Part of Architecture pattern for connected medical devices - Imaging Pillar

Imaging diagnostic pillar

Scope

The imaging diagnostic pillar or imaging 'ecosystem' consists of all components that are involved in the end-to-end imaging diagnostics data flow comprising ordering, image generation, transmission, processing, storage, analysis, and reporting.

It does not include:

imaging via manual or paper methods
imaging diagnostic devices that do not connect to the clinical network

Imaging diagnostics components

These components can be grouped in the following categories:

Clinical application services – Consists of systems such as the electronic patient record (EPR), order entry, health information systems (HIS), and others used by patient care teams in recording information during patient treatment.

Imaging diagnostic devices – Otherwise known as 'modalities'. These are the different types of diagnostics devices connected to the clinical network and used to generate diagnostic images of patients using various imaging mechanisms. Examples include X-ray machines, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound scanners.

Image storage and archiving – These include the picture archiving and communication system (PACS) used for archiving and distribution of images and reports, and off-site archives. In some cases, Vendor Neutral Archives (VNA) are used; these are repositories that store medical images in a standard format received from various PACS systems.

Image visualisation system – These are the various components used by clinicians to view, analyse and generate reports of diagnostics images stored in PACS and VNAs. Examples include Digital Imaging and Communications in Medicine (DICOM) viewer, PACS workstations and other components used by PACS administrators to access images used in hospitals and increasingly in community diagnostic centres.

Image Exchange Portal (IEP) – The IEP is a web-based application that enables health and care professionals to securely transfer patient images between hospital trusts.

Imaging diagnostics component breakdown

Below is a breakdown of various properties of the components identified in the imaging diagnostics pillar:

Modalities

Basic functionality - Modalities are the different types of diagnostic imaging equipment connected to the network and, regardless of the category they fall under (see table 2), are used to generate diagnostic images of patients. Modalities in this context, include for example MRI, CT, ultrasound, and X-ray.

Software/hardware - Vendor dependent hardware and software

Typical locations - Mainly acute hospitals

Data type - Personal confidential data and images usually stored on a temporary basis - roughly 2 weeks depending on the modality. The images are rotated.

Storage - Temporary embedded storage

Underlying operating system (OS) - Many modalities have old OS such as Windows XP

Authentication - Local shared logins (logging in to a CT scanner) generic username/password. Usually managed by vendor or in some cases admin privileges are given to imaging teams.

Active Directory integrated - No

Network information - Historically static IP addresses due to DICOM limitations.

Communications protocol - DICOM and Health Level 7 (HL7) are nearly universal for images and demographics. However, there may be proprietary connections to ancillary devices.

Electronic patient record (EPR)

Basic functionality - These are systems used by patient care teams in recording information during patient treatment. Comprises patient charts and entire patient medical histories.

Software/hardware - Software

Typical locations - Hospitals

Data type - Personal and confidential

Storage - Databases

Underlying operating system (OS) - Windows

Authentication - Role-based access control (RBAC) user

Active Directory integrated - Yes

Network information - Dynamic Host Configuration Protocol (DHCP)

Communications protocol - HL7

PACS

Basic functionality - Picture archiving and communication systems used for archiving and distribution of images and reports.

Software/hardware - PACS software installed on workstations to interact with PACS.

Typical locations - Hospital, imaging network or in a few cases in the cloud.

Data type - Personal confidential and sensitive information contained in images and reports.

Storage - Direct-attached storage (DAS), network-attached storage (NAS), storage area network (SAN) or cloud platform as a service (PaaS).

Underlying operating system (OS) - Usually Oracle SQL database

Authentication - Individual user logins required. Smartcards are used in some cases.

Active Directory integrated - Yes

Network information - Historically static IP addresses due to DICOM limitations.

Communications protocol - DICOM is universal, but some PACS use proprietary protocols for internal communication.

VNA

Basic functionality - VNAs are image repositories that enables multiple healthcare organisations access images from multiple PACS.

Software/hardware - VNA software

Typical locations - Hospital imaging networks

Data type - Personal confidential and sensitive information contained in images and reports.

Storage - Direct-attached storage (DAS), network-attached storage (NAS), storage area network (SAN) or cloud platform as a service (PaaS).

Underlying operating system (OS) - Usually Oracle SQL database

Authentication - Individual user logins required. Smartcards are used in some cases.

