Entorhinal cortex volume in older adults: reliability and validity considerations for three published measurement...

Area of Science:

• Neuroimaging and Cognitive Neuroscience
• Brain Anatomy and Function

Background:

• Accurate measurement of the entorhinal cortex (ERC) is crucial for understanding memory and aging.
• Distinguishing the ERC from the adjacent perirhinal cortex presents a significant methodological challenge.

Purpose of the Study:

• To evaluate the reliability and validity of three different protocols for measuring the entorhinal cortex (ERC).
• To assess how variations in lateral boundary definitions impact ERC measurement and its association with verbal memory.

Main Methods:

• Volumetric magnetic resonance imaging (MRI) scans from 39 healthy older adults were analyzed.
• Three distinct ERC measurement protocols (Goncharova, Honeycutt, Insausti) with varying lateral boundary criteria were applied.
• Inter-rater and intra-rater reliability were assessed, alongside the correlation between ERC volume and verbal memory scores.

Main Results:

• Two ERC measurement protocols (Goncharova, Honeycutt) demonstrated moderate to strong inter-rater reliability.
• The Insausti protocol showed negligible to moderate reliability, potentially due to its reliance on collateral sulcal depth.
• Left ERC volume, measured using Insausti and Goncharova protocols, showed a moderate positive association with story memory, even after controlling for depression.

Conclusions:

• The choice of ERC measurement protocol, particularly its lateral boundary definition, significantly impacts reliability and structure-function associations.
• Protocols with clearly defined lateral endpoints (Goncharova, Honeycutt) offer better reliability for ERC volumetry.
• Researchers should carefully consider rater training and protocol selection when measuring the ERC for cognitive studies.