A Medical Image Transfer Method and its System Technical Field

The invention relates to network communication technology, and more particularly to a medical image transfer method and its system. Background Art

In order to more effectively utilize limited medical

resources such as medical equipment and doctors, tele-therapy and tele-diagnosis enables doctors to provide services to patients via the network, even if the doctor and the patient are not in the same area. Tele-therapy and tele-diagnosis technology transfers medical images, such as an X-ray image, CT image and magnetic resonance images, to doctors for diagnosis and consultation via the network. Due to the special requirements for images in medical

diagnosis, when the medical images are transferred between two places, the packet loss during the network transmission of the medical images, i.e., the integrity of image data, should be stringently controlled. To address this problem, there are two main methods in the prior art:

The first method: the Digital Imaging and Communications in Medicine (DICOM) standard is the medical image transmission standard based on the Transmission Control Protocol

(TCP) /Internet Protocol (IP) and has been used widely. DICOM is realized based on the Local Area Network (LAN) . The LAN is sufficiently stable to ensure the requirements of TCP/IP on packet loss are met, but it cannot realize remote medical image transmission.

The second method: the medical image is transferred in the way of building a private network, for example, building the Integrated Service Digital Network (ISDN). The built private network has a stable transmission bandwidth to meet the packet loss requirement. However, this method requires additional dedicated network cables, network

equipment and maintenance service.

In view of this, the object of the invention is to provide a medical image transfer method and system, which can realize long-distance medical image transmission at lower costs while ensuring the packet loss requirement for the image data is met .

A medical image transfer system, which comprises a transfer client end connected to the source Picture Archiving and Communication System (PACS) , and a transfer server connected to the destination PACS;

said transfer client end is used to receive the medical image data from said source PACS according to the Digital Imaging and Communications in Medicine (DICOM) standard, and compress the medical image data after setting the address of the transfer server connected to the destination PACS as the destination address of said medical image data, and send the compressed medical image data to the Internet by way of broken-point continuous transfer when the monitored status of the Internet satisfies the transfer requirements of the medical image data;

said transfer server is used to receive via the Internet the medical image data, whose destination address is the address of the transfer server, decompress the received medical image data, and send the decompressed medical image data by the DICOM standard to said destination PACS.

Said transfer client end comprises a DICOM image receiving module, a destination address mapping module, an image compression module and an image sending pool module;

said DICOM image receiving module is used for receiving the medical image data from the source PACS according to the DICOM standard, and providing the medical image data to said destination address mapping module;

said destination address mapping module is used to set the destination address of the received medical image data as the address of said transfer server, and provide such address to said image compression module;

said image compression module is used to compress the

received medical image data, and provide the compressed medical image data to said image sending pool module;

said image sending pool module monitors the network status of the Internet, and sends the receive medical image data to the Internet by way of broken-point continuous transfer when the monitored status of Internet satisfies the predetermined transfer requirements;

said transfer server comprises: an image receiving pool module, an image decompression module and a DICOM image sending module;

said image receiving pool module is used to receive via the Internet the medical image data whose destination address is the address of said transfer server, and provide the medical image data to said image decompression module;

said image decompression module is used to decompress the received medical image data, and provide the decompressed medical image data to the DICOM image sending module;

said DICOM image sending module is used to send the received medical image data to the destination PACS according to the DICOM standard.

In particular, after receiving the medical image data, said destination address mapping module determines the transfer server address corresponding to the destination PACS

identification of the medical image data according to the predetermined mapping relation between the destination PACS identification and transfer server address, and sets the determined transfer server address as the destination address of the medical image data. Said image sending pool module comprises: a first processing sub-module, sending queues, monitoring sub-modules and sending sub-modules;

said first processing sub-module sends the received medical image data to said sending queues;

said sending queues are used to buffer the medical image data;

said status monitoring sub-module is used to monitor the status of the connection between said sending sub-modules and said receiving sub-modules in the image receiving pool module; when the connection status does not satisfy the transfer requirement of medical image, said sending sub- modules are controlled to stop sending medical image data, and the position of the current sending medical image data in the sending queues is recorded; when the connection status satisfies the transfer requirement of the medical image, the sending sub-modules are controlled to send the medical image data in the sending queues from the recorded position;

said sending sub-modules send said medical image data in the sending queues to the Internet;

said image receiving pool module comprises receiving sub- modules, receiving queues and a second processing sub-module; said receiving sub-modules receive the medical image data sent from said sending sub-modules via the Internet, and send the received medical image data to the receiving queues.

said receiving queues are used to buffer the medical image data;

said second processing sub-module sends the image data in the receiving queues to said image decompression module.

