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Susceptibility Weighted Imaging

Ken De Smet, Paul-Emile Claus, Gudrun Alliet, An Simpelaere, Geert Desmet
Objective and Importance Lemierre's syndrome (LS) is a rare condition that typically starts with a bacterial oropharyngeal infection complicated by a thrombophlebitis of the internal jugular vein and septic emboli to the lungs or other organs. The most common organism isolated is Fusobacterium necrophorum, although other causative organisms are isolated in rare cases. Case presentation We discuss a case of LS in a 44-year-old, previously healthy man presenting with an oropharyngeal infection. F. necrophorum was isolated from blood cultures and Computed tomography of the chest demonstrated septic emboli in the lungs...
May 21, 2018: Acta Clinica Belgica
Jiaen Liu, Jacco A de Zwart, Peter van Gelderen, Joseph Murphy-Boesch, Jeff H Duyn
PURPOSE: To identify and characterize the sources of B0 field changes due to head motion, to reduce motion sensitivity in human brain MRI. METHODS: B0 fields were measured in 5 healthy human volunteers at various head poses. After measurement of the total field, the field originating from the subject was calculated by subtracting the external field generated by the magnet and shims. A subject-specific susceptibility model was created to quantify the contribution of the head and torso...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
B Wang, B Zhao, Y Zhang, M Ge, P Zhao, Na Sun, C Li, Q Pang, S Xu, Y Liu
AIM: To investigate the efficiency of absolute cerebral blood volume (CBV) in the differentiation of tumour recurrence (TR) and radionecrosis (RN) in brain metastases (BM) and to evaluate the performance of absolute CBV compared to relative CBV (rCBV). MATERIALS AND METHODS: Between March 2015 and June 2017, 46 patients with BM underwent quantitative dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) because new enhancement had been demonstrated in irradiated lesions after gamma knife radiotherapy...
May 12, 2018: Clinical Radiology
Xinling Li, Yunzhi Huang, Luyi Han, Qi Liu, Ling He, Jin Zhang, Junpeng Zhang, Jiang Zhang
To better use the phase information to compensate the influence of blood flow, the phase unwrapping problem in susceptibility weighted imaging (SWI) is studied in this paper. In order to improve the accuracy of unwrapping, this paper proposes a magnitude image-guided phase unwrapping algorithm of SWI. The basic idea is as follows: (1) reduce the influence of noise by improving the rotational invariant non-local principal component analysis method (PRI-NL-PCA); (2) extract the corresponding solid region in the phase image to avoid the influence of the background noise on the phase unwrapping method; (3) use the phase compensation method to constrain the phase image reconstructed by the K-space...
October 1, 2017: Sheng Wu Yi Xue Gong Cheng Xue za Zhi, Journal of Biomedical Engineering, Shengwu Yixue Gongchengxue Zazhi
Wenbin Li, Xuan Wang, Xiaoer Wei, Mingliang Wang
Objective: Encephalomalacia after traumatic brain injury (TBI) is one of the factors leading to epilepsy. In this study, magnetic resonance imaging (MRI) was used to explore the brain image features of epilepsy after traumatic encephalomalacia, and to provide objective evidence for predicting the possible occurrence of epilepsy after traumatic encephalomalacia. Methods: Two-hundred-fifty-two patients with traumatic encephalomalacia were prospectively enrolled in the study...
May 2018: Annals of Clinical and Translational Neurology
Xiang-Xue Zhou, Xun-Hua Li, Ding-Bang Chen, Chao Wu, Li Feng, Jian-Ping Chu, Zhi-Yun Yang, Xin-Bei Li, Haolin Qin, Gui-Dian Li, Hai-Wei Huang, Ying-Ying Liang, Xiu-Ling Liang
Objective: To investigate the cause of the motor asymmetry in Wilson's disease (WD) patients using functional MRI. Methods: Fifty patients with WD and 20 age-matched healthy controls were enrolled. Neurological symptoms were scored using the modified Young Scale. All study subjects underwent diffusion tensor imaging (DTI), susceptibility-weighted imaging (SWI), and resting-state functional MRI (rs-fMRI) of the brain. Six regions of interest (ROI) were chosen. Fiber volumes between ROIs on DTI, corrected phase (CP) values on SWI, amplitude of low-frequency fluctuation (ALFF), and regional homogeneity (REHO) values on rs-fMRI were determined...
