As imaging and sensing technologies grow in both sophistication and accessibility, they do more than just gather data and produce images. They are research tools in their own right, providing scientists with the means to deepen knowledge about fundamental biological processes and the causes and progression of disease. Obtaining the images is only the first step. Significant research and clinical advances require new ways of analyzing the data.

Current biomedical imaging and sensing technologies include computerized tomography, magnetic resonance imaging, optical coherence tomography, spectroscopy, and ultrasound, to name only a few.

These technologies are at the intersection of the physical sciences, mathematics, computer science, and engineering. Columbia Engineering is home to many imaging and sensing labs, some of which collaborate with labs at Columbia University Medical Center. Researchers are using biomedical imaging and sensing to study everything from the development of artificial vision systems to bone biomechanics. Sometimes they work in partnership with technology companies to develop new imaging and sensing techniques. In a constant feedback loop, faculty and researchers pursue technological advances to satisfy unmet scientific and clinical needs; the new technologies then open their eyes to further questions to explore.

Early in her research career, Christine Hendon was drawn to biomedical optics; she was intrigued by this medical technology that did not rely on radiation. Today, her overall goal is to develop optical tools for surgical guidance. "We want to develop optical tools that provide the surgeon with a clear understanding of the tissue," says Hendon, assistant professor of electrical engineering. Her techniques primarily use near-infrared spectroscopy and optical coherence tomography (OCT), which has been dubbed "optical ultrasound."

So-called optical biopsies would offer much higher resolution than current biopsy surrogates such as MRIs, PET tomography, and ultrasound. A potential advantage of OCT is that the surgeon would be able to image a wide area of tissue and, unlike with invasive biopsies, remove as little tissue as possible.

Currently, the main application of Hendon's research is focusing on OCT in the treatment of heart arrhythmias or irregular heart rhythms. A common treatment is ablation, in which the surgeon uses a catheter to detect abnormal electrical signals and then applies radiofrequency energy to remove scar tissue in the malfunctioning area.

Hendon is also using spectroscopy to provide real-time information during surgery. Especially important is the depth of a lesion – the ablated, or dead, tissue area. "Frequently," says Hendon, "patients who have ablation return for a second procedure. We hope that the use of spectroscopy will reduce both procedure time and the number of repeat procedures."