| ultrasonography, doppler, colour | Ultrasonography applying the doppler effect, with the superposition of flow information as colours on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region. (12 Dec 1998) |
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| ultrasonography, doppler, duplex | Ultrasonography applying the doppler effect combined with real-time imaging. The real-time image is created by rapid movement of the ultrasound beam. A powerful advantage of this technique is the ability to estimate the velocity of flow from the doppler shift frequency. (12 Dec 1998) |
| ultrasonography, doppler, pulsed | Ultrasonography applying the doppler effect, with velocity detection combined with range discrimination. Short bursts of ultrasound are transmitted at regular intervals and the echoes are demodulated as they return. (12 Dec 1998) |
| ultrasonography, doppler, transcranial | A non-invasive technique using ultrasound for the measurement of cerebrovascular haemodynamics, particularly cerebral blood flow velocity and cerebral collateral flow. With a high-intensity, low-frequency pulse probe, the intracranial arteries may be studied transtemporally, transorbitally, or from below the foramen magnum. (12 Dec 1998) |
| laser-doppler flowmetry | A method of non-invasive, continuous measurement of microcirculation. The technique is based on the values of the doppler effect of low-power laser light scattered randomly by static structures and moving tissue particulates. (12 Dec 1998) |
| analytic study | In epidemiology, a study designed to examine associations, commonly putative or hypothesised causal relationships; usually concerned with identifying or measuring the effects of risk factors or with the health effects of specific exposures. (05 Mar 2000) |
| blinded study | Clinical trials of drugs are often done blinded so that the patient does not know (is blinded as to) whether they are receiving the product being tested or the control/placebo to ensure that the results of a study are not affected by a possible placebo effect (by the power of suggestion). (12 Dec 1998) |
| blind study | A study in which the experimenter is unaware of which group is subject to which procedure. (05 Mar 2000) |
| case-control study | <epidemiology> A study in which the risk factors of people with a disease are compared with those without a disease. It is an epidemiological method that begins by identifying persons with the disease or condition of interest (the cases) and compares their past history of exposure to identified or suspected risk factors with the past history of similar exposures among persons who resemble the cases but do not have the disease or condition of interest (the controls). The relationship of an attribute to the disease can therefore be examined by comparing affected and non-affected individuals with regard to the frequency or levels of the attribute in each group. (05 May 2002) |
| retrospective study | <epidemiology> A study in which people are enrolled and then have their history of risks, infections or disease measured. (05 Dec 1998) |
| rosenzweig picture-frustration study | A projective test depicting cartoon-like characters in frustrating situations. The scoring of the subject's responses indicates the direction of hostility or aggression, that is, whether he blames himself, the other person, or the set of circumstances. (12 Dec 1998) |
| cohort study | A study using epidemiological methods, such as a clinical trial, in which a cohort with a particular attribute (e.g., smokers, recipients of a drug) is followed prospectively and compared for some outcome (e.g., disease, cure) with another cohort not possessing the attribute. (05 Mar 2000) |
| pioped study | <radiology> 251 patients with documented PE on pulmonary angiograms were given V/Q scans: 102 high probability, 105 intermediate probability, 39 low probability, 5 normal or near-normal (12 Dec 1998) |
| multicenter study | A controlled study executed by several cooperating institutions. (12 Dec 1998) |
| multigeneration study | Toxicity test in which at least 3 generations of the test organisms are exposed to the substance being assessed. Exposure is usually continuous. Any medical study which follows a family of people through several generations. (09 Oct 1997) |