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What is Pacs


What is Pacs?


CommunicationSystem and Picture Archiving

Abstract – Today, with the advancement of information technology in medical sciences and computer networks, there is no need for old clichés to take radiology images and spend the cost of buying and maintaining these films. Because a system called Picture Communication and Archiving System (PACS) has created the possibility of transferring, storing, retrieving and displaying medical images in different places. Imaging devices, a computer network, databases or information banks. and the client image display stations are the four main components of a hospital PACS system. The PACS system can display images from various diagnostic imaging methods such as MRI, SCAN.CT, ultrasound, radiography, angiography, nuclear medicine and… store and read back in the form of digital images. This system provides the possibility of helping doctors far from the treatment center through teleradiology, so that skilled specialists, but far away, can be used in diagnosis and treatment. By reducing the storage costs that are done electronically (compared to film and cliché archives), it helps the hospital management. By sending images through the network, the time for the attending physician to obtain the results of the imaging has been minimized.

Key word – teleradiology (remote radiology through television or video conference). HIS: Hospital Information System – HL7: Information Transfer Protocol in Medical Sciences – MRI: Magnetic Imaging. Stereotype: Radiology Film. RIS: Radiology Information System.

1- Introduction

Taking pictures of body organs helps doctors in diagnosing diseases so that they can be successful in deciding the type of treatment for patients. The decision to treat by observing the changes in the body will be very different from the decision made based on the symptoms and statements of the patient.

It is especially important in bone diseases and tumors. Therefore, the quality of the images taken, the number of images, the dimensions of the images, the speed of image transmission for the attending physician and the type of image archive for quick and repeated access,

All are important factors considered in medical imaging. With the emergence of digital and advanced medical equipment, as well as the trend of the field of medical sciences towards the software movement, as well as the need for hospitals to integrate health and treatment information in the hospitals of the country, paraclinical departments of hospitals, especially medical imaging, to help diagnose radiologists and treat specialists are essential steps. in the use of information technology.

Undoubtedly, the efforts of software and hardware engineers, systems analysts, and medical science experts have been impressive in these developments. Many new imaging methods, including radiography, ultrasound, digital SCAN.CT etc.

What is Pacs?

PACS is one of the most advanced systems in this field. For the first time in 1891, a system was introduced at the Medical Imaging Conference (IEEE) that allowed to store, display and transfer images and other information. This system was approved by the American Radiological Society in the same year, and in Europe received the attention of the European Congress of Radiology (ECR). This system was called PACS. A computer-based image retrieval and archiving system that can store and read back the images obtained from various diagnostic imaging methods as digital images. This system consists of display and editing stations of digital images in internal networks in the hospital or even outside the hospital, which provides the doctor’s access to the stored images and thus reduces the doctor’s dependence on radiology specialists.

2- What is Pacs?

In this article, we have first mentioned the purpose of about What is Pacs? and using the PACS system, then we have made a comparison between this system and analog imaging methods. We have explained the components of the system and its structure, listed its advantages, and finally discussed the result.

1-2: Purpose of using PACS

There are many problems in the stereotyped imaging system which, in addition to the dissatisfaction of doctors and radiologists as well as the patient due to the quality, quantity and the need to repeat the images, has challenged the hospital management in terms of cost and maintaining the films, so the main purpose of using The PACS ( What is Pacs?)  system is an effective work efficiency improvement along with the diagnostic capabilities of doctors.

The use of today’s standards in storing and transferring images is also considered an important goal. Also, the cost of purchasing and safe storage of films is noticeable from a management point of view. The technology of the medical imaging system, along with the imaging device, consists of a number of computers under a network that are used exclusively for storing, retrieving, distributing and displaying images.

In fact, medical images are stored in an independent standard or format, DICOM ( InMedicine Communications Imaging and Digital) is its most important format. Most of the images that are archived and classified through PACS are ultrasound, MRI, CT, endoscopy, mammography and X-ray images.

This system actually replaces hard-copy such as archiving radiology films for managing medical images that may be damaged over time, and increases the capabilities and capabilities of common systems. On the other hand, the staggering cost of radiology films and their maintenance has always been one of the most important problems of hospital managers.

Therefore, we can answer to the question of What is Pacs? as PACS can reduce the purchase cost by removing the film and remove the physical archive by creating an electronic archive.

