X-ray Image Processing Research Articles

A Content Based Approach to Medical X-Ray Image Retrieval using Texture Features

Of late, the amount of digital X-ray images that are produced in hospitals is increasing incredibly fast. Efficient storing, processing and retrieving of X-ray images have thus become an important research topic. With the exponential need that arises in the search for the clinically relevant and visually similar medical images over a vast database, the arena of digital imaging techniques is forced to provide a potential and path-breaking methodology in the midst of technical advancements so as to give the best match in accordance to the user’s query image. CBIR helps doctors to compare X-rays of their current patients with images from similar cases and they could also use these images as queries to find the similar entries in the X-ray database. This paper focuses on six different classes of X-ray images, viz. chest, skull, foot, spine, pelvic and palm for efficient image retrieval. Initially the various X-rays are automatically classified into the six-different classes using BPNN and SVM as classifiers and GLCM co-efficient as features for classification. Indexing is done to make the retrieval fast and retrieval of similar images is based on the city block distance. Â

Influence of Primary Processing on the Segmentation of X-ray Images of Welds

We study the influence of preliminary processing of digital X-ray images by their median filtering and brightness normalization by nonsharp masking and contrast enhancement on the basis of a logarithmictype model on the results of testing. Examples of experimental detection of defects in welds of various types are presented.

Study on image processing of panoramic X-ray using deviation improvement software.

Utilization of panoramic X-ray device is getting wider. Panoramic X-ray has low resolution than general X-ray device and it occurs to distortion by deviation of image synthesis. Due to structural problems, it has been used restrictively to identify of tooth structure, not for whole head. Therefore, it designed and produced panoramic X-ray device which is possible to diagnostic coverage can be extended and had to be adjusted interval control between X-ray generator and image processing for whole of Maxillofacia's diagnosis. Produced panoramic X-ray device is composed basically of short image synthesis. In addition, it was confirmed the results by used the device which was applied deviation of the brightness of the image, filter to improve the location of the deviation and interpolation method. In this study, it was used 13 images including the front. It occurs to brightness deviation, position deviation, and geometric correction when synthesis of image, but it had been solved by deviation improvement software and a change of CCD camera's scan line which is used for image acquisition. Therefore, it confirmed expansion possibility of utilization range to commonly used panoramic X-ray device.

Improving Forecasting Accuracy in the Case of Intermittent Demand Forecasting

In making forecasting, there are many kinds of data. Stationary time series data are relatively easy to make forecasting but random data are very difficult in its execution for forecasting. Intermittent data are often seen in industries. But it is rather difficult to make forecasting in general. In recent years, the needs for intermittent demand forecasting are increasing because of the constraints of strict Supply Chain Management. How to improve the forecasting accuracy is an important issue. There are many researches made on this. But there are rooms for improvement. In this paper, a new method for cumulative forecasting method is proposed. The data is cumulated and to this cumulated time series, the following method is applied to improve the forecasting accuracy. Trend removing by the combination of linear and 2nd order non-linear function and 3rd order non-linear function is executed to the production data of X-ray image intensifier tube device and Diagnostic X-ray image processing apparatus. The forecasting result is compared with those of the non-cumulative forecasting method. The new method shows that it is useful for the forecasting of intermittent demand data. The effectiveness of this method should be examined in various cases.

XMapTools: A MATLAB©-based program for electron microprobe X-ray image processing and geothermobarometry

