Yan Wenming, Department of Radiotherapy, Affiliated Hospital of Inner Mongolia Medical University
[Abstract] With the progress of science and technology, medical imaging technology has made great development. And its position in the medical field will be more important. This paper talks about the history of medical imaging technology development, summarizes the new progress made in recent years, and discusses the hot spots in its next stage.
[Keywords] Medical imaging technology; development; hot spots
ThePast,Presentand Futureof Medical Imaging Technology and Equipment
Abstract With progress of technology medical imagin technology makes considerable development and the position in the medical field will be even more This paper shows the developing process of medical imaging technology ,the achievement of medical imaging technology accomplished during This paper shows the developing process of medical imaging technology ,the achievement of medical imaging technology accomplished during the recent years and discuss what will be the next hot area.
Key words：medical imaging technology；develop；hot area
All things in the universe are composed of molecules. The atoms, which are composed of molecules, are made up of a nucleus and electrons that revolve around the nucleus. X-RAY fluoroscopy and photography, the earliest medical imaging technology, is still one of the most popular and clinically valuable medical diagnostic methods today. Medical imaging technology is mainly a technical means (including principles, methods, devices and procedures) developed by applying the concepts and methods of engineering (engineering) and based on the principles of engineering (engineering), in fact, medical imaging technology is also an important part of medical physics, which is an advanced technical means developed by using the concepts and methods of physics and physical principles. Medical imaging information includes traditional X-ray, CT, MRI, ultrasound, isotope, electronic endoscopy and surgical photography. They are important methods to detect the morphology and function of tissues and organs inside the human body and to diagnose diseases. With the development of medical and health care, film as the main way to display, storage, delivery X-ray camera technology can no longer meet the needs of clinical diagnosis and treatment development, the digital requirements of medical equipment is increasingly strong, fully digital radiology, image guidance and teleradiology will be the inevitable trend in the development of radiology imaging.
1 Traditional photography technology in the mapping
1.1 Computer X-ray photography
X-ray is the earliest developed imaging device. Its application in medicine enabled doctors to observe the internal structures of the human body, which provided important information for doctors to make disease diagnosis. In the decades following 1895, there were a number of developments in x-ray photography, including the use of image intensification tubes, sensitization screens, rotating anode x-ray tubes, and tomography. However, the performance of the overall imaging system was limited by the fact that this conventional X-ray imaging technique displayed three-dimensional body structures on a two-dimensional plane, coupled with its poor diagnostic capability for soft tissues. Starting in the 1950s, medical imaging technology entered a revolutionary period of development, with the emergence of new imaging systems, and in the early 1970s, the rapid development of medical imaging reached a peak due to the advent of computed tomography. Throughout the 1980s, in addition to X-rays, ultrasound, magnetic resonance, single photon, positron, and other tomographic imaging techniques and systems emerged in large numbers. Each of these methods has its own strengths and complements the other, providing doctors with increasingly detailed and accurate information to make a definitive diagnosis. X-ray images account for 80% of all hospital images and are currently the primary source of hospital images. Before the 1950s, X-ray machines were simple in structure and low in image resolution. After the 1950s, resolution and clarity improved, while the dose to the patient was reduced. Today, a variety of special X-ray machines continue to appear, X-ray television equipment is gradually replacing conventional X-ray fluoroscopy equipment, which not only reduces the labor intensity of medical personnel, reduce the patient’s X-ray dose; but also for the application of digital image processing technology to create the conditions. With the development of computers digital imaging technology is increasingly widespread instead of traditional screen photography At this stage, the detection system used for digital photography are the following: (1) storage fluorophore sensitization screen [computer radiography system (computer Radiography. CR)]. (2) Selenium cartridge detectors. (3) Charge Coupled Derices (CCD) based detectors. (4) Flat panel Detector (Flat panel Detector) a: direct conversion (non-crystal selenium) b: non-direct conversion (scintillation crystal). These systems automate, remote control and bright room, reducing radiation damage to the operator.
1.2 X-CT
The introduction of CT is recognized as a major breakthrough since Roentgen’s discovery of X-rays, as he marked a milestone in the integration of medical imaging equipment with computers. There are two modes of this technique, one is called “first-arrival tomography” (FAT) and the other is “photon migration imaging” (PMI).
