Cortical and Subcortical Brain Atrophy Assessment Using Simple Measures on NCCT Compared with MRI in Acute Stroke

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Brain atrophy is a key indicator of brain reserve and the brain's ability to withstand injury, such as stroke.
• The reliability of non-contrast CT (NCCT) for measuring brain atrophy compared to MR imaging is not well-established.

Purpose of the Study:

• To compare pragmatic brain atrophy measurements on NCCT with MR imaging in acute ischemic stroke patients.
• To evaluate the agreement and correlation of cortical and subcortical atrophy assessments between NCCT and MR imaging.

Main Methods:

• Post hoc analysis of NCCT and 24-hour MR imaging data from the ESCAPE-NA1 trial.
• Cortical atrophy measured using the global cortical atrophy scale; subcortical atrophy measured using the intercaudate distance-to-inner-table width (CC/IT) ratio.
• Agreement calculated using Gwet's agreement coefficient 1; correlation calculated using Pearson correlation coefficients.

Main Results:

• NCCT underestimated cortical atrophy severity compared to MR imaging (23.8% vs. 44.3%).
• Cortical atrophy assessments on NCCT demonstrated substantial agreement with MR imaging (Gwet's coefficient > 0.784).
• Subcortical atrophy measures (CC/IT ratio) showed strong correlations between NCCT and MR imaging (Pearson correlation = 0.746).

Conclusions:

• Simple measures on emergent NCCT can evaluate brain atrophy.
• NCCT is a viable tool for assessing subcortical atrophy with strong correlation to MR imaging.
• While NCCT cortical atrophy measures correlate well with MR imaging, they tend to underestimate severity.