Styloid process morphology in extracranial internal carotid artery dissection: a CTA case-control study

Area of Science:

• Radiology
• Neuroradiology
• Vascular Imaging

Background:

• Extracranial internal carotid artery dissection (ICAD) is a significant cause of stroke.
• The association between styloid process (SP) morphology and ICAD is not well understood.
• Computed tomography angiography (CTA) is a key imaging modality for evaluating head and neck vasculature.

Purpose of the Study:

• To investigate the relationship between styloid process (SP) morphology visualized on CTA and the occurrence of extracranial internal carotid artery dissection (ICAD).
• To determine if specific SP morphologic features are independently associated with ICAD.
• To assess the diagnostic performance of CTA-derived SP measurements in identifying patients at risk for ICAD.

Main Methods:

• A retrospective case-control study involving 85 patients with unilateral extracranial ICAD and 85 matched controls.
• Head and neck CTA was performed for all participants.
• Measurements included SP length, SP tip to internal carotid artery (SPT-ICA) distance, and SP orientation (medial and anterior inclination angles).
• Statistical analyses included group comparisons, multivariable logistic regression, and receiver operating characteristic (ROC) analysis.

Main Results:

• Patients with ICAD exhibited a significantly longer SP, shorter SPT-ICA distance, and smaller anterior inclination angle compared to controls (p < 0.001).
• SP length, SPT-ICA distance, and anterior inclination angle were identified as independent predictors of ICAD.
• A combined model incorporating these three SP morphologic features demonstrated the highest diagnostic performance (AUC = 0.836).

Conclusions:

• CTA-derived styloid process (SP) morphologic features, including length, SPT-ICA distance, and anterior inclination angle, are significantly associated with extracranial internal carotid artery dissection (ICAD).
• A combined model utilizing these SP features offers robust diagnostic performance for identifying an anatomic pattern linked to ICAD.
• These findings suggest that SP morphology on CTA may serve as a valuable biomarker for assessing ICAD risk.