A vaginal probe is a small ultrasound transducer (e.g. a biplane probe) that is inserted directly into the vagina. A sterile cover is slipped over the handheld transducer (also handle or probe), which is then covered with lubricating gel and placed in the vagina.
This technique produces a sharp image, not only because of the close proximity to the uterus, but also because this transducer is more sensitive.

A vaginal transducer is a small ultrasound probe that is inserted directly into the vagina. The vaginal transducer is used in gynecological ultrasound scans and has a long and slender shape to fit into the vagina. A cover is used to ensure sterility, and the transducer is lubricated with a water-soluble gel.

See also Transvaginal Sonography.

A validation is a test to confirm calibration and accuracy of a measurement, usually by comparing to a known standard such as timed collection.

See also Image Quality.

Variance is the modification of Doppler frequencies within each pixel during a pulse packet with color Doppler flow imaging. Variance is mapped to the color green and is used to detect turbulence. At low variance (laminar flow) pixels within each range gate are encoded in red or blue according to flow direction. At high variance (turbulent flow) a percentage of pixels within each range gate are encoded with green according to the degree of spectral broadening.

Vascular ultrasound obtains images and measures blood flow velocity in the carotids, abdominal aorta, and vessels of kidneys, arms, or legs. Blockages in arteries, blood clots in veins, or abdominal aortic aneurysm can be detected.
These abnormalities in blood flow are usually examined with different Doppler techniques. In addition, the speed and direction of blood flow can be color coded in a color map. Duplex techniques show both, the vessels and the surrounding tissue. The use of ultrasound contrast agents improves the left ventricular opacification in cardiac ultrasound examination. Usually, for a vascular ultrasound no special preparation is needed.

See also Echocardiography, Venous Ultrasound, Adventitia, Intima, Temporal Mean Velocity, and Intravascular Ultrasound.