Active Directory integrated - Yes

Network information - Static IP

Communications protocol - DICOM

Radiology information system (RIS)

Basic functionality - Radiology information system used for management of imaging services. This includes scheduling patient appointments, tracking, waiting list management, storage and distribution of reports, image sharing, provision of demographics and identifiers to acquisition modalities, and PACS.

Software/hardware - RIS Software can be procured and deployed onto 3rd party hardware.

Typical locations - Mainly acute hospitals

Data type - Personal confidential and sensitive information contained in images and reports.

Storage - Database

Underlying operating system (OS) - SQL database

Authentication - Some smartcard usages for EPR

Active Directory integrated - Yes

Network information - Historically static IP addresses due to DICOM limitations.

Communications protocol - HL7 (mostly v2), DICOM

Hospital information system (HIS)

Basic functionality - HIS is mainly used to record patient information to establish a patient’s identity, deployed mainly at a hospital. PAS is another application used to manage a patient’s hospital activities.

Software/hardware - HIS software

Typical locations - Hospitals

Data type - Personal and confidential

Storage - Database

Underlying operating system (OS) - SQL database

Authentication - Role-based access control (RBAC) user

Active Directory integrated - Yes

Network information - Dynamic Host Configuration Protocol (DHCP)

Communications protocol - HL7

PACS viewer

Basic functionality - These can include various interfaces used for the retrieval and display of images for analysis and interpretation to or from the PACS. They are also used to capture the image interpretation report (examples include workstations and web clients)

Software/hardware - In use hardware is integral to function, but hardware and software may be procured separately. Runs PACS application and sometimes RIS app.

Typical locations - Hospitals mainly but increasing use of these devices for home working and community diagnostic centres in future.

Data type - Processes transmits but does not retain data because connectivity is via streaming.

Storage - Local storage HDD/SSD/NVMe

Underlying operating system (OS) - Legacy Linux, later Windows

Authentication - Individual user logons are required

Active Directory integrated - Yes

Network information - Static or Dynamic Host Configuration Protocol (DHCP)

Communications protocol - Some PACS use proprietary protocols for internal communication.

Imaging diagnostic traffic flow

Almost all clinical images of a patient are viewed by an expert who generates a written report of their findings. This is then made available to the clinicians looking after the patient. As imaging services have become increasingly digital it has become possible to decouple these elements (acquisition, review and reporting) both in space and time.

Trusts can use the IEP to share images and reports. However, local collaboration services have been setup using common platforms or VNAs to achieve this objective.

The diagnostics imaging end to end process can be summarised as:

Patient registration – patient information is registered into HIS and/or patient administration system to establish identity
Order entry – referring clinicians can request a medical imaging procedure for a patient
Schedule and co-ordinate procedures – administrators enter the order information into a RIS to create a worklist and will schedule a medical imaging procedure for the patient
Image acquisition – clinicians will use the applicable modality to capture and generate images for the patient
Post-acquisition review – imaging radiographers and radiologists examine the generated images for clinician’s review
Archiving and reporting – generated images and annotations are stored in PACS and archived in long-term storage which may be a VNA
Analysis and reporting – clinicians retrieve the images from the PACS and uses an image viewing station to review the images and document findings and diagnoses

This process is represented in the diagram below:

Diagnostic imaging end to end process
Figure 2: Sample topology diagram showing end-to-end process flow for the imaging diagnostics pillar

Image description

Each numbered arrow in the diagram shows the typical lifecycle of patient’s diagnostic images.

1. Required Patient information is captured via the applications identified in the 'Clinical applications' group including the radiology information system (RIS), hospital information system (HIS), and/or electronic patient record (EPR).

2. Diagnostic images of patients' are captured using one of the scanners identified in the 'Imaging modalities' group on the left of the diagram and sent to the picture archiving and communication system (PACS).

3. Diagnostic Images are also sent to the Vendor Neutral Archives (VNA) for long time storage.

4A & B. Clinicians, consultants, and other medical professionals will connect to the PACS to analyse the created images via one of the applications identified in the 'Imaging viewers' group on the right-hand side of the diagram. Post analysis, a report will be generated by the consultant and made available to the requestor via PACS.

5A & B. Other NHS trusts can gain access to diagnostic images stored in PACS via the Image Exchange Portal (IEP) as shown on the left provided such connections are permitted by the firewall.

