The technique shown in the video is compression. In ultrasound imaging-especially of soft tissue masses, the bowel, or venous structures-compression is used to evaluate the compressibility of structures. The image demonstrates a classic grayscale ultrasound view of a lesion or structure being compressed with the probe.
Compression sonography is particularly important in:
* Evaluating venous patency (e.g., for deep vein thrombosis)
* Differentiating cystic from solid structures
* Evaluating bowel wall abnormalities or intussusception
* Assessing lymph nodes and soft tissue masses (as shown here)
When a structure compresses easily under probe pressure, it suggests that the lesion is fluid-filled or soft. In contrast, incompressibility may indicate a solid mass or thrombus.
Differentiation from other options:
* B. Valsalva: Involves forced expiration against a closed airway, used primarily to assess venous reflux or inguinal hernias-not what is demonstrated here.
* C. Exhalation: A respiratory maneuver that passively alters thoracoabdominal pressure, not actively performed by the operator or causing focal structural change.
* D. Deep inspiration: Used to improve visualization of the liver, diaphragm, or gallbladder-not to evaluate the compressibility of soft tissue.
References:
Rumack CM, Wilson SR, Charboneau JW, Levine D. Diagnostic Ultrasound. 5th Edition. Elsevier, 2018.
Chapter: Ultrasound Technique and Physics, pp. 35-39.
AIUM Practice Parameter for the Performance of a Diagnostic Ultrasound Examination, 2020.