![]() ![]() McRae's line: This is the plane of foramen magnum, drawn by a line drawn between the basion and opisthion. If more than the defined value it is suggestive of Basilar Invagination (BI).Interpretation: In 90% of individuals the odontoid apex should not lie above this line > 8 mm in males and > 10 mm in females This line is drawn between the posterior pole of the hard palate to the most inferior surface of occipital bone (Figure 1b). McGregor line: McGregor developed a modification of the CL in situations when opisthion could not be identified. If distance of more than 7 mm it is considered abnormal.Maximum distance accepted above the line is 1 ± 6.6 mm.Tip of dens commonly lies below or just tangential to this line or occasionally it may normally project few mm above this line.Ĭhamberlain's line (CL): A line extending between posterior pole of the hard palate and opisthion (Figure 1b) Table 2: Measurement and values for Cranio-vertebral normalcy and common pathological conditions. Description,interpretation and significance of the lines/plane are provided herewith in (Table 2). Utilizing these landmarks, many lines/planes are drawn. Table 1: Shows important landmarks for drawing Cranial and Cranio-cervical planes. Following anatomical landmarks are needed on lateral and coronal views, to assess CVJ relationships and to perform basic craniometric measurements (Figure 1a) (Table 1).īasion (B) Also serves as guide to objective post-surgical follow up. Evaluation of these measurements helps in confirming and documenting CVJ relationship. Measurements can be done using conventional or cross sectional radiological examinations. There are objective measurements for position of various bony components of CVJ on radiography. On radiographs cranio-caudal range of CVJ extends from a line drawn between the internal occipital protuberance and the midpoint of the distance from the dorsum sellae and anterior margin of the Foramen Magnum (FM) to the level of second and third cervical inter-vertebral space. ![]() These imaging studies can additionally provide dynamic information when performed with appropriate movements. It is partially visible in the routine imaging studies of the brain. (Medulla, spinal cord and lower cranial nerves) CVJ is well visualised in many imaging studies, namely the conventional radiography, Computed tomography and Magnetic resonance imaging (MRI) studies. It encloses the soft tissue structures of cervico-medullary junction. The Craniovertebral Junction (CVJ) is a collective term that refers to the following structures-occiput (posterior skull base), atlas, axis and supporting ligaments. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |