The Application Study Of 64-Slice Spiral Computed Tomographic Angiography On Intracranial And Neck Vascular Diseases

Objective:To evaluate the value of digital subtraction computed tomographic angiography ( DSCTA ) with 64-slice spiral computed tomography in diagnosing of intracranial and neck vascular diseases.Methods:Unenhanced and enhanced CT with the same scan protocols for CTA were performed in 134 patients with clinically suspected intracrania(ln=102) and neck(n=32) vascular diseases. The unenhanced bone data sets was subtracted from the enhanced data set to produce subtracted CTA data. The two data sets of unenhanced and enhanced CTA were postprocessed by use of three-dimensional volume rendering(3D VR), maximum intensity projection(MIP), multiple planar reconstruction(MPR) and vessel analysis(VA), then conventional CTA and DSCTA images were obtained. Of the 134 patients, 45 patients (intracranial=40, neck=5) also received conventional digital subtraction angiography(DSA) after the CT scans. The images were assessed carefully to compare the image quality of the conventional CTA and DSCTA. The sensitivity and specificity of diagnosing the intracranial and neck vascular diseases with the conventional CTA and DSCTA were calculated respectively by using the results of the DSA as"gold standard".Results :The conventional CTA demonstrated 31 patients with no abnormality, 103 patients with vascular diseases, in which 62 patients with aneurysms, 12 patients with arteriovenous malformations(AVM), 6 patients with internal carotid-cavernous fistulae(ICCF), 23 patients with arterial vascular stenosis and obstruction. The DSCTA showed 27 patients with no abnormality, 107 patients with vascular diseases, in which 65 patients with aneurysms, 12 patients with arteriovenous malformations(AVM) , 6 patients with internal carotid-cavernous fistulae(ICCF), 23 patients with arterial vascular stenosis and obstruction , and 1 patient with veinal vascular stenosis and obstruction. There was no significant difference in the image quality of conventional CTA and DSCTA. In the 45 patients underwent DSA, there were 3 patients with no abnormality, 42 patients with vascular diseases, in which 26 patients with aneurysms, 6 patients with arteriovenous malformations(AVM), 5 patients with internal carotid-cavernous fistulae(ICCF) and 5 patients with arterial vascular stenosis and obstruction. The sensitivity of the conventional CTA in detecting aneurysms was 92.9%, respectively, and both the sensitivity of the DSCTA in detecting aneurysms was 100%. DSCTA detected all of the aneurysms near the cranial bottom. The ability to detect internal carotid-cavernous fistulae, arteriovenous malformations and arterial stenosis and vascular obstruction were equal in the conventional CTA, DSCTA and DSA. The specificity of DSCTA and conventional CTA in detecting vascular diseases were 100%.Conclusion :Comparing with 16-slice spiral CT or other spiral CT, 64-slice spiral CT shows more superiority in CTA. DSCTA is better than conventional CTA in diagnosing intracranial and neck vascular diseases especially that near the cranial bottom because of eliminated obstruction of bone. DSCTA could replace the DSA as a primary choice for diagnosing and following up the intracranial and neck vascular diseases.