New high-speed 3-D imaging system holds potential for improved cancer screening

August 1, 2011

A 3-D OCT volumetric data set from an excised human colon specimen (credit: MIT)

Researchers at MIT have developed a new imaging system that enables high-speed, 3-D imaging of microscopic pre-cancerous changes in the esophagus or colon.

The new endoscopic optical coherence tomography (OCT) imaging system works at record speeds, capturing data at a rate of 980 frames (equivalent to 480,000 axial scans) per second — nearly 10 times faster than previous devices — while imaging microscopic features less than 8 microns (millionths of a meter) in size.

At such high speeds and super-fine resolution, the novel system promises to enable 3-D microscopic imaging of pre-cancerous changes in the esophagus or colon and the guidance of endoscopic therapies.

Esophageal and colon cancer are diagnosed in more than 1.5 million people worldwide each year, according to the American Cancer Society.

In OCT imaging, microscopic-scale structural and pathological features are examined by directing a beam of light on a tissue and measuring the magnitude and echo time-delay of backscattered light. Because the amount of light that can be recaptured and analyzed decreases quickly with depth in tissue due to scattering, the technique can generally only be used to visualize sub-surface features to a depth of 1 to 2 millimeters.

“However these depths are comparable to those sampled by pinch biopsies and unlike biopsy, information is available in real time,” James G. Fujimoto of MIT says. By using miniature fiber optic scanning catheters or probes, either on their own or in combination with standard endoscopes, colonoscopes, or laparoscopes, OCT imaging can be performed inside the body.

Tsung-Han Tsai, et al., Piezoelectric-transducer-based miniature catheter for ultrahigh-speed endoscopic optical coherence tomography, Biomedical Optics Express, 2011; 2 (8): 2438 [DOI: 10.1364/BOE.2.002438]