More preferably, the number of said sending queues is N, and each sending queue corresponds to a sending thread; said transfer server has N receiving threads, wherein each

receiving thread corresponds to a sending thread, and each receiving thread corresponds to a receiving queue;

said first processing sub-module further segments the

received medical image data of one medical image into multiple data blocks, and sends them to the N sending queues separately;

said sending sub-modules send the data blocks in the sending queues corresponding to the sending sub-modules to the

Internet;

said receiving sub-modules receive the data blocks sent from the sending sub-modules corresponding to the receiving sub- modules, and send the data blocks to the receiving queues corresponding to the receiving sub-modules;

said second processing sub-module merges the data blocks in the receiving queues that belong to the same medical image; said status monitoring sub-module monitors the connection between the sending sub-modules and the receiving sub- modules, and controls the sending sub-modules according to the connecting status of each connection.

Furthermore, said transfer client end further comprises an image safety processing module, used for acquiring the medical image data provided by said image compression module to the image sending pool module, and executing one of and any combination of operations for the medical image data including adding authentication information, encryption and adding integrity check code, and providing the processed medical image data to said image sending pool module;

said transfer server further comprises an image safety processing module, for acquiring the medical image data provided by said image receiving pool module to the image decompression module, executing one of or any combination of operations for the medical image data including

authentication verification, decryption and integrity check, and providing the processed medical image data to said image decompression module when the processing results shows that the medical image data are safe. A medical image transfer method wherein the transfer client end is connected with the source PACS, and the transfer server is connected with the destination PACS, the method includes : said transfer client end receives the medical image data from said source PACS according to the DICOM standard, and

compresses the medical image data after setting the address of the transfer server connected to the destination PACS as the destination address of said medical image data, and sends the compressed medical image data to the Internet by way of broken-point continuous transfer when the monitored status of the Internet satisfies the transfer requirements of the medical image data;

said transfer server receives via the Internet the medical image data, whose destination address is the address of the transfer server, decompresses the received medical image data, and sends the decompressed medical image data by the DICOM standard to said destination PACS.

Specifically, said setting the address of the transfer server connected to the destination PACS as the destination address of the medical image data involves: said transfer client end determining the transfer server address corresponding to the destination PACS identification of the received medical image data according to the predetermined mapping relation between the destination PACS identification and the transfer server address, and setting the determined transfer server address as the destination address of the medical image data.

Particularly, said sending of the compressed medical image data to the Internet by way of broken-point continuous transfer when said monitored status of the Internet satisfies the transfer requirement of the medical image data

specifically comprises said transfer client end sending the compressed medical image data to the sending queues; when it is monitored that the connection status between the sending thread of the transfer client end and the receiving thread of the transfer server does not satisfy the transfer requirement of medical image, the sending thread is controlled to stop sending the medical image data in the sending queues, and the position of the current sending medical image data in the sending queues is recorded; when it is monitored that the connection status between the sending thread of the transfer client end and the receiving thread of the transfer server satisfies the transfer requirement of medical image, the sending thread is controlled to send the medical image data in the sending queues from the recorded position.

More preferably, the number of said sending queues is N, and each sending queue corresponds to a sending thread. Said transfer server has N receiving threads, wherein each

receiving thread corresponds to a sending thread, and each receiving thread corresponds to a receiving queue;

specifically, said sending of the compressed medical image data by said transfer client end to the sending queues involves: the transfer client end segmenting the compressed medical image data into multiple data blocks, and sending them separately to the N sending queues;

specifically, said monitoring operation involves: said transfer client end monitoring the connection status between each sending thread and receiving thread, and executing said control operation to the corresponding sending thread

according to the connection status of the connections;

said method further includes: said receiving thread receives the data blocks sent from the corresponding sending thread and sends them to the corresponding receiving queues, and said transfer server merges the data blocks in the receiving queues that belong to the same medical image.

In addition, after compressing the medical image data and before executing the monitoring operation, there is a further step of: said transfer client end executes one of or any combination of operations for the compressed medical image data including adding authentication information, encryption and adding integrity check code;

before the decompression of received medical image data, there is a further step comprising: said transfer server executes one of or any combination of operations for the received medical image data including authentication

verification, decryption and integrity check, and decompresses the processed medical image data when the processing results shows that the medical image data are safe . It can be seen from the above technical scheme that the present invention realizes the convergence of the DICOM standard supported by PACS and the Internet by setting the transfer client end on the source PACS side and setting the transfer server on the destination PACS side. That is, the transfer server connected to the source PACS is used as the network equipment and the transfer server address is used as the destination address of the medical image data, thus realizing the transmission of medical image data via the Internet to the transfer server and further to the

destination PACS. In addition, in order to ensure the packet loss of the medical image data in the Internet meets the requirements, the transfer client end has the function of network monitoring and broken-point continuous transfer. When the Internet status is monitored to satisfy the transmission requirement for the medical image data, the medical image data are transferred to the Internet by way of broken-point continuous transfer. The present invention utilizes the existing Internet, without building a new private network, thus reducing the implementation cost significantly. That is to say, the present invention can realize the remote medical image transmission at a lower cost while controlling the packet loss of the image data.

