Five Levels of PACS Modularity: Integrating 3D and Other Advanced Visualization Tools

The current array of PACS products and 3D visualization tools presents a wide range of options for applying advanced visualization methods in clinical radiology. The emergence of server-based rendering techniques creates new opportunities for raising the level of clinical image review. However, best-of-breed implementations of core PACS technology, volumetric image navigation, and application-specific 3D packages will, in general, be supplied by different vendors. Integration issues should be carefully considered before deploying such systems. This work presents a classification scheme describing five tiers of PACS modularity and integration with advanced visualization tools, with the goals of characterizing current options for such integration, providing an approach for evaluating such systems, and discussing possible future architectures. These five levels of increasing PACS modularity begin with what was until recently the dominant model for integrating advanced visualization into the clinical radiologist's workflow, consisting of a dedicated stand-alone post-processing workstation in the reading room. Introduction of context-sharing, thin clients using server-based rendering, archive integration, and user-level application hosting at successive levels of the hierarchy lead to a modularized imaging architecture, which promotes user interface integration, resource efficiency, system performance, supportability, and flexibility. These technical factors and system metrics are discussed in the context of the proposed five-level classification scheme.     

The importance of a picture archiving and communications system (PACS) manager for large-scale PACS installations

Installing a picture archiving and communication system (PACS) is a massive undertaking for any radiology department. Facilities making a successful transition to digital systems are finding that a PACS manager helps guide the way and offers a heightened return on the investment. The PACS manager fills a pivotal role in a multiyear, phased PACS installation. PACS managers navigate a facility through the complex sea of issues surrounding a PACS installation by coordinating the efforts of the vendor, radiology staff, hospital administration, and the information technology group. They are involved in the process from the purchase decision through the design and implementation phases. They can help administrators justify a PACS, purchase and shape the request for proposal (RFP) process before a vendor is even chosen. Once a supplier has been selected, the PACS manager works closely with the vendor and facility staff to determine the best equipment configuration for his or her facility, and makes certain that all deadlines are met during the planning and installation phase. The PACS manager also ensures that the infrastructure and backbone of the facility are ready for installation of the equipment. PACS managers also help the radiology staff gain acceptance of the technology by serving as teachers, troubleshooters, and the primary point-of-contact for all PACS issues. This session will demonstrate the value of a PACS manager, as well as point out ways to determine the manager’s responsibilities. By the end of the session, participants will be able to describe the role of a PACS manager as it relates to departmental operation and in partnership with equipment vendors, justify a full-time position for a PACS manager, and identify the qualifications of candidates for the position of PACS manager.     

The reality of picture archiving and communication systems (PACS): A survey

Toward the end of 1997 vendors were succeeding in installing picture, archiving and communication systems (PACS) in larger numbers. It was hard to separate fact from fiction at times. This survey was undertaken by 2 members of the academic community to confirm what was operational, how well the installed systems worked, and what they were doing. Fax questionnaires were sent to nearly 1,000 facilities worldwide to identify PACS of any size in clinical operation on a date certain, February 1, 1998. A total of 177 PACS were identified. Facilities furnished responses during the first survey period from May 1 to November 1, 1998. A second survey, done in February and March of 2000, sought long-term follow-up data. Many systems operated 5 or more types of modalities. Computed tomography (CT) was the most common modality type at 83%, but the distribution of the rest held surprises. There also was an unexpectedly large use of soft copy reading and filmless operation in 1998. Clear trends toward increased use of computed radiography and digital radiography and a significant expansion on the percentage of all of a facility's examinations on the PACS were seen over the 2 years. Satisfaction with original PACS vendors was relatively high. Eighty-nine percent remained with their original vendor. Only 10 sites reported they changed vendors, and 4 facilities said they abandoned their system. The users reported their expectations of the PACS had been met in 81% of cases. Some (65%) declared their systems were cost effective. The most striking response was that 97% of the users would recommend PACS to others.     

