ABSTRACT
Deep brain stimulation (DBS) surgery is an important treatment for patients with Parkinson's disease in the middle and late stages. The accuracy of the implantation of electrode at the location of the nuclei directly determines the therapeutic effect of the operation. At present, there is no single imaging method that can obtain images with electrodes, nuclei and their positional relationship. In addition, the subthalamic nucleus is small in size and the boundary is not obvious, so it cannot be directly segmented. In this paper, a complete end-to-end DBS effect evaluation pipeline was constructed using magnetic resonance (MR) data of T1, T2 and SWI weighted by DBS surgery. Firstly, the images of preoperative and postoperative patients are registered and normalized to the same coordinate space. Secondly, the patient map is obtained by non-rigid registration of brain map and preoperative data, as well as the preoperative nuclear cluster prediction position. Then, a three-dimensional (3D) image of the positional relationship between the electrode and the nucleus is obtained by using the electrode path in the postoperative image and the result of the nuclear segmentation. The 3D image is helpful for the evaluation of the postoperative effect of DBS and provides effective information for postoperative program control. After analysis, the algorithm can achieve a good registration between the patient's DBS surgical image and the brain map. The error between the algorithm and the expert evaluation of the physical coordinates of the center of the thalamus is (1.590 ± 1.063) mm. The problem of postoperative evaluation of the placement of DBS surgical electrodes is solved.
Subject(s)
Humans , Brain Mapping , Methods , Deep Brain Stimulation , Electrodes, Implanted , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Multimodal Imaging , Parkinson Disease , General Surgery , Subthalamic NucleusABSTRACT
Cone beam computer tomography (CBCT) has advantages of high precision, low radiation and high image quality. It has been developing quickly since it was applied clinically. In order to control X-ray TUBE HEAD effectively in Dental CBCT, X-ray TUBE HEAD Control System was designed and realized in this study. This control system is the core of CBTC system, which includes the communication between CBCT system and computer, the control of X-ray tube head by CBCT system main control board and the synchronization between main control board and the flat panel detector. Control circuit of the control system and corresponding operating software were designed with PIC16F877A as the core. This control system has been put into use in current CBCT system successfully.
Subject(s)
Algorithms , Cone-Beam Computed Tomography , Equipment Design , SoftwareABSTRACT
Objective To amend the errors between projective image center and the actual rotational center and improve the quality of reconstructed images. Methods The impact of reconstructed image in which the projection center and the actual center caused the deviation is analyzed, and provides the ways that is based on the gray value difference of objects and background in projection image to calculate actual rotational center, and then mends the projective image based on the actual rotational center. Results The difference between the actual rotational center and the calculated projective image center is less than one pixel. The quality of the reconstructed images is improved greatly. Conclusion The correction method is based on projective images, no need to increase the auxiliary conditions and the number of projection images. And the way as the pre-process of reconstruction, only needs small amount calculation, doesn't affect the reconstructive speed.
ABSTRACT
Objective To study elimination of the Micro CT projective image noise and improve the quality of the recon-structed image for the Micro CT system.Methods The forming factors of the Micro CT projective image noise were analyzed,and proposed the Micro CT projective image correction method to correct the random noise,dark field,light field,response nonuniformity and defect picture element and eliminate the random noise and the ring artifact respectively.Results Through the comparative study,it proposes a simple and practical correction method for the actual response nonuniformity which combines the corrections of light field,dark current and gain inconsistency and settles the three corrections with one circu-lation.The method can enhance the algorithm efficiency greatly and the validity of the correction protocol can be proved through experiments.Conclusion The Micro CT projective image noise is eliminated effectively and the good basis for the following work are established such as three-dimensional reconstruction.