Brief Description of the Drawings

Figure 1 is the structure diagram of the system provided by the invention.

Figure 2 is the detailed structure diagram of the image sending pool module and the image receiving module in Figure 1. Exemplary Embodiment

To make the purpose, technical scheme and advantages of the invention clearer, the following gives a detailed description of the invention in combination with the drawings and

embodiments.

The transfer of medical images is in fact the transfer of the medical images between different Picture Archiving and

Communication Systems (PACS) . PACS is currently widely used in the clinical image departments of the hospital. The main purpose of PACS is to digitally store the massive amount of generated medical images (such as images generated by

magnetic resonance, CT, ultrasound, X-ray machine, infrared instruments, microscopes, etc) , and to enable quick retrieval of them for use with authorization when needed, and

transferal of them to other PACS. The data transmission between the existing PACSs is mainly based on the proven DICOM standard. The inventors consider the reduction of network building costs and utilize the existing Internet for remote medical image transmission. However, the instability and frequent network congestion of the Internet may bring limitations on the packet loss requirements of the medical images. Besides, the convergence of the current DICOM and Internet is needed.

The method provided by the present invention mainly includes: the transfer client end is set at the source PACS side, and the transfer server is set at the destination PACS side; the transfer client end receives the medical image data from the source PACS according to the DICOM standard, sets the

transfer server address connected to the destination PACS as the destination address of the medical image data, compresses the medical image data, and sends the compressed medical image data to the Internet by way of broken-point continuous transfer when the monitored status of the Internet satisfies the transfer requirements of the medical image data; the transfer server receives via the Internet the medical image data whose destination address is the transfer server

address, decompresses the medical image data, and sends the decompressed image data by DICOM standard to the destination PACS .

To make the present invention more apparent, the following gives a further description of the present invention in combination with the specific system structure. Figure 1 is the system structure diagram provided by the present

invention. The system may comprise a transfer client end 100 and a destination client end 200.

The transfer client end 100 receives the medical image data from the source PACS according to the DICOM standard, and compresses the medical image data after setting the address of the transfer server 200 connected to the destination PACS as the destination address of said medical image data, and sends the compressed medical image data to the Internet by way of broken-point continuous transfer when the monitored status of the Internet satisfies the predetermined transfer conditions .

The transfer server 200 receives via the Internet the medical image data, whose destination address is the address of the transfer server, decompresses the received medical image data, and sends the decompressed medical image data by the DICOM standard to the destination PACS.

The transfer client end 100 and the transfer server 200 are connected to the source PACS and the destination PACS

respectively, preferably using the plug and play method. That is, the remote transmission of the source PACS and the destination PACS are required, the transfer client end 100 and transfer server 200 are plugged in the corresponding source PACS and destination PACS; when the LAN transmission of the source PACS and the destination PACS are required, the transfer client end 100 and the transfer server 200 are simply unplugged from the source PACS and destination PACS. This implementation is simple and quick, and the source PACS and the destination PACS are not affected.

The transfer client end 100 connected to the source PACS realizes the convergence of the DICOM standard supported by the source PACS and the Internet. That is, the transfer server 200 connected to the source PACS is used as the network equipment and the address of the transfer server 200 is used as the destination address of the medical image data so that the medical image data can be transferred via the

Internet to the transfer server 200, and the transfer server 200 can send the medical image data to the connected

destination PACS by the DICOM standard. In addition, in order to control the packet loss of the medical image data in the Internet, the transfer client end 100 has the functions of network monitoring and broken-point continuous transfer. When the monitored Internet status satisfies the transmission requirement for the medical image data, the medical image data are transferred to the Internet by way of broken-point continuous transfer, wherein, the predetermined transmission requirement should ensure that the packet loss rate of the medical image data in the Internet is within the range of the required packet loss rate. Said broken-point continuous transfer means stopping transfer of the medical image data to the Internet when the

transmission requirement is not met and continuing transfer of the medical image data from the position where the

transfer is previously stopped. Broken-point continuous transfer is prior established technology and is not further described herein.

