Fundamentals-of-PACS.pptx

Fundamentals-of-PACS PROF. W.K ANTWI DEPT. OF RADIOGRAPHY SBAHS, CHS UG 2024 OUTLINE Fundamentals Image Acquisition Display Workstations Archive Servers Workflow System Architecture Client/Server-Based Systems Distributed Systems Web-Based Systems Display Workstations Radiol...

Fundamentals-of-PACS PROF. W.K ANTWI DEPT. OF RADIOGRAPHY SBAHS, CHS UG 2024 OUTLINE Fundamentals Image Acquisition Display Workstations Archive Servers Workflow System Architecture Client/Server-Based Systems Distributed Systems Web-Based Systems Display Workstations Radiologist Reading Stations Physician Review Stations Technologist QC Stations File Room/Image Management Stations Common Functions Advanced Workstation Functions Objectives On completion of this chapter, you should be able to: Define picture archiving and communication system (PACS). Compare and contrast the various types of PACS display workstations. Differentiate among the different types of digital imaging work flow. Define system architecture and recognize the three major models. Summarize the common functions found on a PACS workstation. Describe the situations and users that may require advanced PACS workstation functions. Major ingredients in the PACS infrastructure design Four major ingredients in the PACS infrastructure design concept are system standardization, open architecture and connectivity, reliability, and security Key Terms Client/server-based system Digital imaging and communications in medicine (DICOM) Display workstation Distributed or stand-alone system File room workstation Hanging protocol Navigation functions Picture archiving and communication system (PACS) Key Terms CONT… Quality control (QC) station Reading station Review workstation Softcopy Study System architecture Web-based system Workflow The picture archiving and communication system (PACS) The picture archiving This lecture outlines the and communication basic concept of a PACS system (PACS) is and its components, becoming more describes common PACS commonplace in today’s architecture, and gives hospitals because hospital examples of typical PACS administrators have come work flows that may be to see the necessity of seen in a hospital. having such a system to serve physicians and patients even though it is expensive. Fundamentals a PACS consists of digital acquisition, display workstations, and storage devices interconnected through an intricate network (Figure 9-1). The PACS is an electronic version of the radiologist reading room and the file room. The first PACSs were used in the early  Large research institutions housed early systems because most were developed by the scientists who worked at those institutions. As vendors became more involved, they developed proprietary systems that were very specific to their modalities. Finally, as physicians and hospitals became interested, it was determined that there must be standardization. FIGURE 9-1 A typical PACS design. Input Modalities  Digital imaging and communications in medicine (DICOM) is a universally accepted standard for exchanging medical images among the modality, viewing stations, and the archive. First completed in 1985, this standard laid the groundwork for the future development of integrated PACSs. Now each modality and PACS communicates via DICOM, and DICOM continues to be refined every year. Every vendor and modality boasts DICOM compatibility ( Figure 9-2), but each DICOM statement must be read carefully to determine the extent of the compatibility.  To understand what a PACS is and how it is used, it helps to look at the system’s individual parts. The following sections break down a PACS into its three fundamental parts (Figure 9-3): image acquisition, display workstations, and archive servers.  FIGURE 9-3 A collage of PACS components: image acquisition, display workstation, and archive server. Image Acquisition In modern radiology departments, most images are acquired in a digital format, meaning that the images are inherently digital and can be transferred via a computer network. Ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine have been digital for many years and have been taking advantage of PACS far longer than general radiography has.  As stated earlier, the first PACS served a single modality, namely, ultrasound. Ultrasound mini-PACS networks were the norm in many hospitals. Radiologists routinely made diagnoses by looking at images on the modality’s computer screen. It was a natural step from there to convert ultrasound to softcopy reporting (i.e., reading images on the computer without hardcopy films).  As the CT and MRI image sets became larger because of the increased number of cross-sectional images per patient, radiologists routinely went to the modality to view the images. This slowed down the scanning process for the technologists, and vendors began getting requests for extra console stations for radiologist viewing. These workstations were directly connected to the modalities. Radiologists could view the large stacks of images and perform simple image manipulation.  These workstations morphed into mini- PACS and eventually into full-blown systems for CT and MRI. General radiography has taken the digital leap with digital projection radiography. Now the conversion to a completely digital radiology department is a reality. Display Workstations A display workstation is any computer that a health care worker uses to view a digital image ( Figure 9-4). It is the most interactive part of a PACS, and these workstations are used inside and outside of radiology. The display station receives images from the archive or from the various radiology modalities and presents them for viewing. Figure 9-4 A display workstation for image review.  