PACS

Question 1

PACS stands for…..

Answer 1

Picture Archiving Communication System

Question 2

PACS comprises of 3 components

Answer 2

• storage
• distribution/viewing
• management

Question 3

PACS work flow in a Typical NHS trust

Answer 3

• 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

Question 4

storage in PACS (resiliency)

Answer 4

• 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

Question 5

storage in PACS (redundancy)

Answer 5

• 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

Question 6

storage in PACS (backups)

Answer 6

• 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

Question 7

why shouldn’t images be left uncompressed

Answer 7

• takes up space
• space is expernsive
• makes bigger files to move around - therefore it takes longer to send things

Question 8

Compression

Answer 8

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

Question 9

types of compression

Answer 9

Lossless and lossy compression

Question 10

lossless compression

Answer 10

• no information is lost, that is within the picture or document when compressed

Question 11

lossy compression

Answer 11

• we can afford to lose some of the information from the image, as the overall impression of the image is present

Question 12

which modalities can we use lossy compression for?

Answer 12

Ultrasound

Question 13

which modalities should we use lossless compression for

Answer 13

• x-ray

Question 14

standards - why are they needed

Answer 14

• allows transfers between trusts
• allows integration
• ensures interoperability between the applications that we want, use the same data

Question 15

examples of standards

Answer 15

• PDF
• Doc
• jpg

Question 16

DICOM stands for

Answer 16

Digital Imaging COmmunications in Medicine

Question 17

DICOM

Answer 17

• main standard utilised universally for medical imaging

- can only be viewed by specialist applications e.g. PACS

Question 18

advantages of PACS

Answer 18

• 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

Question 19

Disadvantages of PACS

Answer 19

• 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

Question 20

monitor resolution

Answer 20

• 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

Question 21

minimum resolution for CT or MRI (monitor resolution)

Answer 21

2 megapixel (1920 x 1080)

Question 22

Minimum Resolution CR or DR (monitor resolution)

Answer 22

3 megapixel (2048 x 1536)

Question 23

minimum resolution mammography (monitor resolution)

Answer 23

5 megapixel (2560 x 1960)

Question 24

Why is image sharing important

Answer 24

• 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

Question 25

how is image sharing done?

Answer 25

• via image exchange portal, google drive, USB, WeTransfer etc.

Question 26

Benefits of image exchange portal

Answer 26

• 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

Question 27

advantages of image sharing

Answer 27

• 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

Question 28

disadvantages of image sharing

Answer 28

• ## no updates to existing examinations if they are changed or altered at the source site

Question 29

what responsibilities do radiographers have when using PACS

Answer 29

• 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