Look-up table (LUT) algorithms have been widely used in digital signal processing, but the article on the application of LUT algorithms in digital subtraction angiography was rarely reported. In this article, the effect of different LUT algorithms on digital subtraction angiography images is introduced. The result reveals that different LUT algorithms can bring about different effects of image. Based on analysis and comparison, we deem it possible to acquire improved images of DSA by use of some LUT algorithms with image processing.
Algorithms ; Angiography, Digital Subtraction ; methods ; Humans ; Radiographic Image Enhancement ; methods ; Radiographic Image Interpretation, Computer-Assisted ; methods

This article analyzes mainly the X-ray imaging acquisition parameters in AXIOM Artis X-ray equipment, the relationship between the parameters, and how to select acquisition parameters in cardioangiography. We have sought a set of X-ray imaging acquisition parameters for producing optimal image in cardioangiography.
Angiography ; instrumentation ; Humans ; Photofluorography ; instrumentation ; Radiographic Image Enhancement ; instrumentation ; methods ; Radiographic Image Interpretation, Computer-Assisted ; instrumentation

Because of the difference in organic density, a simple and effective method for exponent restraint of active edge is applied to X-ray image of bone. And it is easy to use histogram method to get the active image of bone. At last, by associating it with Canny method, the edge of bone can be abstracted from a complex X-ray image.
Algorithms ; Bone and Bones ; diagnostic imaging ; Humans ; Radiographic Image Enhancement ; methods ; Radiographic Image Interpretation, Computer-Assisted ; methods

This paper introduces five dental X-ray machines which are manufactured with IGBT to realize high frequency, real-time sampling and PWM to ensure the closed-loop control for tube current and Anodes's high voltage. These five machines also use microcomputer and combined X-ray tube for precise control. The sets don't have high voltage outside. The error of tube voltage is less than 1% and exposure time is less than 3%. The photos of pulp cavity and surrounding tissue can be seen clearly. These sets surely meet the requirements of perspective use in clinical.
Equipment Design ; Humans ; Radiographic Image Enhancement ; Radiographic Image Interpretation, Computer-Assisted ; methods ; Radiography, Dental ; instrumentation

A wavelet threshold denoising algorithm for CR images is put forward here . A noised CR image is decomposed into wavelet coefficients, which are processed by the algorithm, and the denoised CR image is reconstructed based on the processed coefficients. Examples are too presented to demonstrate the efficiency of the algorithm on denoising and, maintaining the detail of the CR images.
Algorithms ; Radiographic Image Enhancement ; methods ; Radiographic Image Interpretation, Computer-Assisted ; methods ; Radiography ; methods ; Signal Processing, Computer-Assisted

C-arm based surgical navigation system is a kind of computer assisted surgery (CAS) system. In this paper, key techniques concerning this kind of system are presented. The key techniques mainly include XRII image distortion correction and C-arm imaging system calibration. On this basis, we designed relevant tools and made them fabricated, and developed a software system. Experimental results of human fresh spine sample showed that with the surgical navigation system, screw insertion accuracy was much higher than that without the surgical navigation system.
Algorithms ; Calibration ; Humans ; Radiographic Image Enhancement ; methods ; Radiographic Image Interpretation, Computer-Assisted ; methods ; Spine ; surgery ; Surgery, Computer-Assisted ; methods

Based on the developing situation of Computer Aided Diagnosis/Detection (CAD) software, considering the domestic and international regulation of CAD software, according to current Medical Device Classification Catalog and related laws of China Food and Drug Administration (CFDA), this paper investigated and analyzed the classification of CAD software, and provided technical suggestion on classifying principle of CAD software applying Artificial Intelligence (AI) or other advanced technology from medical device regulation scope, for the reference of regulatory and technical departments.
Artificial Intelligence ; China ; Diagnosis, Computer-Assisted ; Radiographic Image Interpretation, Computer-Assisted ; Software

Extracting landmark geometric data in C-arm X-ray images is a key technique of camera calibration process in a fluoroscopic-image-based surgical navigation system. The geometric data is the basis of X-ray image distortion correction and C-arm camera calibration. In this paper we present an integrated clustering algorithm for landmark geometric data extraction. This proposed alorithm, with the advantages of an adaptive thresholding method as well as of a fast quasi connected-component labeling method, needs only one pass to extract the needed geometric data in a gray scale image. It is of high executive efficiency and good robustness as well.
Algorithms ; Calibration ; Humans ; Image Processing, Computer-Assisted ; methods ; Radiographic Image Enhancement ; methods ; Radiographic Image Interpretation, Computer-Assisted ; Surgery, Computer-Assisted ; methods

In order to solve the time-consuming problem in volume CT image reconstruction field, we brought forward a fast reconstructive algorithm method to fit the clinic medicine. First, using the great parallel and Floating-Point power of graphic processing unit (GPU), we proposed a volume CT GPU- based reconstruction method. Second, in order to reduce the repetitive operation, we separated the geometry computation and pixel computation. As a result, the computation efficiency was further improved. At last, based on the background of medical engineering, the parallel of volume CT scan and reconstruction was implemented. The results demonstrated that the volume CT reconstruction time could reduce up to 70 times compared to the previous one in common PC by the fast reconstructive algorithm method.
Algorithms ; Computer Graphics ; Cone-Beam Computed Tomography ; instrumentation ; methods ; Humans ; Image Processing, Computer-Assisted ; methods ; Radiographic Image Enhancement ; methods ; Radiographic Image Interpretation, Computer-Assisted ; methods

Generation of digitally reconstructed radiographs (DDRs) is key to image-guided radiation therapy and widely used for 2D-3D image registration to verify the patient's position. The classic algorithms to generate DRRs with ray casting is time consuming to hamper the registration process. The authors describe the attempt to extend the light field rendering techniques from computer graphics, using the light field computed from ray casting to interpolate a DRRs image from a novel fixed viewpoint. Because most of the computation is performed in a preprocessing step, the speed is greatly accelerated and satisfactory DRRs can be obtained.
Algorithms ; Computer Graphics ; Humans ; Imaging, Three-Dimensional ; Radiographic Image Interpretation, Computer-Assisted ; Radiotherapy ; instrumentation