Finding the optimal picture archvingand communciation system(PACS)architecture: A comparison of three PACS designs

Purpose: At present, there are two basic picture archiving and communication system (PACS) architectures: centralized with a central cache and controller, and distributed with a distributed cache and central controller. A third architecture proposed here is an autonomous one with a distributed cache and no controller. This report will investigate the performance (as measured be central processing unit [CPU] and networkload, scalability, and examination retrieval and display latency) of these three types.Methods: The distributed PACS architecture will be simulated using an IM PAX R3.5 (AGFA, Ridgefield Park, NJ) PACS, while the centralized design will be simulated using an IMPAX R4 (AGFA) PACS. The autonomous system will be designed and implementedin-house. The autonomous system consists of two types of entities: basic components such as acquisition gateways, display stations, and long-term archives, and registry servers, which store global state information about the individual PACS components. The key feature of the autonomous system will be the replacement of the central PACS controller by the registry servers. In this scenario the registry servers monitor the interactions between the components, but do not directly govern them. Instead each component will contain the application logic it requires and will use the state information from the registry servers to take the appropriate action, such as routing images, prefetching studies, and expiring images from near line cache. In addition the routing of examinations will be optimized to reduce the duplication of image data. Display stations will be categorized by specialty (neuroradiology, pediatrics, chest, etc) and will retrieve studies for display on demand from intermediate servers dedicated to the corresponding specialty. Studies will be routed only to the intermediate servers and not to display stations.Results: By distributing the application logic, an autonomous PACS architecture can provide increased fault tolerance and therefore increased uptime. In addition, the lack of a central controller and the use of intermediate servers improve the scalability of the system, as well as reduce CPU and network loads.     

A IHE-Like Approach Method for Quantitative Analysis of PACS Usage

Today, many hospitals have a running enterprise picture archiving and communication system (PACS) and their administrators should have the tools to measure the system activity and, in particular, how much it is used. The information would be valuable for decision-makers to address asset management and the development of policies for its correct utilization and eventually start training initiatives to get the best in resource utilization and operators’ satisfaction. On the economic side, a quantitative method to measure the usage of the workstations would be desirable to better redistribute existing resources and plan the purchase of new ones. The paper exploits in an unconventional way the potential of the IHE Audit Trail and Node Authentication (ATNA) profile: it uses the data generated in order to safeguard the security of patient data and to retrieve information about the workload of each PACS workstation. The method uses the traces recorded, according to the profile, for each access to image data and to calculate how much each station is used. The results, constituted by measures of the frequency of PACS station usage suitably classified and presented according to a convenient format for decision-makers, are encouraging. In the time of the spending review, the careful management of available resources is the top priority for a healthcare organization. Thanks to our work, a common medium such as the ATNA profile appears a very useful resource for purposes other than those for which it was born. This avoids additional investments in management tools and allows optimization of resources at no cost.     

Suggested Connections Between Risk Factors of Intracranial Aneurysms: A Review

The purpose of this article is to review studies of aneurysm risk factors and the suggested hypotheses that connect the different risk factors and the underlying mechanisms governing the aneurysm natural history. The result of this work suggests that at the center of aneurysm evolution there is a cycle of wall degeneration and weakening in response to changing hemodynamic loading and biomechanic stress. This progressive wall degradation drives the geometrical evolution of the aneurysm until it stabilizes or ruptures. Risk factors such as location, genetics, smoking, co-morbidities, and hypertension seem to affect different components of this cycle. However, details of these interactions or their relative importance are still not clearly understood.     

A PACS maturity model: a systematic meta-analytic review on maturation and evolvability of PACS in the hospital enterprise

Introduction

With PACS and medical imaging technology maturing, the importance of organizational maturity and effective deployment of PACS in the hospital enterprise are becoming significant.

Objective

The objective of this paper is twofold. Firstly, PACS literature on maturity and evolvability in the hospital enterprise is analyzed, resulting in an overview of the relevant developments concerning maturity of PACS. Secondly, this paper looks at the development of a maturity model for PACS technology.

