Number of frames per second

Determined by sound speed in the medium and imaging depth

Measured in Hz

"Accuracy in time"

The ability to precisely position moving structures from instant to instant

Determined by frame rate

Measured in Hz

Pulse repetition period

Also considered round trip time of the pulse

Imaging depth

Number of pulses in each picture

Number of pulses per scan line (multi-focus vs single focus)

Sector size

Lines per angle of sector (line density)

Lateral resolution increases with multi-focusing

Spatial resolution increases with higher line density

Frame rate required to reproduce motion in video without a "flickering" effect

Approximately 25 frames per second (fps)