What you see

Equally spaced bright lines repeating deeper into the image, often in the near part of a cyst or the bladder; or a short, tapering bright tail behind a small strong reflector (comet tail), for example behind a needle, clip, metal or crystals.

Why it happens

Sound bounces back and forth between two strong parallel reflectors, and each delayed echo is placed deeper, as if from a deeper structure. A comet tail is reverberation within a small, closely spaced reflector, with each later echo fainter and narrower.

Try first

1. Change the probe angle so the beam meets the reflector more obliquely.
2. Turn on tissue harmonic imaging, which reduces reverberation.
3. Use spatial compounding where available.
4. In a cyst, check whether the “debris” moves with the probe angle rather than with the patient.

Can mimic pathology

Reverberation in the front of a cyst or the bladder can imitate debris or a wall lesion.

Good to know

Reverberation behind a needle helps you find the needle. In one surgical series, comet tails in a thickened gallbladder wall were seen only with benign disease, two of them with coexisting low-grade dysplasia.

Sources: Hindi 2013; Lacefield 2014; Wu 2020; Oh 2019; Anvari 2015; Sharma 2021

What you see

A continuous bright line or bands running deep from a gas collection: bowel gas, gas in the biliary tree or portal veins, an abscess, or near the pleura.

Why it happens

Small gas bubbles resonate when struck by the pulse and send a continuous signal back, which the scanner draws as a streak behind them.

Try first

1. Recognise it as a sign of gas; follow it to its source.
2. Change the probe position or angle to see past it, or use another window.

Good to know

Ring-down marks gas, which can help find gas in the bile ducts, portal venous system or an abscess. Two reviews describe the mechanism.

Sources: Hindi 2013; Wu 2020

What you see

A copy of a structure or lesion appears deeper than a strong curved reflector, most often a liver lesion or vessel shown above the diaphragm in the lung; also beside bone, and on colour Doppler.

Why it happens

A strong, smooth reflector such as the diaphragm and lung base redirects the beam, so echoes return by a longer path and are drawn behind the reflector.

Try first

1. Look for the real structure in front of the reflector: the copy lies at the same distance behind it.
2. Change the probe angle or window; lowering gain deep to the reflector can reduce it.
3. In Doppler, the mirror copy cannot be removed by settings; confirm which vessel is real by tracing it.

Can mimic pathology

A mirrored liver lesion or vessel above the diaphragm can imitate a lung or pleural lesion.

Good to know

In two reported cases, the mirror image above the diaphragm revealed liver lesions that were hard to see directly.

Sources: Lacefield 2014; Hindi 2013; Wu 2020; Terslev 2017; Wang 2024

What you see

A dark band deep to a stone, calcification, bone or gas. A clean shadow is uniformly black (stones, calcification, bone); a dirty shadow contains low-level echoes (gas). A small stone may give a faint or partial shadow.

Why it happens

The structure absorbs or reflects most of the sound, so little reaches the tissue behind. With gas, repeated reflections fill the shadow with low echoes. If the beam is wider than a small stone, part of the beam passes it and the shadow is faint.

Try first

1. To show a small stone’s shadow, put the focal zone at the stone and use a higher frequency.
2. To see behind the structure, scan from the side or another window.
3. Spatial compounding fills in and spreads shadows; turn it off to see a sharp shadow.

Good to know

Shadowing (or its absence) is used to tell stones, calcification and gas apart, and relative attenuation can help with tissue characterisation.

Sources: Hindi 2013; Lacefield 2014; Wu 2020; Wu 2022

What you see

Tissue deep to a fluid-filled structure (cyst, bladder, gallbladder, effusion) looks brighter than the tissue beside it.

Why it happens

Sound loses less energy passing through fluid than through the tissue next to it, so more reaches the tissue behind, and the time gain compensation adds the same amplification on every line.

Try first

1. Use it as a clue that a structure is fluid-filled, but not as proof (below).
2. Lower the deep time gain compensation to see deeper targets more clearly.
3. Spatial compounding spreads the enhancement over a wedge; turn it off to see it clearly.

Can mimic pathology

Some solid lesions that attenuate less than the tissue around them, such as a fibroadenoma, also show enhancement, so enhancement does not prove a lesion is a cyst.

Sources: Hindi 2013; Lacefield 2014; Wu 2020

What you see

A structure appears duplicated or widened, or slightly displaced sideways; or thin dark shadows run deep from the edges of a curved structure such as a cyst, the gallbladder, the bladder or the testis.

Why it happens

When the beam crosses a boundary between tissues with different sound speeds at an angle (for example muscle and fat), it bends, but the scanner draws echoes along the straight line it expected. At curved edges, refraction and defocusing remove sound, leaving an edge shadow.

Try first

1. Change the probe angle or position (heel-toe); a refraction artefact moves or disappears, a real structure does not.
2. Scan in a second plane.

Can mimic pathology

Refraction can duplicate a yolk sac in early pregnancy; an edge shadow can imitate a defect in the bladder wall or diaphragm.

Sources: Hindi 2013; Lacefield 2014; Wu 2020

What you see

Faint echoes or a rounded echo inside an anechoic structure such as the bladder or gallbladder, often near a strong reflector; faint symmetrical copies of a strong reflector off to either side.

Why it happens

Part of the beam’s energy travels off-axis in side lobes (and, in some arrays, grating lobes). A strong reflector hit by these lobes returns echoes that the scanner places on the main beam axis.

Try first

1. Move or angle the probe slightly; echoes that change or disappear are likely artefact.
2. Turn on tissue harmonic imaging, which reduces side- and grating-lobe artefacts.
3. Check in a second plane before reporting debris or a lesion.

Can mimic pathology

Off-axis echoes can imitate sludge, debris or a polyp in the gallbladder or bladder.

Sources: Lacefield 2014; Hindi 2013; Wu 2020; Anvari 2015

What you see

Fine echoes or false “sludge” inside a small cyst or vessel, especially when its wall is hit obliquely or it is away from the focus; edges look blurred.

Why it happens

The beam has thickness. Echoes from tissue next to a small fluid structure fall within the same slice and are averaged into it (partial volume). The slice is thinnest at the focus; in the elevation direction it is set by a fixed lens and is relatively thick, of the order of several millimetres.

Try first

1. Put the focal zone at the depth of the structure.
2. Scan the structure in a second plane and see whether the echoes persist.
3. Use a higher-frequency probe for small superficial structures.

Sources: Hindi 2013; Lacefield 2014; Wu 2020

What you see

A structure behind a region of fat, muscle or a breast implant appears at the wrong depth or with a step in its outline; a straight needle appears bent as it passes between tissues.

Why it happens

The scanner assumes sound travels at 1540 m/s. Sound travels faster in muscle and slower in fat, so echoes behind them are placed too shallow or too deep, and focusing is less accurate.

Try first

1. Be aware of it during needle guidance: aim by the needle tip’s position relative to the target, and image the needle along its length.
2. If your system offers sound-speed correction, use it as the manufacturer advises (it improves focusing); do not use it on a QA phantom calibrated to 1540 m/s.

Good to know

In most soft tissue the distortion is rarely noticeable; it matters most in image-guided procedures and the breast.

Sources: Lacefield 2014; Hindi 2013; Wu 2020

What you see

Part of a tendon, ligament or nerve looks dark (hypoechoic) instead of bright and fibrillar, typically where it curves, such as at an insertion.