May 2018: Brain and Behavior
Fang-Fang Zhao, Hao-Yuan Gao, Yuan Gao, Zhuan Zhao, Juan Li, Fang-Bo Ning, Xin-Na Zhang, Zhi-Gao Wang, Ai-Ling Yu, Yan-Yong Guo, Bao-Liang Sun
PURPOSE: This study aimed to investigate the correlation between cerebral microbleeds and carotid atherosclerosis in patients with ischemic stroke. SUBJECTS AND METHODS: Patients with ischemic stroke treated in a hospital in China from 2016 to 2017 were enrolled in the study. Based on the results from susceptibility-weighted imaging, the patients were divided into cerebral microbleed and noncerebral microbleed groups. The degree of carotid atherosclerosis was assessed with carotid intima-media thickness (CIMB) and Crouse score of carotid plaque...
May 11, 2018: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Adarsh Ghosh, Tulika Singh, Veenu Singla, Rashmi Bagga, Radhika Srinivasan, Niranjan Khandelwal
OBJECTIVE: Susceptibility artefacts from bones and bowel, geometric distortion make diffusion imaging of the pelvis difficult. We discuss the difficulties of single-shot-echoplanar[ss-ep ]DWI and evaluate a new diffusion-weighted imaging technique - readout segmented echo planar[ rs-ep]DWI in endometrial carcinoma and discuss the imaging physics. METHODS: IRB approval was obtained and five consecutive patients underwent both rs-ep and ss-ep-DWI of the female pelvis and two radiologists compared the images...
May 11, 2018: British Journal of Radiology
Yunsup Hwang, Young-Joo Kim
No abstract text is available yet for this article.
May 11, 2018: Canadian Journal of Neurological Sciences. le Journal Canadien des Sciences Neurologiques
Li Guo, Yingjie Mei, Jijing Guan, Xiangliang Tan, Yikai Xu, Wufan Chen, Qianjin Feng, Yanqiu Feng
Quantitative susceptibility mapping (QSM) is a magnetic resonance imaging technique that quantifies the magnetic susceptibility distribution within biological tissues. QSM calculates the underlying magnetic susceptibility by deconvolving the tissue magnetic field map with a unit dipole kernel. However, this deconvolution problem is ill-posed. The morphology enabled dipole inversion (MEDI) introduces total variation (TV) to regularize the susceptibility reconstruction. However, MEDI results still contain artifacts near tissue boundaries because MEDI only imposes TV constraint on voxels inside smooth regions...
2018: PloS One
Ting Duan, Jie Chen, Chun-Chao Xia, Bin Song
OBJECTIVE: To test the capability of intratumoral susceptibility signal intensity (ITSS) in the differentiation of hepatocellular carcinoma (HCC) grades. METHODS: Retrospective reviews of 53 patients with pathologically proven HCCs were performed. All patients underwent both conventional MRI and SWI examinations. The morphological score of ITSS and the number of ITSS per square centimeter were calculated,then compared among low-grade and high-grade HCCs. Spearman correlation coefficients were determined between the morphological scores of ITSS,the number of ITSS per square centimeter and HCC grades...
March 2018: Sichuan da Xue Xue Bao. Yi Xue Ban, Journal of Sichuan University. Medical Science Edition
Akhil Jain, Rina Koyani, Carlos Muñoz, Prakhar Sengar, Oscar E Contreras, Patricia Juárez, Gustavo A Hirata
Nanoparticle (NP) and photosensitizer (PS) conjugates capable of X-ray photodynamic therapy (X-PDT) are a research focus due to their potential applications in cancer treatment. Combined with X-PDT, appropriate imaging properties of the nanocomposite will make it suitable for theranostics of deep lying tumors. In this work, we describe the development of magnetic-luminescent Gd2.98 Ce0.02 Al5 O12 nanoparticles (GAG) coated with mesoporous silica (mSiO2 ) and loaded with rose bengal (RB) to yield a nanocomposite GAG@mSiO2 @RB capable of X-PDT...
April 27, 2018: Journal of Colloid and Interface Science
Xuemei Zhao, Ziqiang Shao, Yu Zhang, Fang Liu, Zhibo Liu, Zunjing Liu
OBJECTIVES: To investigate the relationship between ceruloplasmin (CP) and Parkinson's disease (PD), and the correlation between CP level and the time difference between nonmotor symptoms and motor symptoms and the diagnosis were also mentioned. MATERIALS AND METHODS: Sixty-six patients diagnosed with PD for the first time were included in the study. They were divided into CP reduction group (31 cases) and CP normal group (35 cases) according to their CP level. The estimated time difference between nonmotor symptoms and motor symptoms and the diagnosis were recorded respectively...
May 7, 2018: Brain and Behavior
Dmitriy A Yablonskiy, Alexander L Sukstanskii
The ultimate goal of MRI is to provide information on biological tissue microstructure and function. Quantitative Susceptibility Mapping (QSM) is one of the newer approaches for studying tissue microstructure by means of measuring phase of Gradient Recalled Echo (GRE) MRI signal. The fundamental question in the heart of this approach is: what is the relationship between the net phase/frequency of the GRE signal from an imaging voxel and the underlying tissue microstructure at the cellular and sub-cellular levels? In the presence of external magnetic field, biological media (e...
