Transcranial Doppler (TCD) ultrasonography typically visualizes the posterior cerebral arteries (PCAs) through the transtemporal window, while the basilar and vertebral arteries are assessed via the suboccipital approach. This report describes an unusual technical finding: visualization of PCA flow through the suboccipital window. During routine TCD in a patient with excellent acoustic access, two vascular structures arising from the distal basilar artery were identified at a depth of 92 mm, with flow characteristics consistent with PCAs. Favorable bone transmission and vascular alignment likely enabled this alternative insonation route. This observation suggests that, in exceptional anatomical conditions, suboccipital PCA assessment is feasible and may expand posterior circulation evaluation.



