Optical Coherence Tomography: Clinical Applications in Medical Practice

Abstract

Advances in optical imaging modalities, such as optical coherence tomography (OCT), enable us to observe tissue microstructure at high resolution and in real time. Currently, core-needle biopsies are guided by external imaging modalities such as ultrasound imaging and x-ray computed tomography (CT) for breast and lung masses, respectively. These image-guided procedures are frequently limited by spatial resolution when using ultrasound imaging, or by temporal resolution (rapid real-time feedback capabilities) when using x-ray CT. One feasible approach is to perform OCT within small gauge needles to optically image tissue microstructure. However, to date, no system or core-needle device has been developed that incorporates both three-dimensional OCT imaging and tissue biopsy within the same needle for true OCT-guided core-needle biopsy. We have developed and demonstrate an integrated core-needle biopsy system that utilizes catheter-based 3-D OCT for real-time image-guidance for target tissue localization, imaging of tissue immediately prior to physical biopsy, and subsequent OCT imaging of the biopsied specimen for immediate assessment at the point-of-care. OCT images of biopsied ex vivo tumor specimens acquired during core-needle placement are correlated with corresponding histology, and computational visualization of arbitrary planes within the 3-D OCT volumes enables feedback on specimen tissue type and biopsy quality. These results demonstrate the potential for using real-time 3-D OCT for needle biopsy guidance by imaging within the needle and tissue during biopsy procedures. Magnetic Resonance Imaging Screening Study Group, "Efficacy of MRI and mammography for breast-cancer screening in women with a familial or genetic predisposition," N.

Optical Coherence Tomography Characteristics of Macular Edema and Hard Exudates and Their Association With Lipid Serum Levels in Type 2 Diabetes

“…Second, in spite of overlaying fundus photographs on the OCT images to exclude non-micro exudate pathologies, it is still possible that we misclassified some hyperreflective foci as being micro hard exudates when they in fact represented other retinal pathologies such tiny hemorrhages that were not visible on fundus photographs. 12 …”

“…Since hyperreflective foci can be due to presence of entities other than hard exudates, each OCT image with a hyperreflective focus was overlaid on the corresponding red-free image and a corresponding high quality fundus photograph was placed next to the overlay to rule out other causes of hyperreflectivity (Figure 1). 4, 12, 13 More specifically, when a hyperreflective focus was identified on an OCT line scan, it was overlaid on the red-free image that is available for tracking on the Heidelberg Spectralis device using the device’s software. At the same time, the investigator looked at a high quality fundus photograph that was placed on the adjacent computer monitor.…”

Spectral‐domain optical coherence tomography imaging of normal foveae: A pilot study in 17 diurnal birds of prey

“…Optical coherence tomography (OCT) is a noninvasive cross‐sectional imaging technique designed to produce a two‐dimensional image of the optical scattering from internal tissue microstructures . This imaging technique is analogous to an ultrasound B‐scan that can provide cross‐sectional images of the retina with a micrometer scale resolution, often being described as an in vivo optical biopsy …”

Spectral domain optical coherence tomography evaluation of the feline optic nerve and peripapillary retina

“…Optical coherence tomography (OCT) is a noncontact, topographic biomicroscopic device that provides high‐resolution, cross‐sectional digital images of live biological tissues in vivo and in real time . This imaging technology was initially reported to have 10‐m resolution, however, with recent technology advancements in commercially available OCTs, resolution has improved to approximately 2‐3 m .…”

“…This imaging technology was initially reported to have 10‐m resolution, however, with recent technology advancements in commercially available OCTs, resolution has improved to approximately 2‐3 m . This technology has been shown to be extremely useful detecting early changes in morphology of the retina and optic nerve and has been described multiple times as an in vivo optical biopsy …”