To diagnose heart disease, visualization experts recommend a simpler approach

A team of computer scientists, physicists, and physicians at Harvard have developed a simple yet powerful method of visualizing human arteries that may result in more accurate diagnoses of atherosclerosis and heart disease.

The prototype tool, called “HemoVis,” creates a 2D diagram of arteries that performs better than the traditional 3D, rainbow-colored model. In a clinical setting, the tool has been shown to increase diagnostic accuracy from 39% to 91%.

Presented today at the IEEE Information Visualization Conference (InfoVis 2011), the new visualization method offers insight to clinicians, imaging specialists, engineers, and others in a wide range of fields who need to explore and evaluate complex, branching structures.

“Our goal was to design a visual representation of the data that was as accurate and efficient for patient diagnosis as possible,” says lead author Michelle Borkin, a doctoral candidate at the Harvard School of Engineering and Applied Sciences (SEAS). "What we found is that the prettiest, most popular visualization is not always the most effective."

HemoVis takes data from patient-specific blood flow simulations, combined with traditional imaging data, and visually displays a tree diagram of the arteries with areas of disease highlighted to assist in diagnosis.

Tools for artery visualization in both clinical and research settings commonly use 3D models that portray the shape and spatial arrangement of vessels of interest. These complex tools require users to rotate the models to get a complete perspective of spatial orientation.

By contrast, the new visualization requires no such rotation or interaction. The tool utilizes 2D, circumference-adjusted cylindrical cross sections arranged in tree diagrams.

Though this visualization method may seem less high-tech, the team demonstrated through quantitative evaluation with medical experts that the 2D model is actually more accurate and efficient for patient diagnosis.

"In the 3D case, the more complex and branched the arteries were, the longer it took to complete the patient diagnosis, and the lower the accuracy was," Borkin reflects. "In the 2D representation, it didn't matter how many branches we had or how complex they were—we got consistently fast, accurate results. We weren’t expecting that.”

Tree diagrams are hardly new, as evolutionary biologists will attest, but scientists in many fields are using them to solve a range of very modern and complex problems. In fact, Borkin applied her own experience in astronomy and physics to transform the concept of visualization for SEAS’ Multiscale Hemodynamics research group. In prior work, she had used a very similar type of tree diagram to determine the structure of nebulae in outer space.

“With the consultation and cooperation of clinicians, we were able to draw on fairly well known visualization techniques and principles from computer science to solve a practical clinical problem,” says Hanspeter Pfister, Gordon McKay Professor of the Practice of Computer Science at SEAS.