CPAS CPAS Network & Connectivity 2

Question 1

What compression ratio does JPEG 2000 lossy compression typically achieve for CT or MR images while maintaining diagnostic quality?

Accepted Answer

10:1 to 20:1

Answer

JPEG 2000 lossy typically achieves 10:1 to 20:1 compression for CT/MR studies while retaining sufficient diagnostic quality for most clinical reads.

Question 2

In PACS performance measurement, what does 'latency' specifically refer to?

Accepted Answer

The delay between requesting an image and its appearance on the diagnostic workstation

Answer

Latency is the elapsed time from when a workstation requests an image to when it is fully rendered on screen, directly impacting radiologist reading efficiency.

Question 3

Which DICOM transfer syntax guarantees that no pixel data is altered during compression?

Accepted Answer

JPEG-LS Lossless

Answer

JPEG-LS Lossless preserves every original pixel value exactly, making it suitable for applications where any data alteration is clinically unacceptable.

Question 4

What is the primary clinical benefit of image prefetching in a PACS workflow?

Accepted Answer

Loads prior studies before the radiologist requests them, eliminating wait time during reading

Answer

Prefetching anticipates which prior studies a radiologist will need based on the worklist and pre-loads them into cache, so images appear instantly when opened.

Question 5

What is the primary role of a PACS cache server in a multi-site hospital network?

Accepted Answer

Stores frequently accessed recent images locally to reduce retrieval time from the central archive

Answer

A PACS cache server at each site holds recently accessed studies locally, so radiologists retrieve images quickly without pulling every study from the central archive over the WAN.

CPAS - Certified PACS Associate Practice Test

CPAS - Certified PACS Associate Practice Test

CPAS CPAS Network & Connectivity 2