The CT data of a growth (top) shows good detail but little else. The Definiens 3D representation of the tumor includes the number of vessels, along with diameters and lengths, and the number of termini and branches. Seeing how this data changes over time can guide a more effective treatment.

A German company has devised software that examines MRI or CT data and builds 3D models of tumors, changing organs, and tissues of interest. Software from Definiens, Morristown, N.J., (definiens.com) is built on a CAD program to construct medical images and information that until now was unavailable, such as the volume of a tumor or its number of veins.

This can help radiologists identify and track lesions. The company says one application, LymphExpert software, will help radiologists collect accurate diagnostic data, and reduce human error in similar tasks performed manually. The idea is to compare 3D images taken at different times over a period and reveal detailed volumetric changes. This lets doctors tell if a tumor is growing or shrinking and hence, responding to treatment. Current measurement criteria uses simpler measurements, such a blood cell count.