Why it happens

Tendons reflect sound strongly only when the beam meets them at right angles; even a small tilt off perpendicular makes them look dark.

Try first

1. Rock (heel-toe) or tilt the probe until the beam is perpendicular to the fibres; anisotropy disappears, true disease does not.
2. Use electronic beam steering if available.
3. Scan the structure in both planes.

Can mimic pathology

Anisotropy can imitate tendinosis or a tear.

Sources: Hindi 2013; Wu 2020; Connolly 2001

What you see

The deep part of the image is dark or noisy, and deep structures or the far wall of an organ cannot be seen.

Why it happens

Attenuation rises with frequency, so higher frequencies give better resolution but reach less deep. Large patients, fatty liver and dense tissue absorb more sound.

Try first

1. Switch to a lower frequency or a lower-frequency probe.
2. Adjust the time gain compensation for the deep field and the focal zone to the depth of interest.
3. Try tissue harmonic imaging, or a different window closer to the target.
4. See Large patients and poor windows.

Sources: Hindi 2013; Lacefield 2014; Sharma 2021

What you see

The image is too bright or too dark overall, has a bright or dark horizontal band, the area of interest is small on the screen, or is blurred at the wrong depth; measurements change when settings change.

Why it happens

Overall gain sets brightness; time gain compensation (TGC) offsets attenuation in depth bands; the focal zone gives the best lateral resolution at its depth; dynamic range sets how echo strengths map to grey levels. Excess depth wastes the screen and lowers the frame rate; a band can come from the focal zone or uneven TGC.

Try first

1. Set the depth so the structure fills the screen.
2. Put the focal zone at the structure of interest (more focal zones cost frame rate).
3. Adjust gain and TGC for even brightness from near to far; check the TGC is not set unevenly.
4. Use the same gain, dynamic range and probe position for follow-up measurements: in one phantom study, changing gain or dynamic range changed measured vessel lumen size.
5. Tissue harmonic imaging reduces near-field clutter.

Good to know

No source read describes how a narrow or wide dynamic range looks; follow your preset.

Sources: Lacefield 2014; Sharma 2021; Hindi 2013; Wu 2020; Potter 2008

What you see

Parallel lines resembling septa or echoes inside a large cyst or deep fluid, which do not belong to it.

Why it happens

At a high pulse repetition frequency, echoes from deep structures arrive after the next pulse has been sent and are placed too close to the probe.

Try first

1. Lower the pulse repetition frequency, for example by increasing the depth setting.
2. Check whether the lines move when you change the depth.

Sources: Hindi 2013; Wu 2020; Lacefield 2014

What you see

Spectral Doppler: the top of the waveform is cut off and appears from the bottom of the display. Colour Doppler: colour changes abruptly from one direction to the other in fast central flow, with no black band between them.

Why it happens

Pulsed Doppler samples the signal at the pulse repetition frequency (PRF). Shifts above half the PRF (the Nyquist limit) cannot be measured and wrap round. Deeper gates and higher transmit frequency lower the limit.

Try first

1. Move the baseline first (spectral Doppler).
2. Raise the velocity scale (PRF).
3. Use a lower Doppler frequency, or a shallower window so the gate is less deep.
4. Power Doppler does not alias, if you only need to show flow.

Can mimic pathology

Aliasing can be mistaken for flow reversal; true reversal passes through a black band.

Good to know

Persistent aliasing after raising the scale can point to abnormally fast flow, such as distal to a stenosis. Hindi and colleagues also list increasing the Doppler angle as a fix, but velocity measurements need the angle kept below 60 degrees (see Angle correction).

Sources: Lacefield 2014; Hindi 2013; Terslev 2017; Sharma 2021

What you see

Spectral velocities seem too high or inconsistent between scans, the angle cursor is not aligned with the vessel, or flow appears both above and below the baseline when the vessel runs across the beam.

Why it happens

The Doppler shift depends on the cosine of the angle between the beam and the flow. At 90 degrees there is no shift; near 90 degrees the signal is weak and direction is ambiguous. Velocity can only be calculated if the angle is entered correctly, and errors grow steeply as the angle rises.

Try first

1. Move the probe or steer the beam to get an angle of 60 degrees or less before fine-tuning.
2. Align the angle-correction cursor with the vessel wall or flow direction.
3. Use the same angle approach for follow-up studies.

Good to know

In one worked example, the same vessel measured 130 cm/s with the correct angle but 230 cm/s with the angle wrongly set to 60 degrees (Sharma and colleagues).

Sources: Terslev 2017; Sharma 2021; Elwertowski 2014; Hindi 2013; Lacefield 2014

What you see

The spectral window under the waveform is filled in, as in turbulent flow, although the vessel looks normal.

Why it happens

True broadening comes from turbulence, for example after a stenosis. Spurious broadening comes from a gate that is too large or near the wall, too much spectral gain, or an angle near 90 degrees.

Try first

1. Place a small gate in the centre of the vessel, clear of the walls.
2. Lower the spectral gain until the background is clear.
3. Improve the angle (60 degrees or less).

Where sources differ

Gate size: Hindi and colleagues give 2 to 3 mm normally (wider than 3.5 mm causes spurious broadening); Sharma and colleagues suggest about two thirds of the lumen; the Polish carotid standard a third to a half of the lumen. Follow your protocol.

Sources: Hindi 2013; Sharma 2021; Elwertowski 2014; Pozniak 1992

What you see

Colour fills beyond the vessel walls, so the vessel looks wider than it is or the wall is hidden.

Why it happens

Colour gain set too high spreads colour into surrounding tissue.

Try first

1. Raise the colour gain until noise appears, then lower it until the noise disappears while the lumen stays filled.
2. Use the colour priority setting as your protocol specifies.

Can mimic pathology

Blooming can hide wall thickening.

Sources: Terslev 2017; Sharma 2021

What you see

Large patches of colour that appear briefly across tissue, especially in fluid-filled or dark areas, with breathing, heartbeat or probe movement.

Why it happens

Movement of the patient, probe or organs creates low Doppler shifts that are shown as colour. Motion filters work less well in dark (anechoic) areas.

Try first

1. Keep the probe still and ask the patient to hold their breath briefly if they can.
2. Raise the velocity scale or wall filter slightly; lowering colour priority also helps but can reduce lumen filling.
3. Confirm suspicious colour with spectral Doppler: true flow gives a vascular waveform.

Sources: Hindi 2013; Terslev 2017; Campbell 2004

What you see

A small focus of rapidly alternating colour, sometimes with a colour tail, behind a rough strong reflector, most often a urinary stone; it may be present even when the stone is hard to see in greyscale.

Why it happens

The exact cause is debated: rough, strongly reflecting surfaces are involved, and explanations include machine phase jitter and tiny gas bubbles trapped on the stone’s surface. Its appearance depends on settings, especially colour write priority and colour gain, and on the machine.

Try first

1. Use it as supporting evidence of a stone, and confirm with greyscale and spectral Doppler (twinkling gives a noisy, non-vascular spectrum).
2. Do not rely on its absence to exclude a stone.

Can mimic pathology

In the renal sinus, twinkling can imitate turbulent flow from a fistula or stenosis.

