Single vs. Multiphase Computed Tomography angiography in acute internal carotid artery occlusion: An accuracy and interobserver agreement study

Objective: Accurate differentiation between the intracranial and extracranial location of the acute internal carotid artery (ICA) occlusion is essential for guiding treatment decisions and mechanical thrombectomy planning. Multiphase Computed Tomography angiography (mCTA) appears to be superior to Single-phase Computed Tomography angiography (sCTA) in the evaluation of acute ICA occlusions. The main objective of our research is to study the accuracy of mCTA compared to sCTA in distinguishing isolated acute intracranial ICA occlusion from extracranial or tandem occlusion.Methods: Two observers independently analyzed sCTA and mCTA of patients with acute ICA occlusion at two different time points. The location of the occlusion was categorized as intracranial or extracranial for both imaging techniques and then compared with digital subtraction angiography (gold standard). Sensitivity and specificity rates for isolated intracranial ICA occlusion on sCTA and mCTA were calculated. Kappa statistics were used to assess interobserver agreement.Results: The sensitivity of sCTA and mCTA was 48.28% (28.36%-68.19%) and 79.31% (62.84%-95.78%) respectively for the diagnosis of isolated intracranial ICA occlusion, with an almost perfect interobserver agreement between both observers (p < 0.001). Conclusions: Our research suggests that mCTA is more accurate than sCTA in distinguishing isolated intracranial occlusions from extracranial or tandem occlusions.