2-2: Comparison of PACS with stereotype system

In the analog system, imaging of the patient is done and printed on the radiology stereotypes. The radiologist observes the stereotypes and records a report of his diagnosis on a piece of paper and sends it to the attending physician.

Sometimes the present stereotype is not enough for the final diagnosis and does not help the treating doctor. Sometimes it happens that the cliché is lost for some reason or has a physical problem that needs to be repeated to continue the treatment. Now, due to the introduction of some harmful radiation into the patient’s body at each time of imaging and causing numerous complications, repeating the imaging has its own problems, and if the patient is a pregnant woman or a young child, the problem of complications is very acute and dangerous. It will be great.

Perhaps in order to prevent x-rays from entering the fetus in the mother’s womb, imaging of the injured mother’s body was omitted and the mother’s physical health would have suffered a crisis due to the inability to diagnose, but in using the digital archive system, the problems and dangers caused by Radiography to the patient will also be eliminated as a result of not having to repeat the radiography. One of the systems that has been used in Europe and America since 12 years ago and in Iran for several years is the PACS system, which solved all these problems.

With a single imaging of the patient’s body parts, several images from different dimensions and with suitable quality are taken and stored and archived in the computer’s hard disk. The images in the Medical Diagnosis monitors are exposed to the radiologists in good quality to prepare a proper and complete report.

A copy of the images is also given to the patient in a CD to present to the treating physician when necessary. Also, the images taken and the radiologist’s report on it are available to the attending physician in the inpatient department or operating room online in the shortest possible time.

2-3: What is Pacs of Components or structure system

This system is based on new computer ideas and methods and consists of four basic components. Each of these components work with special equipment. These components are:

1-3-2: Medical imaging devices

2-3-2: Stations

3-3-2: Computer network

4-3-2: Databases and databases

These components together form a system that is responsible for imaging, creating a database, information flow in the network and archiving medical images.
1-3-2: Medical imaging devices

There are various imaging devices. MRI, SCAN.CT, CR, etc., which are related to the PACS system or medical image archiving and communication system.

Consider a CT scan machine. This device consists of a table to place the patient’s body, a gantry in which the patient’s head is placed, an X-ray production source, a system to reveal the radiation emitted from the body and an X-ray generator.

Composed . All these are located in a special room, the walls of which are insulated and the entrance door is made of lead layers.

Imaging of all parts of the body is done with the help of x-rays and computerized CT scan processing, and shows very minor differences in x-ray absorption. This system is able to reveal different densities in soft fabric. In traumas, acute fractures and hairline fractures, tumors play an important diagnostic role.

The working principles of an imaging device such as a CT scan device are briefly as follows: after the patient’s body is placed on the table and the head is placed in the gantry and the conditions of the device are adjusted according to the area to be imaged, a bunch of X-rays is sent by the collimator (limiter). The beam is made into a beam and passes through the patient’s body (is pulsed).

Some of the radiation energy when passing through the absorption body and the rest of the radiation as the output beam that passes through the patient’s body is measured by the detector located in front of the X-ray beam, and after being converted into computer language, it is stored in the computer’s memory immediately. Since the first pulse of radiation was sent to the patient and measured, and the X-ray lamp made a very small rotational movement, the X-ray beam is pulsed again, measured again and stored in the computer memory.

This step is repeated several hundreds or thousands of times depending on the type of device so that all the information related to the desired member is stored in the computer memory. The computer measures the amount of radiation absorbed by any given volume of tissue. This tissue volume is called a voxel, which is similar to a few cubic millimeters of body tissue.

In a CT scan, a cross-sectional layer of the body is divided into these small voxels, which are assigned a number according to the amount of radiation absorbed by each of these voxels. These numbers are also assigned a gray scale density (from white to black) on the image that falls on the TV screen like a computer. The display of each voxel on the monitor is called a pixel. That is, voxels are three-dimensional and pixels are two-dimensional, and the more pixels there are on the monitor, the clearer and more distinguishable the image is.

The numbers assigned to each tissue according to the amount of radiation absorption are called CT numbers or Hunsfield numbers.

For example, fat tissue absorbs radiation less than muscle tissue and muscle tissue less than bone tissue. Therefore, for example, bone is 144, water is 0, fat is 24, and air is 244. The lower these numbers are, on the CT scan, that part tends to be black according to the gray scale, and on the contrary, the higher the CT number is, like bone. The image tends to be white.