Where sources differ

Accuracy for kidney stones differs: a meta-analysis of 16 studies reported pooled sensitivity of 0.86 and specificity of 0.92, while a CT-correlated study found 55% sensitivity for individual stones and that half of twinkling foci were false positives. Whether PRF affects it is also disputed.

Sources: Hindi 2013; Lu 2013; Kamaya 2003; Rahmouni 1996; Dillman 2011; Nabheerong 2023; Bacha 2019; Haluszkiewicz 2017

What you see

A copy of a vessel’s colour deeper than a strong reflector (for example the subclavian artery mirrored by the pleura), or a copy of the spectral waveform on the opposite side of the baseline.

Why it happens

Strong smooth reflectors act as mirrors for Doppler as for greyscale. A spectral copy below the baseline often comes from Doppler gain set too high.

Try first

1. For a spectral copy, lower the Doppler gain.
2. For a colour mirror, trace the vessel to its real position; settings cannot remove it.

Sources: Hindi 2013; Terslev 2017

What you see

A vessel shows little or no colour or spectral signal although it is expected to be patent, or only the centre of the lumen fills.

Why it happens

Common setting causes: velocity scale (PRF) or wall filter too high for slow flow, colour or Doppler gain too low, an angle near 90 degrees, the focus at the wrong depth, colour priority too low, a Doppler frequency that does not penetrate, or a colour box so large the frame rate falls. Probe pressure can occlude a superficial vessel.

Try first

1. Lower the velocity scale and the wall filter.
2. Raise the colour gain until noise appears, then back off slightly.
3. Improve the angle (steer the box or angle the probe), put the focus at the vessel, and make the colour box smaller.
4. Raise colour priority, and change the Doppler frequency (lower for depth, higher for slow superficial flow).
5. Use light pressure and plenty of gel over superficial vessels.
6. Try power Doppler, which is more sensitive to slow flow and much less dependent on angle.

Stop and escalate when

Flow still cannot be shown after optimising: report that flow could not be demonstrated, with the settings used, rather than calling the vessel occluded.

Can mimic pathology

Settings that hide slow flow can imitate thrombosis.

Good to know

A wall filter set too high can also remove low diastolic flow and give a falsely high resistive index.

Sources: Hindi 2013; Terslev 2017; Sharma 2021; Lacefield 2014; Kruskal 2004; Campbell 2004

What you see

The shear-wave system shows no result (no colour or no value) in an area, the quality indicator fails, measurements vary widely, or values are unexpectedly high.

Why it happens

Shear waves do not travel in fluid, may fail in very hard lesions or where the signal is too weak (behind ribs, shadowing, calcification) and below their generated depth. Pressing with the probe (precompression), deep breathing, recent food or exercise, inflammation, cholestasis and congestion raise measured stiffness.

Try first

1. Follow your system’s liver protocol: patient fasted and rested, right arm raised, intercostal approach to the right lobe, probe perpendicular to the capsule, region of interest in uniform tissue away from vessels and below the capsule.
2. Take each measurement in a separate short breath-hold in neutral breathing, with minimal probe pressure.
3. Use the manufacturer’s quality indicator and repeat measurements as your protocol requires; report the median and the interquartile range-to-median ratio.

Stop and escalate when

Results remain unreliable or do not fit the clinical picture: repeat, then report the limitation; another method may be needed.

Good to know

The guideline reliability criterion for kPa is an interquartile range-to-median ratio of 30% or less (as summarised by Souza and colleagues); a 2025 study notes this cut-off was adopted for 2D shear-wave elastography without large-scale validation, though in that study’s own data, on one 2D shear-wave system, the 30% cut-off did separate reliable from unreliable measurements. The primary guidelines could not be read in full for this page.

Sources: Souza 2026; Bauer 2025; Hindi 2013; SRU 2020

What you see

The image looks wrong for the examination (the wrong preset was chosen), or shadows and enhancement look different when compounding or harmonic imaging is switched on or off.

Why it happens

Presets set frequency, depth, gain, dynamic range, compounding, harmonics and Doppler settings for an examination type. Spatial compounding reduces speckle and noise but spreads and partly fills shadows and enhancement and lowers frame rate. Harmonic imaging reduces clutter and some artefacts but lowers axial resolution, and pulse-inversion harmonics can add a streak behind fast-moving reflectors.

Try first

1. Select the preset for the examination and probe, then adjust settings during the scan for the patient and the vessel or organ.
2. Toggle compounding or harmonics off when you need a crisp shadow or enhancement to characterise a structure.
3. Change presets only as your department’s preset policy allows.

Sources: Terslev 2017; Sharma 2021; Wu 2022; Lacefield 2014; Kamaya 2004; Anvari 2015

What you see

A dark vertical stripe or shadow running down from the probe face, seen best on an in-air image or a uniform phantom; a gap or change in the reverberation lines when the probe is held in air; or visible damage to the lens: splits, cuts, wear, lifting or bubbling.

Why it happens

Array probes are made of many small elements. Elements can fail or weaken, the layers of the probe can separate (delamination), and lenses split or wear. In a one-time test of 676 probes in daily use at 32 hospitals, 39.8% had a fault, most often delamination (Mårtensson and colleagues, abstract). In a four-year quality control programme, transducers failed at an average of 13.9% a year, and visual and uniformity checks found most failures (Hangiandreou and colleagues, abstract). Dead or weak elements can reduce resolution and penetration, raise noise and cause Doppler velocity errors.

Try first

1. Each day, look at the lens, housing, cable and connector of every probe you use, and press lightly on the lens edge to check it is bonded to the casing.
2. In-air check: with the probe clean and dry and held in air, turn off harmonics, compounding and trapezoidal imaging and look at the reverberation lines. They should run parallel to the probe face; look for a local gap, shadow or streak (axial banding) and compare with the reference image. This check does not work on phased array probes.
3. Paperclip test: if dropout is suspected, and monthly for phased arrays (where it is the user check for dropout), run the smooth edge of a paperclip slowly along the probe face (a smear of water helps on hard lenses); any loss of echoes along the face indicates element dropout.
4. Shadows or streaks starting at the top of clinical images can mean a more serious fault: report them straight away.

Stop and escalate when

Lens damage, a crack, or dropout on the in-air or paperclip check: report it to the person responsible and take the probe out of use as your QA programme directs. Damage that could let gel or water in is treated as major: the probe comes out of service and has electrical safety testing before reuse.

Where sources differ

There is no agreed number of failed elements at which a probe is withdrawn. SoR and BMUS (UK) say dropout affecting more than one element compromises diagnostic quality; the BMUS QA guideline says any loss of echoes on the paperclip test is likely to be clinically significant; a single laboratory study found Doppler unreliable with four or more neighbouring dead elements; the ACR-AAPM standard (USA) leaves the decision to the medical physicist with the lead interpreting physician.

Sources: SoR/BMUS 2025; BMUS QA 2014; AAA QA 2025; ACR-AAPM US 2026; Mårtensson 2009; Hangiandreou 2011; Vachutka 2014; AIUM Cleaning 2025

What you see

The probe cable is cut, kinked, twisted or worn through; connector pins are bent, misaligned or corroded; or the mains cable or plug is damaged.

Why it happens

Cables are flexed with every scan and can be run over by the scanner’s wheels. Cable breaks were found in 8.4% of probes in one large one-time test (Mårtensson and colleagues, abstract). Damage to a probe or cable may be an electrical or infection hazard as well as an image problem.

