Kind Of Imaging Technique Research Articles

Research advances in imaging techniques related to the diagnosis of pneumoconiosis

Occupational pneumoconiosis (hereinafter referred to as pneumoconiosis) is the most harmful occupational disease in China. According to the current standard GBZ 70-2015 Diagnosis of Occupational Pneumoconiosis, pneumoconiosis is mainly diagnosed and staged by high kilovolt or digital radiography. Chest radiography in pneumoconiosis is the most widely studied and mature imaging technique in the diagnosis of pneumoconiosis. However, this technique has some limitations in the screening of some early pneumoconiosis and occupational health examination, and there is a certain risk of missed diagnosis and misdiagnosis. With the continuous development of imaging examination technology, computed tomography, magnetic resonance imaging, positron emission tomography-computed tomography and artificial intelligence technology as auxiliary imaging examination methods have shown different diagnostic values in the research of auxiliary diagnosis of pneumoconiosis. This paper summarizes the advantages and problems in the application of various kinds of imaging techniques, which provides a direction for the future research of imaging techniques related to the diagnosis of pneumoconiosis.

Toward Small-Sample Radar Target Recognition via Scene Reimaging

Target recognition via deep learning has achieved great performances in the preceding works. Yet this family of method are dependent on large amounts of training data with label information. For radar sensors, it is difficult to collect labeled data in practical due to the absent imaging truth. The commonly used solution is data augmentation. However, seldom studies are devoted to complex-valued radar images. In this paper, a new radar image generation method via target re-imaging is proposed. The original image is first cast into the frequency-aspect domain. The one axis represents the transmitted frequency, while the other presents the synthetic azimuth. The inverse operations of zero-padding and windowing are then applied on the transformed data. Two kinds of imaging techniques, the intra-sample re-imaging and the inter-sample re-imaging are presented to generate new radar images. The generated images are finally used to improve the learning effectiveness of deep models. Multiple comparative studies are performed to demonstrate the advantages of the proposed method.

Label-Free Optical Imaging of the Dynamic Stick-Slip and Migration of Single Sub-100-nm Surface Nanobubbles: A Superlocalization Approach.

The past decade has witnessed theoretical and experimental debates on the extraordinary long lifetime and low contact angle of surface nanobubbles. While several kinds of imaging techniques have provided promising evidence on the lifetime and gaseous nature of single surface nanobubble, each of them suffered from its own limitations before a consensus can be reached. In the present work, we employ a recently developed surface plasmon resonance microscopy (SPRM) to nonintrusively visualize single sub-100-nm surface nanobubble without labeling for the first time. The quantitative dependence between optical signal and nanobubble volume allows for resolving the dissolution kinetics, which is a key for understanding the lifetime. A superlocalization method is further introduced to monitor the trajectory of its mass center during dissolution, which uncovers the stick-slip behavior in the early stage and the migration behavior in the late stage. The label-free, nonintrusive, quantitative and sensitive features of SPRM and the potential compatibility with atomic force microscopy shed new light on the long-standing puzzle behind surface nanobubbles.

Non-destructive study of fruits using grating-based X-ray imaging

Grating-based X-ray imaging can make use of conventional tube sources to provide absorption, refraction and scattering contrast images from a single set of projection images efficiently. In this paper, a fresh cherry tomato and a dried umeboshi are imaged by using X-ray Talbot–Lau interferometer. The seed distribution in the scattering image of the cherry tomato, and the wrinkles of epicarp in the refraction image of the umeboshi, are shown distinctly. The refraction and scattering images provide more information on subtle features than the absorption image. Also, the contrast-to-noise ratio values show distinguishing capacity of the three kinds of imaging techniques. The results confirm that grating-based X-ray imaging is of great potential in non-destructive fruit testing.

Characteristics and enlightenment of teaching and clinical model of medical imaging in Italy

Italian medical imaging education includes two parts: training for radiologists and for radiologic technologists. To be a radiologist, the six-year medical students after graduation must complete specialty training in radiology and pass the examination. Radiologic technologists are selected from the three-year bachelor graduates of medical imaging technology. There are basic medical science courses, cultural practice and clinical practice in medical college every year. Continuing medical imaging education includes lectures, case discussions and other forms. Radiologists are required to master all kinds of imaging techniques, working as clinical rotation in every section of medical imaging depart-ment. Patients need to make an appointment before having the medical imaging examination. Through the analysis of the characteristics of Italian medical imaging teaching and clinical patterns, the author puts forward the suggestion of putting emphasis on medical imaging curriculum reform, the full imple-mentation of the early clinical contact, and at the same time improving the professional medical image training mode to improve the radiologists' clinical ability. Key words: Medical imaging; Medical imaging technology; Clinical medicine

Gravity correlation imaging with a moving data window

As a kind of imaging technique, correlation imaging of potential data can be used to determine the shape and position of sources approximately. In order to improve the resolution of correlation imaging results, I adopted a strategy similar to Euler deconvolution method. This method includes three steps. First, calculate the vertical gradient of gravity anomaly. Then add a moving data window to the correlation imaging procedure. At last, search the local maximum or minimum of the results and output the extreme points that meet the acceptance criterion. In the synthetic model tests, the resolution of correlation imaging is improved. Compared with the Euler deconvolution, the results are closer to the centers of the models. In a case study of a sylvite mine gravity survey in Yunnan Province, China, the positions of extreme points of correlation imaging are in the range of the ore zone defined by drills.

