Fault-Tolerant PACS and Enterprise PACS
The PACS system is mission critical because it runs around the clock, 24/7. Operation reliability is vital to its large computer network and system integration of medical images and databases. The purpose of PACS fault-tolerant design is to maintain the continuous available operability of the system. For an enterprise PACS to develop and operate, system fault-tolerance is mandatory.
This chapter focuses on two major components of this system: fault-tolerant PACS and enterprise PACS. In the fault-tolerant PACS, we first review the concepts of system fault tolerance (FT), definitions of high availability (HA) and continuous availability (CA), and possible causes of PACS system failure. No loss of image data and no interruption of PACS data flow are the two main criteria of success in a PACS operation. The chapter presents these criteria and delineates the methods of how to satisfy them with current PACS technology. The topic on fault tolerance concludes with the current concept of a fault-tolerant PACS design. Enterprise PACS is a component whose concept we had briefly introduced in Section 7.6. In this chapter we provide a detailed discussion of the current state of enterprise PACS and image distribution throughout the PACS system.
Since the presentation in this chapter is related to the combined PACS teleradiology model, for convenience we will use some previously defined system diagrams to explain the concept of FT and CA.