The packet size is the number of sound bursts transmitted per color sector line. The accuracy of the estimated Doppler velocity is influenced by the packet size. A large packet size increases the accuracy of the mean flow velocity by decreasing the frame rate, the line density, or the sector angle.
Dwell time, ensemble length or packet size are synonymous.

(ppm) Part per million is a unit of proportion equal to 10^-6.

A partial volume artifact is caused by the size of the image voxel. The loss of resolution is caused by multiple features present in the image voxel. In ultrasound imaging that occurs when the slice thickness is wider than the scanned structure. This artifact is also called slice thickness artifact or volume averaging artifact.

See also Ultrasound Picture.

(Pa) The SI unit of pressure.
Definition: 1 Pascal is equal to 1 N/m² = 1 J/m³ = 1 kg*m^-1*s^-2
1 kPa = 0.145 lbf/in².
Air pressure is measured in hectoPascal (hPa), with 1 hPa = 1 millibar.
The unit is named for Blaise Pascal (1623-1662), French philosopher and mathematician.

See also Open Circuit Voltage, and Source Level.

From Verathon Inc.;
'The Pediatric BladderScan® is the newest addition to Verathon Inc.'s trusted family of BladderScan® instruments. By enabling health care providers to measure a child's bladder volume noninvasively, this easy-to-use, handheld tool aids in the diagnosis and treatment of urinary conditions.'

See also Urologic Ultrasound, Pediatric Ultrasound, Mirror Artifact, Pelvic Ultrasound, Reflux Sonography and Ultrasonography.