T. Benner et al. Animated 3D visualization of ischemic lesions with diffusion-weighted MR imaging

Materials & Methods

We studied 10 patients with acute stroke according to our routinely used clinical stroke protocol. All patients gave written consent after the nature of the procedure was fully explained. All scans were done at a 1.5 T MR imager (Edge, Picker, Cleveland, OH, USA). Our stroke protocol involves T1-, T2-, diffusion-, and perfusion-weighted sequences as well as a 3D time-of-flight MR angiography (MRA). Out of these sequences only the T2-, and the diffusion-weighted sequences were used for this work. The sequence parameters were as follows:

The diffusion-weighted images and the corresponding T2-weighted images were reviewed in conventional 2D mode. Additionally, the diffusion-weighted images were reviewed in 3D animation mode. Therefore, the diffusion-weighted images were loaded into the angiography module of the MR scanner console. MIPs were performed from 72 directions every 5 degrees around 360 degrees. The rotation plane was tilted about 30 degrees around the left-right axis. The currently available MIP module of our scanner only allows the definition of a view point trajectory within one plane at equidistant angle increments.

For maximum flexibility and optimal display the image data of the shown examples were handled separately. The image data were transferred via DICOM to a workstation (Ultra SPARC, Sun Microsystems, Inc., Mountain View, CA, USA) and converted to ANALYZE format for further processing. Maximum intensity projection as well as the movie generation were done with self-written programs in MATLAB (The MathWorks, Inc., Natick, MA, USA). All images were saved in JPEG format and presented via a Java applet.

[ Title | Abstract | Introduction | Materials & Methods | Results | Conclusion | References ]