Feasibility and clinical application of cerebral double phase subtraction angiography with 16-slice spiral CT

Objective To investigate the application value of double phase bone removal subtraction cerebral angiography(DP-BSCTA) using 16-slice spiral CT.Methods Totally 117 patients who underwent DP-BSCTA were divided into group A(n=50,without cerebrovascular disease,did not undergo DSA),and group B(n=67,with cerebrovascular diseases,underwent DSA).The bone structures were removed with Neuro DSA software.In group A,the postprocessing time was counted.The subtraction images of double phase were scored(1—5) according to various degrees of the residual bones,as well as the vessel displayed and contaminated,respectively.In group B,the difference of diagnosis between DP-BSCTA and DSA was compared.The average radiation dose of DP-BSCTA was calculated in two groups.Results Of group A,the bones were completely removed in 51(51/100,51.00%) phase images(5 points).All residual bones and artificial images of the rest phase images were removed by hand-made.The handling time with Neuro DSA software and with hand-made was(2.97±0.29)min and(2.22±0.96)min,respectively.There were 45(45/50,90.00%) arterial phase and 41(41/50,82.00%) venous phase images scored 4—5.The images of double phase were 4—5 points in 37 cases(37/50,74.00%).Of group B,63 cases were positive in DP-BSCTA(29 cases of aneurysms,11 vascular malformation,3 Moya-moya disease,3 sinus venosus thrombus and 17 cases of arteriostenosis),4 cases were negative.Compared with DSA,the sensibility and specificity of DP-BSCTA was all 100% in diagnosing cerebrovascular disease.The mean dose length product of the two groups was(875.77±67.94)mGy·cm.Conclusion With bone structures rapidly removed,the images of DP-BSCTA in 16-slice CT are approximately similar to DSA.The diagnostic capability of DP-BSCTA for cerebrovascular disease is equal to that of DSA.