Objective To evaluate the diagnostic value of multi-slice thrce-dimensional computed tomographic angiography(MS-CTA) with volume rendering(VR) for Moyamoya disease.Methods MS-CTA of 25 patients with Moyamoya disease verified by DSA were restrospectively analyzed.Source images were got by GE Lightspeed pro scanner.VR was adopted to reconstruct 3D images in all cases.Results Of 25 CT precontrast,13,12 cases showed infarction and hemorrhage respectively,while 11 cases had dialated vessels in thalamus-basal ganglia region on CT.Accuracy of stenosis or occlusion of the bifurcation of ICA, proximal portion of the ACA or MCA was 88.0% (22/25) by MS-CTA.MS-CTA overestimated the degree of stenosis,MS-CTA misdiagnosed 3 cases(12.0%)with stenosis to occlusion.MS-CTA showed fewer small Moyamoya vessels than DSA.MS-CTA only demonstrated 6 cases(25.0%)with collateral vessels.Conclusion CT is still the conventional method for detecting secondary lesions to Moyamoya disease.CT and MS-CTA can accurately diagnose Moyamoya disease.

Objective To evaluate the value of spiral CT volume reconstruetion(VR) technique in high complex anal fistula fistulography. Methods To analyze retrospectively internal openings and secondary tracts of 35 eases with high complex anal fistula verified by operation and follow-up above 3 months with VR,and compared with operation and outcome of follow-up. Results In 35 eases with high complex anal fistula, for detection of the presence of internal openings ,VR has a sensitivity of 72.7% ,a specificity of 100% ,a accuracy of 74.3% ,a positive predictive value of 100% ,and a negative predictive value of 18.1%. Secondary tracts have a sensitivity of 93.8% ,a specificity of 100.0% ,a accuracy of 94.6% ,a positive predictive value of 100.0% ,and a negative predictive value of 72.7%. Conclusion VR can demonstrate the 3D shape of fistula and is reliable in the diagnosis of internal openings and sec-ondary ducts, and is very valuable in the analysis of high complex anal fistula fistulography.