Anatomical variations of the anterior cerebral arterial circle visualized by multidetector computed tomography angiography: Comparison with 3D rotational angiography

Exploring the anatomical configurations of the cerebral arteries in a cohort of South African patients

The cerebral arteries, specifically the anterior cerebral artery (ACA) and posterior cerebral artery (PCA), work together with the smaller calibre arteries to provide effective communication between the anterior and posterior circuits of the brain via the circle of Willis (CoW). Morphologic variations of the cerebral arteries and the CoW may alter blood flow to the brain, resulting in intracranial vascular disorders associated with stroke, and aneurysms. This study aimed to document the morphology of the cerebral arteries and the CoW in the South African population. Two hundred and thirty-nine computed tomography angiography scans were assessed. Cerebral arteries and CoW normal morphology and variations were classified as complete, absent, or hypoplastic. The ACA A1 was absent in 4.91%, hypoplastic in 30.40%, fenestrated in 1.06%, and typical in 63.6%. The ACA A2 was absent in 0.42%, hypoplastic in 26.28%, and typical in 69.44%. We found triple ACA A2 in 2.98%, azygos in 1.28% and fenestrated in 1.28%. The middle cerebral artery (MCA) was hypoplastic in 7.35% and typical in 92.64%. The PCA was hypoplastic in 28.74% and typical in 71.25%. Knowledge of the configuration of the CoW plays a significant role in guiding therapeutic decision-making in treating various neurovascular pathologies.

The study of fetal-type posterior cerebral circulation on multislice CT angiography and its influence on cerebral ischemic strokes

PURPOSE

The purpose was to evaluate if patients with partial and full fetal-type posterior cerebral artery (PCA) could be more prone to lead to ischemic strokes on multislice computed tomographic angiography (MSCTA).

METHODS

A total of 202 patients who had undergone MSCTA examinations were divided into three groups: patients with full fetal-type posterior (FTP), patients with partial FTP, and patients without FTP. The odds ratio of having ischemic strokes was calculated.

RESULTS

The odds of having ischemic strokes in patients with full and partial FTP were 1.448 and 3.027, while P values were .391 and .0307, respectively.

CONCLUSION

Patients with a partial fetal-type PCA could be more prone to develop ischemic strokes.

Computed anatomical modelling of the optic pathway and oculomotor system using magnetic resonance imaging

This study presents a computer-based tool for three-dimensional (3D) visualization of the optic pathway and oculomotor system using 3D high-resolution magnetic resonance imaging (MRI) datasets from a healthy subject. The 3D models were built as wireframe grids co-registered with MRI sections. First, 3D anatomical models were generated of the visual pathway from the eyeball to the primary visual cortex and of the cranial oculomotor nerves from the brain stem to the extrinsic eye muscles. Second, a graphical user interface allowed individual and group visualization, translation, rotation and zooming of the 3D models in different spatial positions simultaneously with MRI orthogonal cut planes. Educational and clinical applications are also discussed.