Anatomy and medical imaging: a symbiotic relationship

Keywords Anatomy Cross-sectional Computedtomography Diffusion tensor imaging X-ray Magnetic resonance imaging fMRIIn 1895, the anterior-posterior plain radiograph of the lefthand of Anna Bertha, the wife of Professor WilhelmConrad Roentgen, physicist in Wu¨rstburg (Germany) wasthe first step of medical imaging [8]. For almost one cen-tury, X-ray projection was the unique tool available fordepicting the human body; what is now called medicalimaging was then called radiography. Directly, X-raysallow only accurate imaging of the bones and the lungs.Direct soft tissue depicting by X-ray projection is verypoor, but progressive use of varied contrast media broughtan important contribution to the field. Through theirinjection into the blood or the lymphatic vessels, as well asinto various organs or anatomical spaces, such as the joints,the digestive tract, the subarachnoidal space, etc., thesecontrast media have gradually enlarged the spectrum ofexploration by X-rays.In the 1970’s, the advent of computed tomography (CT)[1–3], paralleled by ultra-sonography (US) [4] and, later,that of magnetic resonance imaging (MRI) [6] opened thefield of cross-sectional imaging and really revolutionizedthe field of radiography by moving it into true medicalimaging. A new era had begun: the anatomy of livinghuman beings could be depicted by this truly new field inthe medical practice [7].Within the last two decades, there have been otherdramatic improvements observed. Today, medical imagingallows for visualizing long fibrous structures such as thebundles of white matter of the brain through diffusiontensor imaging, as well as depicting the human brain inactivity with functional MRI, or imaging motion of thejoints, among others [5].It must be underlined that the tremendous progress in thefield of informatics has paralleled that of imaging tech-nologies. As a unique example, the plain radiograph filmhas almost completely been replaced by digital images.Continuous technical progress is changing the capabilityof medical imaging techniques almost every day, currentlyallowing for more and more accurate anatomical studies ofliving human beings.The aim of this special issue of Surgical and RadiologicAnatomy is to illustrate a large number of the modernmedical imaging techniques as well as how they can beused for proper anatomical applications.It has been composed by an international panel ofauthors and offers particular insights into the main modernimaging methods, by covering a wide range of anatomicaltopics. They include head and neck, central nervous sys-tem, abdomen and pelvis, musculoskeletal system, andvessels. They have been sorted according to the kind ofimaging technique in order to illustrate the spectrum ofimplementation for each of them.A general review purposes an overview of the mainrecent advances in the field of medical imaging especiallyin order to highlight their potential anatomical applications.The pedagogical section is devoted to anatomicaldrawing. Obviously, it has no specificity to medical

Rigorous theory on elliptical mirror focusing for point scanning microscopy

A rigorous elliptical mirror focusing formula based on spherical wave transformation is derived as a kind of imaging technique with high NA for potential applications in molecule imaging, spectroscopy and industrial artifact microscopy. An apodization factor is given and used to compare the energy conversation rules in lens transmission and parabolic and elliptical mirror reflections. Simulation results indicate that the axial HFWHM of elliptical and parabolic mirrors is about 80% of the corresponding HFWHM of lens in case of NA = 1 and φs = 0, and the side lobe noise is also slightly lower than that of lens, but the transverse HFWHM of mirrors is comparatively wider despite the width of main lobe is still smaller. In comparison with parabolic mirror based system, an elliptical mirror based system is potentially promising in aberration control of incident beam when the aperture of mirror is enlarged to adapt a large stage or specimen container at a small beam shading ratio.

Prospective evaluation of ultrasonography, multi-slice spiral CT, endoscopic ultrasonography, and magnetic resonance imaging in assessment of TNM staging and assessment of resectability in pancreatic carcinoma

