Comparison Of 2D And 3D Digital Subtraction Angiography In Evaluation Of Intracranial Aneurysms

Objective Spontanous subarachnoid hemorrhage(SAH)mostly arises from rupture and bleeding of intracranial aneurysms.Accurate diagnosis and proper evaluation of both location and spatial structure of the aneurysms was critical for clinical treatment of the disease.Routine DSA is only able to display the two-dimensional(2D-DSA)images of cerebral vascular system.But the three-dimensional digital subtraction(3D-DSA)may acquire multi-angle oblique images from reconstruction after rotational collection.Thus its application is very important for aneurysm evaluation and operative method selection.In this study we compared and analyzed the aneurysm detective rate,anatomy of aneurysm and its neck,the dosages of contrast medium.To evaluate and compare the diagnostic value of 3D-DSA and 2D-DSA for intracranial aneurysms.Methods1.Clinical materials:A totle of 53 patients with subarachnoid hemorrhage (SAH)suspected of cerebral aneurysims were selected from 2006.3～2007.2.These patients were inspected by 2D-DSA and 3D-DSA.There were 31 men and 22 women (ranging from 37 to 72 years old,with average age of 56.8).Clinical manifestation were interrupted or gusty headache,paralysis of the unilat cranial nerve,etc.CT or MRI suspected cerebrovascular disease.2.Methods:Philips Allura Xper FD 20 angiography system was taken for acquisition,and Advantage Workstation 4.0 workstation was used for post processing. 2D-DSA was performed with routine femoral artery method to get anterior-posterior, lateral,and oblique if necessary images.3D-DSA underwent rotational acquisition. During the second rotation,contrast media was infused into artery,so that intracranial arteries were persistently displayed.3D reconstruction was made with the workstation.Based on all images of 2D-DSA and 3D-DSA,we evaluated the aneurysm detective rate,visibilities of both aneurismal neck and its relationship with the parent artery,the dose of contrast media.3.Statistics:With SPSS 11.0 software,measurement data was demonstrated by(?)±s,data was analyzed by t test;numeration data was analyzed byχ~2 test;P＜0.05 means the difference is significant.Results1.The comparison of detective resultsIn fifty-three patients,forty-nine aneurysms were diagnosed by 2D-DSA,the accuracy,positive rate,sensitivity and specificity were 84.5%,86.8%,90%,and 66.7%respectively;fifty-eight aneurysms were diagnosed by 3D-DSA,the accuracy and positive rate were 100%and 94.3%,the sensitivity and specificity were both 100%.In the detection of 2D-DSA,there were five false-nagtive cases and one false-positive case,3D-DSA had none.In 46 cases of 2D-DSA,true-positive rate was 90%(45/50),true-nagtive rate was 66.7%(2/3),false-positive rate was 33.3%(1/3),false-nagtive rate was 10%(5/50).In 50 cases of 3D-DSA,true-positive rate was 100%(50/50),true-nagtive rate was 100% (3/3),false-positive and false-nagtive rate were both 0.2.The comparison of both aneurismal neck and its relationship with the parent arteryBy 2D-DSA,23 cases of neck of aneurysm were clearly showed,and 22 cases were surely displayed the source vessel,however,by 3D-DSA,58 cases of neck of aneurysm(χ~2=40.654,P＜0.05 vs 2D-DSA),and 56 cases of source vessels were clearly showed(χ~2=35.869,P＜0.05 vs 2D-DSA),the difference between 2D- and 3D-DSA was significant(P＜0.05). 3.The comparison of contrast media doseThe mean contrast-medium of 2D-DSA was(74.57±11.95)mL,while that of 3D-DSA was(54.15±7.05)mL,the contrast-medium dose are much lower in 3D-DSA than in 2D-DSA,the difference between 2D- and 3D-DSA was significant(t=10.71,P＜0.05).Conclusions Digital subtraction angiography(DSA)was the gold standard for diagnosis of cerebrovascular disease,but if the anatomic structure of vessels were more complicate,2D-DSA would not offer complete informations.Compared with 2D-DSA,3D-DSA had much higher accuracy,positive rate,sensitivity and specificity. Both the aneurismal neck and its relationship with the parent artery were showed more clearly in 3D-DSA.3D-DSA could describe the feature of aneurysms more exactly,which provides fairly valuable information for surgical and interventional treatment of intracranial aneurysms.At the same time,the contrast media dose was much lower than 2D-DSA,so the security of radioprotection was raised by 3D-DSA. Further research in 3D-DSA will bring us more clinical benefits.