Morphometric analysis of normal and variant anatomy of posterior cerebral artery and the incidence of fetal posterior cerebral artery in Uttar Pradesh region: A computed tomography angiographic study

Introduction: The aim is to study morphometric analysis of normal and variant anatomy of posterior cerebral artery (PCA) and incidence of fetal PCA (FPCA) in Uttar Pradesh region. The PCA and its cortical branches supply blood to the occipital lobe, inferomedial temporal lobe, and portions of posterior inferior parietal lobe. Fetal-type PCA is a common anatomic variation of PCA that is closely associated with intracranial aneurysm. The present study provides the description of PCA regarding its normal morphology, morphometry, and variations in Uttar Pradesh region. Material and Methods: The study evaluated 100 computed tomography angiograms. Results: Among arteries that displayed normal anatomy, mean diameter of PCA was observed to be 4.29 ± 0.74 mm on the right side and 2.47 ± 0.74 mm on the left side. Mean diameter in males and in females was found to be 2.48 ± 0.73 mm and 2.47 ± 0.74 mm, respectively. In 56.5% of cases, the diameters of P1 segment of PCAs ranged from 2.1 to 3 mm whereas >3 mm diameter was observed in 18.5% cases. Nineteen percent cases showed 1.1–2 mm. In 6% cases, hypoplasia (≤1 mm) of PCA was observed. FPCA was observed in 26% cases. Unilateral observed in 17% cases and bilateral in 9% cases and the difference was statistically significant (P < 0.000). Discussion and Conclusion: Anomalies of PCA may assume considerable significance in surgeries of head and neck, which require ligation of internal carotid and common carotid artery. Awareness of these anatomical variations described shall prove to be useful for any cerebrovascular procedures.