Sources of variability in carotid duplex examination: a prospective study

Area of Science:

• Vascular Ultrasound
• Medical Imaging
• Diagnostic Accuracy

Background:

• Carotid artery ultrasound is crucial for stroke risk assessment.
• Variability in interpretation can impact clinical decisions.

Purpose of the Study:

• To assess interobserver and intraobserver variability in carotid artery duplex examinations.
• To identify sources of variability in waveform acquisition and disease classification.

Main Methods:

• Prospective, randomized, blinded clinical trial.
• 48 patients underwent 96 carotid artery examinations by two technologists.
• Kappa statistic used to quantify agreement.

Main Results:

• Interobserver agreement for overall examination was moderate (kappa = 0.476).
• Variability noted in waveform acquisition (kappa = 0.536) and disease classification (kappa = 0.609).
• Intraobserver agreement for waveform rereading was high (kappa = 0.842, 0.894).

Conclusions:

• Moderate interobserver variability exists in carotid duplex examinations, particularly for minimal to moderate disease.
• Standardizing recognition of disturbed flow patterns may reduce variability.