Sometimes, contrast materials are used to make the parts that have similar density more clear. We mention some of the applications of imaging with these devices. Diagnosing brain and nerve diseases – the most used PACS system among hospital departments is the neurology department. Because CT scan can show the difference between fresh and old blood, for this reason, it is best used to show emergency cases of brain diseases.

Congenital diseases such as large or small skull – diagnosis of intracranial and extracerebral tumors – bleeding in different parts of the brain and strokes – diagnosis of diseases of intra-abdominal organs such as liver, pancreas, adrenal glands and examination of lung diseases. control room Next to the room where the imaging device is located, a room has been built that acts as a control room. This room overlooks the imaging room through a full glass window, the glass of which is made of a special material and prevents radiation.

In order to be safe from radiation, the radiologist must be stationed outside the imaging room and in the same room, and while observing the patient and communicating with the patient, he controls the imaging device and performs the imaging operation. In this room, there is a computer device for image reconstruction and an operation console on which the radiology technologist is placed. This computer is connected to the imaging device through the network connected to the PACS server to use the database and archive the images taken in it.

The operator of this computer can simultaneously add the images taken in the database and in addition to archiving the files on the server and copy on CD if necessary, print the images on the cliché using special printers.

2-3-2: What is Pacs Stations?

Each workstation is a computer device with appropriate coordinates that is responsible for displaying medical information and images through the internal network of the hospital. Workstations have been defined for two locations. One for the radiologist in the radiology department (photo no. 1) to view the images and write an attached report and his findings on the images, and another for the inpatient departments and the operating room, with a computer in each department, the resident physician in the inpatient department or operating room. Viewing the images requested from the patient as well as the radiologist’s report to treat the patient, performs therapeutic measures. It is necessary for radiologists to use special monitors (Monitor Diagnosis Medical) that have the ability to display images with better quality.

These stations for displaying and editing digital images in each of the departments connected to local or internal networks in the hospital or even the Internet network outside the hospital, the doctor’s access to the stored images and as a result reducing the doctor’s dependence on the radiologists, the simultaneous access of the surgeons in the hospital It provides different and focused advice on the comparison of multiple treatment methods.

There is one of these workstations in the report room located in the radiology department, which is for radiologists to view the images taken, edit images with PACS software tools, and insert a report of their findings on the images or attach them to the images. Another workstation in the radiology department is in the reception area, where the receptionist can prepare and deliver a CD from the images taken for the patient. Multiple workstations can be installed in different parts of a hospital depending on management policies.

3-3-2: What is Pacs Computer network?

Today, almost every hospital in developed countries and first-class hospitals in developing countries are equipped with an internal network for all hospital departments and units to use the integrated hospital information system (HIS) along with the global Internet network. In our country, basic steps have been taken in this direction and despite the specific problems of this matter, our hospitals have been equipped with an internal network and the use of HIS or are looking to start it. One of the paraclinical parts of HIS is the radiology system that can fully support PACS or medical image archiving and communication system.

Therefore, in a hospital, the existence of a network even in the absence of HIS is necessary for the PACS system to establish a connection between the radiology department with the inpatient departments and other related departments for the use of medical images. Of course, this network can communicate with the outside of the hospital through the Internet. The operation of the PACS network starts from the imaging devices. These equipment transfer the images to the server using PLUS PACS software. The internal network transfers the images from the PACS system to different centers inside the hospital and provides them to the authorized people.

On the other hand, the same system can be connected to the global Internet network and the images taken can be transferred outside the hospital and are available to countless people who can access this system and obtain permission to use it. Photo no. Every network has components. There should always be a server device to provide services to all client devices in different parts of the network, which means a computer device with much better specifications and high information processing ability, which is also a place to store information.

The server establishes communication with other parts of the network through several switch devices that act as communication line terminals. Meanwhile, the transmission speed depends on the type of computers and the medium that establishes communication between the system components.. the type of network cable used, of which optical fiber is the best, the type of switches, the type of network card used in workstation computers, keystone and… are among the factors that are very effective in the speed of information transmission.

