Johannes M. Boehme

Evaluation of PACS in ultrasonography.

We review our experience with a picture archiving and communication system to replace film in the ultrasound section of a clinical radiology department. The system includes three ultrasound units connected by a fiberoptic network via acquisition nodes to a central data management system, workstation, and optical jukebox. The system handles 80% of sonographic studies in the department. Image production, interpretation, storage, and retrieval are evaluated. Despite limitations, a picture archiving and communication system can be integrated into a functioning ultrasound section of an active radiology department with minimal disruption and promising results.

Fault tolerant high-performance PACS network design and implementation

The Wake Forest University School of Medicine and the Wake Forest University/Baptist Medical Center (WFUBMC) are implementing a second generation PACS. The first generation PACS provided helpful information about the functional and temporal requirements of the system. It highlighted the importance of image retrieval speed, system availability, RIS/HIS integration, the ability to rapidly view images on any PACS workstation, network bandwidth, equipment redundancy, and the ability for the system to evolve using standards-based components. This paper deals with the network design and implementation of the PACS. The physical layout of the hospital areas served by the PACS, the choice of network equipment and installation issues encountered are addressed. Efforts to optimize fault tolerance are discussed. The PACS network is a gigabit, mixed-media network based on LAN emulation over ATM (LANE) with a rapid migration from LANE to Multiple Protocols Over ATM (MPOA) planned. Two fault-tolerant backbone ATM switches serve to distribute network accesses with two load-balancing 622 megabit per second (Mbps) OC-12 interconnections. The switch was sized to be upgradable to provide a 2.54 Gbps OC-48 interconnection with an OC-12 interconnection as a load-balancing backup. Modalities connect with legacy network interface cards to a switched-ethernet device. This device has two 155 Mbps OC-3 load-balancing uplinks to each of the backbone ATM switches of the PACS. This provides a fault-tolerant logical connection to the modality servers which pass verified DICOM images to the PACS servers and proper PACS diagnostic workstations. Where fiber pulls were prohibitively expensive, edge ATM switches were installed with an OC-12 uplink to a backbone ATM switches. The PACS and data base servers are fault-tolerant, hot-swappable Sun Enterprise Servers with an OC-12 connection to a backbone ATM switch and a fast-ethernet connection to a back-up network. The workstations come with 10/100 BASET autosense cards. A redundant switched-ethernet network will be installed to provide yet another degree of network fault-tolerance. The switched-ethernet devices are connected to each of the backbone ATM switches with two-load-balancing OC-3 connections to provide fault-tolerant connectivity in the event of a primary network failure.

Early Experience In Interfacing PACS To RIS

Picture Archiving and Communications Systems are sophisticated computer systems designed to store and display medical images. It has been suggested that these systems may be more cost effective than film in practicing radiology because of better access to images by multiple users, better integration of information from multiple studies, and more rapid delivery of diagnostic reports to clinical physicians. Development of these systems is in its early stages and questions have arisen as to what functions an image management system should have and how it should interact with stand alone radiology information systems (RIS) and hospital information systems (HIS). Over the past decade, computer systems have undergone gradual reorganization from highly centralized hospital (or medical center) information systems toward decentralized departmental systems. The former systems often provided global functions but did not have the flexibility to meet the needs of individual departments. Some individual departmental systems were developed to meet specific requirements, but they were often unable to communicate with other systems within a medical center. Today many RISs have the ability to provide departmental management tools, as well as to communicate with external systems. In order to achieve a filmless environment, PACS and HIS must be integrated with RIS systems to provide the level of information currently available. An additional goal of these systems is to automate operations and reduce the workload for technologists, admission personnel, file room staff, and radiologists.

Results of a clinical test of an ATM tele-ultrasound system

The AT&T extended multimedia interface (EMMI) is being tested for applicability to wide area network access. Two EMMI units are used. One in the ultrasound examination room is connected to the National Television Standards Committee (NTSC) output of the ultrasound modality and audio communication equipment for the technologist. The other in the ultrasound reading room is connected to a NTSC monitor and audio communication equipment for the radiologist. The EMMIs are interconnected via an ATM permanent virtual circuit that establishes a connection between an ultrasound technologist and radiologist during a procedure. The test monitors 3 items: (1) How often can ultrasound studies be completed by a radiologist without on-site intervention, i.e., by viewing remotely only? (2) How often and on which exam does a technologist require direction remotely from a radiologist to complete a study? (3) How often and which exams require the radiologist to go to the ultrasound examination room to complete the study?

Operational infrastructure for a clinical PACS

Current and future operational requirements that support a picture archiving and communication system that manages filmless digital modality images are described.

Interfacing diverse laser imagers into a comprehensive PACS: operational experiences and observations

In this paper, we describe the development strategies for integrating hard-copy output devices into a comprehensive picture archiving and communication systems (PACS). These strategies were created in response to a need for selective film-based hard copy in a filmless clinical ultrasound section.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Voice recognition interface for a radiology information system

We have implemented a voice recognition interface using a Dragon Systems VoiceScribe-1000 Speech Recognition system installed on an AT&T 6310 personal computer. The Dragon Systems DragonKey software allows the user to emulate keyboard functions using the speech recognition system and replaces the presently used bar code system. The software supports user voice training, grammar design and compilation, as well as speech recognition. We have successfully integrated this voice interface in the clinical report generation system for most standard mammography studies. We have found that the voice system provides a simple, user-friendly interface which is more widely accepted in a medical environment because of its similarities to tradition dictation. Although the system requires some initial time for voice training, it avoids potential delays in transcription and proofreading. This paper describes the design and implementation of this voice recognition interface in our department.

Optimization of image transfer from the central archive to workstations in a PACS

Despite the much-discussed advantages of the all-digital radiology department, the speed of electronic display continues to be a major obstacle to its acceptance; physicians generally agree that sophisticated workstation functionality cannot compensate for an interpretation environment that delays diagnosis. Two design schemes have been devised and discussed at length at the Bowman Gray School of Medicine (BGSM) that will improve the efficiency of image transmission significantly. The first of these is image routing and pre-loading. The central archive can use information associated with each exam and a set of rules to predict which workstations will be used to read the exam. The images can thus be sent automatically before the physician arrives at the workstation to interpret a series of exams. The second scheme, which is intimately associated with the first, allows a workstation to manage its own local disk to remove copies of exams so that new ones may be pre-loaded. This disk management algorithm assigns priorities to the exams based on their status in the acquisition/interpretation cycle and performs automatic deletion as the workstations disk reaches its capacity. The effect is a virtually limitless disk that eliminates the time-consuming task of manual deletion and retrieval of images.