DEFINITION: Diagnostic ultrasound, also called sonography or diagnostic medical sonography, is an imaging method that uses high-frequency sound waves to produce relatively precise images of structures within your body. It does not use X-rays or any other type of possibly harmful radiation and can be used for diagnosing and treating a variety of diseases and conditions.
A Doppler ultrasound test uses reflected sound waves to see how blood flows through a blood vessel. It will assist your doctor in evaluating blood flow through major arteries and veins, such as those of the arms, legs and neck. It can reveal blocked or reduced blood flow through narrowing in major arteries of the neck that may cause a stroke. It can also be used to evaluate blood flow after a stroke or other condition that might be caused by a problem with blood flow. Evaluation of a stroke can be done through a technique called transcranial Doppler (TCD) ultrasound, which evaluates the blood flow of the brain.
WHAT TO EXPECT: For ultrasound testing, gel is applied to the skin to help transmit the sound waves during the exam. A small, handheld instrument called a transducer is passed back and forth over the area of the body that is of interest. The transducer sends out high-pitched sound waves < above the range of human hearing > that are reflected back to the transducer. A computer analyzes the reflected sound waves and converts them into an image that is displayed to the technologist.
HOW TO PREPARE: You may need to stop using products that contain nicotine < cigarettes, chewing tobacco > for 30 minutes to 2 hours before the test. Nicotine causes blood vessels to constrict and may give false results.
RESULTS: One of our specially trained radiologists will analyze the images from your scan and report the findings to your referring physician or primary care doctor. Your doctor will then discuss any important findings and next steps with you.