The medical image information system was originally developed from processing digital images of radiology department. The predecessor of medical image information system is medical image archiving and communication system (PACS, Picture Archiving &; Communication System), the first driving force to promote the development of PACS comes from traditional camera manufacturers. This is because when the digital wave came, they first realized that it was an irreversible huge impact on their products. They have the clearest understanding of the equipment connection ability of various manufacturers; However, as traditional machinery manufacturers, their computer technology is not enough, and they don't know enough about image equipment and image processing.
at first, many equipment manufacturers had great resistance to open network connection. Because they think this is of little significance and conflicts with their interests, the deeper reason is that they don't realize that they have fallen behind the development of information technology; I don't know what information technology will bring to the medical imaging industry.
with the rapid development of computer software and hardware technology, multimedia technology and communication technology, as well as the increasing demand of medical development, the standardization process of PACS has been continuously promoted, especially ACR-NEMA (American College of Radiology &: DICOM (Digital Imaging and Communications in Medicine) 3. standard is generally accepted by National Electrical Manufacturers' Association. At present, PACS has been extended to all medical imaging fields, such as cardiology, pathology, ophthalmology, dermatology, nuclear medicine, ultrasound and dentistry. The contents and capabilities contained in PACS have gone beyond the original meaning of this term. Now PACS generally refers to the Radiology Information System (RIS) and the medical image archiving and communication system (PACS). Communication System) medical image information system. The technical development of PACS medical image information system is mainly reflected in the following aspects:
1. The internal storage format is standardized to DICOM3.
At present, almost all advanced PACS manufacturers in Europe and America use the official DICOM3. file format to store images. The older PACS are designed with ACR-NEMA2. or SPI, and only very old PACS use the format defined by the manufacturer. Using DICOM3. format has many advantages, one of which is that you don't have to find an old PACS manufacturer to convert data when you want to replace PACS in the future. More importantly, DICOM3. file format can add image mode, add, subtract and change the content of image file at any time. However, the traditional fixed field length image format needs to be completely changed if something is added.
2. adopt standard compression algorithm to compress image files.
most of the new PACS adopt standard compression algorithms supported by DICOM, such as JPEG, JPEG loss, JPEG2, JPEG-LS and Deflate. The phenomenon that manufacturers use custom algorithms to compress images is less and less.
3. The three-level storage mode (online, near-line and offline) has been changed to two-level storage (online and backup)
At present, advanced PACS manufacturers in Europe and America are promoting online and backup storage. Backup is just to prevent accidents, such as fire and earthquake. Hard disk is used online, and RAID (Redundant Storage Disk Array) plus NAS(NetworkAttachedStorage) or SAN(StorageAreaNetwork Work) is used. In the past few years, the most common image storage modes in PACS industry are three levels: online, near-line and off-line. The new image is stored online on the hard disk, the older image is stored online in the network server, and the older image is stored offline in MOD or tape.
4. Intelligent medical imaging platform
Intelligent imaging IT platform is the main development direction of hospital information system. Whether all the diagnostic information can be obtained as quickly as possible is the only criterion to evaluate the quality of the imaging workstation. Syngo .via is the world's first "thinking" image working platform, which has changed the traditional image post-processing concept, abandoned the traditional software-oriented CT workstation working mode, opened a new working perspective oriented to anatomy or disease diagnosis, and made a breakthrough in becoming an image working platform directly serving disease diagnosis. Let doctors get rid of the tedious image post-processing and focus on medical diagnosis.
The image IT platform of Siemens syngo.via has the function of image preprocessing, and the image processing and scanning sequence are seamlessly linked and automatically performed without any manual intervention; It has a disease-oriented workflow and automatically enters the work module customized according to the disease or anatomical site; Tailor-made diagnostic modules for each doctor, and integrate related image processing software in any order; With the function of diagnosis bookmark, it can automatically record every lesion measurement and lesion mark of doctors, which is convenient for the communication between doctors in different departments and the review report of doctors at higher levels.
due to the late development and introduction of PACS system in China, few PACS systems have been established and operated effectively (especially in inland provinces and cities). The main reasons are low standardization and poor compatibility. Generally, it is a closed special system, which is neither economical nor expensive. The hardware configuration is not reasonable enough. For hospitals with heavy workload, there is a lack of powerful storage subsystem, which can't support routine radiological images with huge data, so it can't really achieve "no-slice" management. Most PACS systems also have no effective workflow and automatic management functions, nor can they provide all the necessary information for clinical diagnosis, which is manifested in the lack of online information and slow response. It is not reliable in terms of network security, confidentiality and compliance with legal requirements. Most of the existing PACS system designs do not consider the possibility of technical development and expansion, and it is difficult to integrate with the existing HIS/RIS into a system. The research and development of PACS system in different countries have their own characteristics: the research and development of PACS system in the United States is funded by the government and manufacturers; The PACS system in Europe is supported by multinational consortia and national or regional funds, and the research team tends to cooperate with a major manufacturer, focusing on the research of PACS modeling and simulation and image processing components; Japan listed the research and development of PACS system as a national plan, which was completed by manufacturers and university hospitals. Manufacturers were responsible for the integration of PACS system and hospital installation, while hospitals were responsible for the clinical evaluation of the system, and the technical indicators of the system were fixed, leaving little room for hospital researchers to modify. South Korea's PACS system is funded by large private enterprises.
