Basic IT for Radiographers PDF

BASIC IT FOR RADIOGRAPHERS MATT T. DAKOYKOY, RRT  BASIC IT FOR RADIOGRAPHERS Components of IT equipment used within the healthcare environment are many and varied. Those frequently part of the informatics estate can be categorized into two distinct types: Hardware and Software ...

BASIC IT FOR RADIOGRAPHERS MATT T. DAKOYKOY, RRT  BASIC IT FOR RADIOGRAPHERS Components of IT equipment used within the healthcare environment are many and varied. Those frequently part of the informatics estate can be categorized into two distinct types: Hardware and Software  Hardware Workstation/PCs Input/Output Devices Input/Output Devices 1. Processor Input Devices Output Devices 2. Memory 1. Mouse 1. Display 3. Graphics Card 2. Keyboard 2. Printers 4. Storage 3. Foot Pedals 3. Speakers 4. Dictation Microphones Dual Purpose Devices Display Devices 1. Memory Printers Sticks/CD/Digital UPS Versatile Disk Servers (DVD)/Blueray disks Networks and Drives 2. 3.5-inch floppy drives 3. Magneto-optical disks (MODs)  Workstation/PCs 1. Processor The heart of every workstation is a processor. This device in its simplest form takes collections of digital inputs (0 or 1) and processes them into outputs upon the instructions received from the program currently running.  Workstation/PCs 2. Memory Random access memory (RAM) is a highspeed place for items currently in use to be stored. The more RAM available, the more items (programs, instructions, user data, etc.) can be used and manipulated at the same time. Applications, such as three-dimensional (3D) reconstructions, require larger amounts of RAM than viewing a single plain radiographic image. Equated to human task, RAM is equivalent to human short- term memory. Some people can remember longer sequences than number than others. RAM is measured in gigabytes.  Workstation/PCs 3. Graphics Card The graphics card is a second processor and extra memory dedicated to displaying images. It is needed owing to the greater complexity of modern applications requiring different mathematical operations than the standard processor is designed for.  Workstation/PCs 4. Storage The storage is where data are stored even when powered off. A storage can either be a magnetic spinning disk known as a hard disk drive (HDD) or a miniaturized internal device, similar in principle to a large fast memory card known as a Solid State Drive (SSD).  Input Devices 1. Mouse A mouse is a device which provides navigation of the cursor on- screen. Mice can either be (1) traditional in style (pebble shaped), (2) upright (shaped like an iceberg for those with limited wrist movements), (3) 3D (aka a gyromouse/fitted with a gyroscope for handheld use in theaters or multidisciplinary team (MDT) meetings), (4) projection (a sensor detects hand movements within a fixed area), (5) button (shaped as pencil eraser and used in similar manner to a joystick), (6) roller ball (a captive ball, as used in self- check-in kiosks or arcade machines), or (7) trackpad (flat, with touch sensitive box).  MOUSE 1. Traditional 2. Upright 3. 3D (Gyromouse)  MOUSE 4. Projection 5. Button  MOUSE 6. Rollerball  MOUSE 7. Trackpad  Input Devices 2.Keyboard Can incorporate smart card readers and be of many different styles, with or without washable membranes or covers for clinical use and sterilization.  Input Devices 3. Foot Pedals These are used for inputting shortcuts, traditionally in radiology transcription workflows, but are also useful for those with limited hand movements. Use the foot pedal in lieu of a keyboard or mouse to eliminate awkward key combinations, replace common text strings with one touch macros, off-load mouse clicks, or replace a dedicated joystick in specialty applications.  Input Devices 4. Dictation Microphones The most commonly used model in the UK is the Philips SpeechMike (various versions), which has a built-in speaker for playback, a trackball, and several customizable buttons (some used for reporting functions, others for the user’s choice).  Input Devices 5. Touchscreen monitors It can be either capacitive (using the surface to discharge a tiny electrical current through the user’s body)or resistive (a mesh sandwiched between two clear sheets, which closes electrical contacts at specific places on each tap), each giving particular advantages in different situations (resistive screens operate with gloved fingers, capacitive do not if the glove is not conductive).  Output Devices 1. Display Devices Comprising multiple components, display devices are where the primary output of a PC is displayed to the user. The most visible components(s) of this one or more monitors (also known as displays, screens or visible display units (VDUs). Different types of monitors are available depending on the purpose and use of the workstation to which they are attached. High-quality monitors for reporting require dedicated graphics cards to operate – these are specialist processors internal to the workstation in a card shape, which provide the necessary outputs to the monitors.  Output Devices Various types of cabling are used to connect monitors to the graphics cards: the most common high-resolution interfaces being high- definition multimedia interface (HDMI), DisplayPort, Digital Visual Interface (DVI) – digital output only (DVI-D) and combined digital and analog output (DVI-I). Outdated legacy interfaces included video graphics array (VGA), S- Video, and proprietary interfaces, which may still be in service to connect aged infrastructure in MDT or conference room. HDMI & Display Port DVI-D & HDMI DVI-D & DVI-I VGA and S-Video  Output Devices Below are the major types of monitors which are used today: Cathode Ray Tube (CRT) Liquid Crystal Display (LCD) Plasma Screen Before trying to understand how a computer monitor works, we must understand first the terms listed below: 1. Pixel 4. Dot Pitch 2. Resolution 5. Refresh Rate 3. Matrix 6. Viewable area  Output Devices Pixel Short for picture element. A pixel is an individual controllable set of dot triads. A dot triad is a grouping of one red dot, one green dot, and one blue dot.  