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Susceptibility Weighted Imaging
Susceptibility weighted imaging (SWI), originally called BOLD venographic imaging, is an MRI sequence that is exquisitely sensitive to venous blood, hemorrhage and iron storage. SWI uses a fully flow compensated, long echo, gradient recalled echo (GRE) pulse sequence to acquire images. This method exploits the Magnetic susceptibility, susceptibility differences between tissues and uses the phase image to detect these differences. The magnitude and phase data are combined to produce an enhanced contrast magnitude image. The imaging of venous blood with SWI is a blood-oxygen-level dependent (BOLD) technique which is why it was (and is sometimes still) referred to as BOLD venography. Due to its sensitivity to venous blood SWI is commonly used in Traumatic brain injury, traumatic brain injuries (TBI) and for high resolution brain venographies but has many other clinical applications. SWI is offered as a clinical package by Philips and Siemens but can be run on any manufacturer’s machi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SWI 4Tesla
SWI may refer to: Places: * Switzerland (this is not the ISO 3166-1 code, which is CHE) * Swindon railway station (National Rail code SWI), serving Swindon, Wiltshire, United Kingdom In science and technology: * SWI-Prolog, a free implementation of the programming language Prolog * Susceptibility weighted imaging, in magnetic resonance imaging (MRI) used in medical contexts * Software interrupt, an interrupt routine in a computer operating system ** SWI, an assembly language, assembler mnemonic to perform a software interrupt on the ARM microprocessor family * Szilagyi Waterspout Index Other uses: * Swissinfo, a service of the Swiss Broadcasting Corporation * Switzerland, UNDP country code * Structured Word Inquiry, a pedagogical technique involving the scientific investigation of the spelling of words {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SWI Of Sturge-Weber
SWI may refer to: Places: * Switzerland (this is not the ISO 3166-1 code, which is CHE) * Swindon railway station (National Rail code SWI), serving Swindon, Wiltshire, United Kingdom In science and technology: * SWI-Prolog, a free implementation of the programming language Prolog * Susceptibility weighted imaging, in magnetic resonance imaging (MRI) used in medical contexts * Software interrupt, an interrupt routine in a computer operating system ** SWI, an assembler mnemonic to perform a software interrupt on the ARM microprocessor family * Szilagyi Waterspout Index Other uses: * Swissinfo, a service of the Swiss Broadcasting Corporation * Switzerland, UNDP country code * Structured Word Inquiry Structured Word Inquiry (SWI) is a pedagogical technique involving the scientific investigation of the spelling of words. SWI considers morphology, etymology, relatives, and phonology Phonology is the branch of linguistics that studies how ..., a pedagogical technique involving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Resonance Angiography
Magnetic resonance angiography (MRA) is a group of techniques based on magnetic resonance imaging (MRI) to image blood vessels. Magnetic resonance angiography is used to generate images of arteries (and less commonly veins) in order to evaluate them for stenosis (abnormal narrowing), Vascular occlusion, occlusions, aneurysms (vessel wall dilatations, at risk of rupture) or other abnormalities. MRA is often used to evaluate the arteries of the neck and brain, the thoracic and abdominal aorta, the renal arteries, and the legs (the latter exam is often referred to as a "run-off"). Acquisition A variety of techniques can be used to generate the pictures of blood vessels, both artery, arteries and veins, based on flow effects or on contrast (inherent or pharmacologically generated). The most frequently applied MRA methods involve the use intravenous MRI contrast agent, contrast agents, particularly those containing gadolinium to shorten the Spin–lattice relaxation, ''T''1 of blood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pneumocephalus
Pneumocephalus is the presence of air or gas within the cranial cavity. It is usually associated with disruption of the skull: after head and facial trauma, tumors of the skull base, after neurosurgery or otorhinolaryngology, and rarely, spontaneously. Pneumocephalus can occur in scuba diving, but is very rare in this context. If there is a valve mechanism which allows air to enter the skull but prevents it from escaping, a tension pneumocephalus can occur (similar to what can happen in a tension pneumothorax). CT scans of patients with a tension pneumocephalus typically show air that compresses the frontal lobes of the brain, which results in a tented appearance of the brain in the skull known as the Mount Fuji sign. The name is derived from the resemblance of the brain to Mount Fuji in Japan, a volcano known for its symmetrical cone. In typical cases, there is a symmetrical depression near the midline (such as the crater of a volcano), due to intact bridging veins Bridgin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Amyloid Angiopathy
Cerebral amyloid angiopathy (CAA) is a form of angiopathy in which amyloid beta peptide deposits in the walls of small to medium blood vessels of the central nervous system and meninges. The term ''congophilic'' is sometimes used because the presence of the abnormal aggregations of amyloid can be demonstrated by microscopic examination of brain tissue after staining with Congo red. The amyloid material is only found in the brain and as such the disease is not related to other forms of amyloidosis. Signs and symptoms CAA is associated with brain hemorrhages, particularly microhemorrhages. Since CAA can be caused by the same amyloid protein that is associated with Alzheimer's dementia, brain bleeds are more common in people who have a diagnosis of Alzheimer's disease. However, they can also occur in those who have no history of dementia. The bleeding within the brain is usually confined to a particular lobe and this is slightly different compared to brain bleeds which occur as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compare SWI And GRE CAA
Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are Similarity (psychology), similar to the other, which are Difference (philosophy), different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field: To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and in the arts. General usage Comparison is a natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proc Natl Acad Sci U S A
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are ava ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurology (journal)
''Neurology'' is a weekly peer-reviewed medical journal covering research in neurology. It is published by Wolters Kluwer on behalf of the American Academy of Neurology, of which it is the official journal. It has been edited since April 2020 by José G. Merino (University of Rochester Medical Center, University of Maryland). Previous editors-in-chief The following persons have been editors-in-chief: * Russell N. DeJong (1951-1977; University of Michigan Medical School), founding editor-in-chief * Lewis P. Rowland (1977-1987; Columbia University) * Robert B. Daroff (1987-1997; Case Western Reserve University School of Medicine) * Robert C. Griggs (1997-2007; University of Rochester Medical Center) * John H. Noseworthy (2007-2009; Mayo Clinic) * Robert A. Gross (2009-2020; University of Rochester Medical Center) Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'' by Clarivate, the journal has a 2022 impact factor of 11.8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J Magn Reson Imaging
J, or j, is the tenth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its usual name in English is ''jay'' (pronounced ), with a now-uncommon variant ''jy'' ."J", ''Oxford English Dictionary,'' 2nd edition (1989) When used in the International Phonetic Alphabet for the ''y'' sound, it may be called ''yod'' or ''jod'' (pronounced or ). History The letter ''J'' used to be used as the swash letter ''I'', used for the letter I at the end of Roman numerals when following another I, as in XXIIJ or xxiij instead of XXIII or xxiii for the Roman numeral twenty-three. A distinctive usage emerged in Middle High German. Gian Giorgio Trissino (1478–1550) was the first to explicitly distinguish I and J as representing separate sounds, in his ''Ɛpistola del Trissino de le lettere nuωvamente aggiunte ne la lingua italiana'' ("Trissino's epistle about the letters recently added in the Ital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Attenuated Inversion Recovery
Fluid-attenuated inversion recovery (FLAIR) is an MRI sequence with an inversion recovery set to null fluids. For example, it can be used in brain imaging to suppress cerebrospinal fluid (CSF) effects on the image, so as to bring out the periventricular hyperintense lesions, such as multiple sclerosis (MS) plaques. It was invented by Dr. Graeme Bydder. FLAIR can be used with both three-dimensional imaging (3D FLAIR) or two dimensional imaging (2D FLAIR). Technique By carefully choosing the inversion time (TI), the signal from any particular tissue can be nulled. The appropriate TI depends on the tissue via the formula: :\textrm = \ln(2) \cdot T_1,\, in other words, one should typically use a TI of around 70% of the ''T1'' value. In the case of CSF suppression, one aims for ''T1''-weighted images, which prioritize the signal of fat over that of water. Therefore, if the long TI (inversion time) is adjusted to a zero crossing point for water (none of its signal is visible), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Sclerosis
Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This damage disrupts the ability of parts of the nervous system to transmit signals, resulting in a range of signs and symptoms, including physical, mental, and sometimes psychiatric problems. Specific symptoms can include double vision, blindness in one eye, muscle weakness, and trouble with sensation or coordination. MS takes several forms, with new symptoms either occurring in isolated attacks (relapsing forms) or building up over time (progressive forms). In the relapsing forms of MS, between attacks, symptoms may disappear completely, although some permanent neurological problems often remain, especially as the disease advances. While the cause is unclear, the underlying mechanism is thought to be either destruction by the immune system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sturge–Weber Syndrome
Sturge–Weber syndrome, sometimes referred to as encephalotrigeminal angiomatosis, is a rare congenital neurological and skin disorder. It is one of the phakomatoses and is often associated with port-wine stains of the face, glaucoma, seizures, intellectual disability, and ipsilateral leptomeningeal angioma (cerebral malformations and tumors). Sturge–Weber syndrome can be classified into three different types. Type 1 includes facial and leptomeningeal angiomas as well as the possibility of glaucoma or choroidal lesions. Normally, only one side of the brain is affected. This type is the most common. Type 2 involvement includes a facial angioma (port wine stain) with a possibility of glaucoma developing. There is no evidence of brain involvement. Symptoms can show at any time beyond the initial diagnosis of the facial angioma. The symptoms can include glaucoma, cerebral blood flow abnormalities and headaches. More research is needed on this type of Sturge–Weber syndrome. Type 3 h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_Phase_Contrast_(PC)_sequence_MRI_of_arterial_dissections.jpg "Click for more on -> Magnetic Resonance Angiography")
