Question bank
Test yourself.
Short tests on each Wavelength Pearl. Read the pearl, then check what stuck. Every answer comes with an explanation.
Soft tissue
Abscess: make it swirl
An abscess can look grey and solid on a still image. Press gently with the probe. If the contents swirl, it is fluid. Then check colour Doppler before anyone reaches for a needle.
Lung
Consolidation: watch the air bronchograms move
Bright dots in consolidated lung are air in the airways. If they move outwards as the patient breathes in, the airway is open and pneumonia is likely. If they stay still, think about collapse.
Vascular
DVT: compress, don't admire
Fresh clot is often black on screen, so a vein full of thrombus looks like a normal vein. The test is whether the walls meet when you press, in transverse, at every site.
eFAST
eFAST: look at the liver tip first
In the supine patient, free fluid in the right upper quadrant often collects first at the inferior tip of the liver. Scan the whole view, not just Morison's pouch.
Abdomen
Gallbladder: follow the main lobar fissure
Can't find the gallbladder? Find the portal vein, then follow the bright line running from it. The main lobar fissure leads straight to the gallbladder neck.
Abdomen
Gastric POCUS: empty, fluid or solid?
Before sedation, one view of the gastric antrum tells you whether the stomach is empty, holds clear fluid, or holds solid food. Answer that question first.
Renal
Hydronephrosis: black that branches
True hydronephrosis forms connected, branching black spaces running from the renal pelvis into the calyces. Cysts stay round and separate. Sweep the whole kidney before you decide.
Core skills
Five checks before every scan
Probe, preset, depth, gain and focus. Thirty seconds of set-up decides whether the image answers your question.
Lung
Lung: absent sliding is not enough
No sliding means look harder, not pneumothorax. B-lines or a lung pulse rule it out under the probe, and a lung point rules it in.
Lung
Pleural effusion: find the spine above the diaphragm
In a normal scan the spine stops at the diaphragm, because air-filled lung hides it. When fluid fills the base, the spine carries on above the diaphragm. Add black fluid and you have an effusion.
Cardiac
Portal vein pulsatility: a congestion clue
Portal vein flow is normally steady. When pressure backs up from the right heart, it starts to pulse. Read it alongside the IVC, hepatic veins and kidneys, not on its own.
MSK
Shoulder: one posterior view, before and after reduction
Put the probe below the scapular spine and the glenoid and humeral head sit side by side. Where the head lies in relation to the glenoid tells you if the shoulder is out, which way, and if it has gone back in.
Abdomen
Small bowel obstruction: follow the to-and-fro
Dilated, fluid-filled small bowel with contents moving back and forth without getting anywhere suggests mechanical obstruction. Follow the dilated loops until they collapse to find the transition point.
MSK
Tendon tear or anisotropy? Heel-toe before you call it
A normal tendon turns dark when the beam hits it at an angle. Rock the probe until the fibres brighten. If the dark area stays, think tear.
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