Imaging anatomy of the infraorbital ethmoid cells on multislice CT / 中华放射学杂志

ABSTRACT

Objective To study the anatomic characteristics of the infraorbital ethmoid cells on muhislice CT(MSCT)and explore the relationship between the infraobital ethmoid cells and mueosal swelling of sinuses.Methods Two hundred sixty patients(520 sides) of consecutive axial scans by GE HisDeed VCT and the multiplunar reformation(MPR),virtual endoscopy(VE)reconstruction images by GE AW 4.2 workstation were reviewed retrospectively.The following CT features were assessed(1)the anatomic characteristics of the infraobital ethmoid ceils,including the frequency of identification,origin,classification.(2)presence of mucosal swelling of sinuses,(3)the maximal transversal diameter of the inflraobital ethmoid cells in ostium of maxillary sinus(perpendicular to the uncinate process),and the diameter of the ostium of maxillary sinus,(4)presence of infraobital ethmoid ceils inflammatory findings and a contact between the mucosal surface of the ostium of maxillary sinus.The results were analyzed by using Chi-square test and logistic regression analysis with the statistical software SPSS 11.5.Results (1) UniLateral infraobital ethmoid cells were f10und in 68 patients(26.1%),and bilateral infraobital ethmoid cells were found in 81 patients(31.2%).Infraobital ethmoid ceHs were found in 230 sides on left Bide (120 sides)and right side(110 sides).(2)Infraobital ethmoid cells originated from the anterior ethmoid cells in 124 sides(53.9%)and from posterior ethmoidal cells in 62 sides(27%),originated from both the anterior ethmoidal cells and the posterior ethmoidal cells in 44 sides(19.1%).(3)The classification of the infraobital ethmoid cells included three types.Infraobital ethmoid cells with different origination differed significantly in theirtypes(x2=193.433,P<0.01).Most ofthe infraobital ethmoid cells originated from tlle anterior ethmoidal cells were type Ⅰ(160 sides),while the type Ⅱ(48 sides)and Ⅲ(45 sides) frequently originated from the posterior ethmoidal ceHs(4)The mueosal swelling of sinuses,were found in 165 sides in presence of infraobtial ethmoid cells and 192 sides in absence of infraobtial ethmoid cells.The presence of infraobtial ethmoid cells had no effect on mucosal swelling(X2=1.824,P>0.05).The maximal transversal diameter of the infraobital ethmoid cells in ostium of maxillary sinus did not differ significantly between the cases with or without mucosal swelling of sinuses(t=0.273,P>0.05).and the diameter of the ostium of maxillary sinus were not significantly related with mucosal swelling of sinuse8 (Wald=2.534,P>0.05).Presence of infraobital ethmoid cells inflammatory findings (Wald=10.817. P<0.01,OR=4.125)and a contact between the mucosal surface of the ostium of maxillary sinus (Wald= 6.640,P<0.01,OR=3.728)were significantly related to mucosal swelling of 8inuses. Conclusions (1)MSCT scan could clearly demonstrate the detailed information of infraobital ethmoid ceIIs.(2)The presence of infraobtial ethmoid cells Was not a risk factor for chronics sinusitis. When we assess inflraobtial ethmoid cells as a possible etiologic factor in chronics sinusitis we should observe presence of infraobital ethmoid cells inflammatory findings and a contact between the mucosal surface of the ostium of maxillary sinud.