Introduction to the core equipment of the hottest

Introduction to the core equipment of digital medical imaging

the core equipment of digital medical imaging is a medical equipment widely used in hospitals, which takes the digital form that can be recorded by computers as the output for disease diagnosis and treatment. Among them, digital medical imaging equipment, radiotherapy equipment and hyperthermia equipment are the main product types of this kind of equipment. Among them, it can be divided into imaging and radiotherapy equipment of ionizing radiation type material wave source, such as equipment for X-ray imaging, including plane X-ray machines: Cr and Dr, as well as tomography X-CT equipment, and currently developing volume imaging X-ray imaging equipment, which can be abbreviated as v-ct; There are also nuclear medical imaging equipment: single photon emission tomography SPECT and positron emission tomography PET equipment. All X-rays and gamma rays can be used for both imaging and tumor radiotherapy, and they are the mainstream products in the current radiotherapy market. The other is non ionizing radiation imaging diagnosis and treatment equipment. For example, nuclear magnetic resonance imaging equipment and ultrasonic imaging equipment. Now, the material waves in the radio frequency band and ultrasonic mechanical waves can also be used for tumor treatment

the invention and development of medical imaging equipment is a revolutionary progress in human disease diagnosis. It is one of the most valued industrial fields in all countries in the world. Its level is closely related to the overall development level of the country. Measured by the per capita consumption level, the development of this industry in China is far from meeting the needs. From the long-term and huge demand for human health, this is a sunrise industry

the key technologies and development contents involved in digital medical imaging equipment can be summarized into the following 10 key problems and 4 application fields

10 key technologies involved in digital medical imaging equipment:

(1) the principle and key technologies of generating material wave equipment for imaging, that is, the methods and key technologies to improve the efficiency of wave source generating material wave and improve the quality of material beam flow

(2) model the law of interaction between material waves and human tissue, and improve the quantity, quality and speed of image information extraction through the optimization of model parameters

(3) study the detection components such as detectors, sensors or transducers that detect material waves, so that they have better sensitivity and spatial and temporal resolution

(4) amplify, shape and digitize the detected signal, prevent distortion in the coding process of computer recording, and carry out research on methods to improve signal transmission efficiency and fidelity

(5) methodological research on fast and efficient image reconstruction and noise reduction in reconstruction

(6) reduce noise. Some typical cases include artifact and distortion, and methodological research to improve image quality

(7) medical image display methods and key technologies that are more in line with human visual effects

(8) methodology and corresponding software designed to measure and evaluate the performance indicators of the new imaging system

(9) PACS (pictureachievingcommunicationsystem) technology with efficient and fast storage, communication management, retrieval of medical images and the methodology of finding regular knowledge from massive data

10) molecular and gene imaging, in the post gene era after gene sequencing, in order to understand the relationship between genes and biological macromolecules in the human body, diseases and genes, as well as the relationship between biological macromolecules, developing gene and molecular imaging has become a new development direction of medical imaging. Among them, nuclear medical imaging and functional magnetic resonance imaging are molecular and gene ligand imaging that can be used in clinical diagnosis and treatment, while optical imaging is a very promising imaging mode under development

however, due to poor spatial resolution and the limitation of radiolabeled drugs, the potential of nuclear medicine imaging for molecular level imaging has not been well developed. With the advent of the post genetic era, nuclear medical imaging will receive more and more attention. MRI can provide some practical technical means of molecular imaging, such as spectral imaging technology. Molecular imaging tools are necessary tools for new drug development, but few domestic drug developers use such tools. Because using radiolabeled drugs to study drug pathology and toxicity is the most important tool for in vivo level research. Therefore, we summarize the last important direction of imaging technology as: new principles and methods to realize molecular imaging, as well as the improvement technology of existing methods

the four application fields of medical imaging can be summarized as:

(1) the application of non-invasive diagnosis of diseases has involved almost all fields related to human anatomy and physiology, but the most important is the examination of organ injury after tumor, cardiovascular and mechanical trauma, and the measurement of organic lesion parameters or metabolic function parameters of all organs

the content introduced here should also include computer-aided diagnosis. Because the radiology department of the hospital produces too many images every day, the workload of radiologists is too large, and the eyes are prone to fatigue. In addition, personal experience problems, missed diagnosis or misdiagnosis often occur. In order to reduce the workload and the number of people used for biopsy, prevent missed diagnosis and reduce misdiagnosis, it is very necessary to develop medicalimagingbasedcomputedassistantdiagnosis (MICAD) based on medical images