XMapTools is a MATLAB©-based graphical user interface program for electron microprobe X-ray image processing, which can be used to estimate the pressure–temperature conditions of crystallization of minerals in metamorphic rocks. This program (available online at http://www.xmaptools.com) provides a method to standardize raw electron microprobe data and includes functions to calculate the oxide weight percent compositions for various minerals. A set of external functions is provided to calculate structural formulae from the standardized analyses as well as to estimate pressure–temperature conditions of crystallization, using empirical and semi-empirical thermobarometers from the literature. Two graphical user interface modules, Chem2D and Triplot3D, are used to plot mineral compositions into binary and ternary diagrams. As an example, the software is used to study a high-pressure Himalayan eclogite sample from the Stak massif in Pakistan. The high-pressure paragenesis consisting of omphacite and garnet has been retrogressed to a symplectitic assemblage of amphibole, plagioclase and clinopyroxene. Mineral compositions corresponding to ~165,000 analyses yield estimates for the eclogitic pressure–temperature retrograde path from 25kbar to 9kbar. Corresponding pressure–temperature maps were plotted and used to interpret the link between the equilibrium conditions of crystallization and the symplectitic microstructures. This example illustrates the usefulness of XMapTools for studying variations of the chemical composition of minerals and for retrieving information on metamorphic conditions on a microscale, towards computation of continuous pressure–temperature-and relative time path in zoned metamorphic minerals not affected by post-crystallization diffusion.

3D X-ray microtomography study on fibre breakage in noil hemp fibre reinforced polypropylene composites

X-ray microtomography, image processing and Weibull statistical methods were used to characterize the length and width distributions of noil hemp fibres before and after composite fabrication. X-ray microtomography provided direct observations and accurate measurements of length and width of noil hemp fibres within the hemp–polypropylene composite matrix. The effects of the weight content of the noil hemp fibre and the addition of compatibilizer on the fibre breakage and tensile strength of the composites were studied. The results indicated that the tensile strength of the noil hemp fibre reinforced composites without the coupling agent was lower than that of pure polypropylene. Fibre–fibre interaction mechanism indicated that high hemp content caused more fibre breakage. The addition of maleic anhydride grafted polypropylene (MAPP) coupling agent improved the tensile strength of the composites by the enhanced fibre/matrix interfacial adhesion. The addition of MAPP also reduced the fibre breakage due to the better dispersion of fibres.

열교환기 브레이징 결함의 유형 분류 및 형상 디스플레이

X-ray cross-sectional image-based inspection technique is one of the most useful methods to inspect the brazing joints of heat exchanger. Through X-ray cross-sectional image acquisition, image processing, and defect inspection, the defects of brazing joints can be detected. This paper presents a method to judge the type of detected defects automatically, and to display them three-dimensionally. The defect type is classified as unconnected defect, void, and so on, based on location, size, and shape information of defect. Three-dimensional display which is realized using OpenGL (Open Graphics Library) will be helpful to understand the overall situation including location, size, shape of the defects in a test object.

Measurement of intervertebral cervical motion by means of dynamic x-ray image processing and data interpolation.

Accurate measurement of intervertebral kinematics of the cervical spine can support the diagnosis of widespread diseases related to neck pain, such as chronic whiplash dysfunction, arthritis, and segmental degeneration. The natural inaccessibility of the spine, its complex anatomy, and the small range of motion only permit concise measurement in vivo. Low dose X-ray fluoroscopy allows time-continuous screening of cervical spine during patient's spontaneous motion. To obtain accurate motion measurements, each vertebra was tracked by means of image processing along a sequence of radiographic images. To obtain a time-continuous representation of motion and to reduce noise in the experimental data, smoothing spline interpolation was used. Estimation of intervertebral motion for cervical segments was obtained by processing patient's fluoroscopic sequence; intervertebral angle and displacement and the instantaneous centre of rotation were computed. The RMS value of fitting errors resulted in about 0.2 degree for rotation and 0.2 mm for displacements.

Non-Destructive Porosity Calculation of an Indian Fermented Food &quotKhaman&quot using X-Ray Microtomography and Image Processing

To meet the increasing demand of Indian fermented food which is health soothing and to maintain its quality, the automation of the process is a must. Automation helps in enhancing the quality of processed food products. The Indian food: “KHAMAN”, a fermented snack, is made up of pulses powder, oil, curd as starter and water. Thoroughly mixed batter is steamed to produce desired quality spongy “KHAMAN”. The microstructure of this food product is directly related with the textural properties of the food. This paper describes the image processing techniques for the calculation of the void space of the Indian fermented food known as “KHAMAN” using X-ray Microtomograpny (μCT).The X-ray Microtomogrphic images were used for the analysis of percentage void space in the cooked food. The analysis of void space (air measurement) was done using the volume analysis on the set of cross sectional images of the cooked food samples. The μCT is useful for full 3D imaging of large samples (e.g. khaman cake with a length of 10mm) with a resolution of about 6μm. The image analysis was used for the calculation of the % void porosity space in the food. The percentage of void space measured for different food samples using the algorithm were found close to the practical measurements.