Try first

1. With the scanner off, run the cable through your hand and flex it, looking for cuts, wear and twisting; check the connector pins.
2. Never disconnect a probe while it is operating.
3. Stow cables so wheels cannot run over them, and use the probe holders.
4. Clean the cable and connector only with products and methods the manufacturer allows; keep fluid out of the connector.

Stop and escalate when

Any damage to a probe cable, connector or mains cable: take the equipment out of use, label it, and report it.

Sources: BMUS QA 2014; AAA QA 2025; SoR/BMUS 2025; Mårtensson 2009; Philips care 2013

What you see

The scanner does not list a connected probe, shows an error when the probe is connected or at switch-on, the image freezes, the screen flickers, or the system stops responding.

Why it happens

No published user guidance was found for these faults; they depend on the scanner. Quality checks test each probe port with at least one probe, and switch-on checks look for error messages, flicker and excess noise. The US FDA expects manufacturers to build in a probe self-test that runs on connection and can be run by the user, but whether your scanner has one varies.

Try first

1. Note the exact error message and the time, and record them in the fault log.
2. Check the connector pins and the port for damage or debris before reconnecting, following your manual; never disconnect a probe while it is operating.
3. Try the probe in another port, or another probe in the same port, to see whether the fault follows the probe or the port (a general step).
4. Before restarting, check whether the current study has been sent to PACS (see Images not on PACS), then restart only as your operator manual describes (a general step).
5. If your scanner has a probe self-test, run it.

Stop and escalate when

The fault recurs, the probe fails its self-test, or the scanner shows repeated errors: take it out of use and report it to the person responsible and your service provider.

Sources: AAA QA 2025; ACR-AAPM US 2026; FDA US guidance 2023; BMUS QA 2014

What you see

A preset gives an unexpected image, someone has changed or saved over a preset, the displayed thermal or mechanical index is higher than usual at the start of a scan, or the output starts at 100%.

Why it happens

Presets set the starting frequency, gain, processing and acoustic output for each examination type. Vendors differ: some deliver systems with output set to 100%, and neonatal cardiac presets may default to high output. Quality tests depend on using the same recorded preset each time.

Try first

1. At the start of each examination, check the right preset is selected for the examination and the probe.
2. Start each new patient at low output and raise it only if needed, raising receiver gain first.
3. Monitor the displayed thermal and mechanical indices, and reduce the output at the end of the examination so the next user starts low.
4. Report presets that start above your department’s agreed output; changes are made only under your preset policy.

Good to know

BMUS (UK) advises users to set the minimum acceptable output for each mode in each preset at commissioning, with the vendor’s application specialist, and where possible not to exceed the index values at which time limits begin, for example a thermal index of 0.7 for obstetric presets. That minimum is a starting point: output can be raised for an individual patient when it improves the diagnosis.

Sources: BMUS Presets 2023; AIUM ALARA 2020; BMUS Guidelines 2009; EFSUMB Doppler 2021; BMUS Neonatal 2021; AAA QA 2025; BMUS QA 2014

What you see

Images do not reach PACS, fewer images arrive than were taken, the patient is missing from the worklist or shows wrong details, or measurements or safety indices seen on screen are missing from the stored images.

Why it happens

The scanner sends images to PACS and, with storage commitment, PACS confirms storage; only then may the scanner delete its own copies. A send can look complete before PACS has confirmed storage, so the commitment result is what matters. Patient details come from the modality worklist; entering them by hand risks errors. What a scanner does with unsent images differs between models and is set out in its DICOM conformance statement. Information displayed live, such as safety indices, is not always reproduced on stored images.

Try first

1. Check the send queue and the destination, resend failed images, and compare image counts.
2. Do not delete studies from the scanner until PACS has confirmed storage.
3. If the worklist is empty or wrong, check the booking, and enter details by hand only under your downtime procedure.
4. Check that the patient details and annotations on the stored images are correct before the patient leaves.

Stop and escalate when

Images are still missing, or a patient identity error is found: contact your PACS or IT team and report it through your incident process (see Wrong patient or wrong side).

Sources: DICOM PS3.4; Clunie 2014; ACR-AAPM US 2026; SoR/BMUS 2025

What you see

You are unsure which level of cleaning and disinfection a probe needs after an examination, a product is not on the manufacturer’s list, or a lens looks discoloured or brittle after cleaning.

Why it happens

The level depends on what the probe touched. Intact skin: cleaning and low-level disinfection. Mucous membranes or non-intact skin (transvaginal, transrectal, transoesophageal, open wounds): cleaning then high-level disinfection. Sterile tissue or the bloodstream: sterilisation, or as your guideline allows. A probe cover does not lower the level needed, because covers can fail. Products not approved by the probe’s manufacturer can damage the lens and housing, and a damaged probe cannot be reprocessed reliably.

Try first

1. Straight after the examination: remove the cover, wipe off gel and soil, then inspect the probe, cable and scanner for damage.
2. Decide the level from what the probe touched, not from whether a cover was used.
3. For needle procedures through intact skin in Australia and New Zealand, ASUM and ACIPC (2026) accept cleaning and low-level disinfection as a minimum, with a sterile cover; other countries’ guidelines differ (below).
4. Use only products on the probe manufacturer’s compatibility list that are also approved for that use in your country, and follow their contact times and drying steps.
5. Clean the keyboard, touch screen, trackball, cable and handles between patients as your policy and the manufacturer describe.
6. Record each high-level disinfection so the probe can be traced to each patient.

Where sources differ

Probes used for needle procedures through intact skin. The ASUM and ACIPC 2026 guideline (Australia and New Zealand, replacing its 2017 advice) and AIUM (USA) accept cleaning and low-level disinfection with a cover of the right sterility. ASUM cites a randomised trial (Peters and colleagues, 2023; Peters is also the guideline’s first author) in which low-level disinfection was non-inferior to high-level disinfection for clearing microbes from probes used on skin; the trial measured microbial clearance, not infections. ESR (Europe, 2017), the ASA (2022, before the ASUM update) and NHS Scotland (2017, probes used on broken skin) call for high-level disinfection; SDMS (USA) classifies by what the probe touched, including a needle puncture. Follow your infection prevention team.

Sources: AIUM Cleaning 2025; ASUM/ACIPC 2026; CDC Disinfection 2008; SDMS Reprocessing 2022; NHS Scotland 2017; ESR 2017; ASA Intracavity 2022; SoR/BMUS 2025; Peters 2023; FDA US guidance 2023

What you see

The disinfection system reports a failed cycle, an indicator fails, residue is visible after reprocessing, the traceability record is missing, or nobody can confirm that a probe was reprocessed.

Why it happens

Reprocessing is a chain: cleaning, inspection, disinfection or sterilisation, and storage. A missed or faulty step invalidates the whole process. A patient’s death from hepatitis B in the UK may have been linked to a transoesophageal probe not decontaminated between patients.

Try first

1. Do not use the probe. Repeat the full reprocessing, or quarantine the probe until an investigation is complete, as your guideline directs.
2. Tell the person responsible for reprocessing, who decides the corrective action, and record the non-conformance and what was done.
3. Release the probe only when the acceptance checks are met and the traceability record is complete.
4. Find out whether the probe was used on any patient after the failed or missed step.

Stop and escalate when

The probe was used on a patient after a failed or missed high-level disinfection: report it now through your incident process and go to Cover breaks or disinfection missed.

