| CT scan | <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 |
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| scan | A type of imaging, for example ultrasound, MR, CT, scintigram. (16 Dec 1997) |
| scan rate | <microscopy> The number of horizontal-scan lines per frame and vertical scans per second that are repeated in video, for example, 525/60, 625/50. In 525/60, 2: 1 interlaced video, the V scan is repeated at the field rate (which is half of the frame rate for 2: 1 interlaced video) so that 525 H scans take place 30 times a second. The H-scan rate is therefore 525 x 30 = 15.75 kHz. With 525/60, 1: 1 interlace, the H-scan rate would be twice this value. (05 Aug 1998) |
| sector scan | In ultrasonography, a system in which the transducer or transmitted ultrasound beam is rotated through an angle, resulting in a pie-shaped image. (05 Mar 2000) |
| slow scan | <microscopy> A system of video scanning in which the time used to read each line has been increased in comparison to standard video. The bandwidth needed to faithfully transmit or record the signal is reduced in inverse ratio to the scanning time. Slow scan allows the video signal to be transmitted over a telephone line, or line scans to be registered on a chart recorder. (19 Jan 1998) |
| nuclear bone scan | A nuclear medicine test that involves the introduction of a radioactive compound into the blood stream. The radioactive compound acts as a tracer and allows for the imaging of the bony skeleton. (27 Sep 1997) |
| nuclear heart scan | This noninvasive test uses radioactive tracers to delineate the hearts chambers and major vessels. It may be used to detect a heart attack, heart muscle function and coronary artery disease. The patient receives a radioactive tracer by injection (into a vein) and then the heart is imaged using a gamma camera. The heart is imaged before and after exercise. This test may be used to detect and evaluate atrial septal defect, dilated cardiomyopathy, congestive heart failure, cardiomyopathy, Lyme disease (secondary), mitral stenosis and superior vena cava syndrome. (27 Sep 1997) |
| nuclear scan: adrenals | A nuclear scan that images the adrenal glands after a radioactive tracer is injected into the bloodstream. This test is useful in detecting a pheochromocytoma, particularly if it not within the adrenal gland. (27 Sep 1997) |
| duplex Doppler scan | A method of visualizing and selectively assessing the flow patterns of peripheral arteries and veins using ultrasound imaging and pulsed Doppler. (05 Mar 2000) |
| testicular scan | <radiology> Tc-99m pertechnetate 30 mCi, interpretation: torsion = cold defect, epididymo-orchitis = hot spot, trauma = hot or cold (12 Dec 1998) |
| thallium heart scan | <cardiology, investigation, radiology> A test which involves the introduction of a radioactive tracer into the bloodstream. The radioactive tracer is then measured with a special camera and a determination of coronary artery blood flow can be made. (27 Sep 1997) |
| thyroid scan | A picture taken of the thyroid gland after radioactive iodine is taken by mouth. (12 Dec 1998) |
| EMI scan | Historically, the name commonly used for computed tomography of the head, the technique devised by Hounsfield, who was a scientist at EMI, an English electronics firm. (05 Mar 2000) |
| liver scan | <investigation> A way of visualising the liver by injecting into the bloodstream a trace dose of a radioactive substance which helps visualize the organ during X-ray. (09 Oct 1997) |
| liver-spleen scan | <radiology> Tc-99m sulfur colloid or albumin colloid, particles less than 1 m, dose = 4-8 mCi Distribution, liver 85%, spleen 10%, bone marrow 5% Findings, liver: hot / cold, spleen: hot / cold (12 Dec 1998) |