POCUS Dictionary

A.

A4C — Apical 4 Chamber (cardiac) view.

Acustic Shadowing Artifact — Occurs when the waves encounter a structure that strongly absorbs or reflects the waves, creating a shadow posterior in the image to that structure, this happens most notably with structures that are dense like bone or stones, such as ribs and gallstones. *

A-lines — reverberation artifacts that arise when the ultrasound waves bounces between the probe and the visceral-parietal pleural interface, causing the lines to appear with equal distance below the pleural line and fatigue with depth, they are not a pathological finding and are generally found in healthy and aerated lungs, but can also be observed in patients with PTX.

B.

B-lines — hyperechoic vertical lines arising from the pleural line, extending indefinitely, erasing A-lines (when present), and moving in concert with lung sliding, they are an artefact that appears when patients present with sub-pleural thickened interlobular septa. *

BLUE protocol — a lung ultrasound protocol (LUS), the BLUE-protocol pathophysiologic “profiles” based on standardised patterns of artifacts are built and a tentative pathophysiologic basis for each kind of acute respiratory failure proposed, the aim of the BLUE protocol is to suggest a diagnosis with a target overall accuracy of at least 90% or slightly above. *

B-MODE — also called 2D-mode, is the most common ultrasound setting and produces a two-dimensional (2D) image cross section of the area that is examined.

D.

Doppler — when using color doppler, the image superimposes a color-coded map onto a B-mode ultrasound, resulting in vascular structures portraying the color red or blue or a mixture of the two, mnemonic for color doppler is BART: Blue Away Red Towards.

E.

Edge Shadowing Artifact — when sound waves from the probe encounter a cystic wall, like the gallbladder, or a curved surface at a tangential angle the waves are scattered and refracted, leading to energy loss and the formation of a shadow at the edges. *

E-FAST — Extended-Focused Assessment with Sonography in Trauma, same as the FAST exam mentioned under F, but with the added exam focused questions (ii) is there free fluid/blood in the thorax, and (ii) is there signs of a PTX (absence of lung-sliding)?

F.

Fanning — probe movement done when you hold the probe still to the surface and gently tilt/fan it towards either side on the x-axis. *

FALLS — Fluid Administration Limited by Lung Sonography. *

FAST — Focused Assessment with Sonography in Trauma, an exam asking the focused question (i) is there free fluid/blood in the abdomen, and (ii) is there free fluid/blood in the pericardium?

FATE — Focused Assessed Transthoracic Echo. *

Fusion — a technique that enables live navigation of bedside ultrasound side by side with a previously obtained reference series, such as CT, MRI, and PET, enabling the physician to directly correlate anatomy between modalities. *

G.

Gain — increases the brightness of the image but it does not improve resolution.

L.

Long Axis — also called in-plane view when looking at vascular structures (visualized as long tubes/cylinders), is a term used colloquially when orienting the probe against the patient in the sagittal or longitudinal plane.

M.

Medical Ultrasound — electric signals applied to a probe produces pressure waves (sound waves), at high frequencies, that interacts with tissue and returns echos to the processor that in return translates those echoes into an image on the screen.

M-mode — creates a single beam in the ultrasound scan that produces a picture with a motion signal. The moving structure of interest is then (often) depicted in a wavelike matter.

P.

PLAX — Parasternal Long Axis (cardiac) view.

Probe — also called a transducer, is a device that produces sound waves that bounce off body tissues and make echoes.

PSAX — Parasternal Short Axis (cardiac) view.

R.

Reverberation Artifact — occurs when sound waves encounter two strong parallel reflectors, causing the ultrasound beam to reflect back and forth between the reflectors (“reverberates”) and interprets the returning sound waves as deeper structures since they’ve taken longer to return. A-lines are an example of reverberating artifacts. *

RUSH — Rapid Ultrasound for Shock and Hypotension. *

S.

SC — Subcostal (cardiac) view.

Short Axis — also called the out-of-plane view when looking at vascular structures (visualized as circular structures), is a term used colloquially when orienting the probe against the patient in the transverse or horizontal plane.

Sound Wave — can be broken down to amplitude (peak), velocity (speed), frequency (number of times wave is repeated per unit of time), and wavelength (velocity = frequency x wavelength). Link*