CPAS System Integration & Interoperability 2 — Questions and Answers
Question 1: Which DICOM service is used by a PACS to query a remote archive for available studies?
- C-STORE
- C-FIND (Correct answer)
- C-MOVE
- C-ECHO
Correct answer: C-FIND
C-FIND is the DICOM query service that allows a SCU (Service Class User) to search a remote SCP (Service Class Provider) for matching studies, series, or instances.
Question 2: In DICOM networking, what is the purpose of a Service Class Provider (SCP)?
- It initiates a DICOM association to request a service
- It responds to service requests from a Service Class User (Correct answer)
- It compresses images before transmission
- It validates HL7 messages for PACS ingestion
Correct answer: It responds to service requests from a Service Class User
The SCP is the server-side role that receives and fulfills DICOM service requests, such as storing images (C-STORE SCP) or responding to queries (C-FIND SCP).
Question 3: XDS (Cross-Enterprise Document Sharing) is an IHE profile designed to:
- Encrypt DICOM images during modality acquisition
- Share clinical documents including imaging reports across healthcare enterprises (Correct answer)
- Synchronize PACS hardware clocks
- Perform automated quality control on image datasets
Correct answer: Share clinical documents including imaging reports across healthcare enterprises
IHE XDS enables sharing of clinical documents, including radiology reports and image references, across different healthcare organizations using a registry/repository model.
Question 4: A hospital wants clinicians at an affiliated clinic to view PACS images through their EHR without installing separate viewer software. Which approach BEST supports this goal?
- Installing a thick DICOM viewer on every clinic workstation
- Implementing a web-based zero-footprint viewer using WADO-RS or DICOMweb (Correct answer)
- Burning studies to CD for courier delivery
- Configuring a VPN with direct PACS database access
Correct answer: Implementing a web-based zero-footprint viewer using WADO-RS or DICOMweb
A zero-footprint web viewer using DICOMweb standards (WADO-RS, STOW-RS, QIDO-RS) delivers images through any browser without client software installation.
Question 5: What does the acronym RIS stand for in the context of PACS integration?
- Radiology Information System (Correct answer)
- Remote Image Server
- Radiographic Imaging Software
- Rapid Integration Suite
Correct answer: Radiology Information System
RIS (Radiology Information System) manages scheduling, orders, results reporting, and billing in a radiology department, and is a key integration partner for PACS.
Question 6: Which protocol is used to retrieve DICOM objects from a PACS using a RESTful HTTP-based approach?
- DIMSE (DICOM Message Service Element)
- WADO-RS (Web Access to DICOM Objects via RESTful Services) (Correct answer)
- SFTP (Secure File Transfer Protocol)
- HL7 MLLP (Minimal Lower Layer Protocol)
Correct answer: WADO-RS (Web Access to DICOM Objects via RESTful Services)
WADO-RS is the RESTful DICOMweb service that allows HTTP GET requests to retrieve DICOM instances, series, or studies from a compliant PACS server.
Question 7: When configuring a DICOM Application Entity (AE) title, which element uniquely identifies a DICOM device on the network?
- IP address alone
- AE Title combined with hostname/IP and port number (Correct answer)
- MAC address of the network adapter
- Serial number of the imaging device
Correct answer: AE Title combined with hostname/IP and port number
A DICOM node is identified by its AE Title plus the host address and port, forming a unique endpoint used in DICOM association negotiations.
CPAS System Integration & Interoperability 2
Which DICOM service is used by a PACS to query a remote archive for available studies?