Accuracy, repeatability, and reproducibility of Artemis very high-frequency digital ultrasound arc-scan lateral dimension measurements

Purpose

To determine the accuracy, repeatability, and reproducibility of measurement of lateral dimensions using the Artemis (Ultralink LLC) very high-frequency (VHF) digital ultrasound (US) arc scanner.

Setting

London Vision Clinic, London, United Kingdom.

Methods

A test object was measured first with a micrometer and then with the Artemis arc scanner. Five sets of 10 consecutive B-scans of the test object were performed with the scanner. The test object was removed from the system between each scan set. One expert observer and one newly trained observer separately measured the lateral dimension of the test object. Two-factor analysis of variance was performed. The accuracy was calculated as the average bias of the scan set averages. The repeatability and reproducibility coefficients were calculated. The coefficient of variation (CV) was calculated for repeatability and reproducibility.

Results

The test object was measured to be 10.80 mm wide. The mean lateral dimension bias was 0.00 mm. The repeatability coefficient was 0.114 mm. The reproducibility coefficient was 0.026 mm. The repeatability CV was 0.38%, and the reproducibility CV was 0.09%. There was no statistically significant variation between observers (P = .0965). There was a statistically significant variation between scan sets (P = .0036) attributed to minor vertical changes in the alignment of the test object between consecutive scan sets.

Conclusion

The Artemis VHF digital US arc scanner obtained accurate, repeatable, and reproducible measurements of lateral dimensions of the size commonly found in the anterior segment.