Sources: ASUM/ACIPC 2026; NHS Scotland 2017; SDMS Reprocessing 2022; MHRA MDA/2012/037; CDC Disinfection 2008

What you see

A gel bottle is undated, has been refilled, or its tip has touched the patient, the probe or the bed; a gel warmer is dirty or uses water; or you are unsure whether the examination needs sterile gel.

Why it happens

Ordinary gel is not sterile, and contaminated gel has caused outbreaks of serious infection. Bottles that are refilled, stored open or kept warm can grow bacteria.

Try first

1. Use sterile single-use gel for procedures that pass a needle or device into the body, on non-intact skin, and as your guideline lists (for example inside and outside covers on internal probes, and in intensive and neonatal care).
2. Never refill a bottle or decant from a bulk container; date bottles on opening and discard them within the time your guideline sets.
3. Store bottles upright and keep the tip from touching anything.
4. Warm gel only by dry heat and only as your guideline allows; clean warmers regularly.

Where sources differ

Rules differ. Discarding open bottles: after one month in England (UKHSA 2025), within the manufacturer’s time in Australia and New Zealand (ASUM 2026), when empty in the USA (AIUM). If the tip touches something: discard the bottle (UKHSA main text, SDMS) or clean the tip at once (UKHSA appendix). Warming: not advised (SoR/BMUS), not recommended unless of clinical benefit (UKHSA), single-use containers only (ASUM), dry heat only (AIUM, ESR). Endocavity examinations: sterile gel (UKHSA, ASUM), sterile preferred (SDMS), sterile or bacteriostatic to be considered (AIUM).

Sources: UKHSA Gel 2025; ASUM/ACIPC 2026; AIUM Cleaning 2025; SDMS Reprocessing 2022; SoR/BMUS 2025; ESR 2017

What you see

Pain, aching or numbness in your neck, shoulder, upper back, lower back or wrist during or after scanning lists.

Why it happens

Musculoskeletal disorders are common in sonographers: a meta-analysis of 30 studies reported a pooled prevalence of 75.80%, mostly the neck and shoulder, though all the data were self-reported and the studies varied widely. Causes include sustained reaching, twisting, arm abduction, grip force and probe pressure, static postures, workload, room set-up and patients with a high BMI.

Try first

1. Set up before you scan: patient close to your edge of the couch, couch and chair at heights that keep your scanning arm close to your body, and the monitor adjusted so you do not twist your neck.
2. Keep a neutral posture; avoid reaching across the patient, twisting and gripping hard.
3. Take micro-breaks: lift the probe off and rest your arm while you measure or type.
4. Use arm and cable supports where available, and vary sitting and standing.
5. Ask for a mix of case types on lists and enough time for difficult examinations.

Stop and escalate when

Pain that persists or returns: report it to your manager early, in writing, complete an incident report for a work-related injury, and seek occupational health advice.

Good to know

Employers are expected to provide education and a risk assessment that covers equipment, scheduling, breaks and room layout (SDMS standards, USA; SoR, UK).

Sources: Zangiabadi 2024; SDMS WRMSD 2017; AIUM WRMSD 2026; SoR WRMSD 2019; SoR/BMUS 2025

What you see

The patient’s identity needs confirming before scanning: a common name, a patient who cannot answer, a child, a language barrier, a ward or theatre patient, or a request that does not match what the patient expects.

Why it happens

Identification errors happen in all imaging, including ultrasound. A positive, active check of several identifiers against the request prevents it; a room number is never an identifier.

Try first

1. Ask the patient to state their full name, date of birth and address, rather than asking “Are you …?”, and match the answers to the request and the identity band.
2. Confirm what they believe they are having, including the site and side, and check the request and previous imaging.
3. For a patient who cannot answer, follow your documented procedure: their representative, the identity band, or accompanying staff.
4. If you work alone, pause before scanning to confirm patient, examination and side (an internal time-out).
5. Check the patient details and side annotations on the images before they are sent.

Stop and escalate when

Any doubt about identity, or the patient does not expect this examination: do not start; check further with the referrer, and report a mismatch through your incident process.

Sources: CIB US Patient ID 2016; SoR Patient ID 2025; ACSQHC CT/MRI protocol; WHO Patient ID 2007; SDMS Scope 2024; SoR/BMUS 2025

What you see

Organs are deep and poorly seen, the far field is dark or noisy, or the examination cannot answer the question because of body habitus.

Why it happens

Fat attenuates ultrasound, and subcutaneous fat degrades organ images more than fat inside the abdomen. Ultrasound has no table weight or aperture limit, but image quality can fall well short of what is needed.

Try first

1. Use the lowest-frequency probe suited to the depth, and tissue harmonic imaging.
2. Press in with the probe to shorten the path through fat, and place it as close to the organ as possible, using another window or position if needed.
3. Try another scanner if one is available.
4. Plan the room and your posture first: a high patient BMI is a recognised cause of sonographer strain (see Sonographer strain and pain).

Stop and escalate when

The examination remains non-diagnostic: record the limitation in the report; the reporter decides on recall, rescan or another modality.

Sources: Uppot 2018; SoR/BMUS 2025; ASUM 2nd Trimester 2018; Paladini 2009

What you see

Gas obscures the pancreas, aorta, ovaries or other deep structures, with dirty shadowing from bowel loops.

Why it happens

Gas reflects nearly all the sound (see Acoustic shadowing). Fasting reduces bowel gas, and gentle pressure or a change of position can move it out of the way.

Try first

1. Check the patient has fasted as your protocol requires for the examination.
2. Use graded compression with the probe to push gas aside, explaining first why you are pressing.
3. Change the patient’s position (decubitus or erect) and use different phases of breathing.
4. Use other windows: the left lobe of the liver for the pancreas on held breath in, or through the spleen for the pancreatic tail.
5. For the pancreas, oral water can fill the stomach as a window, as your protocol allows.
6. For pelvic organs, a filling bladder lifts bowel loops out of the way.

Stop and escalate when

Structures still cannot be seen: record the limitation, for example “pancreas obscured by bowel gas”, rather than reporting it as normal.

Sources: SoR/BMUS 2025; SoR Chaperone 2023

What you see

The patient cannot hold their breath, keeps moving, cannot turn or lie in the position needed, or is breathless lying flat.

Why it happens

Many views depend on breathing (the liver and pancreas move with the diaphragm) or on position (the gallbladder is best seen in more than one position). Patients who are unwell, in pain or breathless may not manage either.

Try first

1. Explain each breathing instruction before you need it and practise it once (a general step).
2. Use whatever phase of breathing gives the view, and capture cine loops while the patient breathes gently (a general step).
3. Scan in the positions the patient can manage (supine, decubitus, sitting or erect) and use other windows, such as between the ribs.
4. Let the patient rest between views; ask for help before moving a patient who cannot turn alone.

Stop and escalate when

The examination cannot be completed: record the limitation and the reason, such as inability to tolerate the position, and tell the reporter.

Sources: SoR/BMUS 2025; SDMS Scope 2024; SDMS WRMSD 2017

What you see

A child is frightened, will not keep still, or is too young to follow instructions; a newborn needs scanning on or away from the neonatal unit.

