ICU Map
Module 1 · ICU POCUS

🎛️ POCUS Fundamentals & Image Acquisition

Build a safe, repeatable scanning foundation: probes, orientation, machine controls, modes, artifacts, optimization, documentation and limitations.

Study time

~45 min

✓Select an appropriate probe and preset for the target organ.
✓Use marker orientation, depth, gain and focus deliberately rather than by trial and error.
✓Recognize common artifacts and decide when an artifact is diagnostically useful.
✓Document a focused ultrasound study with indication, views, findings, limitations and clinical integration.
1

Probe selection

Choose the transducer that best balances penetration, footprint and resolution.

  • Linear high-frequency probe: vascular access, DVT compression, pleura, peripheral soft tissue and superficial structures.
  • Phased-array probe: cardiac windows and intercostal access where a small footprint matters.
  • Curvilinear probe: abdomen, FAST, renal/bladder, aorta and general lung scanning when deeper penetration is needed.
  • A single probe can sometimes answer the question in a crashing patient, but do not let convenience degrade image quality when the patient is stable enough to switch probes.
Linear vs curvilinear lung windows

Linear vs curvilinear lung windows

Side-by-side lung windows demonstrate how probe footprint and frequency change the field of view. This is useful when choosing between a high-frequency linear probe and a deeper curvilinear view.

Contributor: Anibal Artero

The POCUS Atlas — original media · CC BY-NC 4.0

2

Orientation and probe movements

Know where the marker is and move the beam intentionally.

  • Confirm the screen marker before scanning; cardiac conventions may differ from general ultrasound conventions depending on machine configuration.
  • Slide changes location; fan/sweep interrogates adjacent tissue; rock/heel-toe changes beam angle; rotate changes imaging plane; pressure improves contact but can collapse veins.
  • Anchor one hand when possible to improve control and reproducibility.
Normal FAST — right upper quadrant

Normal FAST — right upper quadrant

Normal RUQ FAST view without free fluid in Morison pouch. Sweep through the entire interface and liver tip rather than judging a single frozen frame.

Contributor: Dr. Justin Bowra

The POCUS Atlas — original media · CC BY-NC 4.0

Normal parasternal long-axis view

Normal parasternal long-axis view

Reference PLAX view for gross LV function, pericardial fluid, aortic root and mitral valve motion.

Contributor: Nigist Taddese, MBChB — Division of Hospital Medicine, John H Stroger Hospital of Cook County

The POCUS Atlas — original media · CC BY-NC 4.0

3

Image controls

Optimize before interpreting.

  • Depth: place the structure of interest in the middle-to-lower portion of the screen without wasting depth.
  • Overall gain: enough to see tissue interfaces without washing out fluid or creating false echoes.
  • Time-gain compensation: correct focal brightness differences only when needed.
  • Focus: position at or just below the structure of interest when the machine allows it.
  • Sector width and dynamic range can be reduced when a narrower field improves frame rate or contrast.
Gain optimization for lung sliding

Gain optimization for lung sliding

Normal lung sliding becomes easier to appreciate as excessive gain is reduced. Optimize gain before declaring pleural motion absent.

Contributor: Aaron Inouye

The POCUS Atlas — original media · CC BY-NC 4.0

4

B-mode, M-mode and Doppler

Use the simplest mode that answers the clinical question.

  • B-mode is the default real-time 2D examination.
  • M-mode displays motion over time and can support evaluation of pleural motion or selected cardiac measurements.
  • Color Doppler helps identify flow and distinguish vessels from fluid-filled structures; optimize the color box, scale and gain.
  • Spectral Doppler is operator- and angle-dependent and moves beyond basic focused POCUS for many applications; use only within training and local scope.
M-mode: seashore versus barcode

M-mode: seashore versus barcode

M-mode example comparing the normal seashore pattern with the barcode/stratosphere pattern seen when pleural sliding is absent. M-mode supports, but does not replace, the complete pneumothorax assessment.

