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 wonder 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 and the increasing demand of medical development, the standardization process of PACS is also advancing, especially ACR-NEMA (American Institute of Radiology &; DICOM (Digital Imaging and Communication in Medicine) 3.0 standard is generally accepted by American 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 functions contained in PACS have gone beyond the original meaning of this term. Now PACS generally refers to radiation information system (RIS) and 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, and the internal storage format is standardized to DICOM3.0.
At present, almost all advanced PACS manufacturers in Europe and America use the official DICOM3.0 file format to store images. The older PACS adopt ACR-NEMA2.0 or SPI design, and only the very old PACS use the format defined by the manufacturer. Using DICOM3.0 format has many advantages, one of which is that you don't need to find an old PACS manufacturer to convert data when you want to replace PACS in the future. More importantly, DICOM3.0 file format can add image mode, and the content of image file can be added, deleted and modified at any time. However, the traditional fixed field length image format needs to be completely changed, if something is added.
2. The standard compression algorithm is adopted to compress the image file.
Most of the new PACS adopt standard compression algorithms supported by DICOM, such as JPEG, JPEGLossless, JPEG2000, JPEG-LS and Deflate. The phenomenon that manufacturers use custom algorithms to compress images is less and less.
3. Three-level storage mode (online, near-line and offline) is changed to two-level storage mode (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. Use hard disk online, using RAID (Redundant Storage Disk Array) plus NAS(NetworkAttachedStorage) or SAN (Storage Area Network). In the past few years, the most common image storage mode in PACS industry is three levels: online, near-line and offline. The new image is stored online on the hard disk, the old image is stored online on the network server, and the old image is stored offline on MOD or tape.
4. Intelligent medical imaging platform
Intelligent image IT platform is the main development direction of hospital information system. Whether all the diagnostic information can be obtained as soon as possible is the only criterion to evaluate the quality of the imaging workstation. Singo 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 for anatomy or disease diagnosis, and achieved a breakthrough in becoming an image working platform directly serving disease diagnosis. Let doctors get rid of complicated image post-processing and focus on medical diagnosis.
Siemens syngo.via image IT platform has image preprocessing function. Image processing and scanning sequence are seamlessly connected and automatically executed 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 module for each doctor, and integrate relevant image processing software in any order; It has the function of diagnosis bookmark, which can automatically record every focus measurement and focus marking of doctors, so as to facilitate 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 the conventional radiation images of massive data and can't really realize "slice-free" management. Most PACS systems also have no effective workflow and automatic management functions, nor can they provide all the information needed for clinical diagnosis, which is characterized by insufficient online information and slow response. It is unreliable 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 systems in different countries have their own characteristics: the research and development of PACS systems in the United States is jointly 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 large 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 jointly completed by manufacturers and university hospitals. The manufacturer is responsible for the integration of PACS system and the installation of the hospital, and the hospital is responsible for the clinical evaluation of the system. The technical indicators of the system are fixed, leaving little room for hospital researchers to modify. PACS system in Korea is funded by large private enterprises.
The development direction of PACS in China is: the system design and fully open architecture should strictly abide by international technical standards, based on international standards such as IHE, DICOM3.0 and HL-7 (medical treatment); A compatible browser/server structure; The network structure based on Internet/Intranet technology needs to support local area network and wide area network for remote consultation. Adopt TB-level or even PB-level storage subsystem to improve response ability; Provide fault tolerance and error correction capabilities, better data security and disaster recovery capabilities, 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; A complete system solution is beneficial to system 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 1950s, ultrasonic technology was used in medical field; CT in 1970s and MRI in 1980s were used in clinic successively. Since then, new medical imaging equipment has 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 also brings new problems. That is, how to manage the data generated by these medical imaging devices, so as 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. 1982 A research group (ACR-NEMA Digital Imaging and Communication Standards Committee) was jointly organized by American Radiological Society (ACR) and Electrical Appliance Manufacturing Association (NEMA) 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 1.0 standard, was formulated, and then ACR-NEMA 2.0 was completed in 1988. Version 3.0 was officially named DICOM 3.0 (Medical Digital Imaging and Communication). However, due to various reasons, the standard was not accepted by medical imaging equipment manufacturers until 1997. Since then, the standard has changed a lot every year, involving every corner of medical images, especially SR (Structured Report), which has just joined the standard recently, involves areas that other standards dare not. At the same time, the standard has made great efforts in security (privacy and authorization), and added 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, DICOM3.0 has been widely followed by international medical imaging equipment manufacturers, and the imaging equipment produced by major manufacturers all provide DICOM3.0 standard communication protocol.
