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Fast Low Angle Shot Magnetic Resonance Imaging
Fast low angle shot magnetic resonance imaging (FLASH MRI) is a particular sequence of magnetic resonance imaging. It is a gradient echo sequence which combines a low-flip angle radio-frequency excitation of the nuclear magnetic resonance signal (recorded as a spatially encoded gradient echo) with a short repetition time. It is the generic form of steady-state free precession imaging. Different manufacturers of MRI equipment use different names for this experiment. Siemens uses the name FLASH, General Electric used the name SPGR (Spoiled Gradient Echo), and Philips uses the name CE-FFE-T1 (Contrast-Enhanced Fast Field Echo) or T1-FFE. Depending on the desired contrast, the generic FLASH technique provides spoiled versions that destroy transverse coherences and yield T1 contrast as well as refocused versions (constant phase per repetition) and fully balanced versions (zero phase per repetition) that incorporate transverse coherences into the steady-state signal and offer T1/T2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRI Sequence
An MRI pulse sequence in magnetic resonance imaging (MRI) is a particular setting of pulse sequences and pulsed field gradients, resulting in a particular image appearance. A multiparametric MRI is a combination of two or more sequences, and/or including Magnetic resonance imaging#Other specialized configurations, other specialized MRI configurations such as In vivo magnetic resonance spectroscopy, spectroscopy. Spin echo T1 and T2 Each tissue returns to its equilibrium state after excitation by the independent relaxation processes of T1 (Spin–lattice relaxation, spin-lattice; that is, magnetization in the same direction as the static magnetic field) and T2 (Spin-spin relaxation time, spin-spin; transverse to the static magnetic field). To create a T1-weighted image, magnetization is allowed to recover before measuring the MR signal by changing the repetition time (TR). This image weighting is useful for assessing the cerebral cortex, identifying fatty tissue, characteriz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart
The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissue, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the thorax, chest, called the mediastinum. In humans, the heart is divided into four chambers: upper left and right Atrium (heart), atria and lower left and right Ventricle (heart), ventricles. Commonly, the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. In a healthy heart, blood flows one way through the heart due to heart valves, which prevent cardiac regurgitation, backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NMR In Biomedicine
''NMR in Biomedicine'' is a monthly peer-reviewed medical journal published since 1988 by John Wiley & Sons. It publishes original full-length papers, rapid communications, and review articles in which magnetic resonance spectroscopy or imaging methods are used to investigate physiological, biochemical, biophysical, or medical problems. The current editor-in-chief is John R. Griffiths (Cancer Research UK). Highest cited articles The following articles have been cited most frequently: # "The basis of anisotropic water diffusion in the nervous system - a technical review", 15 (7-8) Nov-Dec 2002: 435–455, Beaulieu C. # "A review of chemical issues in H-1-NMR spectroscopy - n-acetyl-l-aspartate, creatine and choline", 4 (2) Apr 1991: 47–52, Miller BL. # "Fiber tracking: principles and strategies - a technical review", 15 (7-8) Nov-Dec 2002: 468–480, DMori S, van Zijl PCM. # "Inferring microstructural features and the physiological state of tissues from diffusion-weighted image ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Lancet
''The Lancet'' is a weekly peer-reviewed general medical journal, founded in England in 1823. It is one of the world's highest-impact academic journals and also one of the oldest medical journals still in publication. The journal publishes original research articles, review articles ("seminars" and "reviews"), editorials, book reviews, correspondence, as well as news features and case reports. ''The Lancet'' has been owned by Elsevier since 1991, and its editor-in-chief since 1995 has been Richard Horton. The journal has editorial offices in London, New York City, and Beijing. History ''The Lancet'' was founded in 1823 by Thomas Wakley, an English surgeon who named it after the surgical instrument called a lancet (scalpel). According to BBC, the journal was initially considered to be radical following its founding. Members of the Wakley family retained editorship of the journal until 1908. In 1921, ''The Lancet'' was acquired by Hodder & Stoughton. Elsevier acquire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millisecond
A millisecond (from '' milli-'' and second; symbol: ms) is a unit of time in the International System of Units equal to one thousandth (0.001 or 10−3 or 1/1000) of a second or 1000 microseconds. A millisecond is to one second, as one second is to approximately 16.67 minutes. A unit of 10 milliseconds may be called a centisecond, and one of 100 milliseconds a decisecond, but these names are rarely used. To help compare orders of magnitude of different times, this page lists times between 10−3 seconds and 100 seconds (1 millisecond and one second). ''See also'' times of other orders of magnitude. Examples The Apollo Guidance Computer used metric units internally, with centiseconds used for time calculation and measurement. *1 millisecond (1 ms) – cycle time for frequency 1 kHz; duration of light for typical photo flash strobe; time taken for sound wave to travel about 34 cm; repetition interval of GPS C/A PN code *1 millisecond – time taken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orders Of Magnitude