The PACS system in a network initially consists of an image receiving device (electronic gate), information management system (a special computer that controls the flow of information into the network), image storage device (large and small archives), transmission network (which covers wide and local areas), display bases (including a computer, a text display, an image display and a connecting line for the user to use them) and sometimes, when necessary, equipment that prints images on copy-hard to store, is formed. Of course, today PACS under the web are more common, in such a way that they use the Internet as their main link. In the Internet network, the transfer speed also depends on other important factors. The bandwidth of the Internet network The way of using up-Dial or ADSL is one of the most important factors.

4-3-2: What is Pacs Databases ?

The important thing about the PACS system is its transmission network, which consists of a central server (which stores the database). This database contains information on images taken by MRI, SCAN.CT, CR and… Related to the PACS system, they are taken and stored on the server through LAN (Local Area Network) or Wide Area Network (WAN) and received during the network. The main information is in the server in the database. The structure of this database can be Access and SQL, etc. On the server, the images are stored in their own format that conforms to the DICOM standard and are usually stored with the name of the date of image acquisition along with a patient’s inpatient or outpatient file number. In addition, the files required for the software There will also be PLUS PACS, database facilities such as account creation for authorized users will also be used.

4-2: What is Pacs system structure?

Today, modern radiology equipment directly enters the images of patients into the PACS system in a defined format. A complete PACS system should include a point of access to images and accompanying information. It should also be related to other hospital information systems (HIS) and especially to the radiology information system (RIS). The connection of PACS with RIS is very important because these two systems are complementary in completing the entire mechanized system of the radiology department. The wider the connection between different information systems, the stronger and more reliable the information becomes.

For example, it reduces the risk of wrongly entering patient information, because the standard DICOM format used for this purpose can also receive patient information. The DICOM standard is a global standard in the transmission of medical images, and the systems used in hospitals and health centers such as HIS and PACS must use this standard so that the image format in the used software can be understood and used. The PACS system uses PLUS PACS software, which has the necessary standards. When the acquisition of a patient’s information is complete, the PACS system compares the embedded image data with the programmed record list on the network and identifies any discrepancies.

Any information is stored only with the same person’s profile. When the radiologist has finished reading the images of the assumed patient, the PACS system marks it as “read”, thus preventing re-reading. The doctor’s report is attached to the photo and can be seen on the other side of the connection line. In most cases, the PACS system is connected with the hospital information system (HIS) and the radiology information system (RIS) in order to establish a connection between images and information about patients and the possibility of using teleradiology systems to transmit and receive images and patient information from remote areas. to facilitate The cooperation of these systems can improve the communication between different treatment departments and increase the efficiency and quality of patient care in hospitals.

Image storage and retrieval systems generally consist of host computer communication tools, image archiving tools and display stations connected to the communication network. The use of image storage and retrieval systems will not be limited to imaging, but systems that operate based on PACS are also used in surgery, and in this way, information networks that usually have less errors and mistakes are set up. to be A good PACS, quite definitively, allows the radiologist to take successive images with the least amount of movement and movement compared to the situation that he would have to examine detailed specimens in public, with digital tools guided by a keyboard and with The fingers are interpreted. To start the system in a center, it is very important to pay attention to the structure of a PACS system. In this structure, important things should be taken into consideration, which we refer to as examples:

1-4-2: Checking the physical space required to install the hardware and accessories of the PACS system. In this direction, the existing imaging devices are checked. If this device is analog, a special kit that looks like a relatively large network card should be used in the computer connected to the imaging device. Digital imaging devices are complete and do not need the mentioned kit. Digital devices are the best option for using the PACS system.

2-4-2: Examination of medical equipment and WORK GROUPS provided by the DICOM format global standard committee in this medical center, such as the device… and microscopy, endoscopy, US, CT scan, RI radiology CR

3-4-2: – The PACS system must be able to send and receive digital medical images in DICOM format to workstations inside the treatment center (such as departments, operating rooms, etc.) in workstations of two types of viewers It is used:

A) Viewer, this software shows only images and is installed in most Work Stations.

b) Viewer that allows the processing of digital medical images with DICOM format, which this software is prepared based on need and necessity.

4-4-2: – The PACS system must be able to send and receive digital medical images in DICOM format to the outside of the treatment center through the Internet.

5-4-2: – The PACS system must be able to connect to RIS/HIS under the HL7 protocol (the standard protocol for the transfer of medical science information) based on the working group.