To evaluate prospectively the efficacy and clinical significance of ultrasonography (US), multi-slice spiral CT (MSCT), magnetic resonance imaging (MRI), and endoscopic ultrasonography (EUS) in assessment of the TNM staging and resectability of pancreatic carcinoma. Consecutive 68 patients with pancreatic carcinoma underwent US, MSCT, MRI, and EUS to assess their efficacies in assessment of the size of carcinoma, lymph node metastasis, and distant metastasis. The results of theses imaging techniques were compared with the surgical and pathological findings. EUS was the most precise technique in evaluating the T staging of pancreatic carcinoma with the coefficients of regression of maximum and minimum radii of 1.025 (P=0.043) and 0.987 (P<0.0001). In the assessment of lymph node metastasis, EUS had the highest sensitivity (75.0%), accuracy (87.5%), and negative predictive values (91.7%). Univariate logistic regression showed that EUS was significantly correlated with the surgical findings (OR: 33.00, 95%CI: 7.18-151.77 P<0.0001). Multivariate logistic regression analysis confirmed that EUS had an independent predictive value (OR: 34.50, 95%CI: 6.54-182.09, P<0.0001). MSCT had the highest sensibility (88.9%) in the assessment of distant metastasis and had the highest accuracy (61.8%) in preoperative TNM staging of pancreatic carcinoma. All 4 imaging techniques were correlated with surgical findings in assessment of the resectability. Multivariate logistic regression analysis confirmed that none of the imaging techniques had independent predictive value. MSCT is the best method in preoperative TNM staging of pancreatic carcinoma. EUS is the best methods in the assessment of tumor size and lymph node metastasis. Preoperative assessment of pancreatic carcinoma needs combination of at least two kinds of imaging techniques.

Evaluation of osteoporotic bone structure through synchrotron radiation X-ray microfluorescence images

The abnormal accumulation or deficiency of trace elements may theoretically impair the formation of bone and contribute to osteoporosis. In this context, the knowledge of major and trace elements is very important in order to clarify many issues regarding diseases of the bone, such as osteoporosis, that remain unresolved. Several kinds of imaging techniques can be useful to access morphology and the minerals present in osteoporotic bones. In this work, synchrotron radiation X-ray microfluorescence was used as an X-ray imaging technique to investigate bone structures. Therefore, this research aims to improve the knowledge about some aspects of bone quality. The measurements were carried out at the Brazilian Synchrotron Laboratory Light Laboratory, in Brazil. A white beam with an energy range of 4–23 keV, a 45°/45° geometry and a capillary optics were used. It was demonstrated that bone quality can and must be evaluated not only by considering the architecture of bones but also by taking into account the concentration and the distribution of minerals. Our results showed that the elemental distributions in bone zones on a micron scale were very helpful to understand functions in those structures.

Studies of the correction for phase diverse speckle

Phase diverse speckle is a novel kind of imaging technique and can be used to overcome image degradation from unknown phase aberrations, such as atmospheric turbulence. The wave-front phase expanded on the Zernike polynomials is estimated from a pair of images (in the focal and out of focus planes). In this paper the principle of PDS is analyzed, and genetic algorithm is used as the iterative algorithm to simulate some characteristics, such as the influence of Zernike polynomials’ mode, amplitude of turbulence on the phase estimation. Thus, a new method for recovery of images is explored.

Fast Neutron Radiography at reactor YAYOI

Fast Neutron Radiography (FNR) has been studied with use of the fast neutron source reactor YAYOI of the University of Tokyo. Three kinds of imaging techniques have been applied to the FNR. A CR39 nuclear track detector has been used successfully in the first FNR experiments at YAYOI. This is called as a CR39 track-etch method. The etched out images on the CR39 sheet usually have a low optical density. In order to perform an imaging technique with high resolving power and high contrast, a combination method of a thin type of luminescent converter and X-ray film (a film method) has been developed for the FNR. The converter is made of mixture of PMMA and ZnS(Ag), the thickness of which is 40 μ m. The system could observe the gap of 100 μ m. In the procedure with use of the CR39, it took long time, about 24 hours, to get images. And it took about 3 hours to get imaging results by the film method. A fast neutron television method (FNR-TV) was proposed for shortening the time of taking the images and for taking real time images. The same technique as a current thermal neutron television system was applied to the system while different luminescent converter was used. The prototype converter was made of mixture of polypropylene resin and ZnS(Ag). Static images and real time images were obtained successfully by the fast neutron television method.

Characterization of the YAYOI fast neutron radiography field

Fast Neutron Radiography (FNR) has been studied with the use of the fast neutron source reactor YAYOI of the University of Tokyo. Three kinds of imaging techniques have been applied to the FNR. A CR39 nuclear track detector called the track-etch method has been successfully used in the first FNR experiments at YAYOI. The etched out images on the CR39 sheet usually have a low optical density, and took about 24 hours to get images. In order to perform an imaging technique with a high resolving power and high contrast, a thin type of luminescent converter and X-ray film method (film method) has been developed for the FNR. The converter is made of a mixture of PMMA and ZnS(Ag). the thickness of which is 40 μm. The system could observe a gap of 100 μm, and took about 3 hours to get results. To make the required imaging time shorter, a television system of fast neutron radiography (FNR-TV) was proposed. In the system, the same technique as a current thermal neutron television system was applied while using a different luminescent converter. The prototype converter was made of a mixture of polypropylene resin and ZnS(Ag). A method of determining L and D was proposed in this paper. Experimental result of L agreed with the geometric dimension of L, while the value of D will be discussed in another paper.