In a ratio scale based on powers of ten, the order of magnitude is a measure of the nearness of two figures. Two numbers are "within an order of magnitude" of each other if their ratio is between 1/10 and 10. In other words, the two numbers are within about a factor of 10 of each other. For example, 1 and 1.02 are within an order of magnitude. So are 1 and 2, 1 and 9, or 1 and 0.2. However, 1 and 15 are not within an order of magnitude, since their ratio is 15/1 = 15 > 10. The reciprocal ratio, 1/15, is less than 0.1, so the same result is obtained. Difference (mathematics), Differences in order of magnitude can be measured on a base-10 logarithmic scale in "Decade (log scale), decades" (i.e., factors of ten). For example, there is one order of magnitude between 2 and 20, and two orders of magnitude between 2 and 200. Each division or multiplication by 10 is called an order of magnitude. This phrasing helps quickly express the difference in scale between 2 and 2,000,000: they di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Göttingen
Göttingen (, ; ; ) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. According to the 2022 German census, the population of Göttingen was 124,548. Overview The origins of Göttingen lay in a village called ''Gutingi, ''first mentioned in a document in 953 AD. The city was founded northwest of this village, between 1150 and 1200 AD, and adopted its name. In Middle Ages, medieval times the city was a member of the Hanseatic League and hence a wealthy town. Today, Göttingen is famous for its old university (''Georgia Augusta'', or University of Göttingen, "Georg-August-Universität"), which was founded in 1734 (first classes in 1737) and became the most visited university of Europe. In 1837, seven professors protested against the absolute sovereignty of the House of Hanover, kings of Kingdom of Hanover, Hanover; they lost their positions, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dieter Matthaei
Dieter Matthaei (born 1 February 1949 in Clausthal-Zellerfeld, Germany) is a German radiotherapist and internist. Matthaei studied physics and medicine at the universities of Berlin and Göttingen. In 1977, he received his doctorate from the University of Göttingen. He was from 1983 to 1987 a research associate at the Max-Planck-Institut für biophysikalische Chemie in Göttingen and is now medical specialist for internal medicine in Göttingen. Matthaei worked at the University of Göttingen and at the Max Planck Institute for Nuclear magnetic resonance in biological systems. He was looking for a scientific development of NMR Nuclear magnetic resonance (NMR) is a physical phenomenon in which atomic nucleus, nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near and far field, near field) and respond by producing ... techniques based on magnetic resonance imagery. With Axel Haase and Jens Frahm he succeeded in 1985 wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jens Frahm
Jens Frahm (born 29 March 1951 in Oldenburg, Germany) is a German biophysicist and physicochemist. He is Research Group Leader of the Biomedical NMR group at the Max Planck Institute (MPI) for Multidisciplinary Sciences in Göttingen, Germany (prior to January 1, 2022, at the former MPI for Biophysical Chemistry). Early life and education From 1969 to 1974 Frahm studied physics at the University of Göttingen. His PhD thesis under the guidance of Hans Strehlow at the MPI for Biophysical Chemistry was devoted to the use of nuclear magnetic resonance (NMR) spectroscopy for a characterization of the molecular dynamics of hydrated ions in complex solutions. He received his PhD degree in 1977 in physical chemistry. Career Early Working as a research assistant at the Göttingen MPI since 1977 Frahm formed an independent research team which focused on the new possibilities offered by spatially resolved NMR and magnetic resonance imaging (MRI) – discovered in 1974, by Paul Lauterbur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasculature
In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek meaning ''heart'', and Latin meaning ''vessels''). The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms ''cardiovascular system'' and ''vascular system'' interchangeably with ''circulatory system''. The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Many invertebrates such as arthropods have an open circulatory system with a heart tha ... [...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 bloo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-dimensional Space
In geometry, a three-dimensional space (3D space, 3-space or, rarely, tri-dimensional space) is a mathematical space in which three values ('' coordinates'') are required to determine the position of a point. Most commonly, it is the three-dimensional Euclidean space, that is, the Euclidean space of dimension three, which models physical space. More general three-dimensional spaces are called '' 3-manifolds''. The term may also refer colloquially to a subset of space, a ''three-dimensional region'' (or 3D domain), a '' solid figure''. Technically, a tuple of numbers can be understood as the Cartesian coordinates of a location in a -dimensional Euclidean space. The set of these -tuples is commonly denoted \R^n, and can be identified to the pair formed by a -dimensional Euclidean space and a Cartesian coordinate system. When , this space is called the three-dimensional Euclidean space (or simply "Euclidean space" when the context is clear). In classical physics, it serve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