Why it happens

Children cooperate better with time, rapport and a familiar adult. The neonatal brain and spine are sensitive tissues, and cranial scanning (high-frequency probes, bone either side of the fontanelle, a narrow focus and little probe movement) raises local heating. Neonatal lung bleeding has been seen in laboratory animals at settings in common neonatal use. Some neonatal cardiac presets default to high output.

Try first

1. Use a child-friendly room at a comfortable temperature, ideally on a paediatric list, and build rapport before you start.
2. Position for cooperation: a distressed child may sit on a parent’s knee in a “bear hug”, and you may need to improvise views.
3. Keep newborns out of the neonatal unit for the shortest possible time.
4. Monitor the thermal index (TIC for brain and spine scans, TIB for other scans) and the mechanical index; raise receiver gain rather than output, find vessels with colour before using pulsed Doppler, and keep scan time short.
5. Use sterile gel for newborns and in neonatal intensive care, as your gel guideline requires.

Sources: SoR/BMUS 2025; BMUS Neonatal 2021; EFSUMB Doppler 2021; BMUS Guidelines 2009; AIUM Cleaning 2025; UKHSA Gel 2025

What you see

An obstetric scan, a gynaecological scan when pregnancy is possible, a request for Doppler in early pregnancy, a long or difficult scan, or a pregnant patient with a fever.

Why it happens

There is no evidence that diagnostic ultrasound has harmed humans, including the fetus, but modern equipment has higher output, and laboratory studies show heating and other effects at inappropriate power or long exposure. The thermal index (TI) estimates temperature rise and can underestimate it by up to a factor of two; the mechanical index (MI) indicates the potential for non-thermal effects. The embryo, the fetal head, brain and spine, and the eye are the most sensitive tissues. Spectral pulsed Doppler has the greatest heating potential, with colour and power Doppler in between.

Try first

1. Scan only for a medical indication, never solely for keepsake images.
2. Start at low output and monitor the displayed TI and MI: the soft-tissue index (TIS) up to 10 weeks after the last menstrual period, and the bone index (TIB) after that.
3. Keep the examination short: lift the probe off when you are not imaging, and review on freeze and cine.
4. Document the embryonic or fetal heart rate with M-mode or B-mode cine rather than spectral Doppler, unless spectral Doppler is clinically indicated.
5. A pregnant patient with a raised temperature: reduce output and minimise exposure; AIUM advises deferring the scan until the temperature is normal if possible.
6. Do not use an internal probe that becomes noticeably warm when running in air.

Where sources differ

Doppler in the first trimester. ISUOG (2021): not used routinely in the embryonic period (to 10 weeks 6 days); from 11 to 13 weeks 6 days it may be used for clinical indications with a displayed TI of 1.0 or less and exposure usually no longer than 5 to 10 minutes. AIUM (2020): pulsed Doppler not routine, all scans begin at TI 0.7, displayed TI 0.7 or less where adequate images can be obtained. EFSUMB (2021): routine Doppler of the first-trimester embryo should not be done. All agree that uterine artery Doppler with the embryo outside the beam is unlikely to matter for the fetus.

Good to know

BMUS (UK, 2009) and AIUM (USA, reapproved 2022) give the same obstetric time limits by displayed TI: no limit at 0.7 or below; then up to 60 minutes above 0.7 to 1.0, 30 above 1.0 to 1.5, 15 above 1.5 to 2.0, 4 above 2.0 to 2.5, 1 above 2.5 to 3.0, and not recommended above 3.0. AIUM adds that times should be cut by a third for pulsed Doppler near bone, because the TI tends to underestimate heating there. Safety indices shown on screen may not appear on stored images.

Sources: BMUS Guidelines 2009; BMUS Hazards 2012; AIUM Pregnancy 2020; AIUM TI Times 2022; AIUM In Vivo 2021; ISUOG Doppler 2021; WFUMB/ISUOG Doppler 2015; EFSUMB Doppler 2021; ASUM 2nd Trimester 2018; SoR/BMUS 2025

What you see

A transvaginal, transrectal, scrotal, breast or groin examination; a patient who seems unsure; a request for a chaperone or for a practitioner of a particular gender; or no chaperone is available.

Why it happens

What feels intimate differs between people and cultures; groin and even transabdominal scans may feel intimate to some. Consent is a continuum: the patient can decline or stop at any time. A chaperone is an impartial observer who protects both the patient and the practitioner.

Try first

1. Before anything, including asking the patient to move clothing, explain what will be touched, with what, and why, and that they can stop at any point.
2. Offer a chaperone, irrespective of your gender and the examination; a chaperone is normally a trained staff member, not a relative or friend, and never someone under 18.
3. Give privacy to undress and a sheet to stay covered; expose only the area being examined; keep interruptions out.
4. For a transvaginal scan, offer the patient the option of inserting the probe herself; if it is declined or impossible, offer a transabdominal scan or discuss alternatives once the patient has dressed.
5. Record that a chaperone was offered, used or declined, with their name and role, and the consent given.

Stop and escalate when

The patient withdraws consent, shows distress or resists: stop. If you will not proceed without a chaperone and none is available, offer to rebook unless delay would harm the patient.

Where sources differ

Consent and chaperone rules differ. UK (SoR 2023): witnessed verbal consent is usually enough; a practitioner may request a chaperone, and local policy may require one. Australia and New Zealand (ASA 2024): verbal consent for routine intimate examinations, written for interventional or other high-risk ones; implied consent is not enough; for transvaginal scans in patients under 14, a parent’s or guardian’s written consent as well as the child’s. New Zealand: the HDC Code gives the right to informed consent, to refuse or withdraw, to a support person, and to have a preference about who provides care met where practicable. Canada: entry-level competencies include deciding the need for a chaperone. Follow your employer’s policy.

Sources: SoR Chaperone 2023; ASA Intimate Exams 2024; ASUM Vaginal Scanning 2014; ASUM Gynaecological 2020; SoR/BMUS 2025; HDC Code 1996; Sonography Canada NCP 2026

What you see

The patient reports a latex allergy, or develops itching, rash or swelling after an internal examination with a cover or gloves.

Why it happens

Guidelines ask about latex allergy in the history and expect latex-free probe covers and gloves to be used for patients who are allergic.

Try first

1. Ask about latex allergy before any internal examination.
2. Use latex-free probe covers and gloves, and record it, for example “Due to latex allergy, a latex-free probe cover was used”.
3. Use only purpose-made covers that your guideline approves; if condoms are used where allowed, they are non-lubricated and non-medicated.

Stop and escalate when

Breathing difficulty, swelling of the face or throat, or collapse: call for help through your emergency procedure and treat as anaphylaxis (see Contrast reaction for positioning and Arrest).

Where sources differ

Condoms as covers: AIUM (USA) accepts them; ASUM 2026 (Australia and New Zealand) does not recommend them; ESR (Europe) calls them questionable.

Sources: ASUM Gynaecological 2020; AIUM Cleaning 2025; WFUMB Endocavity 2024; SoR/BMUS 2025; ASUM/ACIPC 2026; ESR 2017; ASCIA 2026

What you see

The patient is anxious, in pain, crying, or becomes upset during the scan, for example during an internal examination or after seeing something on the screen.

Why it happens

Many patients are very anxious, particularly for gynaecological, scrotal and obstetric scans. Survivors of sexual violence may find intimate examinations especially hard.

