imagectn doubt

[Brazillian]

Hello,
I am a Brazilian Computer Science undergraduate Student and I have a doubt in relation to DCMTK library. I am studying client-server applications at the University and I chosen the DCMTK based in the utility that it has in the health-care area. I like to study real and useful systems. This way I am using the imagectn application for to listen image DICOM. But, my doubt is: How to assure that the image arrived(in the server listener) without corruption ? My class questioned me about the persistency of the image. If I to create a program that get the image for visualization how I know that choosen image do not be corrupted by unfinished write process ?

Sorry for the mistakes in the english language. But, please, help-me !

Daniel

[Marco Eichelberg]

The DICOM network protocol implements a minimal level of error checking. First of all, DICOM is an application level protocol on top of TCP, and TCP implements a reliable transport channel (re-transmission of lost packets, checksums etc). Furthermore, imagectn performs a (very basic) check whether the incoming image is readable and contains at least a SOP class UID and SOP instance UID, clearly marking it as a DICOM image, before the receipt is accepted. If something goes wrong during receipt (transport connection fails, image is "garbage" and cannot be read), imagectn will delete the file, will not register it in the database (index.dat file) and will report an error code back to the sender in the C-STORE-RSP message (if the communication channel is still open, of course). This means that everything that ends up being on the harddisk and registered in the database is something that was successfully sent by a DICOM system, is complete and has DICOM encoding.

[Brazillian]

Hello again,
To manage the images that are arriving in my directory way imagectn i am create a program that copies the images for another place. However I need to check if already they are registered in index.dat for to prevent consistency problems. But, how I can make to consult this archive through my java program ? it´s possible ? I want only comparate the filenames. This way i can proof the consistency of the image(s).

Thanks for your attention or in Brazilian Language: "Obrigado pela sua atenção"


Daniel

[Marco Eichelberg]

There is no portable way to inspect the content of the index.dat file (the format of which is binary, version and platform specific) other than through the API provided with DCMTK, which also makes sure (through locks) that concurrent accesses to this file do not produce inconsistencies. As a simple solution, you could run the dbregimg tool with the -p option and grep the output for the filename in question.