Computer-Aided Analysis of Orbital Volume

A Novel Technique

Abstract

Objective: 

To demonstrate the accuracy and efficiency of a novel software tool designed specifically for volumetric analysis of the orbit.

Methods: 

The software was evaluated for accuracy and speed in analysis of orbital CT data sets. The analysis included: 1) intraoperator error: one operator repeatedly evaluated a single orbit multiple times. The variation in volumes was compared; 2) interoperator error: 3 operators evaluated the same orbits multiple times. The variation in volume measurements among operators was compared; 3) interscan error: one operator evaluated the volume of single orbit scanned on multiple occasions by different CT scanners. The variation in volume measurements among scans performed at different times was compared; and 4) time for analysis: one operator evaluated 52 orbits, recording the time it took to analyze each orbit.

Results: 

Intraoperator error was 0.08 cc (95% confidence interval, 0.06–0.10). Interoperator error was 0.18 cc (95% confidence interval, 0.14–0.20). Interscan variability data showed a trend toward increasing error for repeated patient scans using different CT scanners. Average time for analysis of single orbit was 138 seconds (standard deviation = 24; range, 95–217 seconds).

Conclusions: 

Maxillo is an accurate and efficient tool for semiautomatic evaluation of orbital volume in nontraumatized orbits.