Table of Contents
Abstract
Objective: The purpose of this paper is to function as a succinct guide for setting up homeworking radiology capability amidst the COVID-19 pandemic. It covers non-technical and technical aspects, with reference to normal standards. This paper will be relevant to radiologists working in hospital and private clinic settings as well as other disciplines actively engaged in formal interpretation of images. Readers who are interested in adopting higher standards of review of images for clinical work may also find this guide useful.
Conclusion: Setting up homeworking radiology is an important means of social distancing and continuity of care during the COVID-19 pandemic. In the long term, it may help with 24/7 subspecialty coverage, facilitate flexible work, unlock more manpower hours and decrease high-end workstation growth.
Introduction
The COVID-19 pandemic has accelerated the implementation of homeworking in many countries as a means of social distancing and isolation, avoiding crowded commutes to work whilst ensuring business continuity. Globally, most institutions and radiology practices have a Picture Archiving and Communications System (PACS) storing radiology studies which are mostly native digital images. Thus, image review and reporting are inherently suited for home-based work.
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This document details both the non-technical and technical aspects of setting up homeworking teleradiology. It is based on our experience conducting our institution’s pilot since Jan 2020. This paper will be beneficial to radiologists as well as other disciplines actively engaged in formal interpretation of images, for example cardiologists for cardiac imaging. Readers who are interested in adopting higher standards of review of images for clinical work may also find this guide useful.
Basic requirements for reporting imaging studies from home are as follows:
- Core applications/systems, secure network connectivity and home Internet access
- Home reporting setup
- Reading environment
- Personal Computer (PC)
- Display monitor
- Primary diagnostic monitor calibration and parameters
- Productivity tools (optional)
- Image reporting testing, policy and support
Core Applications/Systems, Secure Network Connectivity, and Home Internet Access
Core applications/systems required for image viewing and interpretation include PACS, Radiological Information System (RIS), Electronic Health Record (EHR), and access to institutional contact directories for urgent finding notification. These applications/systems must be connected to a remote access server, and privilege granted to the user to access these securely over the Internet.
The remote connectivity option should preserve image quality. For example, site-to-site Secure Sockets Layer Virtual Private Network (SSL VPN) which allows direct access to the core application servers within the organisation’s network, thus maintaining the same image quality as on-site. On the other hand, remote connectivity using real time screen sharing and lossy compression algorithms degrade image quality and are best avoided for diagnostic reporting.
Nevertheless, in times of crisis such as the COVID-19 pandemic, these standards may be lowered and issuing reports using suboptimal modes of connectivity may be allowed with consideration of additional disclaimers (1).
Internet service provider data transmission speeds required for optimal core application/system functionality need to be established and communicated to the user. A 1Gbps fibre broad-band connection speeds is preferred. Latency will depend on a multitude of factors including server bandwidth and concurrent users which may be beyond immediate control.
Reliable and secure data transmission such as direct LAN cable connection between the PC and router is preferred.
Reading Environment
A quiet, private room is strongly advised to avoid issues with personal data privacy and security as well as to minimize distractions and noise.
Air-conditioning and other external temperature/humidity control solutions can prevent degradation of equipment and promote user comfort.
Ergonomics (particularly chair and desk height) should be optimized, with screen to reader distance of around 60cm, the screen correctly angulated and in plane with the reader’s eyes (2). Height adjustable tables can also be purchased.
Ambient lighting should be controlled and maintained at the same level for primary diagnosis of images. The reader is advised to refer to the section “Primary Diagnostic Monitor Calibration and Parameters” (below) for details.
Sufficient power socket access should be available.
Personal Computer (PC)
Minimum PC specifications will need to be met if diagnostic image quality, dual monitor set up and satisfactory performance are required. Local testing may be required to experiment with what is readily available and cost-effective. The following are key components.
- Graphics card/Graphical Processing Unit (GPU). This should be able to support the resolution of the primary diagnostic monitor. The GPU should also support multi-monitor configurations. External GPUs are a relatively new offering that may boost PCs lacking GPU performance such as laptops through Thunderbolt 3 connectivity, thereby allowing the PC to support Dedicated Medical Displays (DMD).
- Memory. A safe amount of Random Access Memory (RAM) would be 16 GB.
- Processor. Users should check with their Picture Archiving and Communication System (PACS) provider what are the minimum recommended CPUs. At the point of time of writing, the Intel I9 and AMD Ryzen Threadripper series are at the high-end range.
Display Monitor
The primary diagnostic monitor is the display monitor used for viewing and interpretation of radiological images for the purpose of issuing a final medico-legally binding report. It should be a flat panel Liquid Crystal Display (LCD) screen which meets requirements as listed in Table 1 (2, 3).