the development direction of PACS in China focuses on the following aspects: the system design and completely open architecture of PACS should strictly comply with international technical standards, based on international standards such as IHE, DICOM3. and HL-7 (medical care); Browser/server structure with good compatibility; The network structure based on Internet/Intranet technology needs to support local area network (LAN) and wide area network (WAN) for remote consultation; Adopt TB-level or even PB-level storage subsystem to improve response ability; Provide fault tolerance, error correction ability, better data security and disaster recovery ability, and have high performance data compression technology; The system has friendly interface, strong Chinese support ability, easy to learn and use; Seamless integration of voice, image and data transmission technologies; Have a complete system solution, the system is conducive to maintenance and technical support. In the last century, with the development of science and technology, the medical level has been continuously improved, and various new medical imaging devices have emerged. In 195s, ultrasonic technology was used in medical field; CT in 197s and MRI in 198s were used in clinic successively. Since then, new types of medical imaging equipment have been invented basically every two or three years. On the one hand, more and more medical imaging equipment improves the accuracy of diagnosis, on the other hand, it brings new problems. That is how to manage the data generated by these medical imaging devices, in order to obtain the data generated by medical imaging devices in a certain range and ensure that the data of imaging devices from different manufacturers can be interconnected. In 1982, American Radiological Society (ACR) and Electrical Appliance Manufacturing Association (NEMA) jointly organized a research group (ACR-NEMA Digital Imaging and Communication Standards Committee) to study how to formulate a unified communication standard to ensure the information interconnection of imaging equipment from different manufacturers. After consensus, a set of format standards for digital medical images, namely ACR-NEMA 1. standard, was worked out, and then ACR-NEMA 2. was completed in 1988. Version 3. released in 1993 was officially named DICOM 3. (Digital Imaging and Communications in Medicine). However, due to various reasons, this standard was slowly accepted by various medical imaging equipment manufacturers until 1997. Since then, the standard has changed greatly every year, involving every corner of medical imaging, especially the SR (Structured Report) which has just joined the standard recently involves areas that other standards dare not involve. At the same time, the standard has made great efforts in security (privacy and authorization), adding TSL/SSL, digital signature, digital authorization and data encryption support. In order to support data exchange in different fields, XML support is also added. In a word, DICOM standard is developing with each passing day.
at present, DICOM3. has been widely followed by international medical imaging equipment manufacturers, and all imaging equipment produced by major manufacturers provide DICOM3. standard communication protocol.
DICOM3. standard must be supported in the output and input of the system, which has become the international standard of PACS. Only PACS established under DICOM3. standard can provide users with the best system connection and expansion functions.
(1) DICOM 3.
The full name of DICOM standard is "digital imaging and communication in medicine" standard, which was formulated and developed according to NEMA program. It is actually the third edition of ACR-NEMA. The reason why it was renamed DICOM3. instead of ACR-NEMA3. is as follows: ① This standard was not only formulated by the joint committee of ACR-NEMA, but also participated in its formulation and development by other standardization organizations in the world. These standardization organizations include european committee for standardization 251 Technical Committee (CENTC251), which has already worked out a DICOM-compatible standard based on DICOM; There are Jira (Japanese industry radiology apparatus) and Medical Information y Stem Development Center in Japan. The main contribution of these two organizations to DICOM is to put forward the standard of using removable media (optical disk, etc.) to store and exchange medical images. In the process of formulating standards, some other organizations, including IEEE, HL7 and ANSI, were also consulted. ② The standard not only supports medical radiation images, but also is extensible, facing all medical images, as long as the corresponding service object class (SOP) is simply added. The work of extending it to ECG (cardiology), endoscopy, dentistry, pathology and other types of images is currently under way. Like its previous versions 1. and 2., DICOM took into account the research results of some related standardization organizations at the beginning of its formulation, which was not only to avoid repetitive work, but also to provide important background and technology for DICOM. Because it is a communication standard oriented to network environment, ISO-OSI, which is the international organization for standardization, has the greatest influence on DICOM.
(2) HL7
HL7 is a standard for exchanging electronic data in a medical environment, especially in hospital patients. In May, 1987, a committee composed of medical units (and users), manufacturers and medical consultants was set up in the University Hospital of Pennsylvania. This committee was mainly responsible for the work of HL7, with the aim of simplifying the interface implementation of computing applications of different manufacturers (especially competing manufacturers) in the medical field. Its main application field is HIS/RIS.
at present, HL7 mainly regulates the communication between HIS/RIS system and its equipment as follows: patient admission/registration, discharge or transfer data (ADT-admissions/registration, discharge, transfer) and inquiry, patient arrangement, reservation, finance, clinical observation, medical records, patient treatment, master file update information, etc.
functional specification
with the development of information technology and the transformation of hospital operation mechanism, hospital information system has become an indispensable and important infrastructure and supporting environment for modern hospitals. In order to actively promote the development of information network infrastructure and speed up the construction and management of hospital informatization, the Ministry of Health has formulated the Basic Function Specification of Hospital Information System. Among them, the following specifications are set for the functions of the medical image information system.
(1) image processing
1. data receiving function: receiving and obtaining image data in DICOM3. and non-DICOM3. formats of image equipment, and supporting the conversion of images from non-DICOM image equipment into DICOM3. standard data.
2. image processing function: customize the relevant information of the displayed image, such as name, age, equipment model and other parameters. Provides functions such as scaling, moving, mirroring, inverting, rotating, filtering, sharpening, false color, playing, window width and window level adjustment.
3. measurement function: provide the measurement of ROI value, length, angle, area and other data; As well as that function of marking and annotate.
4. Save function: supports saving in various formats, such as JPG and BMP, and the function of converting into DIDICOM3. format.
5. management function: support the transmission of images between devices, and provide the function of simultaneously accessing images and reports of patients in different periods and different imaging devices. Support DICOM3.