The output and input of the system must support DICOM3.0 standard, which has become the international standard of PACS. Only PACS established under DICOM3.0 standard can provide users with the best system connection and expansion functions.
( 1) DICOM3.0
The full name of DICOM standard is "medical digital imaging and communication", which is formulated and developed according to NEMA plan. This is actually the third edition of ACR-NEMA. The reason why it was renamed DICOM3.0 instead of ACR-NEMA3.0 is as follows: ① This standard was not only formulated by ACR-NEMA Joint Committee, but also participated in its formulation and development by other standardization organizations in the world. These standardization organizations include european committee for standardization 25 1 Technical Committee (CENTC25 1), which has formulated DICOM compatibility standards based on DICOM; Japan has Jila (Japan Industrial Radiation Equipment) and Medical Information System Development Center. The main contribution of these two organizations to DICOM is to put forward the standard of using removable media (optical disks, etc.). ) to store and exchange medical images. In the process of formulating standards, some other organizations were consulted, including IEEE, HL7 and ANSI. ② The standard not only supports medical radiological images, but also has extensibility, and is applicable to all medical images, so long as the corresponding service object class (SOP) is simply added. At present, it is being extended to electrocardiogram (cardiology), endoscopy, dentistry, pathology and other types of images. Like the previous versions of 1.0 and 2.0, DICOM considered the research results of some related standardization organizations at the beginning of its formulation, which not only avoided repetitive work, but also provided important background and technology for DICOM. Because it is a communication standard for network environment, ISO-OSI has the greatest influence on DICOM.
(2) HL7
HL7 is the standard for exchanging electronic data in medical environment, especially in hospitals. 1987 In May, a committee composed of medical units (and users), manufacturers and medical consultants was established in the University Hospital of Pennsylvania. This committee is mainly responsible for the work of HL7, aiming at simplifying the interface implementation of computing applications of different manufacturers (especially competitors) 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 (collectively referred to as ADT- admission/registration, discharge and transfer) and inquiry, patient arrangement, appointment, financial, 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 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: receive and obtain image data in DICOM3.0 and non-DICOM3.0 formats of image devices, and support converting images of non-DICOM image devices into DICOM3.0 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, reversing, rotating, filtering, sharpening, pseudo-color, playing, window width and window level adjustment.
3. Measurement function: provide data measurement such as ROI value, length, angle and area; As well as marking and annotation functions.
4. Save function: supports saving in various formats such as JPG and BMP, and the function of converting into DIDICOM3.0 format.
5. Management function: it supports the transmission of images between devices and provides the function of accessing images and reports of patients in different periods and different imaging devices at the same time. Support DICOM3.0 printout, mass data storage and migration management.
6. Telemedicine function: Support remote sending and receiving of image data.
7. System parameter setting function: user-defined parameters such as window width and window level value and magnifying glass magnification are supported.
(2) Report management
1. Appointment registration function.
2. triage function: basic information of patients, examination equipment, examination site, examination method, pricing and charging.
3. Diagnostic report function: generate inspection report, and support second-level doctor's audit. Support typical case management.
4. Template function; Users can define templates conveniently and flexibly to improve the speed of report generation.
5. Query function: support various forms of combined query such as name and image number.
6. Statistical function: You can count users' workload, outpatient service, film volume and cost information.
(3) Operating requirements
1.* * * Enjoy the patient information in the hospital information system.
2. Network operation: accurate and reliable data and information with high speed.
3. Security management: Set access rights to ensure data security.
4. Establish a reliable storage system and backup scheme to realize long-term preservation of patient information.
5. The reporting system supports the general medical terminology set at home and abroad.