Output Devices Pixel and Resolution The number of pixels on a display is known as its resolution. 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.  Output Devices Pixel and Matrix Matrix is the arrangement of pixels into rows and columns. The location of the pixel within the image matrix corresponds to an area within the patient volume of tissue. Common screen matrix sizes are 1024 x 768, 1280 x 1024, 2048 x 1536, and 2048 x 2560. Matrix size tells you the total number of pixels. The higher the matrix size, the better the resolution.  Output Devices Dot Pitch Dot pitch is the measurement of how close the dots are located to one another within a pixel; the smaller the dot pitch of a display, the finer the resolution. Dot pitch may be expressed as aperture grille pitch or slot pitch, depending on the monitor maker.  Output Devices Refresh Rate The screen refresh rate is also known as the vertical scanning rate. The refresh rate is the measure of how fast the monitor rewrites the screen or the number of times that the image is redrawn on the display each second. The refresh rate helps to control the flicker seen by the user; the higher the refresh rate, the less flicker. Most refresh rates on today’s computers are set between 60 and 75 Hz; the image is redrawn 60 to 75 times per second.  Output Devices Aspect Ratio The aspect ratio is the ratio of the width of the monitor to the height of the monitor. Most CRT monitors have an aspect ratio of 4:3; LCD monitors have a ratio of 16:9.  Output Devices Viewable Area The viewable area is measured diagonally from one corner of the display to the opposite corner.  Output Devices Concerns Regarding Computer Monitors Owing to manufacturing processes, many low-end monitors have a number of ‘dead’ or ‘stuck’ pixels even when new. Dead pixels are tiny sections of the screen that do not operate, whereas stuck pixels are tiny areas that are permanently on, displaying their color.  Output Devices Dead Pixels  Output Devices Stuck Pixels  Major Types of Monitor CRT The CRT consists of a cathode and anode within a vacuum tube. The CRT works much like an x-ray tube, in that the cathode boils off a cloud of electrons and then a potential difference is placed on the tube. A stream of electrons is sent across to the monitor’s anode, which is a sheet of glass coated with a phosphor layer. The electrons strike the phosphor on the glass, causing the glass to emit a color, which is determined by the intensity of the interaction and area with which the electrons interacted.  Major Types of Monitor The electrons interact with either a red, green, or blue dot to form the color and image that is being sent from the video card signal. The electron beam starts in the upper left corner and scans across the glass from side to side and top to bottom, and once it reaches the bottom, it starts back over at the top left. On average, most monitors have 350 lines to be scanned. Earlier we discussed the refresh rate being 60 to 75 Hz. This equates to 350 lines being scanned 60 to 75 times per second. Major Types of Monitor  Major Types of Monitor LCD An LCD monitor produces images by shining or reflecting light through a layer of liquid crystal and a series of color filters. An LCD has two pieces of polarized glass with a liquid crystal material between the two. Light is allowed through the first layer of glass, and when a current is applied to the liquid crystal, it aligns and allows light in varying intensities through to the next layer of glass through color filters to form the colors and images seen on the display. Major Types of Monitor  Major Types of Monitor Plasma displays are still new to the consumer market. They have been heavily used in government and military applications since the late 1960s. The plasma displays are made up of many small fluorescent lights that are illuminated to form the color of the image. The plasma display varies the intensities of the various light combinations to produce a full range of color.  Major Types of Monitor Monitor Advantages and Disadvantages Most consumers want a monitor that can provide the highest resolution for the best price. Table 2-1 outlines the advantages and disadvantages of the three major types of monitors. Most radiology departments have traditionally used the CRT because of its superior resolution, but LCDs are increasingly gaining popularity because they are slimmer and lighter.  Output Devices 2. Printers Covering a variety of outputs, three main types of printer are found in imaging departments: 1. Plain Paper 2. Thermal Paper 3. Film  Output Devices 1. Plain Paper For appointment letters, documents, printed lists, etc. (standard office laser or inkjet printers, similar to domestic counterparts, but with larger toner/ink capacities) 2. Thermal Paper For labels, stickers, CD/DVD tops or patient wristbands; being either direct thermal (burning the surface of the sticker) or indirect dye sublimation (melting dye from a plastic carrier ribbon to transfer ink onto the surface of the sticker).  Output Devices 3. Film Film for limited uses, such as patients returning to non-digital healthcare systems abroad. Film printers were previously widely used for business continuity during PACS outages, but are now being depreciated within the UK Radiology Departments because of the limited shelf life of the film packs used, physical size of the units, and annual maintenance costs involved. As PACS and the supporting hospital infrastructure are now routinely very stable, it is no longer necessary or common for departments to retain film printing technology on-site.  