The display workstation has PACS application software that allows the user to perform minor image-manipulation techniques to optimize the image being viewed. Some display stations have advanced software to perform more complex image-manipulation techniques. More details about display workstations are given later Archive Servers An archive server is the file room of the PACS. It is composed of a database server or image manager, short-term and long-term storage, and a computer that controls the PACS workflow, known as a workflow manager (Figure 9-5). FIGURE 9-5 The common components of an archive. Workflow Workflow is a term that can be used in any industry or in any organization. It simply means how a process is done, step by step. In radiology, the term workflow has always been used to describe how an examination is completed, from order entry to transcribed report. This section describes a generic film-based workflow and then compares it with a generic PACS workflow. The workflow in each radiology department is different because there are many variables. Film-Based Workflow. Most departments were designed years ago for film and chemical processing. Pass boxes were built into walls that fed into darkrooms and into large open reading rooms that had gigantic multiviewer lightboxes lining the walls (see Figure 9-11). Eventually chemical-processing time decreased from a few minutes to less than 60 seconds in some cases.  As film and processing technology advanced, workflow became more efficient, despite the fact that technologists still have to hand-deliver film to radiologists and make the occasional copy for a referring physician. The following list outlines a typical workflow in a radiology department, from entering the order to transcribing the report (Figure 9-6).  The first step in any radiology department workflow is the entry of the order. The order may be a paper prescription from the ordering doctor, or the order may have been placed in the computer system by any hospital staff member. Either way, an order is placed in the radiology information system (RIS), and a requisition is generated. A requisition generally contains the following information:  Patient’s name Patient’s hospital identification (ID) number Date of birth Ordering physician’s name Examination ordered Reason for examination Chief complaint  The paper requisition is then passed on to the technologist who will be performing the examination. The technologist prepares the room for the patient and brings the patient back to the room. The technologist verifies all of the patient’s information and completes a patient history. The technologist also inquires whether the patient needs a complete set of copies to take to the next doctor’s appointment. The technologist performs the examination and processes all of the film after the complete examination is done.  The technologist critiques each film and repeats exposures as necessary. The technologist makes copies if necessary and releases the patient with the copies. The technologist goes to the file room to find the film jacket with all of the patient’s historic images, if applicable. The film jacket may not be located on site and may be kept at an off-site storage location. The film jacket is ordered to be picked up by the film courier.  The film jacket arrives a couple of hours or even days later, and the current films are hung on a multiviewer lightbox to be read by a radiologist. The file room clerk may hang a set of historic images from the film jacket for comparison. The radiologist reads the films and dictates a report into the dictation system. The multiviewer lightbox is cleared of read films by the file room clerk, and the films are placed back into the film jacket. The film jacket is filed in the file room. A transcriptionist retrieves the recorded dictation and transcribes a report into the RIS. This may occur later that same day or the next day.  The radiologist reviews the report, makes corrections, and signs the report as final. The final report is printed and placed in the patient’s film jacket along with any previous reports. A final report is also sent to the ordering physician for review. This final report may come several days after the examination was completed.  FIGURE 9-6 A typical film-based workflow from order entry to transcribed report. Generic PACS Workflow. The PACS workflow is in many ways different from the film-based workflow (Figure 9-7). The technologist may get the order via an electronic worklist or a paper requisition, but after that, the process begins to change. Changes in the order entry are on the horizon, but for now, the order-entry process is the same as in film-based departments. The technologist needs a requisition to verify the patient ID and to take a patient history.  The order is input into the RIS, and the RIS sends a message to the PACS to find all historic images and put them on the short-term archive. This eliminates waiting for the file room to retrieve a film jacket from the off-site storage location.(With the digital age these are not needed). The technologist prepares the room, retrieves the patient, and performs the patient history. The history is recorded on the paper requisition or input electronically into the patient’s computerized medical record.  