Siemens MRI respiration and HB signals

Amir Shmuel asked:

Ron and David are telling me that the respiration and HB signals cannot be copied with the MRI data to the server because of some restrictions/regulations.

To reduce complications, all data related to MRI scans, including the HB and respiration waves, should be copied together to the server.

It makes sense to me to restrict who can write onto this server, but not the type of data they can write.

Rick Hoge replied:

There are a couple of misunderstandings here:

Siemens prohibits nothing - there just isn’t any reason for them to have this functionality in the clinical front end of their system.

The MRI scanner has basic capabilities for detecting and recording respiration and heartbeat. The purpose of this is for triggering of acquisitions - these signals are usually discarded, and the MRI operating software is not designed to store them or transfer them in normal use. The MR techs are able to to retrieve the signals using a combination of system service tools, but there is no user-level capability for archiving and retrieval/transfer like there is for the actual imaging data (and the signals are not linked to the imaging data in the internal database). This is not something that is realistically likely to change, or be different on clinical scanners from other vendors.

Other groups use a similar approach - UPenn has a good writeup:
(there is a link to a command-line program ‘exvolt’ that can be used to extract data for specific DICOM files)

Note also that this has nothing to do with write permissions on the archiving server - the data logged by the MPCU are simply never associated with the DICOM files, and thus not available when pushing images to the archive.

My group generally uses the BioPac for recording physiological signals - you can record the scanner logic pulses to a spare channel for synchronization purposes. Most users find this preferable, as the recording capabilities of the scanner are rather crude (although I can see where they would be useful).

Hope that’s helpful,