Practical tips in Clinical Sonography

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Tricks of the trade that turn your ok images into amazing images
  1. Small movements – If you get lost, STOP & THINK about the anatomy, probe orientation and angles before SLOWLY readjusting your probe. Access deep organs from different surface vantage points of patient
  2. Depth, Zoom and Sector size – Chop out the bits which you aren’t interested in and always make sure the bit you are looking at is as big as possible to maximise image definition. Think of the area-of-interest, not a pretty panoramic view
  3. Optimise Gain – Any structures which are expected to be fluid-filled should be black e.g. vessels, heart chamber, bladder, renal collecting system
  4. Slide and Fan or Rotate – If you aren’t sure it is an artifact, take an image from different angles or contact point. If it remains, it’s for real
  5. DDx also exist in ultrasound – for any given appearance there is usually several possibilities – know them and how you would differentiate them
  6. Patient manoeuvres – If you can’t find what you need to or the image is poor change the patient’s position (including standing or semi-prone) or try breathing manoeuvres e.g. held inspiration/expiration, Valsalva etc
  7. Maintain contact – Adequate gel and increasing probe pressure can often improve poor images
  8. Air is your enemy (unless doing lung ultrasound) – Progressively push bowel gas away with your probe, move lung away with breathing manoeuvres or altering patient position
  9. Optimise acoustic windows e.g full bladder for uterus, liver windows for subcostal heart, standoffs for superficial structures
  10. Define structures properly – Slide, Fan and Rotate through large organs, Rotate to differentiate (spherical structures) e.g. cysts from (tubular structures) e.g. vessels
  11. Angles are extremely important in MSK/Nerve ultrasound – Probe surface should run as close to parallel to muscle fibres, ligaments and nerves due to anisotropy
  12. Get probe stability – Steady the blade of your probe hand against the patient, ‘lean’ the edge of the probe on ribs and bony protuberances whilst fanning, use both hands when rotating probe over small region
  13. 2D before doppler – ensure your 2D/B-mode image is optimised (see above) before turning on any doppler settings
  14. Use colour to differentiate vessels from ducts
  15. Be meticulous with probe handling when using doppler – absolute probe stability and elimination of patient movement is required when using doppler
  16. Accurate doppler (especially spectral) needs images with flow directly towards or away from probe and definitely never at right angles to this
  17. Optimal colour gain – just before background speckle occurs
  18. Understand Pulse Repetition Frequency – Before measuring flow consider the expected velocity of the moving medium (high PRF = fast, low PRF = slow)
  19. Remember BART – Blue is flow Away, Red is flow Toward (not artery versus vein)
  20. Recognise aliasing – Blue<>Yellow<>Red = normal flow reversal, Blue<>Red = aliasing (need to increase PRF)

1 thought on “Practical tips in Clinical Sonography

  1. sk

    Very very helpful tips Derek.
    we tend to ignore these subtle but very useful techniques when we set out learning u/s and find ourselves in world of pain.

    Reply

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