Is there a sonographer effect? Sonographer as a source of variability for Shear Wave Elastography

Area of Science:

• Medical Imaging
• Diagnostic Ultrasound

Background:

• Shear Wave Elastography (SWE) is a non-invasive ultrasound technique used to assess tissue stiffness.
• Variability in SWE measurements can impact diagnostic accuracy and clinical decision-making.

Purpose of the Study:

• To quantify the contribution of sonographer variability to systematic variance in SWE measurements.
• To assess the impact of inter-sonographer differences on the reliability of SWE values.

Main Methods:

• Two studies employed a block design with six trained sonographers scanning six healthy liver volunteers.
• Standardized procedures and the same ultrasound machine were used for all measurements.
• Each sonographer performed ten SWE measurements per volunteer in the right liver lobe.

Main Results:

• Intraclass correlation coefficients (ICC) varied significantly based on scanning day (0.23 vs. 0.83).
• Sonographer differences accounted for 17% of the total variability in SWE measurements.
• Statistically significant differences in SWE values were observed between sonographers, approaching clinical thresholds.

Conclusions:

• Sonographer performance is a significant factor influencing SWE values.
• Standardization of SWE protocols is essential to minimize inter-sonographer variability.
• The inherent variability may challenge the clinical utility of established SWE thresholds.