In the system, one source PACS can correspond to one

destination PACS, and can also correspond to multiple

destination PACSs, i.e., one source PACS can send the medical image to one destination PACS or to multiple destination PACSs. That is to say, one transfer client 100 can correspond to one or more transfer servers 200. In particular, the transfer client end 100 comprises: a DICOM image receiving module 101, a destination address mapping module 102, an image compression module 103 and an image sending pool module 104.

The DICOM image receiving module 101 receives the medical image data from the source PACS according to the DICOM standard, and provides the medical image data to the

destination address mapping module 102.

The destination address mapping module 102 sets the

destination address of the received medical image data as the address of the transfer server 200 connected to the

destination PACS, and provides such address to the image compression module 103.

As the source PACS adopts the DICOM standard, the transferred medical image data carry the destination identification, which is the identification of individual PACSs in LAN, i.e., ID of designation PACSs. If the medical image data are transferred in the Internet, mapping from the destination identification to the destination address is needed. The mapping relation between the source PACS identification and the address of the transfer server connected to the

destination PACS identification can be predetermined in the destination address mapping module 102. The destination address mapping module 102 receives the medical image data and sets the address of the transfer server 200 connected to the source PACS as the destination address of the medical image data according to the mapping relation.

The image compression module 103 compresses the received medical image data, and provides the compressed medical image data to said image sending pool module 104. The image compression module 103 can adopt various lossless or loss compression methods, such as JPEG2000, CALIC, JPEG LS, etc. The image sending pool module 104 monitors the status of the Internet, and sends the receive medical image data to the Internet by way of resuming broken-point transforming when the monitored status of the Internet satisfies the

predetermined transfer requirements.

Accordingly, the transfer server 200 can comprise an image receiving pool module 201, an image decompression module 202 and a DICOM image sending module 203. The image receiving pool module 201 receives the medical image data whose destination address is the address of said transfer server via the Internet, and provides the medical image data to the image decompression module 202. The image compression module 202 compresses the received medical image data, and provides the compressed medical image data to the DICOM image sending pool module 203.

The DICOM image sending module 203 sends the received medical image data to the destination PACS according to the DICOM standard .

The way of communication between the image sending pool module 104 and the image receiving pool 201 is described in detail below. As shown in Figure 2, the image sending pool module 104 can comprise a first processing sub-module 1041, sending queues 1042, a monitoring sub-module 1043 and sending sub-modules 1044. The first processing sub-module 1041 sends the received medical image data to the sending queues 1042.

The sending queues 1042 buffer the medical image data. The status monitoring sub-module 1043 monitors the connection status between the sending sub-modules 1044 and the receiving sub-modules 2011 in the image receiving pool module 201; when the connection status does not satisfy the transfer

requirement of the medical image, the sending sub-modules 1044 are controlled to stop sending medical image data, and the position of the current sending medical image data in the sending queues 1042 is recorded; when the connection status satisfies the transfer requirement of the medical image, the sending sub-modules 1044 are controlled to send the medical image data in the sending queues 1042 from the recorded position . The sending sub-modules 1044 send the medical image data in the sending queues 1042 to the Internet.

Accordingly, the image receiving pool module 201 can comprise receiving sub-modules 2011, receiving queues 2012 and a second processing sub-module 2013.

The receiving sub-modules 2011 receive the medical image data sent from said sending sub-modules 1044 via the Internet, and send the received medical image data to the receiving queues 2012.

The receiving queues 2012 buffer the medical image data.

The second processing sub-module 2013 sends the image data in the receiving queues 2012 to the image decompression module.

Said sending sub-modules in fact correspond to the sending threads in the transfer client end, and the receiving sub- modules in fact correspond to the receiving threads in the transfer server.

More preferably, in order to improve the system resource utilization efficiency, the number of said sending queues 1042, sending sub-modules 1044, receiving sub-modules 2011 and receiving sub-modules 2012 can be N, wherein one sending sub-module corresponds to one sending thread and one

receiving thread corresponds to one sending thread, and one receiving thread corresponds to one receiving queue.

The first processing sub-module 1041 further segments the received medical image data of one medical image into multiple data blocks, and sends them separately to the N sending queues 1042.

The sending sub-modules 1044 send the data blocks in the sending queues 1042 corresponding to the sending sub-modules to the Internet.

The receiving sub-modules 2011 receive the data blocks sent from the sending sub-modules 1044 corresponding to the receiving sub-modules 2011, and send the data blocks to the receiving queues corresponding to the receiving sub-modules 2012.

The second processing sub-modules 2013 also merge the data blocks in the receiving queues 2012 that belong to the same medical image.

The status monitoring sub-module 1043 monitors the connection between the sending sub-modules 1044 and the receiving sub- modules 2011, and controls the sending sub-modules 1044 according to the connection status of the each connection.

