Algorithm: From 2 Different Sources
A set of instructions performed in a logical sequence to solve a problem. Algorithms are used increasingly in emergency situations, for example by ambulance controllers or by organisations such as NHS Direct. Each answer to a question leads on down a decision tree to the next question, eventually resulting in a recommended action or response.
n. a sequential set of instructions used in calculations or problem solving. A reconstruction algorithm is a complex mathematical formula used by a computer to construct images from the data acquired by CT, MRI, or other scanners. A diagnostic algorithm or a therapeutic algorithm consists of a stepwise series of instructions with branching pathways to be followed to assist a physician in coming to a diagnosis or deciding on a management strategy, respectively.
(ALS) a structured and algorithm-driven method of life support for use in the severest of medical emergencies, especially cardiac arrest. Doctors, nurses, and paramedic personnel involved in ALS receive special training in the use of equipment (e.g. defibrillators and appropriate drugs). Paediatric advanced life support (PALS) is ALS for use in severe medical emergencies in children, while advanced trauma life support(ATLS) is specifically for patients who have been subjected to major trauma, such as a serious road accident. Compare basic life support.... advanced life support
(multiple-gated acquisition scan) a technique used in *nuclear medicine for studying the left-ventricular function and wall motion of the heart. The patient’s red cells are labelled with radioactive technetium-99m. A gamma camera, connected to an ECG, collects information over a prolonged period for each phase of heart movement (ECG gating) to form an image of the blood pool within the heart at specific points in the cardiac cycle. Tomographic reconstructions can be made to give cross-sectional images of the heart in different phases of the cardiac cycle, using reconstruction *algorithms comparable to CT scanning (see SPECT scanning).... muga scan
(PET) a technique in nuclear medicine for *cross-sectional imaging that enables a noninvasive assessment and localization of metabolic activity to be made. Originally used to study activity in the brain, PET is now also used for investigating the chest and abdomen. Emission of a *positron by a radioisotope results in annihilation of the positron on collision with an electron, and the creation of two gamma rays of known energy travelling in exactly opposite directions. The PET scanner has detectors on each side of the patient to detect the simultaneous arrival of the gamma rays. Images are created using reconstruction *algorithms similar to CT scanning. *Fluorodeoxyglucose, labelled with fluorine-18, is used to examine glucose metabolism, and ammonia, labelled with nitrogen-13, gives information on perfusion. Carbon-11 and oxygen-15 can also be used as radioisotopes for PET scanning. Some diseases result in decreased uptake of the radio-labelled material due to decreased function; others show increased glucose metabolism and concentrate the isotope avidly. In this way functional activity of the tissues can be compared with anatomical images obtained by CT or MRI scanning (see PET/CT scanning). Localized areas of increased glucose uptake revealed by PET scans can sometimes signify functional activity of malignant cells, which use more glucose than normal cells, although other processes, such as infection, can produce similar scans. PET scans can help to localize metastatic disease (see metastasis) that is not identified by other scanning techniques. See also tomography. Compare computerized tomography.... positron emission tomography
a computer algorithm that estimates the risk of a heart attack or stroke in a person over the next ten years. QRISK2 uses traditional risk factors, such as age, systolic blood pressure, smoking status, and ratio of total cholesterol to high-density lipoprotein, together with additional risk factors, including body mass index and family history of premature ischaemic heart disease. Someone with a QRISK2 score of 20% (or more) is regarded as high risk and should consider lifestyle modification and preventative medication.... qrisk2
(single photon emission computing tomography) (in nuclear medicine) a *cross-sectional imaging technique for observing an organ or part of the body using a *gamma camera; images are produced after injecting a radioactive *tracer. The camera is rotated around the patient being scanned. Using a computer reconstruction *algorithm similar to that of a *computerized tomography scanner, multiple ‘slices’ are made through the area of interest. SPECT scanning is used particularly in cardiac nuclear medicine imaging (see MUGA scan). It differs from PET scanning in that radioactive decay gives off only a single gamma ray.... spect scanning
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