Interrater Agreement and Detection Accuracy for Medium-Vessel Occlusions Using Single-Phase and Multiphase CT...

Area of Science:

• Neuroradiology
• Vascular Imaging
• Stroke Diagnosis

Background:

• Accurate detection of medium-vessel occlusions is crucial for acute ischemic stroke diagnosis and treatment.
• Medium-vessel occlusions present detection challenges, particularly for less experienced readers.
• Computed Tomography Angiography (CTA) is a key imaging modality for stroke assessment.

Purpose of the Study:

• To evaluate the accuracy and interrater agreement of detecting medium-vessel occlusions.
• To compare the performance of single-phase CTA versus multiphase CTA for this detection.
• To assess the impact of reader experience on detection accuracy.

Main Methods:

• Retrospective analysis of 120 acute ischemic stroke patient CTAs (single-phase and multiphase).
• Three readers with varying experience levels assessed occlusions (no occlusion, large-vessel, medium-vessel).
• Interrater agreement calculated using Fleiss κ; accuracy determined via classification tables.

Main Results:

• Interrater agreement for occlusion type improved from moderate (κ=0.58) with single-phase CTA to almost perfect (κ=0.81) with multiphase CTA.
• Accuracy for medium-vessel occlusion detection increased substantially: 57-61% with single-phase CTA to 86-89% with multiphase CTA.
• Interrater agreement for detailed occlusion sites was also higher with multiphase CTA (κ=0.71) vs. single-phase CTA (κ=0.55).

Conclusions:

• Multiphase CTA demonstrates significantly higher accuracy and interrater agreement for medium-vessel occlusion detection compared to single-phase CTA.
• Multiphase CTA is a valuable tool for improving the assessment of medium-vessel occlusion stroke.
• The findings suggest a potential improvement in stroke diagnosis and treatment initiation.