PITRE: software for phase-sensitive X-ray image processing and tomography reconstruction

Synchrotron-radiation computed tomography has been applied in many research fields. Here, PITRE (Phase-sensitive X-ray Image processing and Tomography REconstruction) and PITRE_BM (PITRE Batch Manager) are presented. PITRE supports phase retrieval for propagation-based phase-contrast imaging/tomography (PPCI/PPCT), extracts apparent absorption, refractive and scattering information of diffraction enhanced imaging (DEI), and allows parallel-beam tomography reconstruction for conventional absorption CT data and for PPCT phase retrieved and DEI-CT extracted information. PITRE_BM is a batch processing manager for PITRE: it executes a series of tasks, created via PITRE, without manual intervention. Both PITRE and PITRE_BM are coded in Interactive Data Language (IDL), and have a user-friendly graphical user interface. They are freeware and can run on Microsoft Windows systems via IDL Virtual Machine, which can be downloaded for free and does not require a license. The data-processing principle and some examples of application will be presented.

Vision base Tool Monitoring System for a Reconfigure Micro Factory System

During the past decade, new sensing technologies, such as are optical measurement, image processing (edge detection, pattern matching, x-ray image processing), acceleration sensor, vibration sensor, inductive loops, laser range scanners, computer vision sensors have been greatly enhanced and applied to the Intelligent in Automatic Tool Wear Monitoring System (ATWMS) area. On-line tool monitoring system may realize substantial cost saving through image processing. Currently, tool wear monitoring performed by vibration, inductive and debris sensors. Oil debris sensor is a popular measurement device used to collect oil condition data. This sensor generates an output signature with the passage of a metallic particle through the oil return lines. However, the signal measured through the oil debris sensor is severely tainted by various noises, e.g., the background noise present as well as the interferences caused by the vibrations of the structure where the sensor is mounted. These interferences affect the performance of the health assessment unit considerably. As such this paper focuses on the tool condition monitoring direct by metal chips using image processing technology.

The impact of digital image processing artefacts mimicking pathological features associated with restorations

Image processing of digital X-ray images is known to have the potential to produce artefacts that may mimic pathology. A study was conducted at a UK dental radiology conference to demonstrate this effect in dentistry. Sixteen digital X-rays of single teeth containing restorations were randomly presented in both unprocessed and processed formats to an auditorium of 42 participants. Participants interactively scored each image on a scale from 1-5 where 1 was definitely no pathology and 5 was definitely pathology. The display conditions were confirmed for each participant using a validated threshold contrast test. The results show that 52% (81/157) of responses at level 1 for the unprocessed images changed to levels 4 or 5 after image processing. This study illustrates the potential for image processing artefacts to mimic pathology particularly at high contrast boundaries and introduces the risk of unnecessary interventions. In order to minimise this risk, it is recommended that for digital radiographs containing pathology relating to high contrast boundaries, non-related high contrast features such as unrelated restorations or tooth/bone margins are also considered to exclude the possibility of artefact. If there is doubt, reference should be made to the unprocessed data.

Preheating of a target by laser radiation through plasma and polymer aerogel

Processing of X-ray and optical streak-camera images after brightness amplification 5 proves unambiguously the existence of a preheating of the foil in two-layer targets (polymer aerogel plus Al foil). We observed this effect earlier at the accuracy limit of the experiment. Preheating may be explained by the initial transmission of laser radiation by an inhomogeneous plasma and aerogel remnants. The fraction of laser energy that passed through a microheterogeneous plasma to the foil or shell is small in comparison with the total energy in the pulse, but it comes to the target (foil or shell) at the initial period of the laser pulse and can be significantly affected by the dynamics of plasma and the efficiency of spherical cryogenic thermonuclear targets.