That is, the transfer client end first sends the medical image data to be transmitted to the sending queues, and the network status monitoring thread is charge of the monitoring of the Internet network status, i.e., the monitoring of the connection status between the local-end sending thread and the opposite-end receiving thread. If the connection cannot satisfy the transmission requirement of the medical image, for example, if the connection is off, that sending medical image data of local-end sending thread is stopped, and the current position of sending medical image data in the queue is recorded; if the connection can satisfy the transmission requirement of the medical image, for example, the connection is normal, that sending the medical image data in the sending queues from the recorded position is started.

In order to increase the system resource utilization ratio, the method of multiple threads can be used to transfer the medical image data, by which the transfer client end segments one medical image into the many data blocks, and after block ID is added, sends to the different sending queues

separately. Multiple sending threads are started, and the data blocks in all sending queues are sent. The data block ID can include the ID of medical image which the data block belongs to and the number of data block in the medical image.

Accordingly, the transfer server can also adopt the multi- thread receiving mode, i.e., multiple receiving thread. Each sending thread corresponds to one receiving thread

respectively. The network monitoring thread in the transfer client end can monitor the connection between the sending thread and the receiving thread, and perform broken-point continuous transfer. Each receiving thread can send the received data blocks to the corresponding receiving queues. In addition, the transfer server first picks up the data blocks from the receiving queues, and then merges the data blocks belonging to one medical image according to the block data ID before decompressing them.

Furthermore, because the medical image data is related to the patient's privacy and the Internet is open, the safety of medical image data should be further strengthened during the Internet transfer. Therefore, more preferably, the transfer client end 100 further comprises an image safety processing module 105, for acquiring the medical image data provided by the image compression module 103 to the image sending pool module 104, and executing one of and any combination of operations for the medical image data including adding authentication information, encryption or adding integrity check code, and providing the processed medical image data to the image sending pool module 104.

Accordingly, the transfer server 200 further comprises an image safety processing module 204 for acquiring the medical image data provided by said image receiving pool module 201 to the image decompression module 202, executing one of or any combination of operations for the medical image data including authentication verification, decryption and

integrity check, and providing the processed medical image data to said image decompression module 202 when the

processing results shows that the medical image data are safe.

The image safety processing module 204 performs

authentication verification for the acquired medical image data by using the authentication information. If the

authentication fails, the medical image data are not further provided to the image decompression module 202 and are abandoned .

The image safety processing module 204 uses the decryption algorithms corresponding to the encryption algorithm used by the image safety processing module 105 to decrypt the

acquired medical image data. If the decryption fails, the medical image data are not further provided to the image decompression module 202 and are abandoned.

The image safety processing module 204 executes the integrity check for the acquired medical image data using the integrity check code in the medical image data. If the integrity check fails, the medical image data are not further provided to the image decompression module 202 and are abandoned. For

example, the cyclic redundancy check (CRC) can be used. The image safety processing module 105 can calculate the CRC code of the medical image data by CRC algorithm., ana adds the CRC code to the medical image data. The safety processing module 204 receives the medical image data, re-calculates the CRC code, and compares it with the CRC code carried in the medical image data. If the two codes match, the checking is successful. If they do not match, the check fails.

It can be seen from the above description that the method and system provided by the present invention has the following advantages :

1) The convergence of the DICOM standard supported by the PACS and the Internet is realized by setting the transfer client end at the source PACS side and setting the transfer server at the destination PACS side. That is, the transfer server connected with the source PACS is used as the network equipment and the transfer server address is used as the destination address of the medical image data, thus realizing transmission of medical image data via the Internet to the transfer server and further to the destination PACS. In addition, in order to ensure the requirement of packet loss for the medical image data in the Internet, the transfer client end has the functions of network monitoring and broken-point continuous transfer. When the Internet status is monitored to satisfy the transmission requirement for the medical image data, the medical image data are transferred to the Internet by way of broken-point continuous transfer. The present invention utilizes the existing Internet, without the need to build a private network, thus significantly reducing the implementation costs. That is, the present invention can realize the remote medical image transmission at a lower cost while ensuring the packet loss requirements for the medical image data are met.

2) The present invention can transfer and process the medical image data in the multiple thread mode, which can make the most of the bandwidth and system resource utilization. 3) The transfer client end and the transfer server provided by the present invention can further ensure the safety and integrity of the medical image data transmission through one of or any combination of the operations for the medical image data, including authentication, encryption and integrity check .

The above are only the more preferable embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements without departing from the spirit and principle of the present invention are within the protective scope of the present invention.