Informatics Midterm Notes 2020-2021 PDF

Informatics & Imaging Science Display Workstations: primary reading stations for radiologists review stations for referring physicians technologi...

Informatics & Imaging Science Display Workstations: primary reading stations for radiologists review stations for referring physicians technologist quality control (QC) stations where technologists review images PACS FUNDAMENTALS: image management stations for Common function the file room personnel. Navigation function Study function Image manipulation Enhancement function Hanging protocols Maestro Reynaldo John Tabhan  Display Workstations The display workstation is the most interactive part of a PACS, consisting of a monitor and a computer with a mouse and keyboard. In addition, each system has hardware that fits the users’ requirements. conventional film/screen radiography uses large multi-viewer lightboxes to display the images. Early in the history of PACS, radiologists believed that they needed four to six monitors to match the viewing capability they had with the lightboxes. As the radiologists have become more comfortable viewing images on monitors, the number of monitors required by the radiologists has decreased to an average of two. This decrease can also be attributed in part to the Continued development of viewing software and better hardware, namely, mice. The monitor is one of the most important elements of a PACS display station. The cathode ray tube (CRT) and the liquid crystal display (LCD) are the most popular types of monitors in a radiology department. The LCD has increased in quality during the past few years and will soon take over the entire PACS display market because of its size, resolution, and lack of heat production. The LCD also requires less maintenance, gives out more light, and can be used in areas with a high amount of ambient light. Most cross-sectional imaging is read on a 1K square monitor (Figure 8-15), and most CR and DR are read on at least a 2K portrait monitor Basic picture element on a display is known as a pixel. The number of pixels contained on a display is known as its resolution. The relationship between pixels and resolution can be stated as follows: the more pixels in an image, the higher the resolution of the image, and the more information that can be displayed. Resolution can also be defined as the process or capability of distinguishing between individual parts of an image that are adjacent. Pixels are arranged in a matrix. A matrix is a rectangular or square table of numbers that represents the pixel intensity to be displayed on the monitor. Common screen resolutions that are found on today’s monitors are 1280 × 1024 (1K), 1600 × 1200 (2K), 2048 × 1536 (3K), and 2048 × 2560 (5K). Medical displays are generally of a higher quality than displays used for other applications. Radiologists often use the highest resolution monitors available for the modality that is being read. For example, mammography requires a 5K or 5-megapixel resolution to provide the viewing capacity needed, but a cross-sectional image requires only a 1K monitor to view the necessary information. Because a referring physician is not the primary doctor reading the examinations, a 1K monitor would be sufficient for his or her viewing needs. Display stations can be categorized by their primary use: primary reading stations for radiologists, review stations for referring physicians, technologist quality control (QC) stations where technologists review images, and image management stations for the file room personnel. Each of these workstations has one specific main purpose and is strategically located near the end-user of its designated purpose. Radiologist Reading Stations: The radiologist reading station is used by a radiologist when making a primary diagnosis. The reading station has the highest quality hardware, including the best monitor. The computer hardware meets the needs of the PACS vendor, but it will usually be very robust, requiring little downtime. The keyboard and mouse can be customized. There are many different styles of mice available that can increase the efficiency of the software being used. Physician Review Stations: The physician review workstation (Figure 8-19) is a step-down model of the radiologist reading station. Many vendors use the same level of software but may eliminate some of the more advanced functions. One of the most important features on a physician review station is the ability to view current and previous reports along with the images. This can be accomplished with the integration of RIS functions with the PACS software. Most referring physicians want to read the radiologist’s report along with seeing the patient’s images, and often the report is more important to them than the images. This is one way that PACSs have improved continuity and speed of patient care. One of the greatest advantages of a PACS is the ability to view the same set of images in multiple locations at one time. The software may either be loaded on a stand-alone station that is dedicated to viewing images, or it may be delivered over a web browser on any personal computer (PC) within an office or on a floor. In high-volume areas such as the ER and ICU Technologist QC Stations: The technologist QC station (Figure 8-21) is used to review images after acquisition but before sending them to the radiologist. The QC station may be used to improve or adjust image quality characteristics, or it may be used to verify patient demographic information. Many QC stations are placed between the CR and DR acquisition modalities as a pass-through to ensure that the images have met the departmental quality standard. The technologist QC station generally has a 1K monitor. When manipulating images, the technologist must be careful not to change the appearance too much from the original acquired image. The technologist should consult frequently with the radiologist to ensure that the images being sent are of the required quality. The QC workstation can also be used to query and retrieve historic images before beginning an examination so that the technologist can check previous pathology or body characteristics. This can help with the selection of technical factors or procedural protocol. It is common protocol in a film-based department to pull film jackets on patients before performing an examination. The QC station affords the same benefit as pulling the film jacket. File Room/Image Management Stations: The file room in a PACS environment has seen many changes in the past few years. Before PACS, the file room was a large open room with endless rows of shelves full of film jackets. Today a file room in a PACS environment may be as simple as a couple of computers and a dry laser to make copies for outside needs. The file room workstation may be used to look up examinations for a physician or to print copies of images for the patient to take to an outside physician. Many hospitals are moving away from printing films to save the cost of the film and are instead moving toward burning compact disks (CDs) with the patient’s images because they are less expensive. The CD of images can be viewed on any PC and generally comes with easy-to-use software burned onto it with the images. The file room may also be responsible for correcting patient demographics. If images with incorrect demographics are sent to the archive, then it is difficult to pull those images the next time the patient comes in for an examination. The