Misalignment inspection of multilayer PCBs with an automated X-ray machine vision system

In recent times, multilayer printed circuit boards (PCBs) have been extensively applied in the electronics industry owing to their high capacities for complex and densely packed circuit layouts arranged in a limited space. The inspection of fabricated multilayer PCBs is thus important in order to ensure quality control and improve the fabrication process. In this paper, an automated X-ray machine vision system was developed exclusively for the inspection of the layer-to-layer misalignment of laminated multilayer PCBs. Based on a mechatronics system and X-ray image processing techniques, an automated misalignment inspection process was established. Experiments meant to inspect three critical layer-to-layer misalignment modes, expansion, contraction, and offset, found within ten-layer PCB samples, were conducted to test the feasibility of the developed machine inspection system. The experimental results show that the developed X-ray machine vision system, combined with the automated misalignment inspection process, was able to undertake misalignment inspection of certain multilayer PCBs.

Contrast enhancement of x-ray image based on singular value selection

Low-contrast profile images are frequently encountered in medical practice, and the correct interpretation of these images is of vital importance. This study introduces a contrast enhancement technique based on singular value decomposition (SVD) to enhance low-contrast fracture x-ray images. We propose a development of the traditional singular value solution by applying a feature selection process on the extracted singular values. The proposal calls for the establishment of a feature space in which the interpretability or perception of information in images for human viewers is enhanced, while noise and blurring are reduced. In this approach, the area of interest is manually cropped, and histogram equalization (HE) and singular value selection procedures are then conducted for comparative study. This approach exploits the spectral property of SVD, and the singular value selection algorithm is developed based on the corresponding Fourier domain technique for high frequency enhancement. The proposed method can generate more enhanced views of the target images than HE processing. Ten physicians confirm the performance of the proposed model using the visual analog scale (VAS). The average VAS score improves from 2.5 with HE to 8.3 using the proposed method. Experimental results indicate that the proposed method is helpful in fracture x-ray image processing.

Development of Mould Core Apple Detection System Using X-ray

In order to improve apples quality, many methods have been done on planting, harvesting and storing. However, mould core apples are caused by fungi or/and humid storage condition. Therefore, mould core apples should be selected as the last step to improve the apples quality before selling. This paper describes a detection system depending on X-ray technology, which can get the internal image of the detection objection, to detect the mould core apple. Nevertheless, X-ray is always avoided in the fruit detection because of the radiation of X-ray and the food safety. This paper solves this problem by using a low-level radiation of X-ray radiant. However, the low-level radiation of X-ray radiant generates a low contrast image, which raises a problem in X-ray image processing because it is difficult to distinguish the background and foreground in the low contrast image. In order to perform successful detection of mould core apple, in this paper, firstly, the Wiener filter is utilized for decreasing the image noise from the camera or/and X-ray machine imaging system. Then, the X-ray image is enhanced using contrast enhancement method to solve the problem of low contrast X-ray image. Thirdly, the mould core area is extracted by region recognition and edge detection method after using Lifting Wavelet Transform (LWT). Finally, support vector machine (SVM) is utilized to classify the mould core apple. The experiment results show that the image processing and classification method could detect mould core apple with a success rate of 95%.

