ABSTRACT
Objective To study a rare CT finding of pulsatile tinnitus(FT)caused by sigmoid sinus abnormalities.Methods The imaging data of PT caused by sigmoid sinus abnormalities were analyzed retrospectively in 15 patients(15 female).The median age was 45 years(24 to 63 years).The duration of persistence pulsatile tinnitus was from 0.5 year to 36.0 years(median time,2.0 years).The tinnitus was at left side in 5 patients and right side in 10 patients.Fifteen patients underwent HRCT of the temporal bone.Of them,12 patients underwent cerebral CT angiography and CT venogram(CTA/CTV),and 9 patients underwent cerebral digital subtraction angiography(DSA).Nine patients underwent transmastoid reconstruction surgery of the sigmoid sinus.Of them,the tinnitus was at left side in 2 patients and right side in 7 patients.Paired rank sum test was used to compare the cross-sectional area of the sigmoid sinus of the tinnitus side and normal side.Results On HRCT,focal bony coarse defect is shown in the anterior sigmoid wall in 11 patients and anterolateral sigmoid wall in 4 patients.On CTA/CTV,the sigmoid sinus focally protruded into the adjacent mastoid air cells and formed diverticulum in 10 patients.The pulsatile tinnitus disappeared immediately after transmastoid reconstruction surgery of the sigmoid sinus in all 9 patients.The cross-sectional area of the sigmoid sinus of the tinnitus side was 100.6(41.5-96.2)mm~2,it was 77.0(92.1-122.4)mm~2 in the nonmal side(Z=2.158,P=0.031).Conclusion Focal bony defect of the sigmoid wall with sigmoid sinus diverticula is one of the causes which lead to pulsatile tinnitus,which can be easily identified by imaging examination.