1.3 Magnetic Resonance Imaging
Magnetic resonance imaging, now known as MRI, is performed without radiation damage and without bone loss. It has the unique advantages of no radiation damage, no bony artifacts, multifaceted and multiparametric imaging, high soft tissue resolution, and the ability to show vascular structures without the use of contrast agents.
1.4 Digital subtraction angiography
It uses a computer system to convert the fluoroscopic image of the contrast injection at the imaging site into digital form and store it on a memory disk, called a mask. Then the fluoroscopic image of the contrast area after the injection of contrast agent is also converted into digital, and the digital mask is subtracted, and the remaining digital is converted into image again, that is, the bone and soft tissue image seen on the fluoroscopic image before the injection of contrast agent is removed, and what remains is a clear pure angiographic image.
2 Digital photography technology is becoming more and more perfect
In June 1981 in Brussels at the 15th International Society of Radiology academic meeting, the first time the physical concept of mathematical X-ray imaging technology and clinical application results. This brought medical imaging technology into a new era of digitalization. In fact, the trend of digitalization of medical imaging technology has become clearer in the past 10 years. In 1998, the “Annual North American Radiology Conference”, which reflects the highest level of international medical imaging technology, reflected the trend of digitalization of medical imaging equipment, both from academic reports and exhibitions.
The imaging technology of digital radiography includes imaging plate technology, parallel plate detection technology and the use of charge coupler or CMOS devices and line scan technology. Imaging plate technology is a method of replacing the traditional film sensitization screen to take pictures and then record them on film. Parallel plate detection technology can be further divided into two types of structures: direct and indirect. The direct FPT structure is mainly a flat plate detector consisting of a non-pint selenium and thin film semiconductor array. Indirect FPT structure is mainly composed of scintillator or fluorescence body layer plus a non-picture silicon layer with photodiode effect in addition to TFT arrays constitute the flat plate detector. Charge-coupled or CMOS devices and line scan and other technologies structured to include visible conversion screens, optical systems and CCD or CMOS.
3 Imaging fast reading
As a result of improvements in imaging methods, the number of images has increased dramatically in addition to significant improvements in imaging quality. For example, with the introduction of multilayer CT, the number of images per CT examination can be more than a thousand, so it is inconceivable that the dynamic information contained in these images can be read by conventional methods. This is when the “soft reading” on the monitor is gradually showing its unparalleled superiority. Soft copy reading refers to the observation of images on a workstation image display, and in the case of radiography, this type of reading can take advantage of the much greater dynamic range of digital images to obtain a wealth of diagnostic information.
The Past, Present and Future of Imaging Technology and Equipment From:Bookmark the permalink www.shu1000.com4PACS的广阔发展空间
With the rapid development of computer and network technology, the existing medical imaging equipment continues to be the data acquisition and imaging method for decades, which is far from being able to meet the development of modern medicine and the needs of clinicians. PACS system can be connected with hospital information management system radiology information management system and other systems to realize filmless, paperless and resource sharing of the whole hospital, and can also use network technology to realize remote consultation or international information exchange. the creation of PACS system marks the arrival of network imaging and filmless era. A complete PACS system should contain an image acquisition system, storage and management of data, data transmission system, and analysis and processing system of images. The data acquisition system is the core of the whole PACS system and is the key part to determine the quality of the system, which can pick up the images generated by various different imaging systems into the computer network. Since the data volume of medical images is very large, the choice of data storage method is crucial. Optical disk towers, tape libraries, and disk displays are currently better storage methods. Data transmission is mainly used for in-hospital emergency and consultation, and there is also the possibility of remote diagnosis through the Internet, microwave and other technologies for long-distance transmission of data. The analysis and processing system of images is a tool directly used by clinicians and radiologists, and its function and quality play a decisive role in the efficiency of doctors in using clinical imaging resources. In summary, PACS technology can be divided into three stages, (1) users find the database; (2) data find the device; (3) image information and text information actively find the user.
5 New Technology —- Molecular Imaging
With the rapid development of medical imaging technology, today has the ability to microscopic resolution, its visual range has been extended to the cellular and molecular level, thus changing the traditional medical imaging can only show anatomical and pathological changes in the morphological imaging capabilities. In 1999, Weissleder introduced the concept of molecular imaging: the qualitative and quantitative study of biological processes at the cellular and molecular levels in a living state.
