Cardiac Strain

Having defined the endo- and epicardial borders at all time points, and set up the segments, you can perform cardiac strain analysis. Strain analysis uses an image registration technique to assess the movement of tissue across time-points, and is applicable to any cardiac cine sequence, whether tagged or not.

Select the "Strain" tab in the Cardiac Segment toolkit:

Cardiac Strain analysis

Then press the Button to do the analysis button. This will start the registration process, and after a few minutes, you will see pop-up graphs showing the radial and circumferential strain in each segment through the cardiac cycle, and a dialog asking whether you want to save the results of the analysis to a report:

Dialog for the Cardiac Strain analysis results

You can:

  • Write to a text file report. A File chooser will appear, for you to choose a log file name. The default file extension for log files is ".log". If the chosen file already exists, an entry will be appended to the log file.
  • Write to a PDF file report. A File chooser will appear, for you to choose a PDF file name. If the chosen file already exists, an entry will be appended to the PDF file.
  • Send a PDF report to a DICOM server. The DICOM server to which it will be sent must already have been set up, and is the current server selected in the DICOM Query/Retrieve tool. See these instructions for how to set up the connection to remote DICOM servers.
  • Save PDF and Send to DICOM. Both save to disk and send to a DICOM server.

If you write a report, it will contain tables of radial and circumferential strain for each physical image slice. Any division into endo- and epicardium is ignored.

In addition there are bulls-eye plots (in a PDF report) and tables showing the minimum (maximum negative) circumferential strain and maximum radial strain, as shown in the examples below for a 6-slice image, where 4 of the slices has the endo- and epicardial borders defined, and the last 2 apical slices did not.

Bullseye plot of minimum circumferential strain

Bullseye plot of maximum radial strain

Strain analysis also outputs cine images showing the radial and circumferential strain through the cardiac cycle. The images will have the same name as the input image, but with the suffixes _eRR for the radial strain image, and _eCC for the circumferential strain. The examples shown below were calculated from a regular (non-tagged) cine pulse sequence.

(Animated: View cine on-line version)
Radial strain image Circumferential strain image