Output Devices 3. Speakers These are used for playback of audio.  Dual Purpose Devices 1. Memory Sticks/CD/Digital Versatile Disk (DVD)/Blu-ray disks and Drives Comparatively low capacity removable media used generally for the physical transfer of images to solicitors or by patients for onward care. These devices could also be used for input purposes.  Dual Purpose Devices 2. 3.5-inch floppy drives obsolete in many uses because of their lack of capacity; however, firmware updates for some CR machines (the raw machine operating instruction coding) still utilize these formats for both input and output owing to the resilience and longevity of the media.  Dual Purpose Devices Magneto-optical disks (MODs) For long-term archival of larger volumes of data, these were historically common for storing unprocessed CT data (the raw output of the scan before processing took place) or older PACS archives, sometimes in large jukebox machines for automated physical storage or retrieval. Again, these may be utilized for both input and output.  UPS Uninterruptable power supplies (UPS) provide a temporary source of replacement battery power should mains supply be lost, either accidentally or as part of a planned test. They connect in series between the wall socket and workstation to allow enough time for either the mains power to be restored or for the computer to be shut down gracefully (by saving documents, sending images or completing any reports in progress, etc.).  UPS They are recommended for all clinical workstations or devices (including modalities) where abrupt shutdown of a machine would present a clinical risk or disruption to the service. UPS devices traditionally also ‘filter’ incoming mains power of any harmful spikes in voltage, which may damage the more expensive workstations.  Servers Servers are the devices that run centralized applications, such as the backend functionality of a PACS or RIS, and in most cases are housed within a dedicated environment managed by the local IT department, known as the server room.  Servers Servers are effectively powerful customized workstations and can either be dedicated (known as ‘pizza box’ servers owing to their shape) or virtual (running as virtual instances on shared hardware). MORE ON DEDICATED SERVER Dedicated pizza box servers are measured in physical size in ‘U’s, with 1 U being 4.4 cm of height in a standard server rack, with cooling requirements measured in British thermal units (BTUs). An IT department uses the total number of BTUs output by all servers in a given area to calculate the volume of air conditioning required.  Servers Dedicated Server (Pizza Box)  Servers Virtual Server  Servers UPDATING OF DEDICATED SERVER Within the server room, when adding or updating a dedicated server, considerations include whether there is sufficient power available, sufficient cooling, and whether any infrastructure (network, cabling, physical space) is suitable for the revised requirements.  Servers MORE ON VIRTUAL SERVERS Virtual servers can be measured in many ways, but commonly with processor ‘seats’ being indicated (the more of these seats, the more ‘powerful’ the virtual server can be made). As virtual servers can share physical hardware in the server room (and so have lower power, cabling, and cooling requirements), they are commonly preferred by IT departments; however, as PACS and imaging informatics applications have heavy demands on hardware, debate is ongoing as to whether this is the best option, or whether dedicated pizza box servers remain the better choice in the long term, despite the higher physical space, power, and overall cooling requirements.  Servers Connected to either type of radiology server is typically a storage array, UPS, and backup device to hold all the data being utilized and provide protection.  Networks Networks provide the physical interconnections and backbone between pieces of IT. A surprising amount of work for the imaging informatics professional originates from the network infrastructure of the healthcare institution (or faults therein!). This provides an incentive for informatics professionals in the field to study network-based training programs to help them understand the potential problems and configuration options to speed up or increase reliability of radiology services.  Networks Some of the components of a network infrastructure that needs to be understand are as follows: 1. Cabling 5. Port 2. Internet Protocol Addresses 6. VPN 3. Routers 7. Bandwidth 4. Switches  Networks 1. CABLING The physical make-up of network cabling is either traditional copper (utilizing the flow of electrons/electricity) or now the more common glass fiber-based cabling (utilizing the flow of photons/light).  Networks Working Principle of Fiber-glass cable or Fiber optics.  Networks Glass fiber-based networking has theoretically much higher speeds than that utilizing copper owing to the physics behind the two technologies. However, due to the relative newness of the glass fiber- based networking devices, while it is currently commonplace for the ‘spine’ of a network to utilize this newer technology, the ‘final hop’ (final connection) to the workstation, server, or device typically remains made in copper cable. This will change over the coming years as the higher raw material cost of copper balances out the higher cost of glass fiber installations, with greater throughput (amounts of data that can be moved around) being the consequence.  