The advent of molecular imaging brought light to the dawn of a new era of medical imaging. Gene expression and therapy, on the other hand, offer the possibility of a complete cure for certain diseases. Therefore, the whole world is currently dedicated to research and pioneering molecular imaging and gene therapy, which is the imaging of the 21st century. The new medical imaging has to look beyond the current concepts of anatomy and pathology and go deeper into the molecules and atoms of tissues. The key to this is with the help of magical probes – i.e. molecular probes. So far, the imaging techniques of molecular imaging mainly include MRI, nuclear medicine and optical imaging techniques. Some knowledgeable people believe that since interventional radiology, which is both diagnostic and therapeutic, has reached the level of molecular biology, molecular imaging should include the study of interventional radiology at the molecular level.
6 Interdisciplinary combination of disciplines
Cross-discipline, edge disciplines is the trend of scientific development today. The most adjacent discipline of imaging technology should be diagnostic imaging. The former is dedicated to the acquisition, storage, transmission and management of information and the development of new technical methods; the latter combines information with knowledge and experience, focusing on the content of information and the identification of normal anatomical structures and the diagnosis of lesions based on images. The two complement each other and rely on each other. Therefore, the development of imaging technology cannot be separated from the closer communication and integration of diagnostic imaging will make useful contributions to improve and expand the original imaging modality and open up new imaging modalities. Medical diagnostic imaging devices are used to observe the structure of the internal organs of the human body in detail, to find out the location of lesions mg size, and some can also make judgments about the function of organs . There are also medical imaging diagnostic equipment, has become a measure of the level of hospital modernization.
7 Talk about the next hot spot of medical imaging technology
The economic embarrassment of the health care business has made the 90s since a period of relative silence without the large-scale promotion of a new imaging technology, continuing the development of some existing imaging technologies, so that none of them has so far been able to have a huge impact on imaging. With the development of technology, a number of promising imaging techniques have been gradually developed recently. Such as: magnetic resonance spectroscopy (MRS), positron emission imaging (PET) single photon emission imaging (SPECT), impedance imaging (EIT) and optical imaging (OCT or NRI). They have the potential to soon become imaging techniques for large-scale applications that will provide new information for imaging the brain, lungs, breast and other sites.
7.1 Magnetic source imaging
The movement of ions inside and outside the cell membrane in the human body can form a bio-current. Such bio-currents can generate magnetic phenomena, and detection of magnetic fields generated by bio-currents in the heart or brain can lead to cardiomagnetism or magnetoencephalography. Such magnetic phenomena can reflect the depth of electron activity occurring and carry a great deal of information about human tissues and organs.
7.2 PET and SPECT
Single photon emission tomography (SPECT) and positron emission tomography (PET) are two CT techniques in nuclear medicine. ECT is based on the radiotracer principle of nuclear medicine for in vivo diagnosis, using radionuclides in the human body. the main problem with ECT is the low spatial resolution. Recent technological developments may promote the use of ECT.
7.3 Impedance Imaging (EIT)
EIT is performed by applying a voltage to the body and measuring the current flowing between electrodes to obtain an image of the change in tissue conductivity. The aim is to form an estimate of the impedance at a point in the body. The advantage of this technique is that the current used is harmless to the body and thus there are no restrictions on the object to be imaged. The temporal resolution of this technique is good, thus allowing continuous monitoring of practical applications, and experimental prototypes of medical EIT at video frame rate have been realized.
7.4 Optical imaging (OTC or NIR)
Some substantial recent advances suggest that optical imaging has the potential to evolve in the last few years into an imaging device that can be used in a truly clinical setting. Its advantages are: the radiation at optical wavelengths is non-ionizing and thus harmless to the body and can be repeatedly exposed; they can distinguish soft tissues that have different absorption and scattering at optical wavelengths but cannot be identified by other techniques; and the absorption characteristic of natural chromophores allows functional information to be obtained. It is opening up its clinical field.
7.5 MRS
MRS is an extremely useful tool for the non-invasive study of human tissue physiochemistry. The biochemical information it yields can be correlated with human tissue metabolism and indicates differences in the way it normalizes tissue. MRS is not yet routinely used in clinical practice, but a large number of techniques are already undergoing formal application.
Which of the above mentioned advanced technologies can become the hotspot of medical imaging technology, we believe should be the most important to have maximum benefit, safety and economy. In the past 20th century, medical imaging technology has gone through the process of conception, growth and development, and in retrospect, we can assert that it has been instrumental in preventing human diseases and extending the average life expectancy. In the 21st century, where everything is “people-oriented”, people will continue to use medical imaging technology to serve their health.
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