Study Of The Key Technology Of C-Arm Cone-Beam Computed Tomography Cerebral Angiography

Purpose:C-arm cone-beam computed tomography(C-arm CBCT) is a new technology of digital subtraction angiography (DSA)system. This study was to explore the key technology of C-arm CBCT cerebral angiography and its clinical applications.Methods:C-arm CBCT was performed on the standard CT quality control phantom and steel ball. When the experiment performed the phantom and steel ball were placed on the center point and different point off-center respectively. Image Noise (standard deviations of X ray attenuation values) and the degrees of the deformations were measured and calculated. C-arm cone-beam computed tomography of cerebral angiography was performed on the male anthropomorphic head phantom, the acquisition time was set to 5s,8s and 20s respectively. Image Noise, Signal to noise ratio(SNR), Contrast to noise ratio(CNR) were measured and calculated. Volume Rendering(VR), Maximum intensity projection(MIP) and Multiplanar reconstruction(MPR) images were reconstructed and evaluated. We recorded the dose area product (DAP) of each acquisition time and the effective dose(ED) was calculated to assess the radiation dose. The clinical data of 137 patients who underwent C-arm CBCT cerebral angiography were analyzed retrospectively. Analysis the display features of different acquisition time of C-arm CBCT cerebral angiography imaging and its clinical applications.Results:As the offsetting center distance increased the image noise of C-arm CBCT imaging decreased and the degree of the diameter deformations in different directions would increase, and the result showed a significant difference (P<0.05).The image quality of C-arm CBCT 20s imaging were higher than those with 8s and 5s. However, with the acquisition times of 5s,8s and 20s the radiation doses were 0.91 mSv,1.38 mSv,5.84 mSv respectively, they increased gradually, and the results showed a significant difference (P<0.05). C-arm CBCT 5sDSAmode can clearly display the intracranial arteries in multi-angle, which can be used in the diagnosis and treatment for aneurysm, arteriovenous malformation, the supply arteries of cerebral tumor and cerebral vascular stenosis. C-arm CBCT 8sDSA model can clearly display the intracranial venous, applicable to the detection and treatment of intracranial venous. C-arm CBCT 20s Digital Radiography (DR) mode can be used for displaying intracranial hemorrhage lesions and arterial stenting.Conclusion:Image noise and deformations are statistically different when offset center point in different directions and different distances in C-arm CBCT imaging. To master the rules has guiding significance on clinical interventional diagnosis and treatment, when implementing the technology in orientation imaging area and ROI selection of vascular measurements. The image quality and radiation dose of C-arm CBCT cerebral vascular imaging are closely related with the acquisition time, and its range of applications are different, the selection of suitable imaging time is favorable for clinical applications.