Occipital lobe morphology in normal individuals assessed by magnetic resonance imaging (MRI)

Bilateral comparison of occipital lobe sulci: A sulcus identifying algorithm

“…The results of the present study showed, however, that the asymmetry in the sulcal pattern in the occipital lobe is meager. This is consistent with the previous findings based on an interactive identification of occipital sulci on MR images (Myslobodsky et al, 1991). However, the present finding suggests that sulcal complexity might be an acceptable measure of right-left differences in sulcal patterns.…”

“…Only in one case with a somewhat idiosyncratic sulcal pattern did the algorithm forced a false identification of the calcarine sulcus. Consistent with Myslobodsky et al (1991), this is most likely when its course is interrupted by side branches, especially if they are connected with the paracalcarine sulcus. Another advantage of ASI mentioned above, compared to available packages, is in that it permitted an automatic search, extraction, and quantification of the same feature in a different hemisphere.…”

“…Another advantage of ASI mentioned above, compared to available packages, is in that it permitted an automatic search, extraction, and quantification of the same feature in a different hemisphere. We used ASI for a problem that has a wide range of applications, in interpreting the electrophysiology of the visual system (Myslobodsky et al, 1991;Srebro, 1990), neurosurgery (Stensaas et al, 1974), in a search of anatomical correlates of brain laterality (Habib et al, 1984;Geschwind and Levitsky, 1986), in identifying interindividual variance of sulcal profiles, etc. So far, the bilateral comparison of sulcal patterns was conducted interactively for the major brain sulci, such as the Central and Sylvian fissures (Habib et al, 1984;Geschwind and Levitsky, 1986;Steinmetz et al, 1989).…”

“…Its deepest point that was read as the nasal root could vary and show asymmetry in the two paramedial cuts. The opposite landmark, the inion, is often difficult to define inasmuch as in MR images it is seen as a signal void and it may not be coplanar with the interhemispheric fissure (Myslobodsky and BarZiv, 1989;Myslobodsky et aL, 1991). Therefore, the right and left ni lines may not be strictly parallel.…”

“…MR imaging was performed on a 0.5 Tesla Elscint (GYREX 5000 with matrix size of 256 x 256 as described elsewhere (Myslobodsky et al, 1991). The position of the head was adjusted under the control of repeated, multiplanar, fast-locating MR scans to align the interhemispheric fissure with the sagittal imaging plane.…”