DMDs are typically used in institutional radiology workstations as they readily meet the above requirements, have longer lifespans, and better display uniformity. However, they are expensive, physically bulky and heavy and may have limited compatibility with non-vendor graphics cards.
Commercial-Off-The-Shelf (COTS) monitors on the other hand, are significantly cheaper, lighter, more readily available and compatible with most PCs but suffer from lower luminance capacities and shorter lifespan.
On a practical note, users will want to check the connectivity options available between their PC and monitor. Typically, these will be High-Definition Multimedia Interface (HDMI), DisplayPort (DP) and Universal Serial Bus (USB)-C. Analog video interfaces such as Video Graphics Array (VGA) are strongly discouraged since it can introduce image degradation (3).
COTS monitors are not recommended for mammography which requires much higher standards. They are suitable for all other imaging modalities as listed in Table 1.
COTS monitors have a limited lifespan for primary diagnosis due to luminance degradation, and it is estimated that they last 1.5 years on continuous usage (4), though anecdotally some can last up to 3 years. Users are therefore advised to avoid turning on their primary diagnostic monitors for purposes other than image reporting.
During this pandemic, global supply chain disruption may limit access to COTS monitors and institutions may temporarily lower display requirements.
A secondary monitor used for viewing other applications is ideally part of this set up. No specific requirements are needed for this monitor.
Primary Diagnostic Monitor Calibration and Parameters
Digital Imaging and Communications in Medicine Grayscale Standard Display Function (DICOM GSDF) calibration is the typical recommended form of gray-scale calibration of a display monitor to ensure adequate contrast and uniformity of appearance of an imaging study across all calibrated monitors (5). This is achieved by using a calibration software and a photometer, which are in-built with DMDs but need to be purchased separately with COTS monitors. Recommended standards for primary diagnosis (excluding mammography) are in Table 2 (2, 3, 5).
In times of crisis in order to rapidly roll out home reporting, calibration standards may be temporarily lowered allowing users to adopt a best-as-reasonably-possible calibration. Typically, users calibrate qualitatively against test patterns such as TG18-QC with focus on luminance assessment (5), adjusting display brightness, contrast and gamma with monitor buttons and/or readily available software such as Nvidia Control Panel (6). These new lowered standards will need to be defined locally and agreed with the user’s organisation.
A calibrated monitor is, strictly speaking, tied to a single setting of ambient lighting. Typical overhead room lighting promotes specular (mirror-like) reflection off the primary diagnostic monitor and should be turned off during interpretation of images (6). Dimmable Light-Emitting Diode (LED) strips stuck to the back of the calibrated monitor can provide ambient backlighting. Other sources of dimmable ambient lighting in the room may be used, but these should be carefully positioned in relation to the monitor to avoid specular reflection. Natural lighting varies throughout the day and is best eliminated. An overall ambient illuminance of 25 to 50 lux is suggested to promote productivity (3).
Productivity Tools (Optional)
Voice Recognition (VR) software improves reporting productivity and is considered indispensable by most radiologists. The mode of network connectivity available may or may not allow access to the organization’s VR solution. If it does not, there are commercial solutions available which can be installed on the user’s PC.
Dictation devices range from microphones to headsets, with activation of recording by microphone buttons, foot pedal, PACS software buttons or PACS keyboard shortcuts. From our experience, headsets tend to be more economical.
PACS user interface devices such as those featuring jog wheels and programmable buttons may facilitate reporting and reduce repetitive strain injury (7). A multi-button gaming mouse is a cheap solution which can be used if a specialized scroll wheel is not required.
Home Reporting Testing, Policy and Support
User testing of ease and speed of set up, functionality of reporting applications, maximum number of concurrent users, work volumes achieved, and overall consistency and reliability of the home reporting system is important to provide data for work planning and request for enhancements.
Local policy needs to be developed by leadership to delimit when homeworking can be used to issue reports, for what kinds of studies, as well as need for a standardized disclaimer tagged to homeworking reports (1).
IT department remote and/or on-site support is critical. Applications for remote troubleshooting will be very helpful.
Training and close communication with organization staff are required to ensure that users are adequately prepared to use a homeworking set up when called upon.
A summary checklist is available in Table 3, and an example of such a setup in Fig 1.
Conclusion
Homeworking radiology is an important means of social distancing and defense-in-depth during disease outbreaks such as COVID-19. In the long term, home reporting with diagnostic quality setups may help with 24/7 subspecialty coverage, facilitate flexible work, unlock more manpower hours, decrease high-end workstation growth and save on staff commuting time. Close coordination between users and IT support and approval of organizational leadership is required to achieve mission success.
