| REL | rate of energy loss; recommended exposure limit; resting expiratory level |
|---|---|
| ALARA | as low as reasonably achievable [radiation exposure] |
| REG | radiation exposure guide; radioencephalogram, radioencephalography |
| HCG, hCG | Human Chorionic Gonadotropin; 사람융모성성선자극호르몬 1. Placental Glycoprotein Hormone &nbs... |
| CCL | carcinoma cell line; certified cell line; Charcot-Leyden crystal; continuing care level; critical ca... |
| ACE level | <investigation> This is a blood test which measures the concentration of angiotensin-converting enzyme (ACE) in the bloodstream. Elevations in angiotensin-converting enzyme are seen sarcoidosis, histoplasmosis, alcoholic cirrhosis, asbestosis, berylliosis, diabetes, Hodgkin's disease, hyperthyroidism, amyloidosis, primary biliary cirrhosis, idiopathic pulmonary fibrosis, pulmonary embolism, scleroderma, silicosis, tuberculosis, Gaucher's disease and leprosy. The normal values are 18 to 67 U/ml over 20 years of age (people under 20 have higher levels). (15 Jan 1998) |
|---|---|
| acoustic reference level | The biological reference level for sound measurements. When the term decibel is used to indicate the noise level, a reference quantity is implied; this reference value is usually expressed as a sound pressure of 20 micronewtons per square meter. The reference level is referred to as 0 decibels, the baseline of the scale of noise level's; this baseline is considered the weakest sound that can be heard by a person with very good hearing in an extremely quiet location. Other equivalent reference level's still being used include 0.0002 microbar and 0.0002 dyne per square centimeter. (05 Mar 2000) |
| background level | The average amount of a substance present in the environment. Originally referring to naturally occurring phenomena. Used in toxic substance monitoring. (05 Dec 1998) |
| blood porphyrin level | A test which is used to measure red blood cell porphyrin levels. Porphyrins are pigments found in both animal and plant life. This test is useful in evaluating any number of porphyrin disorders (involving the various porphyrins) of red blood cells. Increased levels of coproporphyrins can indicate congenital erythropoietic porphyria or sideroblastic anaemia. Increased protoporphyrins may be seen in infection, thalassaemia, sideroblastic anaemia, iron deficient anaemia, increased erythropoiesis and lead poisoning. Increased uroporphyrins may indicate congenital erythropoietic porphyria or erythropoietic protoporphyria. (27 Sep 1997) |
| carbon dioxide blood level | A measure of the bicarbonate level in the blood based on a venipuncture specimen. The serum carbon dioxide is one of the normally reported values in the electrolytes profile. Lower levels of carbon dioxide indicate an acidosis. The normal level is 20 to 29 mEq/L. Lower than normal levels can indicate diabetic ketoacidosis, lactic acidosis, alcoholic ketoacidosis, kidney disease, renal failure, diarrhoea, Addison's disease, ethylene glycol poisoning or methanol poisoning. Greater than normal levels can be seen with excessive vomiting, hyperaldosteronism and Cushing's syndrome. (27 Sep 1997) |
| vasopressin level | This test measures the amount of ADH in the serum. It is used to detect disorders that may affect the level of ADH in the serum. Normal values are: 0 to 4.7 pg/ml. Elevated ADH levels can indicate a CNS infection, fluid imbalance, CNS tumour, SIADH or acute porphyria. Low levels can indicate: diabetes insipidus or damage to the pituitary gland. (27 Sep 1997) |
| mean sea level | <marine biology> A tidal datum: the arithmetic mean of hourly water elevations observed over a specific 19-year cycle. Points on land can be referenced to a mean sea level, in which case the datum assumes zero elevation. (09 Oct 1997) |
| gray level also gray value | <microscopy> The brightness of pixels in a digitised video image, commonly expressed in integers ranging from 0 (black) to 255 (white) for an 8-bit digital signal. (05 Aug 1998) |
| gray level histogram | <microscopy> In digital image processing, a histogram that depicts the number of pixels at each gray value. The histogram can be used to measure the areas that have given ranges of gray values or to adjust image contrast by histogram stretching or equalisation. See: Image histogram. (05 Aug 1998) |
| Clark's level | The level of invasion of primary malignant melanoma of the skin; limited to the epidermis, I; into the underlying papillary dermis, II; to the junction of the papillary and reticular dermis, III; into the reticular dermis, IV; into the subcutaneous fat, V. The prognosis is worse with each successive deeper level of invasion. (05 Mar 2000) |
| cohb level | A blood test which is performed on an arterial specimen and is a measurement of the amount of carbon monoxide which is present and bound to haemoglobin. This is an important test to diagnosis carbon monoxide toxicity (smoke inhalation). Normal carboxyhaemoglobin may be from 3% to as high as 12% in heavy smokers. Symptoms of carbon monoxide poisoning begin at about 20% carboxyhaemoglobin. (27 Sep 1997) |
| white level | <microscopy> Also reference white level. The IEEE scale, or voltage level, of the video picture signal that corresponds to a specified maximum limit for white peaks. (05 Aug 1998) |
| window level | The CT number setting in Hounsfield units of the midpoint of the window width, which is the gray scale of the image; a typical window level for imaging the lungs if -500; for the abdomen, 0. (05 Mar 2000) |
| hearing level | The measure of the status of hearing as read directly on the hearing loss scale of an audiometer; described in decibels as a deviation from a standard value for zero on the audiometer. (05 Mar 2000) |
| serum iron level | A test that measures the amount of iron (Fe ++) in the blood. The test is performed when iron deficiency is suspected. Normal serum iron is 60 to 170 mcg/dl. Increased levels may be seen in the following: haemochromatosis, haemolysis, haemolytic anaemia, hepatitis, liver necrosis, haemosiderosis, iron poisoning and lead toxicity. Lower than normal levels are seen in chronic GI blood loss, iron deficiency anaemia, insufficient dietary iron, malabsorption, chronic heavy menstrual bleeding, nephrosis and late pregnancy. (27 Sep 1997) |