External support teams shown on the top right-hand corner can also gain access to the PACS to provide technical support if required provided such connectivity is permitted through the firewall.

Cloud-based PACS

Recently, cloud-based PACS solutions (and reporting solutions) are becoming more common, as are web ‘extensions’ to conventional systems, as it provides:

easier archiving to scale and faster, secure access to shared images
access to PACS over web services from any location with any device with diagnostic capabilities

Asset inventory of the imaging diagnostics components in an NHS trust (sample)

Imaging device type	Vendor	Modal serial no.	Host name	IP address	Underlying operating system (OS)	MAC address or Manufacturer OUI	VLAN	Location
X-ray	Siemens AG	SE745608	Siemens XRAY ICC	172.16.2.3	Windows 10	88:48:39	100	Radiology 3rd floor Room 301
CT scanner	Siemens AG	CT VA40	SOMATOM X. cite	172.16.4.2 172.16.4.3	Windows 10	88:48:39	101	Radiology 2nd floor Room 202
MRI scanner	GE Health Care	SIGNA HDXT	Signa_HD3T	172.16.7.6	Enterprise Linux OS 7.x	00:01:E3	100	Radiology 4th floor Room 401
Positron emission tomography (PET) scanner	Siemens AG	MicroSelectron Digital	GMDN 38300	172.16.5.2	Windows 10	88:48:39	201	Radiology 2nd floor Room 209
Ultrasound scanner	Canon Medical Systems Corp	TUS-X200	Can-Ultra-S X200	172.16.6.3	Embedded OS	00:02:20	301	Ultrasound lower ground floor
PACS	Sectra	SEC27XMP	PACS Radiology	172.16.7.2	Embedded OS	00:C0:70	401	PACS room
VNA	Sectra	SEC77XMP	VNA 100	172.16.8.3	Embedded OS	00:C0:70	401	VNA room
PACS viewer	MedDream	TBC	PACS Viewer 01	172.31.2.2	Windows 10	Host system's MAC address	501	PACS room
DICOM viewer	RadiANT	TBC	DICOM Viewer 06	172.31.2.3	Windows 10	Host system's MAC address	501	PACS room

Table 2: Sample asset inventory list for a medium sized NHS trust

OUI - organisationally unique identifier

VLAN - virtual local area network

Imaging connected medical device (CMD) data flow

	Connectivity	Modalities	HIS	RIS	PACS	VNA	PACS viewer
1	Spine PDS			HL7
2	Modalities	DICOM		DICOM	DICOM	DICOM
3	PACS	DICOM		HL7		DICOM	HTTPS
4	RIS	DICOM	HL7		HL7
5	Supplier remote support	VPN, VDI		VPN, VDI	VPN, VDI
6	Device outbound connectivity	Different methods
7	Image Exchange Portal (IEP)				DICOM	DICOM
8	Image viewer workstation				VPN, VDI	VPN, VDI
9	External workstations			VPN, VDI	VPN, VDI
10	Core services	HTTPS

Table 3: Sample imaging components communication information

Sample logical grouping of imaging CMD

Logical group	Applicable criteria	Assets
Imaging connected medical devices	Imaging modalities	CT scanners MRI scanners, ultrasound scanners, PET scanners, X-ray machines
CMD repositories	Imaging repositories	PACS VNAs
Image reporting	Reporting workstations	PACS workstations
Clinical applications	Order entry, scheduling	EPR, HIS, RIS
PACS viewer	View, analyse and create reports of images	DICOM viewer, PACS workstation, web client
Remote access	Bastion hosts for remote connection	Citrix server farm, remove access server
Office equipment	Office network devices	Printers, computers, tablet
Wireless	Wireless communication	Access points, wireless routers, mobile devices
Core systems	Security controls	DHCP, DNS, Active Directory servers

Table 4: Sample logical grouping of CMD in a medium sized NHS trust

Last edited: 1 November 2023 1:49 pm

Imaging diagnostic pillar

Scope

Imaging diagnostics components

Imaging diagnostics component breakdown

Imaging diagnostic traffic flow

Cloud-based PACS

Asset inventory of the imaging diagnostics components in an NHS trust (sample)

Imaging connected medical device (CMD) data flow

Sample logical grouping of imaging CMD

Chapters