Methods and results

Using structured search queries, we identified 34 papers reporting relevant aspects of maturity and evolvability of PACS. From the results of a meta-analytic review on PACS maturity and evolvability, we propose a model - the PACS maturity model (PMM) - that describes five levels of PACS maturity and the corresponding process focus.

Conclusion

We argue that this model can help hospitals to gain insights into their (strategic) objectives for growth and maturity with regard to PACS, the electronic patient record (EPR) and other health information systems. Moreover, the proposed model can be applied as a valuable tool for organizational assessments, monitoring and benchmarking purposes. Hence, the PMM contributes to an integral alignment model for PACS technology.     

Defining the PACS Profession: An Initial Survey of Skills, Training, and Capabilities for PACS Administrators

The need for specialized individuals to manage picture archiving and communications systems (PACS) has been recognized with the creation of a new professional title: PACS administrator. This position requires skill sets that bridge the current domains of radiology technologists (RTs), information systems analysts, and radiology administrators. Health care organizations, however, have reported difficfiulty in defining the functions that a PACS administrator should perform—a challenge compounded when the tries to combine this complex set of capabilities into one individual. As part of a larger effort to define the PACS professional, we developed an extensive but not exclusive consensus list of business, technical, and behavioral competencies desirable in the dedicated PACS professional. Through an on-line survey, radiologists, RTs, information technology specialists, corporate information officers, and radiology administrators rated the importance of these competencies. The results of this survey are presented, and the implications for implementation in training and certification efforts are discussed.     

The Effect of Wireless LAN-Based PACS Device for Portable Imaging Modalities

The aim of this study was to develop wireless Picture Archiving and Communication System (PACS) device and to analyze its effect on image transfer from portable imaging modalities to the main PACS server. Using a laptop computer equipped with wireless local area network (LAN), the authors developed a wireless PACS device with DICOM modality worklist and DICOM storage server modules. This laptop computer could be easily fixed to portable imaging modalities such as ultrasound machines. From May to August 2007, 112 portable examinations were evaluated. Of these, 62 were done with wireless LAN-based PACS device, and 50 were done without wireless PACS device. To evaluate the impact of the wireless LAN-based PACS device on productivity and workflow, we analyzed the mean time delay and standard deviations (SD) both in cases where wireless LAN-based PACS device was used and in cases where it was not used. Statistical analysis was performed using a t test. The mean time interval from image acquisition to storage in the main PACS when the wireless LAN-based PACS device was used was 342.4 s (5 min and 42.4 s, SD = 509.2 s). When the wireless PACS was not used, the mean time interval was 2,305.5 s (38 min and 25.5 s, SD = 1,371.8 s). The mean time interval was statistically different between the two groups (t test, p < 0.001). The wireless LAN-based PACS device could help in reducing the storage intervals of images obtained by portable machines and in promoting effective and rapid treatment of patients who have undergone portable imaging examinations.     

不同程度肾积水对肾盂尿流动力学影响的模型研究

目的 基于计算流体动力学方法,研究不同程度肾积水中尿液的尿流动力学变化,从而评估肾积水程度对肾脏排石能力的影响。方法 建立分支型肾盂A组(正常A1、轻度肾积水A2、中度肾积水A3、重度肾积水A4),成熟壶腹型肾盂B组（正常B1、轻度肾积水B2、中度肾积水B3、重度肾积水B4）,胚胎壶腹型肾盂C组（正常C1、轻度肾积水C2、中度肾积水C3、重度肾积水C4）共12个模型,通过计算流体力学计算尿液在肾小盏颈部、肾大盏颈部、肾盂出口处的流速及速度矢量。结果 随着肾积水程度的增加,尿液在肾小盏颈部、肾大盏颈部、肾盂出口处的流速逐渐降低。在肾脏集合系统内的循环停滞区与速度边界层逐渐增大,结石受到的尿液剪切力随之降低,肾脏的排石能力也逐渐下降大。结论 肾积水会导致尿液的尿流动力学发生改变。在临床中选择肾结石治疗方式时,应该充分考虑不同程度肾积水对患者术后排石能力的影响,从而选择更合适的治疗策略。