Useful Value Of Energy Subtract Angiography In Diagnosis Of Cerebral Aneurysms Using Dual Source CT

ObjectiveTo explore the useful value of energy subtract angiography in aneurysms of cerebral aneurysms using dual source CT in comparison with imitating conventional reconstruction.MethodsForty-three patients with clinical suspected intracranial aneurysm were involved in the study.There were 20 males and 23 females,and their age range from 39 to 78 years, the average age was 54.6 years old.All these patients underwent DSCT,Choicing of dual energy scanning conditions:routine double location image scanned.the horizon for the baseline,and laying cervical vertebra to calotte as the scanning ambit.Contrast agent:omnipaque:30 gl/100ml,NS:20ml.Contrast agent injected intravenously at the speed of 4.0ml/s.Using Bolus Tracking,visual monitoring,when vascellum become brightly to trigger scanning in hand-motion,delaying time was2s.Scanning condition: sucker A 140 Kv,75 mas,sucker B 80Kv,318mas.The scanning parameters: collimating apparatus wide 64χ0.6mm.helical pitch 0.7mm,circuitation time;0.5s. Reconstruction parameter:image slice thickness:10mm,overlap 0.7mm.Reconstruction function D30f,DE:0.3.That is the coalesce of 70%low KV and 30%high KV data.The data which was gained from scanning was processed into Siemens dual source CT to be treated specially by post-processing software,(version:Syngo 2007). Method A was processing the data which is obtained by scanning into DE software and select skull des-bone mode to deal with.Then loading the subtraction image into the same machine's inspace 3D post-processing software to SVR reconstruction directly, SVR reconstruction should resection reliquus cancellated bone and superficial vein and sinus venosces.Method B is use the composite data from high KV and low KV the data which is adjusted by CT value that is scanning by dual source CT that is processed into post-processing software inspace 3D,reconstruction directly with SVR.Images obtained from method A and B was adjusted with one accord in amplification ratio.(W 150,L 250,B 97,O 75),Method A and B SVR reconstruction include 10 images:each of the ten images was post-processing by two high past service radiologist,each one estimate of the method to compare the detection rate of the aneurysm.The evaluation of aneurysm is in image post-processing station,SVR reconstruction image dissection in random,observation freedom rotation,the aneurysm neck and the aneurysm body were displayed clearly.The estimate of aneurysm is the visibility of aneurysm neck and aneurysm body and was demonstrated by half enumeration data,all the results was analyzed by SPSS 12.0.ResultsIn 43 patients,39 aneurysms was detected in method A and 38 aneurysms was detected in method B,the method B missed 1 in left arteria carotis intema microaneurysm in method A.The detection of location and number of aneurysm were the same in the rest aneurysm in two method.The minimum of the diameter of aneurysmmatic body is about 3mm and the maximal was about 16mm.The detection rate in method A and B were 100%and 97.4%,respectively(P>0.05).The display scores of aneurysm neck both wereⅢlevel 37,Ⅱlevel 2 in method A and method B.The display score of aneurysm body both wereⅢlevel 35,Ⅱlevel 4 in method A and method B. Statistically both no differences in display score of aneurysm neck and body were showed between method A and method B.ConclusionDual energy subtract CT angiography makes post-processing time saved by automatically removing disturbance of basic skull and also reaches the same satisfactory result in the detection rate of aneurysm and display of the neck and body of aneurysm compared with conventionally simulated CTA.