Contrast ratio is the ratio of luminance between the brightest white and the darkest black of a particular device or a particular environment. Projected cinema film, or a photographic reflection print, has a contrast ratio of about 80:1. Television assumes a contrast ratio, in your living room, of about 30:1. Typical office viewing conditions restrict the contrast ratio of a CRT display to about 5:1.

The light and dark patterns seen when observing a faceted diamond. It can be positive or negative in its optical effect. Usually caused by, but not limited to, the observer's head. Top

Intravenous contrast is used in CT to help highlight blood vessels and to enhance the tissue structure of various organs such as the brain, spine, liver and kidneys. "Intravenous" means that the contrast is injected into a vein using a small needle. Typically the contrast is loaded into a power injector, which injects the CT contrast using tubing through the needle into the body during a specific period in the CT exam.

This substance is given to highlight various body parts and is eliminated in a day or two. It is usually given by mouth or injection. It is normal to feel a warm sensation as the dye makes its way through your body.

Acid reflux disease, also known as gastroesophageal reflux disease (GERD) is a fairly common affliction. It is characterized by bouts of intense heartburn or a burning sensation in the back of the throat. Zenith 42 Plasma HDTV sets, also known as plasma HDTV displays have been obtainable for several years; however, they are more popular than ever today. find articles | submit articles | link to us | site map | terms of use | privacy policy | contact us | advertising | partner with us

The oral contrast drink is for patients who are having for a stomach/bowel CT scan. The barium-based drink essentially “enhances” the gastrointestinal tract so it can be better defined on the CT images.

Allergies to shellfish or iodine need to be pre-medicated before you are injected with contrast media. Tell your doctor about your allergies. You will be asked again about any allergies before you have a test that involves taking contrast material and the technologist or nurse will make sure you are pre-medicated.

Not all CT examinations require the use of a contrast agent. When a contrast agent is required, it is because the radiologist and referring physician determine that it is necessary for diagnosis. Contrast agents are considered to be safe and side effects are uncommon. The benefits associated with the improved imaging of particular organs generally outweigh the low risk of allergic reaction.

The camera measures light from an object at each point in an image and assigns it a number from zero to 4095 depending on its brightness. Sometimes the scientist can't afford to send this amount of data for each pixel because of the amount of storage it takes. The camera has the ability to convert this range of values to those from zero to 255. The camera does this according to a preset table of values designed by the scientists.

Sometimes your Doctor will order a CT scan "with contrast". This means a trained CT Technologist will insert a thin, plastic IV catheter into a vein, usually in your arm. The contrast will flow through this catheter into your arteries and veins to highlight them and give the Radiologist a more detailed study. Most patients feel some degree of warmth and get a salty taste in their mouth as the contrast is flowing through their blood vessels. These sensations last for just a few minutes

Please take a look at the index "laser engravings of industry articles" and "laser engravings of promotion articles" with the sub-index "reaction of materials".

SpikeNet’s algorithm is designed to be extremely good at detecting objects even when the contrast in the image is very low. One problem that this can cause is that in an image where the only interesting objects are at high contrasts, unwanted detections may occur in regions of very low contrast. To avoid detecting details which are not relevant, you can raise the Minimum Contrast value that is normally fixed at 0.

Lenox Hill radiology only uses the newest and safest "non ionic" contrast available on the market. This is shown to have a much lower incidence of allergic reaction than the older "ionic" contrast. The most common side effect of the contrast includes a warm or hot "flushed" sensation during the actual injection and a "metallic" taste in the mouth, which usually lasts less than a minute or so. There is no treatment necessary for this as it is only a passing sensation.

The injected contrast medium in blood, the body cavities, lymphatic tissue or organs (liver, kidney) is nearly completely eliminated through the kidneys within 15 to 30 minutes. The contrast medium you drink does not react with the body and is eliminated naturally through the intestines. Some contrast media, known as bile-permeable contrast media pass through the liver and the bile ducts and then enter the intestines.

POP has only one contrast, which is equivalent to a grade 0 or 00 enlarging paper. Thus your negatives must be made to "fit" the paper, with a density range of about 2.

The contrast is injected into a vein using a small needle during a specific period in the CT exam. The contrast circulates the blood stream, through the heart and arteries, capillaries and veins, to essentially “enhance” the tissue structure of your organs so they appear highlighted on the CT images for a more precise diagnosis.

Varicose veins are larger, twisted and more prominent than normal veins. Quite frequently, they are associated with many spider veins.

Oral contrast is used to image the stomach and intestines. It is a very dilute, flavored barium solution that you drink approximately 1 hour prior to an examination. Intravenous contrast is sometimes referred to as "dye". Although colorless, it contains iodine, which makes specific organs, blood vessels, and tissues visible on x-rays for better detection of disease or injury. It is not radioactive.

Contrast media (CM) possess a different density than body tissue and therefore create better contrast (as the name suggests). After a contrast medium is injected, it is enriched by organs that are richly supplied with blood. This causes the liver, spleen, brain, etc. to be visualised much better. Most tumours and inflammations are also supplied more strongly with blood and therefore seen in sharp contrast to their surroundings.

Contrast medium is used to increase tissue contrast between normal and abnormal structures hence allowing better differentiation and more precise diagnosis. The intravenously injected contrast medium becomes distributed all over the tissues of the body and consequently increases their density; therefore increases the ability of these tissues to absorb and attenuate the x-ray beam and the more the tissue takes contrast medium the more they appear bright in CT.