PACS Flashcards
PACS stands for…..
Picture Archiving Communication System
PACS comprises of 3 components
- storage
- distribution/viewing
- management
PACS work flow in a Typical NHS trust
- clinician orders imaging study
- examination is scheduled
- patient arrives at department and images are acquired
- images are sent to PACS
- images are manipulated and reviewed by radiologists and a report is generated
storage in PACS (resiliency)
- the ability to provide and maintain an acceptable level of service in the face of challenges to normal operation e.g. snapshots, disaster recovery planning
storage in PACS (redundancy)
- the duplication of critical components/functions of a system with the intention of increasing reliability of the system e.g. failover to a server in another datacentre
storage in PACS (backups)
- should have 3 copies ( 2 should be in the trust itself), (1 copy should be isolated from the trust
- one in each datacentre and one away from the trust - in case of encryption
why shouldn’t images be left uncompressed
- takes up space
- space is expernsive
- makes bigger files to move around - therefore it takes longer to send things
Compression
modality device transfers image to PACS
- Once image is received, it is compressed and stored
- compressed image is transferred to a viewing application, where is is uncompressed again
types of compression
Lossless and lossy compression
lossless compression
- no information is lost, that is within the picture or document when compressed
lossy compression
- we can afford to lose some of the information from the image, as the overall impression of the image is present
which modalities can we use lossy compression for?
Ultrasound
which modalities should we use lossless compression for
- x-ray
standards - why are they needed
- allows transfers between trusts
- allows integration
- ensures interoperability between the applications that we want, use the same data
examples of standards
- Doc
- jpg
DICOM stands for
Digital Imaging COmmunications in Medicine
DICOM
- main standard utilised universally for medical imaging
- can only be viewed by specialist applications e.g. PACS
advantages of PACS
- saves money on space
- transfer information
- allows more than one clinician to view/manipulate images at once
- integration with other hospital systems, to allow authorised access to images systems
- secure single imaging record
- easy manipulation of images that may have previously required repeating
- improved productivity in reporting, due to reduced time for image acquisition
Disadvantages of PACS
- expensive and needs continuous updating
- time needed to train users- particularly when updates occur
- costly to ensure business continuity in the event of a failure
- administration staff to manage the solution
monitor resolution
- must meet DICOM standards for imaging display
- must be approved by the Medicines and Healthcare products regulatory agency
- resolution based on pixel matrix more pixels = higher resolution
- also need the greyscale
minimum resolution for CT or MRI (monitor resolution)
2 megapixel (1920 x 1080)
Minimum Resolution CR or DR (monitor resolution)
3 megapixel (2048 x 1536)
minimum resolution mammography (monitor resolution)
5 megapixel (2560 x 1960)
Why is image sharing important
- continuity of care - can make referrals to hospitals
- reduces the necessity to duplicate examinations - thus reducing the dose to patients
- can provide medico-legal evidence: expert witnesses and disclosure of patient imaging
- allows patients to have access and copies of their images where appropriate
how is image sharing done?
- via image exchange portal, google drive, USB, WeTransfer etc.
Benefits of image exchange portal
- data is transferred in an encrypted state from source to destination
- reduces the necessity for duplicate examinations to be undertaken
- allows users to send and receive images
advantages of image sharing
- data transferred is encrypted from the source to the destination
- reduces the necessity for duplicate examinations to be undertaken - thus reducing the dose to the patient
- allows users to send and receive images
disadvantages of image sharing
- ## no updates to existing examinations if they are changed or altered at the source site
what responsibilities do radiographers have when using PACS
- checking that all images have gone to PACS correctly
- Always use the worklist on PACS and never manually enter things onto the system
- never try to hide errors or delete/manipulate the images to conceal errors - this may harm the patient outcome.
- if an incorrect marker is used, the PACS team/Superuser must be contacted to rectify the error
- reporting any issues, problems or mistakes immediately to the PACS team or senior radiographer
- Data protection - never sharing images from PACS to external sources and ensure that any images used for educational purposes are anonymised