Try first

1. Slow down: explain what you are doing before you do it, and check consent again as you go.
2. Ask the patient to tell you about pain or if they want to stop; watch for non-verbal signs.
3. Offer a chaperone or a support person.
4. For a frightened child, let a parent hold them and take time to build rapport.
5. If you see an unexpected finding, follow Unexpected findings rather than reacting in front of the patient.

Stop and escalate when

The patient asks you to stop, or significant discomfort occurs during an internal scan: stop, and ask the supervising practitioner to assess the patient. Discuss next steps once they are dressed.

Sources: SoR Chaperone 2023; ASA Intimate Exams 2024; ASUM Vaginal Scanning 2014; SoR/BMUS 2025; EFSUMB Doppler 2021

What you see

You see something unexpected, and the patient asks what it means, or you are unsure how much you may say.

Why it happens

The sonographer is often the first to see a finding, and research suggests parents prefer to hear unexpected news from their sonographer. How much a sonographer may tell a patient differs between countries and employers.

Try first

1. Know your department’s written policy on what you may say before you need it.
2. Tell the patient that the images will be reviewed, by whom, and how they will get the result; do not discuss diagnosis, treatment or prognosis beyond your role.
3. If you cannot give a full and clear explanation, ask the reporting sonologist, radiologist or senior sonographer to speak to the patient before they leave, as your policy allows.
4. Record what was said, to whom and when.

Stop and escalate when

A finding that may need urgent action: go to Urgent unexpected finding before the patient leaves.

Where sources differ

Who tells the patient. Australia (ASUM): the supervising medical practitioner decides how much of the findings is communicated, within the practice’s documented policies; for obstetric news, a sonologist or senior sonographer speaks to the parent before they leave if the sonographer cannot. USA (SDMS, ACR): the sonographer’s findings are for the interpreting physician, not the patient, and are communicated to the patient only as directed. Canada (Sonography Canada): sonographers give a technical impression to the interpreting physician. UK (SoR and BMUS): findings are explained and discussed within local guidelines, with training before giving unexpected news. New Zealand: sonographers are responsible for the outcome of the examination (MRTB scope), and patients have the right to their test results (HDC Code).

Sources: ASUM Sonographer Practice 2014; ASUM Parent-centred 2022; SDMS Scope 2024; ACR Communication 2025; Sonography Canada NCP 2026; SoR/BMUS 2025; MRTB Scope 2025; HDC Code 1996

What you see

The patient does not share your language, is Deaf or hard of hearing, has a learning disability or sight loss, or cannot follow consent or breathing instructions.

Why it happens

Identification, consent, breathing instructions and any discussion of findings depend on two-way communication. Patients have a right to communication they understand, including a competent interpreter where needed.

Try first

1. Arrange a qualified interpreter, face to face, by phone or by video, before consent is sought.
2. Avoid using family or friends to interpret; if the patient wants a relative to interpret, get their consent in their own language, independently of that person, and record it. Do not use children to interpret except in an emergency.
3. Use aids that suit the person: written information, sign language interpreters, large print, or pictures for children.
4. Agree simple signals for breathing and stopping before you start.

Stop and escalate when

Identity or consent cannot be established reliably, particularly for an intimate examination: do not proceed until an interpreter is available, unless delay would harm the patient.

Sources: HDC Code 1996; NHS England Interpreting 2018; SoR/BMUS 2025; ASUM Consent 2018; ASA Intimate Exams 2021; ASUM Parent-centred 2022

What you see

A probe cover tears, leaks or is found damaged during or after an internal or sterile examination, or you discover that a probe was used on a patient after its high-level disinfection was missed, failed or cannot be confirmed.

Why it happens

Covers can fail, which is why internal probes are disinfected to a high level between patients whether or not a cover was used. A missed or failed disinfection is different: the next patient may have been exposed to the previous patient’s body fluids. Hepatitis B and C infections, some fatal, have been linked to inadequately reprocessed devices.

Do this now

1. Cover breaks during a procedure: remove and replace the cover at once; if possible, swap to a correctly reprocessed probe before continuing, because the probe may now have touched tissue its preparation was not meant for.
2. Afterwards, inspect the used cover, record any damage in the decontamination record and the patient’s notes, and reprocess the probe in full.
3. Disinfection missed or failed before use on a patient: take the probe out of use, report it through your incident process, and tell your infection prevention team straight away.
4. Keep the traceability records: they identify which patients were scanned with the probe and after which reprocessing cycle.
5. The infection prevention team assesses the risk and decides whether patients need to be told and offered testing; your open disclosure or duty of candour policy applies.

Good to know

The guidelines read for this page do not set out what to tell patients after a cover breaks, and none sets out an ultrasound-specific pathway for a missed disinfection. A published 14-step method for assessing disinfection failures, which includes deciding how patients are notified, was available only as an abstract. In one US look-back after a reprocessing lapse with prostate biopsy equipment, exposed patients were offered testing for hepatitis B, hepatitis C and HIV (abstract only). AIUM notes that a visibly broken cover does not change the disinfection protocol, because high-level disinfection already assumes covers can fail.

Sources: SDMS Reprocessing 2022; NHS Scotland 2017; AIUM Cleaning 2025; ASUM/ACIPC 2026; CDC Disinfection 2008; Rutala 2007; Lessa 2008; WFUMB Endocavity 2024; SoR/BMUS 2025

What you see

You are stuck by a used needle, cut by a used sharp, or splashed with blood or body fluid in the eyes, mouth or on broken skin during a biopsy, drainage, cannulation or other guided procedure.

Why it happens

A used needle can carry bloodborne viruses. Post-exposure treatment works best when started early, so the first steps and reporting happen straight away, not at the end of the list.

Do this now

1. Stop, make the sharp and the procedure field secure, and hand over care of the patient to a colleague (a general step).
2. Wash the wound and skin with soap and water. Rinse eyes (remove contact lenses) and mouth with water or saline; spit out and rinse. Do not inject antiseptics or disinfectants into the wound.
3. Report it to your supervisor at once and get urgent medical assessment through occupational health or the emergency department, as your local policy directs.
4. Record the details: what you were doing, the type of exposure, the device, the fluid, the first aid given and the source patient.
5. Testing the source patient needs their consent, or the legal process that applies where they cannot consent.

Where sources differ

Timing of HIV post-exposure treatment. ASHM, Australia’s national PEP guideline, says start as soon as possible and within 72 hours. No national New Zealand guideline was found; as an example of a local New Zealand policy, one Dunedin hospital says within 4 hours is optimal, with some benefit up to 48 hours. Both mean go now. UK law requires employees to report sharps injuries and employers to provide immediate access to medical advice and post-exposure treatment. Follow your local occupational health or infection prevention policy.

Sources: ASHM PEP 2025; CDC NIOSH Bloodborne 2025; NSW Health GL2024_002; HSE Sharps 2013; Mercy BBFE 2025

What you see

During or after a contrast-enhanced ultrasound injection, the patient develops a rash, itching, flushing, breathlessness, wheeze, swelling, nausea, dizziness, a low blood pressure or a slow or fast pulse, or collapses.

Why it happens

Microbubble contrast agents have a low rate of adverse events, mostly mild (headache, nausea, warmth, altered taste). Serious reactions are reported at about 1 in 10,000 administrations and most occur within 30 minutes. Hypersensitivity can occur with no previous exposure; some agents contain polyethylene glycol (PEG).

