Article Figures & Data
Figures
- Fig 1.
Example of the thin post cg sign, and the midline sulcus sign. The precentral gyrus has a thicker anteroposterior diameter (large white arrow) compared with the postcentral gyrus (small white arrow). The longest sulcus running horizontally and entering the interhemispheric fissure (black arrow) is the central sulcus.
- Fig 2.
Variants of the handknob. In our study, we only considered the inverted Ω shape (white arrow) because other variants, such as inverted ε (continuous black arrows), and multiple bulgings (dotted black arrows) were not assessed.
- Fig 3.
The U sign. Right hemisphere. Absence of the subcentral gyrus as a rare variant, the central sulcus (asterisk) terminates into the Sylvian fissure (white arrow). Gray arrows mark the precentral (continuous arrow) and postcentral (dotted arrow) gyri. Left hemisphere: The subcentral gyrus connects the pre- and postcentral gyri (U sign).
- Fig 4.
Examples of all 10 landmarks in 1 single section: 1 indicates the upper T sign; 2, the L sign (duplicated as a variant); 3, the lower T sign; 4, the M sign; 5, the bracket sign; 6, the bifid post cg sign; 7, the thin post cg sign (fenestrated post cg as a variant); 8, the midline sulcus sign; 9, the subcentral gyrus sign; 10, the handknob. Only 1 hemisphere is depicted and was mirrored for better visualization.
- Fig 5.
Barplots representing the frequency of landmark identification as a percentage of all (blue), right (purple), and left (yellow) hemispheres.
Tables
Frequency of all landmarks
All Hemispheres (n = 178) Right (n = 88) Left (n = 90) Upper T sign 109 (61.2%) 51 (58%) 58 (64.4%) L sign 107 (60.1%) 55 (62.5%) 52 (57.8%) Lower T sign 138 (77.5%) 69 (78.4%) 69 (76.7%) M sign 157 (88.2%) 77 (87.5%) 80 (88.9%) Bifid pc sign 157 (88.2%) 76 (86.4%) 81 (90%) Midline sulcus sign 159 (87.5%) 77 (87.5%) 82 (91.1%) Bracket sign 82% (of 78 patients) Thin post cg sign 170 (95.5%) 85 (96.6%) 85 (94.4%) Handknob sign 97 (54.5%) 49 (55.7%) 48 (53.3%) Subcentral gyrus sign 176 (98.9%) 84 (95.5%) 88 (97.8%) Note:—Bifid pc sign indicates the bifid post cg sign.
