Satoshi Tsutsumi1, Hideo Ono2, Yukimasa Yasumoto3. 1. Department of Neurological Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan. shotaro@juntendo-urayasu.jp. 2. Division of Radiological Technology, Medical Satellite Yaesu Clinic, Tokyo, Japan. 3. Department of Neurological Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
Abstract
PURPOSE: The chiasmatic recess (CR) is a small, downward extension in the most rostral third ventricle. Few studies have highlighted its morphology. Accordingly, we explored the CR using magnetic resonance imaging. METHODS: A total of 104 patients were enrolled in this study. Magnetic resonance imaging examinations were performed in axial and sagittal sections. Imaging data were obtained as thin-sliced, seamless sections. RESULTS: The CR was clearly identified in 98 % of axial and 96 % of sagittal sections. The lamina terminalis was delineated as a membranous structure with homogenous thickness. The CR was consistently delineated as a smoothly tapering, cerebrospinal fluid-filled space. The number of axial images required to encompass the entire CR was 1 slice for 1.9 % of samples, 2 for 32.7 %, 3 for 49 %, 4 for 12.5 %, 5 for 1 %, and 6 for 1 %. On axial view, the CR generally presented as a long horizontal ellipse. On sagittal view, the CR showed variable shape and length. The optic chiasm-lamina terminalis angle, formed by the upper surface of the optic chiasm and inner surface of the lamina terminalis and measured on midsagittal sections, showed considerable variability. CONCLUSIONS: The CR is a hollow structure with various contours. Recognition of the morphological characteristics of the CR and lamina terminalis may be helpful for safe perforation of the lamina terminalis. Magnetic resonance imaging is useful for exploring the CR.
PURPOSE: The chiasmatic recess (CR) is a small, downward extension in the most rostral third ventricle. Few studies have highlighted its morphology. Accordingly, we explored the CR using magnetic resonance imaging. METHODS: A total of 104 patients were enrolled in this study. Magnetic resonance imaging examinations were performed in axial and sagittal sections. Imaging data were obtained as thin-sliced, seamless sections. RESULTS: The CR was clearly identified in 98 % of axial and 96 % of sagittal sections. The lamina terminalis was delineated as a membranous structure with homogenous thickness. The CR was consistently delineated as a smoothly tapering, cerebrospinal fluid-filled space. The number of axial images required to encompass the entire CR was 1 slice for 1.9 % of samples, 2 for 32.7 %, 3 for 49 %, 4 for 12.5 %, 5 for 1 %, and 6 for 1 %. On axial view, the CR generally presented as a long horizontal ellipse. On sagittal view, the CR showed variable shape and length. The optic chiasm-lamina terminalis angle, formed by the upper surface of the optic chiasm and inner surface of the lamina terminalis and measured on midsagittal sections, showed considerable variability. CONCLUSIONS: The CR is a hollow structure with various contours. Recognition of the morphological characteristics of the CR and lamina terminalis may be helpful for safe perforation of the lamina terminalis. Magnetic resonance imaging is useful for exploring the CR.
Entities:
Keywords:
Chiasmatic recess; Lamina terminalis; MRI; Third ventricle