archive is a database and is only as good as the information that is put into it. Common Functions This section provides an overview of common functions found on a PACS workstation. All of the functions should be available on any level of the workstation except for the advanced functions. which are specific to different types of workstations. The functions can be broken down into four categories: navigation functions, image Manipulation and enhancement functions, image management functions, and advanced workstation functions. Navigation Functions Navigation functions (Figure 8-23) are used to move through images, series, studies, and patients. The worklist is used to navigate through patients. Most worklists are customizable for the user. One doctor may want to see only unread CT studies, and another may want to see all neurologic studies done that day regardless of the modality. Most modern PACS software conforms to the Windows (Microsoft, Redmond, WA) look and feel. The use of grab bars on the right side of Windows to scroll through a list and the activation of the scroll wheel on the mouse to scroll through the list are common features. The mouse is also a very useful navigation tool. The right mouse offers many short-cut features in a menu of frequently used tasks and applications. Hanging Protocols Once a patient has been selected from the worklist, the images load into the display software. In most PACSs, each user has the ability to set up custom hanging protocols. A hanging protocol is how a set of images will be displayed on the monitor. For example, when I select a CT examination, I want to view four images on each monitor, but when I view a CR image, I want to view one image on each monitor. Once the hanging protocols have been set, the most efficient study navigation is determined. Study Navigation: A study in PACS is the current or previous examination being viewed. A study may comprise two or three single images such as the case with CR and DR, or it may contain several series of images such as the case with MRI. The images can be paged through either with the scroll wheel or with arrows on the keyboard, or they can be run through in stacks. Many vendors call the stack mode of scrolling through images cine. This term comes from the word cinematic, and it means to move through frame by frame of the series of images. The images can be quickly moved through manually using the mouse, an automatic setting that runs through the images at a preset pace. The cine function is used most often in cross-sectional imaging. It provide icons (pictures within the software that activate software functions) that allow the user to move among a patient’s various studies or open the next unread patient in the worklist after having read the current study. Another navigation tool that is commonly found is a close patient or close study icon. This icon closes the active patient or study and either pulls up the worklist or moves to the next unread patient in the worklist. Users can set up these tools according to their preferences. Image Manipulation and Enhancement Functions Once the images have been opened on the display, there are many tools that can be used to change the appearance of the image. Here is a bulleted list of some of the most commonly used functions: Window/level : This is usually a default function of the left mouse button when an image is actively displayed in the software. By depressing and holding down the mouse button and moving the mouse up and down and left and right, the window and level can be adjusted. The window represents the range of gray values that are being viewed, and the level represents the center value of the range. Changing the window and level changes the brightness and contrast of the image on screen. Annotations : Most PACSs can annotate text or graphics onto the image. This function should NOT be used to label left or right to indicate the patient’s side because digital R and L will not hold up in court because of the ability to mark anywhere on the image and flip and rotate the image into any layout on the screen. Annotations can indicate prone or supine, 30 minutes, upright or flat, or any other image information the department deems appropriate. Radiologists frequently place arrows or circles around pathology or questionable areas so that the referring physician can pinpoint what is in question. Flip and rotate : These functions are used to orient the image in the anatomical hanging position desired by the department. There are usually left-to- right flip and 90-degree clockwise and counterclockwise icons. This function makes it very important that lead markers are used to ensure that the radiologist reads the correct side. Pan, zoom, and magnify : These functions are used primarily by the radiologist to increase the size of an area on the image. The magnify function will usually enlarge a square area of the image, and the square can be moved around the image to quickly see various areas enlarged. The pan and zoom functions are usually used together. The image is first zoomed up to the desired magnified level, and then the pan icon is activated so that the zoomed image can be moved around,b allowing the user to view the different areas of the image. Measurements (Figure 8-29): There are various measurement functions found on a PACS station. The most common is the distance measurement. The size of a pixel is a known measurement, so the software can measure structures on the image based on this known measurement. Another common measurement is the angle measurement, which measures the angle between two structures. It is commonly used when reading spine studies. Another common measurement a radiologist may use is a region of interest (ROI). It will determine the pixel intensity of a certain area. Because each type of tissue or fluid has a little bit different intensity reading, the radiologist can make a determination whether something is solid or fluid. Image Management Functions : Most PACSs allow the user to modify patient demographics at the technologist QC station, the reading station, and the file room station. It is imperative that the patient demographics are correct. If wrong information is archived, images will not come up when correct information is entered when trying to retrieve them. Only make changes when the information is absolutely known to be wrong. To minimize errors, many hospitals only allow certain people the access to change demographics. Another image management function is the query/retrieve function used to retrieve studies from the archive (Figure 8-31). The query function allows the user to query a study on multiple fields such as the patient’s name or ID, date of service, or modality. Some systems also allow a query based on a diagnosis code or comment field. Health Insurance Portability and Accountability Act (HIPAA) compliance must also be maintained. Another common feature is the ability to copy and paste images into a document. This is frequently used with the web-based systems when creating presentations for conferences. The patient information must be removed from the image before it is placed into a presentation. Some hospitals have retained the ability to print films for outside use. This is also usually done only in the file room so that control can be maintained over the printed films for HIPAA purposes and cost reasons. Some hospitals have also connected Workstations to paper printers for quick consults and medical records. THANK YOU