Networks 2. Internet Protocol Addresses (IP Address) Networks are also on the cusp of another change: addressing the data flowing around a network is much like a telephone or postal system using telephone numbers or post codes.  Networks IPV4 Data to be moved around, such as a webpage or radiology image, is broken down into thousands of tiny ‘packets’ of data, each containing a destination and technical data. The main ‘addressing’ system used throughout the world is currently the same as that devised in 1981, namely internet protocol (IP)V4 (where addresses are denoted as blocks of numbers in fixed ranges, such as 192.168.0.1, similar to telephone numbers with area codes). However, as IPV4 has a fixed number of addresses that have now run out (because items such as internet connected mobile telephones, fridges, and closed-circuit TV cameras were not foreseen in the 1980s) a transition to a newer addressing standard, IPV6, is underway.  Networks IPV6 IPV6 uses hexadecimal addresses (fd00:ab4f:4201:abf2:fbc4:f1ac:ba53:abc1), which offer substantially more combinations than with IPV4. There are central ‘directories’ of IP addresses within both an institution, country, and the world to ensure duplication is minimized on the wider internet, and also to provide routing details.  Networks 3. Routers These connect several different networks and operate at the network layer (level 3) of the open systems interconnection (OSI) model. These devices can broadcast data packets within an internal intranet network (a local area network: LAN) and outwards into a wide area network (WAN), such as the general internet. Routers typically assign and maintain the local IP addresses and associated directory to machines, workstations, and devices that connect to the network, plus critically the most direct/fastest routes between various points.  Networks 4. Switches These create a network, operating at the data link layer (level 2) of the OSI model and receive and forward data packets in the internal network only, using the router’s instructions.  Networks 5. Port This is a digital entry or exit point, similar to a real-life ferry terminal, bus station, or airport. The de facto port used for unsecure digital imaging and communications in medicine (DICOM) transmission is 104, with secure DICOM passing into the specialty allocated and reserved port 2762.  Networks 6. VPN A virtual private network (VPN) allows for connections between two normally separate networks to take place, creating a secure ‘tunnel’ between the two points. Most typically this is observed between a hospital network and the homes of staff – allowing for staff to access internal hospital applications in a secure manner. VPN tunneling can either be ‘full’ or ‘split’.  Networks Full tunneling should be utilized wherever possible, which directs all traffic (including general internet searches and printer requests) onto the remote network, allowing the user to experience it as if they were in the hospital itself. Split tunneling directs only specific traffic and is more open to security risks but is cheaper (less traffic load is placed into the remote site).  Networks 7. Bandwidth This is the amount of data that can be simultaneously sent over a given connection, which is a crucial consideration when a large number of either modalities (perhaps CT scanners) or radiology reporting workstations are situated close together; is there sufficient bandwidth in that area for all the machines planned?  SOFTWARE Software plays a supporting role in making best use of the hardware capabilities and is responsible for the interface with which the user interacts. Good interfaces speed up human interaction times and increase productivity.  Operating System The main component running on any workstation or server. An operating system (OS) is the program that, after being initially loaded into the computer by a boot program, manages all of the other application programs in a computer.  Backups A hybrid of hardware and software, undertaking and verifying backups is a common daily task (or chore!) for PACS team members owing to the consequences of losing medical data (which would include reirradiation of patients if related imaging data were lost) Verifying these backups is a frequently missed task for Radiology departments, but is necessary for validating that the backups would be useful in the event of them being called into use.  Backups Below are the types of backups: 1. Full Backups 2. Incremental Backups 3. Differential Backups 4. Resilience  Backups 1. Full Backups take the entire dataset (e.g. a RIS database, or a PACS repository) and create an identical copy, either by lossless compression or in raw 1:1 format. This is both time consuming and resource intensive.  Backups 2. Incremental Backups include only data that have changed from the previous backup.  Backups 3. Differential Backups are similar to incremental backups, but include all data changed from the very first, full backup (rather than a previous differential backup).  Backups 4. Resilience Some systems make use of identical copies of their hardware, which can ‘load balance’ (share loading to provide even wear) between each other during normal use, or ‘failover’ (continuing to use the non- failed components) in the event one piece fails in order to provide redundancy. For storage, a redundant array of inexpensive disks (RAID) can be utilized to give the same resilience for disks (and also performance boosts in some cases).  Backups Various ‘levels’ of RAID provide different amounts of failure tolerance, with RAID 10, e.g. providing data mirroring and striping across multiple disks allowing at minimum one disk out of the ‘array’ to fail yet the system being able to continue operating with no data loss. RAID only provides resilience and should not be considered a backup solution.