CPAS Network & Connectivity Flashcards

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

Answer: 10:1 to 20:1

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

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

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

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.

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

Answer: JPEG-LS Lossless

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

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

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

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.

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

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

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.

Which network performance metric best measures a PACS network's ability to sustain continuous image delivery for multiple simultaneous users?

Answer: Throughput (effective bandwidth)

Throughput measures actual sustained data delivery capacity, determining how many radiologists can simultaneously stream large image sets without performance degradation.