Abstract:
A medical imaging system has a modality for acquiring images, components for processing the images, a communication linkage for the transmission of the images and memory arrangement for storing the images with a number of separate memory systems. The memory arrangement includes a control system which causes successive image datasets to be stored in separate memory systems.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to a medical imaging system of the type operable in a modality for acquiring images, and having means for processing the images, means for the transmission of the images and means for storing the images including a number of separate memories. 
     2. Description of the Prior Art 
     The book “Bildgebende Systeme für die medizinische Diagnostik”, edited by H. Momeburg, 3 rd  Edition, 1995, pages 689 ff. discloses that image and data sequences associated with one another be respectively stored in a specific memory system in medical image systems. A problem with this generalized approach is that spontaneously occurring load peaks, that negatively influence the entire system arise within a networked system. It is also disadvantageous that all data of a given procedure are lost given outage of a memory. 
     Previous memory cluster solutions together with RAID technology already offer very high technical dependability and high performance, however, there are dependability gaps and performance bottlenecks at the application level in a networked environment. Imaging systems will be increasingly employed for small and mid-sized applications. Economical systems that enable system dependability, failsafe operation and high system performance with standard components are required therefor. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a medical imaging system of the type initially described, which enables a good load distribution and dependable storage over the-entire imaging system. 
     This object is inventively achieved in an imaging system having a number of memory systems and a control system, which controls storage of the image data in the memory systems that is fashioned such that successive image datasets are stored in separate memory systems. A medical image system having self-controlled, distributed storing is thereby obtained. The distribution of the loads onto different memory systems results in peak loads being avoided. Moreover, in the case of brief-duration or longer-lasting outage of a memory system, the data can be rerouted automatically to other memory systems, so that no data jam (backlog) arises. 
     In an imaging system, the memory systems are-classified in memory hierarchies. On-line memories with disk storage units in RAID technology are provided for short-term storage with limited memory capacity and fast access. A memory capacity that is multiples higher, but with diminished performance, is available in a following memory level. Jukeboxes with optical disks as storage media, file servers with tape systems, etc., are usually utilized for the on-line access. 
     It has proven advantageous in a such an-image system when the control unit, given outage of one of the memory systems, automatically causes subsequent data to be stored in one of the other memory systems or image stores. 
     The control can be simplified when distributors are arranged between the memory systems and the image stores. 
     The control can be simplified further, and the data flow and the use of the memory systems improved, when the image datasets are additionally provided with control data. The system components are then able to control the data flow dependent on the system status autonomously and decentrally. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a conventional imaging system having a networked data bank system. 
     FIG. 2 shows the structure of an inventively controlled memory system for use an imaging system. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows the system architecture of a conventional medical imaging communication network as an example. The modalities  1  through  4 , which, for example, can include a CT unit  1  for computed tomography, an MR unit  2  for magnetic resonance imaging, a DSA unit  3  for digital subtraction angiography and an X-ray unit  4  for digital radiography as image-generating units, serve for the acquisition of medical images. Work stations  5  through  8  with which the acquired medical images can be processed and locally stored can be connected to the modalities  1  through  4 . For example, such a work station can be a very fast, small computer having one or more fast processors. 
     The work stations  5  through  8  are connected to an image communication network  9  for the distribution of the generated images and for communication. Thus, for example, the images generated in- the modalities  1  through  4  and the images further-processed in the work stations  5  through  8  can be deposited in a central image storage system, such as an image memory  10 , or can be forwarded to other work stations. 
     Further work stations (diagnostic consoles)  11  and  12  are connected to the image communication network  9  as diagnosis consoles that contain local image memories. The images that have been acquired and deposited in the image memory  10  can be subsequently retrieved for diagnosis in the work stations  11  and  12  and are then deposited in the work station&#39;s local image memory, from which they can be immediately available to the diagnostician working at the work station  11  or  12 . 
     The image and data exchange via the image communication network  9  can ensue according to the DICOM standard, an industrial standard for the transmission of images and other medical information between computers for enabling digital communication between diagnostic and therapy apparatuses of different manufacturers. A network interface  13 , via which the internal. image communication network  9  is connected to a global data network, can be connected to the image communication network  9 , so that the standardized data can be exchanged world-wide with different networks. 
     FIG. 2 shows the memory structure of an inventive imaging system in detail. In addition to the work stations  11  and  12 , a patient data server  14  is connected to the image communication network  9 . The patient data server  14  serves the purpose of storing the image data flow. Additionally, those memory systems and memory levels in which the appertaining image datasets are deposited are known system-wide on the basis of the patient data and control data. 
     File servers  18  through  21  are connected to memory systems (distributors)  15  and  16  and are also connected to a number of jukeboxes  22  through  25  serving as image memories. 
     The patient data server  14  and the image data communication components of the work stations  11  and  12  and distributors  15  and  16  control the storage of the image datasets such that these datasets—independently of the sender—are routed in alternation into the distributors  15  and  16  connected to the image communication network  9  and their following memory levels, for example the file servers  18  through  21 , the jukeboxes  22  through  25  or other memory peripheries. Appropriately timed enablement of the various components to transmit or receive data is accomplished via control line  17 . The patient data server  14  also performs the function of causing these image datasets to be relocated only via the patient data, regardless of where they are stored. A balanced load when writing as well as when reading the image data in large systems as well as in small systems is achieved as a result of this new archiving principle of distributing the data stream over a number of memory systems and memory levels. 
     Given outage of individual memory elements, the others automatically assume their task. 
     Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.