Detection of pulsation in unruptured cerebral aneurysms by electrocardiographic-gated 4-dimensional computed tomographic angiography and follow-up evaluation / 中华放射学杂志

ABSTRACT

Objective To evaluate the electrocardiographic(ECG)-gated 4-dimensional computed tomographic angiography (4D-CTA) in the determination of pulsation of unruptured cerebral aneurysms (URCAs).Methods This study included 48 patients with 62 URCAs.Examinations of ECG gated 4D-CTA of dual-source CT were performed.Twenty sets of image data with the time intervals of 5％ in a cardiac cycle were obtained after postprocessing on the workstation.The convex was defined as the point of pulsation if small bubble or small pointed convex could be found in continuous three or more images at the same location.The 62 URCAs were divided into two groups based on whether having a point of pulsation.All the URCAs were scanned at the follow-up by 3D-CTA or ECG gated 4D-CTA more than 120 days later.The diameters of aneurysms and aspect ratio between the two groups were compared with independent t test,while neck of aneurysms and follow-up time were compared with two-independent samples Mann-Whitney U test.The other variables including history of hypertension,type 2 diabetes,smoking et al between the two groups were analyzed by x2 test.The sensitivity and specificity of aspect ratio for diagnosis of pulsation were analyzed by receiver operating characteristic (ROC) curve.Results Pulsation was observed in 28 of the 62 URCAs.Aspect ratios in whose pulsation was or was not detected were 1.5±0.3 and 1.1±0.3,respectivelyThe difference between the two groups was statistically significant (t=-2.274,P＜0.001).The sensitivity and specificity of the aspect ratio were 75.0％ and 70.6％.After follow-up more than 3 months,of the 28 URCAs in which pulsation was observed,11 showed a change in shape,while in 34 URCAs without visible pulsation,5 showed a change in shape.The aneurysms with detectable pulsation were more likely to show a change in shape (x2=4.891,P=0.027),with an odds ratio of 3.753.Conclusions URCAs with a large aspect ratio are easily to show the pulsation by ECG gated 4D-CTA.Besides,the aneurysms with visible pulsation are more likely to show a change in shape after follow-up,which suggests a higher risk of rupture.