| HP | halogen phosphorus; handicapped person; haptoglobin; hard palate; Harvard pump; health profession(al... |
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| HR | heart rate; hemorrhagic retinopathy; high resolution; higher rate; histamine receptor; hormonal resp... |
| HRC | hereditary renal cancer; high-resolution chromatography; horse red cell; human rights committee |
| HRE | hepatic reticuloendothelial [cell]; high-resolution electrocardiography; hormone receptor enzyme |
| HREM | high-resolution electron microscopy |
| computerised axial tomography | Cat scanning adds X-ray images with the aid of a computer to generate cross-sectional views anatomy. It can identify normal and abnormal structures and be used to guide procedures. CAT scanning is painless. Iodine-containing contrast material is sometimes used in CAT scanning. If you are having a CAT scan and are allergic to iodine or contrast materials, you should notify your physicians and radiology staff. (12 Dec 1998) |
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| computerised tomography | <investigation, procedure, radiology> A special radiographic technique that uses a computer to assimilate multiple X-ray images into a 2 dimentional cross-sectional image. This can reveal many soft tissue structures not shown by conventional radiography. Scans may also be dynamic in which a movement of a dye is tracked. Cuts may be 5 or 10 mm apart or, in some instances even further apart. A special dye material may be injected into the patients vein prior to the scan to help differentiate abnormal tissue and vasculature. The machine rotates 180 |
| conventional tomography | <procedure, radiology> The recording of internal body images at a predetermined plane by means of the tomograph, also called body section roentgenography. Origin: Gr. Graphein = to write (18 Nov 1997) |
| positron emission tomography | <radiology> A highly specialised research imaging technique using short lived radioactive substances - usually those made with a cyclotron. This technique is very sensitive in picking up active tumour tissue but does not measure the size of it. Tomographic images are formed by computer analysis of photons detected from annihilation of positrons emitted by radionuclides incorporated into biochemical substances; the images, often quantitated with a colour scale, show the uptake and distribution of the substances in the tissue, permitting analysis and localization of metabolic and physiological function. Because the half-lives of the radionuclides are so short (20 minutes to 2 hours), and the equipment expensive, PET is rarely used in a clinical setting. But since its development in the mid-1970s, it has proved the most important tool yet devised for experimental investigation of the living brain, whether healthy, traumatised, or diseased. With CT and MRI, it represents a new generation of computer imaging techniques that have revolutionised medicine and physiology. Acronym: PET (20 Jun 2000) |
| nuclear magnetic resonance tomography | A special imaging technique used to image internal stuctures of the body, particularly the soft tissues. An MRI image is often superior to a normal X-ray image. It uses the influence of a large magnet to polarize hydrogen atoms in the tissues and then monitors the summation of the spinning energies within living cells. Images are very clear and are particularly good for soft tissue, brain and spinal cord, joints and abdomen. These scans may be used for detecting some cancers or for following their progress. Acronym: MRI (11 Nov 1997) |
| tomography | <procedure, radiology> The recording of internal body images at a predetermined plane by means of the tomograph, also called body section roentgenography. Origin: Gr. Graphein = to write (18 Nov 1997) |
| blood pressure, high | High blood pressure (hypertension) is a repeatedly elevated blood pressure exceeding 140 over 90 mmHg. High blood pressure is also called the silent killer. Chronically high blood pressure can cause blood vessel changes in the back of the eye (retina), thickening of the heart muscle, kidney failure, and brain damage. No specific cause for high blood pressure is found in 95% of patients. High blood pressure is treated with salt restriction, regular aerobic exercise, and medications. (12 Dec 1998) |
| blood sugar, high | Elevated levels of blood glucose (hyperglycaemia) can be found in a number of conditions. The hyperglycaemia leads to spillage of glucose into the urine, hence the term sweet urine. (Diabetes mellitus means sweet urine. ) (12 Dec 1998) |
| cardiac output, high | A state of elevated cardiac output. Conditions that lower peripheral vascular resistance, such as anaemia, arteriovenous fistulas, thyrotoxicosis, and pregnancy, are among the most important factors augmenting the venous return and therefore elevating cardiac output. Increased cardiac output also occurs in muscular exercise, fever, and severe anoxia. (12 Dec 1998) |
| radiotherapy, high-energy | Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; X-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle. (12 Dec 1998) |
| mean higher high water | <marine biology> The average height of the higher high water over a 19-year period. For shorter periods of observation, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year value. (09 Oct 1997) |
| mean high water | <marine biology> The average height of the high water over a 19-year period. For shorter periods of observation, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year value. All high-waters heights are included in the average where the type of tide is either semidiurnal or mixed. Only the higher high-water heights are included in the average where the type of tide is diurnal. So determined, mean high water in the latter case is the same as mean higher high water. (09 Oct 1997) |
| chromatography, high pressure liquid | Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed. (12 Dec 1998) |
| pregnancy, high-risk | Pregnancy in which the mother and/or foetus are at greater than normal risk of morbidity or mortality. Causes include lack of adequate prenatal care, previous obstetrical history, pre-existing maternal disease or pregnancy-induced disease, and multiple gestation, as well as advanced maternal age. (12 Dec 1998) |
| hearing loss, high-frequency | Hearing loss in frequencies above 1000 hertz. (12 Dec 1998) |