Information Technology Fundamentals Flashcards

The DICOM standard specifies protocols for communication between medical imaging devices. At which layer of the Open Systems Interconnection (OSI) model does the DICOM Upper Layer Protocol primarily operate?

Answer: Application Layer

The DICOM standard itself is an application layer protocol (Layer 7). It relies on underlying protocols like TCP (Transport Layer, Layer 4) and IP (Network Layer, Layer 3) to establish connections and transport data, but the DICOM-specific commands (DIMSEs) and data structures (IODs) exist at the application layer.

An imaging informatics administrator is configuring a new storage array for a PACS short-term cache, where both fast read/write performance and protection against a single disk failure are critical requirements. Which RAID configuration BEST meets these needs?

Answer: RAID 10 (Stripe of Mirrors)

RAID 10 combines the speed of RAID 0 (striping) with the redundancy of RAID 1 (mirroring). It provides excellent read and write performance and can withstand at least a single disk failure, making it ideal for high-performance, critical applications like a PACS cache. RAID 0 has speed but no redundancy. RAID 1 has redundancy but is slower for writes than RAID 10. RAID 5 has a 'write penalty' due to parity calculations, making it less ideal for write-intensive applications compared to RAID 10.

A radiologist reports that searching for a patient's prior exams in the PACS is consistently slow. An analysis of the PACS database reveals that the query is performing a full table scan. Which of the following database optimizations would MOST likely resolve this performance issue?

Answer: Creating an index on the patient ID and study date columns

A database index acts like a book's index, allowing the database engine to quickly locate rows based on the indexed columns (e.g., PatientID, StudyDate) without having to scan the entire table. This dramatically improves query performance for common search operations. While other options might offer marginal benefits, indexing directly addresses the inefficiency of a full table scan.

A teleradiology service needs to receive patient imaging studies from a partner hospital over the public internet. Which of the following is the MOST secure method to ensure the confidentiality and integrity of the DICOM data during transmission?

Answer: Encapsulating the DICOM traffic within a Virtual Private Network (VPN) tunnel

A VPN creates an encrypted tunnel between the two sites over the public internet. All data, including the DICOM traffic, passed through this tunnel is encrypted, protecting its confidentiality and integrity from eavesdropping or alteration. Standard DICOM is unencrypted, compression does not provide security, and IP address filtering is a basic security measure that doesn't encrypt the data in transit.

An imaging department's server room contains multiple aging, physical servers, each dedicated to a single application (e.g., RIS broker, DICOM router, HL7 interface engine). To reduce hardware costs, power consumption, and administrative overhead, the IT department wants to consolidate these applications onto a single, more powerful physical server. Which technology enables this consolidation?

Answer: Server virtualization

Server virtualization allows a single physical server (the host) to run multiple independent virtual machines (guests). Each virtual machine can run its own operating system and applications, effectively consolidating the functions of multiple physical servers onto one piece of hardware. This directly addresses the goal of reducing the physical server count and associated costs.

A CT scanner technologist reports they can no longer send images to the PACS server. An informatics specialist uses the `ping` command from the CT scanner's console and receives a successful reply from the PACS server's IP address. What can be concluded from this test result?

Answer: Basic IP network connectivity exists between the scanner and the server.

The `ping` command operates at the Network Layer (Layer 3) of the OSI model and uses ICMP. A successful ping confirms that a valid network path exists between the source (scanner) and the destination (server) and that the server's network interface is responding. It does NOT confirm that the application layer service (the DICOM storage service) is running, correctly configured, or not blocked by a firewall. It also proves the network cable is NOT faulty.