Stack image viewing comes to a radiology presentation near you

Representing 3D radiologic information during traditional presentations can be a problem. Tackling the challenge, researchers at the University of Michigan and Yale University have developed a tool that allows presenters to manipulate image stacks just as they would using a PACS workstation.

The standard presentation platform (PowerPoint, Microsoft) does not provide radiologists the ability to interact with images the way they do in clinical practice, making representation of 3D information in radiologic presentations difficult.

The solution, called StackViewer, is described in the September issue of the American Journal of Roentgenology.

"This new tool enables radiologists to easily and interactively display stacks of images in PowerPoint presentations," said StackViewer designer Dr. Benoit Desjardins of the University of Michigan radiology department.

Before StackViewer, there was no way to do that, because tools were created as ActiveX controls, with a number of inherent limitations, he said.

"No tool had been able to save the images in a stack within the PowerPoint file itself," said author Thomas Gniadek, a second year Yale medical student.

Thus, moving a presentation file to a different computer required moving a directory of image files along with it.

ActiveX controls have to be installed on a computer before they run. While this is simple enough, it nevertheless requires another step that can hinder transfer and distribution of presentations. Finally, ActiveX controls do not run on Mac OS X.

StackViewer allows stacks of 2D images to be displayed interactively on Windows-based or Mac OS X computers without compromising portability or compatibility.

When radiologists run their PowerPoint presentations, they can interact with the stack in the same way used on most PACS, Desjardins said.

"The real beauty of our tool is that all the code to interact with the stacks of images is integrated in the PowerPoint presentation," he said.

This means that no additional software needs to be installed on the computer to view the stacks. StackViewer components are embedded directly into PowerPoint files when the presentations are created, yielding true portability.

Desjardins created the tool in 2002, but it proved too difficult for regular radiologists to use. Last year, he teamed up with Gniadek to create an interface. StackViewer is the result.

StackViewer is so popular with radiologists who have tested it that the AJR decided to fast-track the paper for the benefit of everyone, Desjardins said.

The latest version of StackViewer can be downloaded free of charge at http://www.StackViewer.com, although the print edition of the AJR paper incorrectly directs readers to http://www.StackView.com, which is actually a site for magicians interested in exploiting the advantages of stacked decks.