6-4-2: – PACS system should have the possibility of clinical training protocol for medical students and staff.

7-4-2: The PACS system should have the possibility of burning on a CD or DVD to present to the patient instead of stereotypes.

5-2: What is Pacs Advantages of using the PACS system?

The use of this system solves problems related to imaging. Archiving and storing films in special warehouses requires special physical space. This space should have suitable and non-harmful light for films and suitable temperature and heat. A suitable safety system should also be considered to prevent fire and loss of films. The loss of videos or their damage and the need to re-request the videos from the attending physician or the need for these videos to train medical students are among the problems of the stereotypical system.

On the other hand, the volume and high cost of movies always worries the directors. The PACS system introduces the Less Film system by electronicizing the images and prevents this problem. One of the concerns of the hospital managers is the material and spiritual cost of the presence of radiologists in the hospital, during non-office hours, which is done informally. In emergency situations or before surgery, even in the middle of the night, images are scanned from the patient and must be interpreted by a radiology specialist. For this, a radiology specialist should be contacted to be present at the hospital at the same time. Or that the graphic films are sent by a person to the radiologist’s house and the said person waits for the radiologist to report his interpretation and is returned to the hospital by that person.

During this time, the attending physician and the surgical team are waiting, and sometimes there are problems in delaying the operation for the patient, which also has legal consequences. The PACS system has solved this problem and only the radiologist is informed by phone so that he can enter the hospital system at his home through the Internet and view the relevant images on his monitor and even manipulate the image with the PLUS PACS software tool. and type your findings. In the shortest possible time, the treating doctor will observe the report in the operating room or emergency room and treat or operate according to the resulting diagnosis. The PACS system provides the possibility of remote training or diagnosis through the Internet and television and helps doctors to obtain similar and updated information at the same time, wherever they are on the globe, which is called teleradiology. PACS systems have many advantages by reducing storage costs that are done electronically (compared to film archives).

By using PACS imaging informatics systems, we can archive radiology images and use it to send images to any part of the world, so we must use systems in which the image output is digital. Expanding the use of the PACS system prevents the enlargement of centers and the placement of more film archives, which is an advantage for small centers. Preparing the image on a CD or DVD and presenting it to the patient helps the patient to continue his treatment to other centers, while it is very difficult for the patient to carry and store the film and stereotype, and sometimes the film is lost or distorted. falls down. Sometimes it happens that for the treatment of the patient, the consultation of a specialist abroad is used. Teleradiology and the PACS system provide images quickly and in the best possible condition to the relevant specialist on the other side of the country and improve the process of disease recovery.

In fact, with the progress of medical science and related equipment, each of which creates a world of images, the need for systems like PACS is fully felt to help the economy of the medical world. On the other hand, it enables faster and more accurate diagnosis of the disease and saves a lot of time and money. In fact, the main purpose of using the PACS system is to improve the effective work efficiency along with the diagnostic capabilities of doctors. In other words, the mechanization of the imaging process is from the purchase of basic facilities to the satisfaction of the patient, doctors and staff.

3- Connection of this system with HIS

This system, like many HIS satellite programs, must have the ability to connect to it in order to serve the doctors and medical team in the hospital. In this integration, the PACS system receives the patient’s identity information and file number from HIS and stores it so that it can be recognized by the medical team.

4 – What is Pacs Conclusion?

Digital photography has been in an extraordinary position and has overcome many initial obstacles such as insufficient industrial works, production bottlenecks, high prices especially for film and low customer desire. The increase of archival images and communication systems (PACS) is an incentive to accept complementary digital technology that will be effective in halving the prices and increasing the quality of images and can easily replace film in photography. Also, it eliminates the time delay and inherent inefficiency in film production and allows the hospital to save space and radiology staff. The problem of delay in the radiologist’s report on the films, in addition to causing a delay in the doctor’s diagnosis and treatment of the patient, also causes a delay in the payment of the cost by the insurance organizations, which the PACS system solves this problem. Obtaining the consent of the medical diagnosis and treatment team, the patient and related organizations, managing financial and human costs and turning to mechanized systems are all factors that today challenge the managers of hospitals and even small centers and make the use of the PACS system an unavoidable necessity. has done

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Written by: Engineer Ali Nik Maram


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