Software-enabled CT analysis of optic nerve position and paranasal sinus pneumatization patterns.
OBJECTIVE
Delineate the relationships among the optic nerve (CN II), the sphenoid sinus, and the sphenoethmoid cell.


METHODS
High-resolution CT scans of 64 frozen human cadavers were obtained on a Siemens VolumeZoom CT scanner (Munich, Germany) and transferred to a CBYON Suite Doctor Station version 2.6 (CBYON, Mountain View CA) for standardized review.


RESULTS
Pneumatization around CN II was categorized into 5 types: no adjacent pneumatization (type 0), pneumatization adjacent to CN II (type 1), adjacent pneumatization with indentation (type 2), pneumatization of <50% CN II circumference (type 3), and pneumatization of >50% CN II circumference (type 4). The prevalence of types 0 to 4 CN II position relative to the sphenoid sinus was 4.7%, 25.8%, 39.8%, 14.1%, and 15.6%, respectively. The prevalence of sphenoethmoid cells was 28.1%. The prevalences of types 0, 1, 2, 3, and 4 CN II positions relative to the sphenoethmoid cell was 5.6%, 58.3%, 25%, 2.8%, and 8.3% respectively.


CONCLUSIONS
Software-enabled CT review facilitated precise study of the anatomic relationships of CN II. Caution must be exercised during sinonasal surgery to minimize the risk of inadvertent CN II injury.


METHODS
D.
Batra
Pete S
PS
Cleveland Clinic Foundation, Department of Otolaryngology, Section of Nasal and Sinus Disorders, Ohio 44195, USA.
Citardi
Martin J
MJ
Gallivan
Ryan P
RP
Roh
Hwan-Jung
HJ
Lanza
Donald C
DC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005005:Ethmoid Sinus / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D010256:Paranasal Sinuses / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D012984:Software; D013101:Sphenoid Sinus / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*