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Susceptibility Weighted Imaging

Thobias Romu, Nils Dahlström, Olof Dahlqvist Leinhard, Magnus Borga
PURPOSE: The purpose of this work was to develop and evaluate a robust water-fat separation method for T1-weighted symmetric two-point Dixon data. THEORY AND METHODS: A method for water-fat separation by phase unwrapping of the opposite-phase images by phase-sensitive reconstruction (PSR) is introduced. PSR consists of three steps; (1), identification of clusters of tissue voxels; (2), unwrapping of the phase in each cluster by solving Poisson's equation; and (3), finding the correct sign of each unwrapped opposite-phase cluster, so that the water-fat images are assigned the correct identities...
October 24, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Ming-Liang Wang, Wen-Bin Li
Traumatic brain injury (TBI) is closely related to increased incidence of cognitive impairment from the acute phase to chronic phase. At present, the pathological mechanism leading to cognitive impairment after TBI is still not fully understood. We hypothesize that neuron loss, diffuse axonal injury, microbleed, and blood-brain barrier (BBB) disruption altogether contribute to the development of cognitive impairment. Furthermore, the disruption of structural and functional neural network related to the cognitive function might bring about the final step in the occurrence of cognitive impairment after TBI...
November 15, 2016: Journal of the Neurological Sciences
Zhe Zhang, Bing Zhang, Ming Li, Xue Liang, Xiaodong Chen, Renyuan Liu, Xin Zhang, Hua Guo
PURPOSE: To report a diffusion imaging technique insensitive to off-resonance artifacts and motion-induced ghost artifacts using mulitshot Cartesian turbo spin-echo (TSE) acquisition and iterative POCS-based reconstruction of multiplexed sensitivity encoded magnetic resonance imaging (MRI) (POCSMUSE) for phase correction. MATERIALS AND METHODS: Phase insensitive diffusion preparation was used to deal with the violation of the Carr-Purcell-Meiboom-Gill (CPMG) conditions of TSE diffusion-weighted imaging (DWI), followed by a mulitshot Cartesian TSE readout for data acquisition...
October 20, 2016: Journal of Magnetic Resonance Imaging: JMRI
Zhibin Wang, Xiao-Guang Luo, Chao Gao
In the clinic, the diagnosis of Parkinson's disease (PD) largely depends on clinicians' experience. When the diagnosis is made, approximately 80% of dopaminergic cells in the substantia nigra (SN) have been lost. Additionally, it is rather challenging to differentiate PD from atypical parkinsonian disorders (APD). Clinially-available 3T conventional MRI contributes little to solve these problems. The pathologic alterations of parkinsonism show abnormal brain iron deposition, and therefore susceptibility-weighted imaging (SWI), which is sensitive to iron concentration, has been applied to find iron-related lesions for the diagnosis and differentiation of PD in recent decades...
2016: Translational Neurodegeneration
Chang Y Ho, Melissa Gener, Jose Bonnin, Stephen F Kralik
We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases...
July 2016: Journal of Radiology Case Reports
Melinda A Ma, Rajesh Kumar, Paul M Macey, Frisca L Yan-Go, Ronald M Harper
INTRODUCTION: Obstructive sleep apnea (OSA) is a male-predominant condition, characterized by repeated upper-airway collapse with continued diaphragmatic efforts during sleep, and is accompanied by severe physiological consequences. Multiple morphological aspects, including epiglottis cross-sectional area (CSA) and oropharyngeal airway length (OPAL), can contribute to airway collapsibility in the condition. This study focused on the effects of OSA severity, sex, and race on OPA dimensions...
2016: Nature and Science of Sleep
Jerrold L Boxerman, Mark S Shiroishi, Benjamin M Ellingson, Whitney B Pope
Dynamic susceptibility contrast (DSC) MR imaging, a perfusion-weighted MR imaging technique typically used in neuro-oncologic applications for estimating the relative cerebral blood volume within brain tumors, has demonstrated much potential for determining prognosis, predicting therapeutic response, and assessing early treatment response of gliomas. This review highlights recent developments using DSC-MR imaging and emphasizes the need for technical standardization and validation in prospective studies in order for this technique to become incorporated into standard-of-care imaging for patients with brain tumors...
