Christopher Petersen

Intravascular optical coherence tomography opens a window onto coronary artery disease

In the United States alone, more than 650,000 people die each year of heart attacks related to coronary artery disease. A new technique, intravascular optical coherence tomography, may play an important role in guiding therapeutic interventions, diagnosing atherosclerosis and researching the causes of coronary artery disease.

Clinical studies of frequency domain optical coherence tomography in the coronary arteries: the first 200 patients

We report clinical study results of three-dimensional (3D) in vivo imaging of human coronary arteries using frequency domain optical coherence tomography (FD-OCT). At the time of this report, over 2000 patients in over 10 countries have been imaged using FD-OCT systems and disposable fiberoptic catheters developed by LightLab Imaging Inc. The first commercial versions of the systems were introduced in Europe in May 2009. The system operates at 50,000 axial lines/s, performing a 50 mm spiral pullback in 2.5 seconds with a rotational frame rate of 100 Hz. The commercial system employs a proprietary micro-cavity swept laser, allowing imaging of vessel diameters up to 10 mm. Data compiled from early studies indicate that FD-OCT is being used for post-intervention imaging of deployed coronary stents in over 40% of cases. High-resolution 3D imaging of stent geometry immediately following deployment enables detection of stent malapposition, which can increase the risk of thrombosis. Longer term follow-up imaging of stented vessels can detect thrombus formation, which can be treated pharmacologically, and excessive neointimal growth, which may require angioplasty or re-stenting. FD-OCT is also being used for pre-intervention imaging of stenotic lesions in about 60% of cases. Here FD-OCT is used to measure the minimum lumen area and to identify calcified deposits, side branches, or other vascular structures that could interfere with the stenting procedure. Overall, FD-OCT continues to be adopted at an increasing rate and has provided interventional cardiologists with a powerful tool for pre- and postintervention assessment of the coronary arteries.

System design and image processing algorithms for frequency domain optical coherence tomography in the coronary arteries

We report on the design of a frequency domain optical coherence tomography (FD-OCT) system, fiber optic imaging catheter, and image processing algorithms for in vivo clinical use in the human coronary arteries. This technology represents the third generation of commercially-available OCT system developed at LightLab Imaging Inc. over the last ten years, enabling three-dimensional (3D) intravascular imaging at unprecedented speeds and resolutions for a commercial system. The FD-OCT engine is designed around an exclusively licensed micro-cavity swept laser that was co-developed with AXSUN Technologies Ltd. The lasers unique combination of high sweep rates, broad tuning ranges, and narrow linewidth enable imaging at 50,000 axial lines/s with an axial resolution of < 16 μm in tissue. The disposable 2.7 French (0.9 mm) imaging catheter provides a spot size of < 30 μm at a working distance of 2 mm. The catheter is rotated at 100 Hz and pulled back 50 mm at 20 mm/s to conduct a high-density spiral scan in 2.5 s. Image processing algorithms have been developed to provide clinically important measurements of vessel lumen dimensions, stent malapposition, and neointimal thickness. This system has been used in over 2000 procedures since August 2007 at over 40 clinical sites, providing cardiologists with an advanced tool for 3D assessment of the coronary arteries.

Endoscopic imaging in rabbit gastrointestinal tract with high resolution Optical Coherence Tomography

Ultrahigh resolution endoscopic OCT using broadband Cr4+:Forsterite laser light source and linear-scanning catheter is performed in the in vivo rabbit model. Imaging of the gastrointestinal tract with < 4-um axial resolution in tissue was demonstrated.