(2) the application in the basic research of brain functional imaging is also an important content of future development. It is self-evident that the role of the brain is important to people. At present, brain functional imaging is the only effective method to study the working mechanism of human brain and diagnose brain diseases without trauma. From the perspective of basic research, they are the main tools of experimental psychology; From a medical point of view, it is mainly used to diagnose brain functional diseases, provide brain functional diseases for brain space occupying lesions, and provide information about the redistribution of functional modules for brain space occupying lesions, so as to provide a basis for accurate treatment. In fact, brain diseases are common and frequently occurring diseases. The diagnosis and treatment of these diseases require functional imaging of the brain. Solving these problems is a challenge facing mankind in the 21st century, and it is also a place where there may be major breakthroughs in science and medicine. In fact, brain cognitive function imaging has been fully available for clinical diagnosis

(3) imaging equipment is also an auxiliary tool for disease treatment, which mainly includes the design of surgery or tumor radiotherapy plan, image supervision technology during treatment, verification and prognosis after treatment. At the same time, virtual endoscopy technology, surgical planning, image-guided surgery, radiotherapy planning based on image information, and image-guided interventional therapy, which are completed through information integration, are important application fields of medical imaging, and their applications are in the ascendant

(4) medical images are also widely used in the teaching of anatomy and physiology. In the future, medical students should have a wide range of knowledge, such as the basic medical image generation mechanism, the design principle of various imaging devices and detection standards, so as to lay a foundation for him to choose reasonable imaging tools after becoming a formal doctor

to sum up, medical image is the largest information source of the human body. Through non-invasive data acquisition, the information measurement of the human body on the time axis in three-dimensional space is realized. Through the analysis of the measured data, the internal anatomy, physiological function and brain cognitive psychological information of the human body are obtained. It is an industrial group that collects the macro and micro information of the human body and has a very wide range of applications. Working around this industrial cluster is not only the R & D, production, sales and after-sales service personnel of such products, but also the medical personnel, medical physicists, clinical engineers and technicians who use these equipment

to sum up, medical imaging is an important tool for human information acquisition, analysis and diagnosis and treatment of human diseases. The development of these industries reflects the overall strength of a country and the comprehensive level of science and technology

however, at present, any imaging tool can only obtain part of the information of the human body. Local or partial information is not enough to provide sufficient basis for accurate diagnosis, so tumor biopsy cannot be abolished. Coupled with various reasons, artifacts and noise are also entrained in the image, so the correct use of imaging tools, continuous improvement of the quality of medical images, and research and development of new imaging tools are the problems that we need to solve for a long time in our future development

2. Current situation in the field of medical imaging

2.1 Four imaging systems widely used in clinic

(1) X-ray imaging r

since roentgen discovered X-ray, almost all the physics departments of universities in the world have established X-ray generation and imaging equipment, and soon have been widely used in medicine. Today, 110 years later, it is estimated that about 700 people in every 1000 people use X-ray examination every year, and modern people have to do dozens of X-ray imaging examinations in their lives. Therefore, X-ray imaging and its application can be called the most important milestone in the history of world science and medical development. X-ray fluoroscopy and X-ray radiography, which are based on the different absorption characteristics of X-rays in different organs and tissues of the human body, provide a powerful means for the diagnosis and location of diseases or injuries of human bones and internal organs. At the same time, they also bring film into the field of medical imaging, making it the main tool of image display for more than 110 years

after planar X-ray imaging, imaging enhancers have been greatly developed. Angiography technology and specialized X-ray machines of other organs have been extended one after another, greatly expanding the application range of X-ray imaging. At present, among all angiography technologies, X-ray angiography is still the most classic technology, which can be used as the gold standard of other imaging technologies

the future development direction of planar X-ray imaging is digital X-ray machine technology. This technology comes from the criticism of the traditional X-ray machine. The dose of traditional X-ray machine photography technology may increase the incidence rate of cancer, thus limiting its application in maternal and child health examination; Because the size of particles used in film imaging has been limited, and it is very difficult to further overcome factors such as particle heterogeneity, the further improvement of film image quality is limited. The biggest problem of using film as the imaging medium is that film images cannot be used for computer processing and storage, and cannot be transmitted on

at present, digitizing the traditional X-ray machine is the trend of development, including direct digitalization of X-ray machine (DR) and image version of X-ray machine (CR). Of course, the ultimate goal is Dr, but the popularization of Dr needs to further improve the feasibility of products and reduce the price of products

(2) X-ray tomography (X-CT). This is the inevitable result of the further development of planar X-ray imaging after its full development. X-CT has developed from simple imaging equipment in the early 1970s to multi-slice spiral CT technology today. It is one of the most mature imaging modes in the development of traditional imaging technology, and its speed has been fast enough to realize the dynamic imaging of the heart. However, how to choose between patient dose and film thickness is a problem that often needs to be considered in clinic; The further improvement of spatial resolution and contrast is also subject to many constraints. However, multimodal integrated imaging equipment, such as PET-CT, MRI-CT, sub linear accelerator/ct, have come out one after another, providing users with more