April 26, 2018: Journal of Magnetic Resonance
John C Benson, Gustavo Cervantes, Thomas R Baron, Andrew E Tyan, Siobhan Flanagan, Leandro T Lucato, Alexander M McKinney, Frederick Ott
Background: Neurotoxoplasmosis is a common opportunistic infection in HIV/AIDS patients. Imaging identification of neurotoxoplasmosis assists in timely treatment. Purpose: To delineate the frequency of imaging abnormalities in patients with neurotoxoplasmosis on different MR sequences with a particular focus on SWI, and NCCT. Material and methods: The PACS database was retroactively searched over a 5-year period for patients with neurotoxoplasmosis who underwent MRI with SWI...
2018: European Journal of Radiology Open
Atsuko Arisawa, Yoshiyuki Watanabe, Hisashi Tanaka, Hiroto Takahashi, Chisato Matsuo, Takuya Fujiwara, Masahiro Fujiwara, Yasunori Fujimoto, Noriyuki Tomiyama
PURPOSE: Arterial spin labeling (ASL) is a non-invasive perfusion technique that may be an alternative to dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) for assessment of brain tumors. To our knowledge, there have been no reports on histogram analysis of ASL. The purpose of this study was to determine whether ASL is comparable with DSC-MRI in terms of differentiating high-grade and low-grade gliomas by evaluating the histogram analysis of cerebral blood flow (CBF) in the entire tumor...
April 29, 2018: Neuroradiology
Ryota Sato, Toru Shirai, Yo Taniguchi, Takenori Murase, Yoshitaka Bito, Yoshihisa Soutome, Hisaaki Ochi
To realize susceptibility-weighted imaging in vertical-field magnetic resonance imaging (MRI), we developed an image-processing method called "susceptibility difference weighted imaging" (SDWI). In SDWI, contrasts are enhanced using a susceptibility map calculated by using a weighted least-square algorithm with a small iteration number. Experiments were performed on human volunteers to compare image contrast obtained from the conventional method (SWI) and SDWI. In horizontal-field MRI, SDWI results show that veins and deep-gray-matter nuclei were visualized as well as those with SWI...
April 26, 2018: Radiological Physics and Technology
T Sartoretti, E Sartoretti, C Binkert, A Gutzeit, C Reischauer, D Czell, M Wyss, E Brüllmann, S Sartoretti-Schefer
Diffusion restriction is the morphologic hallmark of acute ischemic infarcts and excitotoxic brain injury in various cerebral pathologies. Diffusion restriction is visible as hyperintensity on DWI and as hypointensity on ADC maps. Due to the vicinity of multiple anatomic structures in the brain stem and hippocampus, very small lesions with diffusion restriction may result in severe clinical symptomatology, but these small lesions easily go undetected on standard cerebral DWI due to insufficient spatial resolution, T2* blurring, and image artifacts caused by susceptibility-related image distortions...
April 26, 2018: AJNR. American Journal of Neuroradiology
Bao Wang, Peng Zhao, Yi Zhang, Mingxu Ge, Chuanjin Lan, Chuanting Li, Qi Pang, Shangchen Xu, Yingchao Liu
INTRODUCTION: Treatment of recurrent high-grade gliomas (rHGG) has always been challenging. This study aimed to explore the treatment effect of quantitative dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI)-guided gamma knife radiosurgery (GKRS) on rHGG. METHODS: Between April 2014 and July 2016, 26 consecutive patients were treated by quantitative DSC-PWI-guided GKRS as salvage treatment for rHGG. The gross tumor volume (GTV) was defined as the high perfusion area on absolute cerebral blood volume maps, with a cutoff value of 22 ml/100 g...
April 26, 2018: Journal of Neuro-oncology
Till M Schneider, Armin M Nagel, Markus Zorn, Andreas Wetscherek, Martin Bendszus, Mark E Ladd, Sina Straub
Blood clotting is a fundamental biochemical process in post-hemorrhagic hemostasis. Although the varying appearance of coagulating blood in T1 - and T2 -weighted images is widely used to qualitatively determine bleeding age, the technique permits only a rough discrimination of coagulation stages, and it remains difficult to distinguish acute and chronic hemorrhagic stages because of low T1 - and T2 -weighted signal intensities in both instances. To investigate new biomedical parameters for magnetic resonance imaging-based characterization of blood clotting kinetics, sodium imaging and quantitative susceptibility mapping (QSM) were compared with conventional T1 - and T2 -weighted imaging, as well as with biochemical hemolysis parameters...
April 25, 2018: NMR in Biomedicine
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