Fuzzy intelligent quality monitoring model for X-ray image processing

Today's imaging diagnosis needs to adapt modern techniques of quality engineering to maintain and improve its accuracy and reliability in health care system. One of the main factors that influences diagnostic accuracy of plain film X-ray on detecting pathology is the level of film exposure. If the level of film exposure is not adequate, a normal body structure may be interpretated as pathology and vice versa. This not only influences the patient management but also has an impact on health care cost and patient's quality of life. Therefore, providing an accurate and high quality image is the first step toward an excellent patient management in any health care system. In this paper, we study these techniques and also present a fuzzy intelligent quality monitoring model, which can be used to keep variables from degrading the image quality. The variables derived from chemical activity, cleaning procedures, maintenance, and monitoring may not be sensed, measured, or calculated precisely due to uncertain situations. Therefore, the gamma-level fuzzy Bayesian model for quality monitoring of an image processing is proposed. In order to apply the Bayesian concept, the fuzzy quality characteristics are assumed as fuzzy random variables. Using the fuzzy quality characteristics, the newly developed model calculates the degradation risk for image processing. A numerical example is also presented to demonstrate the application of the model.

Radiographic Marking of Patient’s Gravity Line on X-Ray Images

Objective: To develop a clinically feasible apparatus for measuring and marking patient’s gravity line position on spinal x-ray images. Background: Spinal balance of patients with deformity or instability is an important clinical parameter for patient diagnosis, surgery planning and treatment outcome evaluation. Traditional assessment of spinal balance is performed on full spine x-ray images using C7 plumb line relative to central sacral line in the coronal plane or posterior superior corner of S1 in the sagittal plane. Researchers have developed measurement techniques using a force plate synchronized with x-ray equipment and offline x-ray image processing. The complexity of these techniques limits their clinical applications. In this study, we present a new system to mark gravity line directly on an x-ray image. Methods: The system consists of a force plate, a signal conditioner and processor, a motion controller and a motor assembly that moves a radio-opaque marker. The processor calculates the location of gravity line and marker position, and transmits motion commands to the motion controller, which drives a motor assembly and moves the marker to appropriate positions. The acquired x-ray image has a mark indicating the instantaneous gravity line position. Evaluation: A prototype was installed in the radiology department. More than 200 patients were instructed to stand on the force plate. Exposure was performed as in routine x-ray imaging. The system does not affect routine x-ray workflow and provides valuable information for spine surgeons.

X-ray imaging in pin-in-paste technology

Today, pin-in-paste technology is used extensively. With the help of pin-in-paste, through-hole devices can be soldered using a standard surface mount technology (SMT) process and hereby a reduction in wave soldering is possible. This can result in cost savings and a decrease in production cycle time. To ensure successful pin-in-paste soldering the following steps must be taken: solder paste volume calculations for through-hole components; stencil aperture design for the pin-in-paste application; solder paste deposition through stencil printing, application of solder volume increasing techniques after printing; reflow profile optimization; inspections using special methods for each individual process; final tests. The paste is printed into the through-holes. For high quality pin-in-paste solder joints a sufficient volume of paste is a fundamental requirement. Nevertheless, after printing the through-hole-filling is usually unknown. In this paper a new method is described how to accurately determine the volume of solder alloy in solder paste that is present in the through-hole, using X-ray measurements, image processing and calculations. In addition, a method is suggested to determine the measuring characteristics and gray-scale linearity of the X-ray machine.

DEVELOPMENT OF A COMPUTER-AIDED TRAINING SYSTEM FOR PEDICLE SCREW IMPLANTATION

In this research, we developed an intelligent, computer-assisted training system for pedicle screw implantation in spinal surgery. Base on the biplane X-ray imaging of a pre-drilled saw bone of lumbosacral spine, spatial coordinate correlations between the physical saw bone and the 3D digitizer built an off-line training environment. A senior spine surgeon prepares the pre-drilled position as a standard and the trainee uses the 3D digitizer to approach the referential standard. The techniques developed in this system involve X-ray imaging rectification, registration, image processing, imaging dilation and erosion, bi-plane calibration, and spatial geometric transformation, which will be a pioneer study of further clinical applications. The position accuracy of the guiding system is within 1 mm, and angular accuracy is within 1.5°, which may meet the basic surgical requirements for lumbosacral spine. Eventually, the developed training device was applied to several orthopedics surgeons to collect and analyze the angulation test results.