The technologist performs the examination, and depending on the type of image acquisition device, the images are processed and repeated as necessary and sent to the appropriate PACS device. The patient images have been tagged with information from the RIS so that historic image reports are available at the PACS when the new images are sent. If the patient’s physician does not have access to the electronic images, a compact disk (CD) or  The requisition is either taken to the radiologist, or the radiologist may pull the images from an electronic worklist. The radiologist also pulls up historic images and reports and compares the previous images with the current images. The radiologist dictates a report and has it transcribed, or voice recognition software may be used. If the radiologist uses voice recognition software, he or she can review the report right after dictation, make corrections, and sign the report,  FIGURE 9-7 This diagram represents a typical PACS-based workflow from order entry to transcribed report.  With PACS it is possible that the time it takes from performing the examination to completing the final radiologist’s report is only a couple of hours, compared with a couple of days for the film-based workflow. System Architecture System architecture can be defined as the hardware and software infrastructure of a computer system. In a PACS, the system architecture normally consists of acquisition devices, storage, display workstations, and an image management system. The following discussion outlines three common PACS architectures and takes a look at the flow of images after acquisition. Client/Server-Based Systems In a client/server-based system, images are sent directly to the archive server after acquisition and are centrally located (Figure 9-8). The display workstation functions as a client of the archive server and accesses images based on a centralized worklist that is generated at the archive server. FIGURE 9-8 A client/server-based system architecture.  The health care worker at the display workstation chooses a name from the central list, and the archive server sends the image data to the display station. After the “client” is finished, the image data are flushed from its memory. Most systems allow basic image manipulation at the display workstation or “client,” and the changes are saved on the archive server.  The archive is the central part of the PACS and houses all of the historic data along with the current data being generated. In many institutions the archive serves as the central hub that receives all images before they are released to the radiologists for interpretation. What are the fundamental parts of PACS? PACS consists of four major components: Image acquisition devices (imaging modalities), Communication networks, PACS archive and server, and Integrated display workstations (WS) What are the 3 components of PACS? PACS components consist of acquisition nodes, archives, and output devices. Acquisition nodes may include: "digital modalities" such as CT, MRI, nuclear medicine, and computed radiography (CR), along with devices to convert from analog to digital, such as digitizers and frame grabbers. How does a PACS system work? Picture Archiving and Communication System (PACS) is a medical imaging technology that provides storage and access to digital images acquired by imaging modalities. It transmits digital images and reports electronically, which eliminates the need to manually file, retrieve, and transport film jackets What is the first step in the PACS system? The first step in typical PACS systems is the modality. Modalities are typically: computed tomography (CT),  ultrasound, nuclear medicine, positron emission tomography (PET), and magnetic resonance imaging (MRI). What is the difference between DICOM and PACS? While PACS and DICOM are often used together, they are different. PACS refers to the overall system used to manage medical images, while DICOM refers to the specific standard encoded and transmitted images and data. In other words, PACS is a system that uses the DICOM standard to store and communicate medical images. What are the principal components of a PACS quizlet? The four principle components of a PACS system are the image acquisition system, display system, network, and storage system. What are the two types of gateways in PACS? There are two types of gateways (GW) to the PACS server and archive, the database GW (Fig 7.2, green) for textual data, and the image acquisition GW (Fig. 7.2, yellow) for imaging data. What are the advantages of PACS? The Benefits of PACS Any examination sent to the PACS is available anywhere without other interventions. Enhanced Analysis & Viewing. One of the main benefits of using a PACS is the digital imaging technology they can include.... Improved Data Management.... Unmatched Mobility.... User-Friendly, Standards-Based Reporting.... Streamlined Workflows. What are the disadvantages of PACS? Some of the critical issues in PACS today include system integration issues, cost, access issues, data migration issues, and difficulty in transmitting images. However, most of these issues are technical in nature. What format is PACS data? The Image Storage Format For PACS The universal format for PACS image storage and transfer is DICOM, which is Digital Imaging and Communications in Medicine What are the two types of DICOM services? DICOM Service Element (DIMSE) are used by Application Entities (AE). There are two types of DIMSE Services, Composite DIMSE-C and Normalized DIMSE-N. These support operations and notifications like storage, retrieval, printing etc. on the SOP instances. How is a PACS used in a radiology? Simply put, PACS is a picture archiving and communications system. This system electronically stores images and reports, instead of using the old method of manually filing, retrieving and transporting film jackets, which are used for storing X-ray film. What is this two main criteria of success in a PACS operation? No loss of image data and no interruption of PACS data flow are the two main criteria of success in a PACS operation.