Evaluation of Inter-System Variability in Liver Stiffness Measurements

Area of Science:

• Hepatology
• Medical Imaging
• Diagnostic Technologies

Background:

• Liver stiffness measurements (LSMs) are crucial for assessing liver fibrosis.
• Variability in LSMs across different ultrasound (US) systems and observers can impact clinical decisions.
• Standardization of LSMs is essential for accurate diagnosis and patient management.

Purpose of the Study:

• To evaluate the inter-system variability of liver stiffness measurements (LSMs) using various ultrasound (US) systems.
• To assess the inter-observer variability of LSMs in patients with chronic hepatitis C.
• To compare the performance of point shear wave elastography (p-SWE) and 2D shear wave elastography (2D-SWE) systems.

Main Methods:

• Prospective enrollment of 21 patients with chronic hepatitis C and 5 healthy individuals.
• LSMs were performed using six US systems (four p-SWE, two 2D-SWE), with Fibroscan as the reference standard.
• Four observers conducted paired measurements, analyzed using Lin's concordance correlation coefficient and Bland-Altman limits of agreement.

Main Results:

• Agreement above 0.80 was observed for all pairs of US systems.
• Mean difference between 2D-SWE systems was 1.54 kPa; maximum mean difference for p-SWE systems was 0.79 kPa.
• Intra-patient concordance was 0.89, and inter-observer agreement ranged from 0.93 to 0.96.

Conclusions:

• Good to excellent agreement exists between different US systems for LSMs.
• High inter-observer agreement (above 0.90) was achieved under expert conditions.
• These findings support the reliability of LSMs across multiple devices and experienced clinicians.