Lamina terminalis: Radiological analysis with a proposed anatomical classification

Area of Science:

• Neurosurgery
• Radiology
• Neuroanatomy

Background:

• The lamina terminalis (LT) is a critical anatomical landmark in neurosurgery, forming the anterior wall of the third ventricle.
• Radiological characterization of the LT is limited, hindering its clinical application.

Purpose of the Study:

• To evaluate the radiological dimensions of the lamina terminalis (LT).
• To propose a novel classification system for LT angulation.
• To investigate associations between LT morphology and optic chiasm position.

Main Methods:

• Retrospective analysis of 160 adult brain MRIs (1.5 Tesla).
• Measurements included LT length, width, angle, LT-AComA distance, and optic chiasm position.
• Two blinded observers performed measurements; SPSS v25.0 used for analysis (P < 0.05).

Main Results:

• The LT exhibited a mean length of 10.7 mm and width of 3.75 mm.
• A novel LT angulation classification (Type 1: <100°, Type 2: 100°-110°, Type 3: >110°) was proposed; Type 2 was most common (47.5%).
• LT angulation showed a significant association with optic chiasm position (P=0.015).

Conclusions:

• The lamina terminalis (LT) is morphologically diverse with significant individual variability in its radiological parameters.
• LT angulation variations are significantly associated with optic chiasm position.
• These findings provide valuable anatomical insights for neurosurgical planning and interventions.