Craniometric points in neurosurgery: When anatomy is the best imaging guidance system

Abstract

The anatomy of both the skull and the brain offers many landmarks that could help surgery. The craniometric points were described a long time ago, depicting precisely the position of underlying neurological structures: sulci, gyri, white matter fasciculi, deep gray nuclei, ventricles [1], [2], [3], [4]. Advances in technology have brought imaging guidance systems, also called neuro-navigation, that give the real-time intra-operative position of the surgical instruments. Though the imaging guidance can be inaccurate or even wrong, the anatomical knowledge of such craniometry is disappearing. In this work, we summarize all craniometric points and their relative brain components to renew their interest in modern cranial surgery. Craniometric points were collected through a scientific literature review. Specimens were prepared at the anatomy lab of Pittsburgh, and pictures were taken to expose skull and brain from lateral, superior, posterior, and “operative” views. A high-definition camera (EOS E700; Canon, Tokyo, Japan) was used with specific settings. Then, pictures were modified (Adobe Photoshop, Adobe Systems, San Jose, CA) to allow the superimposition of landmarks and neurological structures. From various views, 16 craniometric points were depicted: anterior and superior squamous point; pre- and retro-coronal point; superior sagittal point; intraparietal point; superior temporal point; pre-auricular point; nasion; bregma; stephanion; euryon; lambda; asterion; opistocranion; and inion. Each of these led to underlying landmarks and brain components: anterior and posterior sylvian point; superior and inferior rolandic point; supramarginal gyrus; lingual gyrus; Heschl's gyrus; parieto-occipital fissure; meeting point between inferior frontal and pre-central sulcus, superior frontal and pre-central sulcus, intraparietal and post-central sulcus. A comprehensive knowledge of 16 craniometric points and their related brain structures could be a useful tool for any neurosurgeon who wants a double-check of his/her surgical progression, in addition to imaging guidance and a mental map of the surrounding anatomical environment.