Vascular sonography

Definition

Vascular sonography, also called vascular ultrasound, is a diagnostic manner of proceeding that uses sound waves to bring into view images of the blood utensils and blood flow.

Purpose

Vascular sonography is used to evaluate vital current flow in the arteries and veins. This experiment has many applications, including diagnosis of reaching far down vein thrombosis (DVT), claudication, atherosclerosis, and congenital vascular malformations. In addition to its diagnostic capabilities, vascular sonography can be used to determine whether a patient is a serviceable candidate for a vascular process such as angioplasty. It can also be used to evaluate the succes of a surgical conduct such as bypass surgery or graft transplantation (adequate life-blood flow to the graft would indicate a fortunate graft transplantation). Furthermore, vascular sonography may be used to determine the life-current flow to tumors and chronic hurts in order to aid in treatment planning.

Finally, vascular sonography can be used to identify life-blood clots and other blockages to life-blood flow. The test can reveal vital fluid clots requiring anticoagulant therapy, life-blood clots that may embolize (travel) to other organs (including the lungs) and blockages to vital fluid flow in the brain that might rise in a stroke.

Vascular sonography is usually performed in a hospital's radiology department, or its vascular laboratory, which focuses upon vascular imaging and evaluation. However, because vascular ultrasound units are portable, vascular sonography can be performed at the bedside of patients in the push room, or anywhere else in the hospital, if necessary.

Vascular sonography may be commended by a primary care physician after detecting entires of abnormal blood flow (usually via stethoscope) It may be performed in patients with suspected narrowing of the carotid arteries in the neck (who are at increased risk of stroke) or in patients with suspected abnormalities in the superficial vital fluid vessels in the arms and leg It may also be used to descry narrowing of the deeper abdominal utensils (such as the renal arteries and superior mesenteric artery), or to command out bleeding in the abdomen following trauma.

Precautions

Because smoking can cause constriction of life-blood vessels, patients should not sooty vapor before vascular sonography.

Description

Medical ultrasound scanning works in a manner similar to sonar and radar. Vascular sonography relies upon ultrasonic sound waves transmitted at high frequencies (approximately 2 to 10 megahertz) beyond the horizontal of human hearing. The uninjured waves are aimed at the area of interest. Depending upon the tissue or liquid the unmutilated waves encounter, different echoes turn back to the scanner. The scanner then interprets these echoe to bring out an image.

Vascular sonography may be performed using a handheld portable ultrasound scanner or a larger mobile scanner, one as well as the other of which have an ultrasound probe with a transducer, and a computer that processe the repercussion of sounded sound waves into an image. Larger scanners are usually equipped with a videotape recorder or digital image acquisition a whole to record the examination, as well as a medical image printer for hard copies.

For vascular sonography, the patient is positioned upon a bed or table in like manner that the area to be imaged can be easily accessed. A special gel called acoustic coupling gel is placed upon the skin over the area to be imaged to enhance the transmission of unbroken waves. The probe is held above the area of interest and occasionally mov The ultrasound probe's transducer emits whole waves that are transmitted [i]or[/i] part of to the other the body and reflected back as echoe which are then changeed into an image. The probe can be positioned along the utensil for a longitudinal scan or across the utensil for a transverse scan. During an abdominal or neck examination, the patient may be asked to clutch the breath or stop swallowing. Examinations of the arms and leg may require that the limb be elevated or compressed

Vascular ultrasound images can be acquired and displayed as gray-scale or Doppler images. Gray-scale images use different shades of gray to indicate differences in the might of echoes; echoes from life-blood are of lower strength and appear darker than surrounding tissue. Gray-scale images can depict the layers of the utensil wall and show real-time arterial motion.

Doppler imaging uses the frequent occurrence shift caused by the Doppler issue to produce images of vital fluid flow. The Doppler effect is a principle of physics involving light and sound; relative to an spectator the frequency of any light or unhurt wave will vary as the source of the wave approaches or propels away. Ultrasound scanners with Doppler imaging capability lay open and calculate the changes in oftenness of the speed of vital fluid flow relative to a computer marker placed by the agency of the sonographer. Color Doppler imaging superimposes color above moving structures on the gray-scale images. For example, r and gold-colored in a blood vessel image indicates run away from the probe, while sky-colored and green indicates flow toward the probe. Color Doppler imaging can be used to identify areas of arterial narrowing.