Do this now

1. Stop the injection, stay with the patient and call for help through your emergency process.
2. Assess quickly: appearance, speech and voice, breathing, pulse and blood pressure.
3. Anaphylaxis: lay the patient flat, or with legs slightly raised; let them sit with legs out only if breathing is the main problem; do not let them stand or walk. Adrenaline is the first-line treatment, given by staff trained to use it under your protocol.
4. If the patient becomes unresponsive and is not breathing normally, start CPR (see Arrest).
5. Mild allergic-like reactions: observe the patient for at least 20 to 30 minutes.
6. Record the reaction and its treatment in the report and the patient’s record, and report it through your incident system.

Where sources differ

Product information differs by region. EU and Canada: monitor patients closely for at least 30 minutes after the injection, and the agent is contraindicated in known right-to-left shunts, severe pulmonary hypertension, uncontrolled hypertension and ARDS. USA: the label says most serious reactions occur within 30 minutes and to monitor all patients; the shunt contraindication has been removed. New Zealand and Australian product information was not read for this page; follow your local data sheet.

Good to know

Before injecting: ask about previous reactions to contrast agents and to PEG-containing products such as some bowel preparations and laxatives; have resuscitation equipment and trained staff readily available. Beta blockers, including eye drops, may make emergency treatment less effective.

Sources: ACR Contrast Media 2026; WFUMB/EFSUMB Liver CEUS 2020; ASE PEG 2021; SonoVue SmPC; Lumason PI; SonoVue Canada 2021; ASCIA 2026; AIUM Contrast 2021

What you see

The patient feels faint, light-headed, weak or sick, goes pale, or their vision greys, for example during an internal examination or a needle procedure, or when getting up.

Why it happens

A vasovagal episode slows the heart and widens blood vessels, often after pain or emotional stress. It usually settles lying down. Persistent or recurring symptoms can mean a more serious illness, and after contrast it can be the start of a reaction.

Do this now

1. Stop the scan, lie the patient down if possible, and ask them to tense their leg, arm and stomach muscles, cross their legs or grip their hands; raising the legs may help.
2. If they fainted or fell, check for injuries.
3. If symptoms do not settle, call for help through your emergency process; if contrast was given, go to Contrast reaction.
4. Unresponsive and not breathing normally: start CPR (see Arrest).
5. Before they stand, sit them up slowly and stay with them; record the episode (a general step).

Sources: ANZCOR Guideline 9.2.13 2023; SonoVue SmPC; ANZCOR Guideline 8 2021

What you see

A patient falls, slips or is lowered to the floor while getting on or off the couch, turning, sitting up after a scan, or walking in the department.

Why it happens

Falls happen in imaging departments, and most patients who fall have at least one risk factor; some are injured. No ultrasound-specific falls data were found.

Do this now

1. Call for help, stay with the patient and check whether they are hurt; get a doctor to assess them (a general step; follow your falls procedure).
2. Do not lift the patient alone: use the handling aids and the number of staff your assessment calls for.
3. Record the fall and report it through your incident process, and follow up as your policy requires.

Good to know

Prevention: assess each patient’s fall risk under your policy, lower the couch before they get on or off, help patients sit up slowly after lying flat, and keep the floor clear of cables and gel (a general step).

Sources: CAMRT BPG Falls; Abujudeh 2011

What you see

You notice a cracked housing or lens, exposed wiring or a damaged cable on a probe that has been in contact with a patient; the patient reports a tingle, a shock or heat from the probe; or an internal probe feels hot.

Why it happens

A damaged probe may be an electrical or infection hazard, especially if gel or fluid can get inside. Probes have been recalled for inadequate protection against electric shock. Contact surfaces are designed to stay within temperature limits, and an internal probe that self-heats noticeably in air is not used.

Do this now

1. Stop scanning and remove the probe from the patient.
2. Check the patient and the skin or mucosa in contact, and ask for a medical review if they report a shock, burn or pain (a general step).
3. Take the probe out of use and label it. Equipment sent for repair is cleaned first and goes with a decontamination certificate.
4. Report it to the person responsible and through your incident system; your organisation reports device incidents to the regulator as required.
5. The probe has electrical safety testing and inspection before it is used again.

Sources: SoR/BMUS 2025; BMUS QA 2014; AAA QA 2025; FDA recall Z-0816-2018; BMUS Guidelines 2009; NHS Scotland 2017; MHRA MDA/2012/037; SDMS Reprocessing 2022

What you see

The patient is unresponsive and not breathing normally, or only gasping.

Do this now

1. Call the resuscitation team on your emergency number.
2. Start chest compressions at once: CPR is started for anyone unresponsive and not breathing normally, even with occasional gasps. Staff trained and willing to give rescue breaths do so.
3. Attach a defibrillator or AED as soon as it arrives and follow its prompts. Minimise pauses in compressions.
4. Move the scanner out of the team’s way.
5. Afterwards, record the times and events and report the incident.

Sources: ANZCOR Guideline 8 2021; SDMS Scope 2024

What you see

You find that the person scanned was not the patient on the request, the wrong side or examination was scanned, or images or a report were stored under the wrong patient.

Do this now

1. Stop, check on the patients involved and confirm who each one is.
2. Tell the reporting practitioner now, so that no report is issued on the wrong patient and any urgent finding reaches the right person.
3. Keep the images; do not delete anything. Correct the records through your authorised correction process.
4. Report it through your incident system. The referrer and the patient are told what happened under your open disclosure or duty of candour policy.
5. Rebook the correct examination for the right patient.

Sources: CIB US Patient ID 2016; SoR Patient ID 2025; SoR/BMUS 2025; HDC Open Disclosure 2019; ACSQHC CT/MRI protocol

What you see

The scan shows something that may need action within hours, for example a suspected ectopic pregnancy, testicular or ovarian torsion, aortic rupture or impending rupture, deep vein thrombosis, placental abruption or fetal demise.

Why it happens

Critical findings lose their value if the result waits for the routine report. Guidelines expect direct, documented communication to the person responsible for the patient’s care.

Do this now

1. Tell the reporting radiologist or sonologist, or the most responsible clinician, straight away and directly (in person or by phone), and get acknowledgement.
2. Keep the patient in the department, under supervision, until a clinician has been consulted; tell the patient that the images are being reviewed and that they will be directed to follow-up, without giving a diagnosis beyond your role.
3. If the responsible clinician cannot be reached, follow your escalation route; one Canadian guideline says to transfer the patient to an emergency department.
4. Record the finding, who you told, how, and when.

Where sources differ

The ACR (USA) says the interpreting physician may tell the patient directly if the referrer cannot be reached promptly. ASUM (Australia and New Zealand) asks the sonologist to make every reasonable attempt to reach the referrer, record actual and attempted contact, and coordinate care if the referrer cannot be reached. In the UK, the referrer or clinical team is considered best placed to tell the patient about alert findings.

Good to know

The UK intercollegiate alert list includes ectopic pregnancy, placental abruption or praevia, uterine rupture, fetal demise, testicular or ovarian torsion, aortic rupture or suspected impending rupture and deep vein thrombosis; it is not definitive and can be adapted locally.

Sources: AoMRC Alerts 2022; ACR Communication 2025; CAR Communication 2010; CAMRT BPG Critical; ASUM Parent-centred 2022; SDMS Scope 2024; SoR/BMUS 2025