Circumferential optical coherence tomography angiography imaging of the swine esophagus using a micromotor balloon catheter

Abstract

Abstract:We demonstrate a micromotor balloon imaging catheter for ultrahigh speed endoscopic optical coherence tomography (OCT) which provides wide area, circumferential structural and angiographic imaging of the esophagus without contrast agents. Using a 1310 nm MEMS tunable wavelength swept VCSEL light source, the system has a 1.2 MHz A-scan rate and ~8.5 µm axial resolution in tissue. The micromotor balloon catheter enables circumferential imaging of the esophagus at 240 frames per second (fps) with a ~30 µm (FWHM) spot size. Volumetric imaging is achieved by proximal pullback of the micromotor assembly within the balloon at 1.5 mm/sec. Volumetric data consisting of 4200 circumferential images of 5,000 A-scans each over a 2.6 cm length, covering a ~13 cm 2 area is acquired in <18 seconds. A non-rigid image registration algorithm is used to suppress motion artifacts from non-uniform rotational distortion (NURD), cardiac motion or respiration. En face OCT images at various depths can be generated. OCT angiography (OCTA) is computed using intensity decorrelation between sequential pairs of circumferential scans and enables three-dimensional visualization of vasculature. Wide area volumetric OCT and OCTA imaging of the swine esophagus in vivo is demonstrated.

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Endoscopic optical coherence tomography angiography microvascular features associated with dysplasia in Barrett's esophagus (with video)

“…Our prototype instrument and catheter can perform OCTA of a 1 cm circumference x 1.6 cm length in 8 seconds. A recent study by our group using an ultrahigh speed OCT system and a micromotor balloon catheter demonstrated circumferential OCTA imaging of the swine esophagus over a 5 cm circumference x 2.6 cm length <18 seconds 36 . This result suggests that wide area OCTA in human subjects is feasible.…”