Ultrasound Physics and Transducer Motion Review

Practice fill-in-the-blank flashcards covering transducer movements, image parameters, physics resolutions, and acoustic interactions.

When the transducer is kept at the same location on the chest and the sound beam is directed to show a new structure, this transducer movement is called __________.

Tilt

The transducer movement where multiple transducer movements are used to record a long video clip to show multiple anatomic structures is called __________.

Sweep

__________ refers to maintaining a stationary position with the transducer while the index marker is moved to a new position.

Rotate

When the transducer moves across the patient's skin to a new position, the movement is defined as __________.

Slide

Within the same imaging plane, the transducer changes orientation either toward or away from the orientation marker during the movement known as __________.

Rock

The transducer maintains the same axis orientation to the heart but moves to a different imaging plane during the movement called __________.

Angle

In a Grayscale Image, the brightness of each dot represents the echo __________ (amplitude).

strength

When the grayscale image is transformed to a different range of colors (e.g., sepia, a light pink color) instead of grays, it is called __________.

B-Mode Colorization

The parameter that adjusts the appearance of the shades of gray on the image is called __________.

Dynamic Range

The operating frequency of the imaging transducer is the __________ Frequency.

Transmit

In __________, returning frequencies that are multiples of the transmit (fundamental) frequencies are used to create the ultrasound image.

Harmonic Imaging

The parameter that adjusts the brightness of the image equally throughout the entire sector is __________ Gain.

Overall

__________ is usually set up as a series of pods that can be adjusted to amplify a particular portion of the image to compensate for depth attenuation.

Time-Gain Compensation (TGC)

The loss of ultrasound signal intensity and amplitude as it travels deeper into the body is defined as __________.

Attenuation

The ability to discern between two points in close proximity is defined as __________ Resolution.

Spatial

The ability to discern between two points along or parallel to the beam's path is __________ Resolution.

Axial

Axial resolution is determined by frequency, bandwidth, and __________ pulse length (SPL).

spatial

The ability to discern between two points perpendicular to the beam's path and the lateral axis is __________ Resolution.

Lateral

Elevational resolution is the ability to discern between two points perpendicular to the beam's path in the elevational plane, also known as __________ thickness.

slice

Temporal resolution tracks a moving target on different frames over time (frame rate) and is improved by reducing depth, focal zones, or __________ width.

sector

The ability to distinguish between different echo amplitudes of adjacent structures is called __________ Resolution.

Contrast

Acoustic Impedance ($Z$) is defined by tissue density ($p$) and propagation velocity ($c$) as __________ .

$$Z = p \times c$$

The return of an ultrasound signal back to the transducer from a smooth tissue boundary (specular surface) is known as __________.

Reflection

The radiation of ultrasound in multiple directions from a small structure or rough boundary (e.g., blood cells) is called __________.

Scattering

Refraction is the change in direction (bending) of wave propagation when traveling from one medium to another with __________ incidence.

oblique

The number of transmission-receive cycles (pulses) per second is the Pulse __________ Frequency (PRF).

Repetition

The percentage or fraction of time that ultrasound energy is actively transmitted is called the __________ Factor.

Duty

The distance from the transducer where beam shape and focusing are optimized for peak lateral resolution is the __________ Depth.

Focal