-using-magnetic-resonance-imaging
#16
Chun-Juan Jiang, Zhong-Juan Wang, Yan-Jun Zhao, Zhui-Yang Zhang, Jing-Jing Tao, Jian-Yong Ma
Some in vitro experiments have shown that erythropoietin (EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia. However, results from in vivo studies are rarely reported. Perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore, we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion...
September 2016: Neural Regeneration Research
https://www.readbyqxmd.com/read/27823971/combined-use-of-susceptibility-weighted-magnetic-resonance-imaging-sequences-and-dynamic-susceptibility-contrast-perfusion-weighted-imaging-to-improve-the-accuracy-of-the-differential-diagnosis-of-recurrence-and-radionecrosis-in-high-grade-glioma-patients
#17
Tae-Hyung Kim, Tae Jin Yun, Chul-Kee Park, Tae Min Kim, Ji-Hoon Kim, Chul-Ho Sohn, Jae Kyung Won, Sung-Hye Park, Il Han Kim, Seung Hong Choi
Purpose was to assess predictive power for overall survival (OS) and diagnostic performance of combination of susceptibility-weighted MRI sequences (SWMRI) and dynamic susceptibility contrast (DSC) perfusion-weighted imaging (PWI) for differentiation of recurrence and radionecrosis in high-grade glioma (HGG). We enrolled 51 patients who underwent radiation therapy or gamma knife surgeryfollowed by resection for HGG and who developed new measurable enhancement more than six months after complete response. The lesions were confirmed as recurrence (n = 32) or radionecrosis (n = 19)...
November 3, 2016: Oncotarget
https://www.readbyqxmd.com/read/27812502/comparison-of-unsupervised-classification-methods-for-brain-tumor-segmentation-using-multi-parametric-mri
#18
N Sauwen, M Acou, S Van Cauter, D M Sima, J Veraart, F Maes, U Himmelreich, E Achten, S Van Huffel
Tumor segmentation is a particularly challenging task in high-grade gliomas (HGGs), as they are among the most heterogeneous tumors in oncology. An accurate delineation of the lesion and its main subcomponents contributes to optimal treatment planning, prognosis and follow-up. Conventional MRI (cMRI) is the imaging modality of choice for manual segmentation, and is also considered in the vast majority of automated segmentation studies. Advanced MRI modalities such as perfusion-weighted imaging (PWI), diffusion-weighted imaging (DWI) and magnetic resonance spectroscopic imaging (MRSI) have already shown their added value in tumor tissue characterization, hence there have been recent suggestions of combining different MRI modalities into a multi-parametric MRI (MP-MRI) approach for brain tumor segmentation...
2016: NeuroImage: Clinical
https://www.readbyqxmd.com/read/27807223/alcohol-use-and-mental-health-conditions-among-black-college-males-do-those-attending-postsecondary-minority-institutions-fare-better-than-those-at-primarily-white-institutions
#19
Adam E Barry, Zachary Jackson, Daphne C Watkins, Janelle R Goodwill, Haslyn E R Hunte
While there is a sizeable body of research examining the association between alcohol use and mental health conditions among college students, there are sparse investigations specifically focusing on these associations among Black college students. This is concerning given Black college students face different stressors compared with their non-Black peers. Black males appear especially at risk, exhibiting increased susceptibility to mental health issues and drinking in greater quantities and more frequently than Black females...
November 2, 2016: American Journal of Men's Health
https://www.readbyqxmd.com/read/27760656/-analysis-on-clinical-features-and-functional-mri-of-mitochondrial-encephalomyopathy-with-lactic-acidosis-and-stroke-like-episodes
#20
Y H Shi, J H Zhao, J L Song, Y J Li, K Liang
Objective: To explore the clinical and perfusion weighted imaging (PWI) characteristics of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) in order to improve the early diagnosis rate. Methods: Clinical and imaging data of 46 patients with final diagnosis of MELAS treated in Henan Province People's Hospital from January 2012 to June 2016 were collected. Results: Patients presented with symptoms of epilepsy, hemiplegia, language disorders, and decreased visual acuity and so on...
October 11, 2016: Zhonghua Yi Xue za Zhi [Chinese medical journal]
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