November 2016: Magnetic Resonance Imaging Clinics of North America
Mirza A Baig, Joshua P Klein, Laszlo L Mechtler
PURPOSE OF REVIEW: Neuroimaging is an essential tool for the diagnosis and management of brain tumors. RECENT FINDINGS: Advances in neuroimaging have allowed for noninvasive visualization of tumors and have changed how brain tumors are diagnosed and treated. Presurgical planning with the use of functional MRI (fMRI) and diffusion tensor MRI helps to preserve eloquent regions of the brain and fiber tracts, thereby decreasing patients' postsurgical morbidity. With the use of susceptibility-weighted imaging (SWI) filtered phase images, diffusion-weighted studies, and perfusion imaging techniques, deciphering posttreatment effects versus tumor progression can be facilitated...
October 2016: Continuum: Lifelong Learning in Neurology
Lei Wu, Di Jin, Xuan Sun, Liang Liang, Deihui Huang, Zhao Dong, Shengyuan Yu
Wernicke's encephalopathy (WE) is a thiamine deficiency-related condition, in which lesions are usually present in the periventricular and subcortical areas of the brain. However, lesions have also been found in atypical areas, such as the cerebral cortex. The present study summarizes the clinical outcomes and radiological features of WE with cortical impairment. We report two cases of cortical involvement in patients with WE, and review 22 similar cases from other reports. Among all 24 cases, 4 patients had a confirmed history of chronic daily alcohol abuse, and 19 of them had an identified causes of thiamine deficiency...
October 12, 2016: Metabolic Brain Disease
Rachel Denholm, Bianca De Stavola, John H Hipwell, Simon J Doran, Marta C Busana, Amanda Eng, Mona Jeffreys, Martin O Leach, David Hawkes, Isabel Dos Santos Silva
BACKGROUND: Breast density, the amount of fibroglandular tissue in the adult breast for a women's age and body mass index, is a strong biomarker of susceptibility to breast cancer, which may, like breast cancer risk itself, be influenced by events early in life. In the present study, we investigated the association between pre-natal exposures and breast tissue composition. METHODS: A sample of 500 young, nulliparous women (aged approximately 21 years) from a U...
October 12, 2016: Breast Cancer Research: BCR
Zhengzhen Chen, Huihuang Qiao, Yu Guo, Jiance Li, Huizhong Miao, Caiyun Wen, Xindong Wen, Xiaofen Zhang, Xindong Yang, Chengchun Chen
BACKGROUND AND PURPOSE: Understanding the anatomy of the anterior septal vein (ASV) is critical for minimally invasive procedures to the third ventricle and for assessing lesion size and venous drainage in the anterior cranial fossa. Accordingly, this study evaluated topographic anatomy and anatomic variation of the ASV using susceptibility-weighted imaging (SWI). METHODS: Sixty volunteers were examined using a 3.0T MR system. The diameter of the ASV and distance between bilateral septal points were measured...
2016: PloS One
Ryosuke Tomio, Takenori Akiyama, Masahiro Toda, Takayuki Ohira, Kazunari Yoshida
OBJECTIVE Transcranial motor evoked potential (tMEP) monitoring is popular in neurosurgery; however, the accuracy of tMEP can be impaired by craniotomy. Each craniotomy procedure and changes in the CSF levels affects the current spread. The aim of this study was to investigate the influence of several craniotomies on tMEP monitoring by using C3-4 transcranial electrical stimulation (TES). METHODS The authors used the finite element method to visualize the electric field in the brain, which was generated by TES, using realistic 3D head models developed from T1-weighted MR images...
October 7, 2016: Journal of Neurosurgery
Marc C Mabray, Soonmee Cha
This article presents a summary of advanced MR imaging techniques and their use in the evaluation of patients with brain tumors. It reviews diffusion-weighted imaging, diffusion-tensor imaging, T2* susceptibility-sensitive imaging, MR spectroscopy, MR perfusion, and functional MR imaging, and discusses their current roles in the evaluation of patients with brain tumors.
November 2016: Neuroimaging Clinics of North America
Ramon Francisco Barajas, Soonmee Cha
Metastatic cancer to the central nervous system is primarily deposited by hematogenous spread in various anatomically distinct regions: calvarial, pachymeningeal, leptomeningeal, and brain parenchyma. A patient's overall clinical status and the information needed to make treatment decisions are the primary considerations in initial imaging modality selection. Contrast-enhanced MR imaging is the preferred imaging modality. Morphologic MR imaging is limited to delineating anatomic deraignment of tissues. Dynamic susceptibility contrast-enhanced perfusion and diffusion-weighted physiology-based MR imaging sequences have been developed that complement morphologic MR imaging by providing additional diagnostic information...
