Operational definitions improve reliability of the age-related white matter changes scale

Area of Science:

• Neuroradiology
• Medical Imaging Analysis

Background:

• The age-related white matter changes (ARWMC) scale assesses white matter changes (WMC) severity on MRI and CT.
• Current inter-rater reliability of the ARWMC scale on CT is only fair.

Purpose of the Study:

• To operationalize the ARWMC scale for improved reliability and validity.
• To assess the impact of operationalization on ARWMC scale performance on MRI and CT.

Main Methods:

• Developed operational definitions for the ARWMC scale based on existing research criteria.
• Eight observers rated WMC using both original and operationalized ARWMC scales on MRI and CT data from 97 stroke patients.
• Evaluated inter-rater and intrarater reliability and validity against WMC volume.

Main Results:

• Operationalized ARWMC scale significantly improved inter-rater reliability on CT (0.874) compared to the original scale (0.569).
• Reliability of the operationalized scale on MRI and intrarater reliability on CT were comparable to the original scale.
• Administration time for the operationalized scale was similar to the original scale.
• Both scales demonstrated significant correlation with WMC volume.

Conclusions:

• Operational definitions enhance the inter-rater reliability of the ARWMC scale on CT.
• The operationalized ARWMC scale maintains good reliability and validity, correlating with volumetric measurements.