Contributor: Dr. Eric Roseman — Kings County Emergency/Internal Medicine

The POCUS Atlas — original media · CC BY-NC 4.0

Carotid artery and internal jugular vein

Carotid artery and internal jugular vein

Short-axis Doppler view differentiating the common carotid artery and internal jugular vein. For line placement, compressibility and real-time B-mode anatomy remain essential.

Contributor: Hannah Kopinski; Dr. Lindsay Davis — NYU Emergency Medicine

The POCUS Atlas — original media · CC BY-NC 4.0

5

Artifacts you must recognize

Some artifacts are noise; others are the diagnostic signal.

  • Reverberation creates repeated horizontal echoes such as A-lines.
  • Acoustic shadowing occurs behind strongly attenuating objects such as rib, stone or calcification.
  • Posterior acoustic enhancement occurs behind low-attenuation fluid structures.
  • Mirror artifact can duplicate structures across a strong reflector such as the diaphragm.
  • Ring-down/comet-tail and B-line artifacts arise from complex interactions at gas-fluid/tissue interfaces.
A-lines in normally aerated lung

A-lines in normally aerated lung

Horizontal reverberation artifacts repeating below the pleural line. A-lines are a normal aeration pattern and illustrate how artifacts can be diagnostically useful.

Contributor: Hannah Kopinski; Dr. Lindsay Davis; Dr. Matthew Riscinti

The POCUS Atlas — original media · CC BY-NC 4.0

B-lines in pulmonary edema

B-lines in pulmonary edema

Vertical artifacts arising from the pleural line. B-lines indicate loss of aeration/interstitial syndrome and must be interpreted in clinical context; they are not specific for cardiogenic edema.

Contributor: Dr. Justin Bowra et al.

The POCUS Atlas — original media · CC BY-NC 4.0

6

Safety, cleaning and documentation

POCUS is a clinical test and should be treated like one.

  • Use approved probe disinfection based on body site and procedure; sterile sheath and sterile gel are required for sterile vascular procedures.
  • Save representative clips/stills when institutional systems support archiving.
  • Document indication, views obtained, key findings, technically limited areas and how the study changed or did not change management.
  • Escalate to formal imaging when the focused study is nondiagnostic or the question exceeds the operator's scope.
Subclavian vein in long axis

Subclavian vein in long axis

Supraclavicular long-axis view of the subclavian vein. The image emphasizes deliberate target identification before central venous access.

Contributor: Renato Tambelli — Hospital das Clínicas de Marília

The POCUS Atlas — original media · CC BY-NC 4.0

Common pitfalls

  • Interpreting before optimizing depth and gain.
  • Assuming a technically limited negative scan excludes disease.
  • Treating a POCUS finding as independent of pretest probability and the rest of the clinical assessment.

Bedside acquisition checklist

☐ Clinical question stated before probe touches the patient.
☐ Correct preset and probe selected.
☐ Marker/orientation confirmed.
☐ Depth, gain and focus optimized.
☐ Abnormality confirmed in more than one plane when feasible.
☐ Study limitation explicitly recognized.
☐ Images archived and findings documented when possible.

Check your interpretation

1. A structure is too small and surrounded by unused depth. What should you change first? →

Answer: Reduce depth so the target occupies more of the screen, then re-optimize gain and focus.

2. Why is a negative technically limited scan dangerous? →

Answer: Because failure to visualize the relevant anatomy is not equivalent to absence of pathology; the limitation must drive repeat scanning, another window or formal imaging.

Evidence & sources

  1. Díaz-Gómez JL, et al. Society of Critical Care Medicine guidelines on adult critical care ultrasonography: focused update 2024. Crit Care Med. 2025;53(2):e447-e458.
  2. ISCCM Expert Panel. Competencies for Point-of-care Ultrasonography in ICU: practice recommendation. Indian J Crit Care Med. 2023.
  3. The POCUS Atlas. Legal / Licensing: CC BY-NC 4.0. https://www.thepocusatlas.com/legal
Media license: The POCUS Atlas states that its content is licensed under CC BY-NC 4.0. Contributor credits are retained beside each media item. POCUS Atlas media is noncommercial. If ICU Knowledge Map becomes paid or otherwise commercial, obtain permission or replace these assets before monetization.