November 2016: Neuroimaging Clinics of North America
Yuki Shinohara, Ayumi Kato, Eijiro Yamashita, Toshihide Ogawa
BACKGROUND: To evaluate the detectability of arterial acute thrombus on R2* map by iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) IQ compared with T2*-weighted imaging (T2*WI). METHODS: Twenty-six patients with acute cerebral infarction who underwent R2* map and T2*WI were reviewed. We performed visual assessment of each sequence regarding the visibility of susceptibility effect reflecting acute thrombus and quantitative evaluation of the thrombus on R2* map...
September 2016: Yonago Acta Medica
Bilge Öztoprak
OBJECTIVES: Clinical applications of susceptibility-weighted imaging (SWI) are increasing steadily. The aim of this study is to investigate the appearance of cerebral veins on SWI, which is very sensitive to the deoxyhaemoglobin level in vessels, in pulmonary embolism (PE). METHODS: The cranial SWI images of 19 patients with PE and 22 controls from September 2013 through March 2016 were retrospectively examined for the presence of prominent cerebral veins. MRI findings were correlated with blood oxygen levels...
October 4, 2016: European Radiology
Bruce A Bowser, Norbert G Campeau, Carrie M Carr, Felix E Diehn, Jennifer S McDonald, Gary M Miller, Timothy J Kaufmann
INTRODUCTION: Ferumoxytol (Feraheme) is a parenteral therapy approved for treatment of iron deficiency anemia. The product insert for ferumoxytol states that it may affect the diagnostic ability of MRI for up to 3 months. However, the expected effects may not be commonly recognized among clinical neuroradiologists. Our purpose is to describe the artifacts we have seen at our institution during routine clinical practice. METHODS: We reviewed the patients at our institution that had brain MRI performed within 90 days of receiving intravenous ferumoxytol...
October 4, 2016: Neuroradiology
Takuya Hinoda, Yasutaka Fushimi, Tomohisa Okada, Yoshiki Arakawa, Chunlei Liu, Akira Yamamoto, Tsutomu Okada, Kazumichi Yoshida, Susumu Miyamoto, Kaori Togashi
PURPOSE: Gadolinium deposition in dentate nucleus (DN) has been reported after serial administration of gadolinium-based contrast agents (GBCAs). Gadolinium complexes have paramagnetic properties; therefore, we evaluated susceptibility changes of gadolinium deposition in DN using quantitative susceptibility mapping (QSM) for patients after serial administration of GBCAs. MATERIALS AND METHODS: In all, 48 patients with brain tumors, who had had serial GBCA administrations (GBCA group), and 48 healthy volunteers without any history of GBCA administrations (non-GBCA group) were enrolled in this study...
September 24, 2016: Journal of Magnetic Resonance Imaging: JMRI
Benjamin Y M Kwan, Fateme Salehi, Pavlo Ohorodnyk, Donald H Lee, Jorge G Burneo, Seyed M Mirsattari, David Steven, Robert Hammond, Terry M Peters, Ali R Khan
OBJECTIVES: Ultra high field MRI at 7T is able to provide much improved spatial and contrast resolution which may aid in the diagnosis of hippocampal abnormalities. This paper presents a preliminary experience on qualitative evaluation of 7T MRI in temporal lobe epilepsy patients with a focus on comparison to histopathology. METHODS: 7T ultra high field MRI data, using T1-weighted, T2*-weighted and susceptibility-weighted images (SWI), were acquired for 13 patients with drug resistant temporal lobe epilepsy (TLE) during evaluation for potential epilepsy surgery...
October 15, 2016: Journal of the Neurological Sciences
Ahmed Abdel Khalek Abdel Razek, Sieza Samir, Germeen Albair Ashmalla
PURPOSE: To characterize parotid tumors with dynamic susceptibility contrast perfusion-weighted magnetic resonance (MR) imaging and diffusion-weighted MR imaging. MATERIAL AND METHODS: Prospective study was conducted upon 48 consecutive patients (27 men, 21 women; aged 15-75 years; mean, 45 years) with parotid tumors that underwent dynamic susceptibility contrast perfusion-weighted MR imaging was performed after bolus injection of gadopentate dimeglumine and diffusion-weighted MR imaging...
September 16, 2016: Journal of Computer Assisted Tomography
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