ABSTRACT
Cutaneous blood flow plays a key role in numerous physiological and pathological processes and has significant potential to be used as a biomarker to diagnose skin diseases such as basal cell carcinoma (BCC). The determination of the lesion area and vascular parameters within it, such as vessel density, is essential for diagnosis, surgical treatment and follow-up procedures. Here, an automatic skin lesion area determination algorithm based on optical coherence tomography angiography (OCTA) images is presented for the first time. The blood vessels are segmented within the OCTA images and then skeletonized. Subsequently, the skeleton is searched over the volume and numerous quantitative vascular parameters are calculated. The vascular density is then used to segment the lesion area. The algorithm is tested on both nodular and superficial BCC, and comparing with dermatological and histological results, the proposed method provides an accurate, non-invasive, quantitative and automatic tool for BCC lesion area determination.
Subject(s)
Angiography/methods , Carcinoma, Basal Cell/blood supply , Carcinoma, Basal Cell/diagnostic imaging , Skin Neoplasms/blood supply , Skin Neoplasms/diagnostic imaging , Tomography, Optical Coherence/methods , Adult , Aged , Algorithms , Angiography/instrumentation , Angiography/statistics & numerical data , Blood Vessels/diagnostic imaging , Diagnosis, Computer-Assisted , Equipment Design , Female , Humans , Image Interpretation, Computer-Assisted , Imaging, Three-Dimensional , Male , Middle Aged , Tomography, Optical Coherence/instrumentation , Tomography, Optical Coherence/statistics & numerical dataABSTRACT
A forward imaging endoscope for optical coherence tomography angiography (OCTA) featuring a piezoelectric fiber scanner is presented. Imaging is performed with an optical coherence tomography (OCT) system incorporating an akinetic light source with a center wavelength of 1300 nm, bandwidth of 90 nm and A-line rate of 173 kHz. The endoscope operates in contact mode to avoid motion artifacts, in particular, beneficial for OCTA measurements, and achieves a transversal resolution of 12 µm in air at a rigid probe size of 4 mm in diameter and 11.3 mm in length. A spiral scan pattern is generated at a scanning frequency of 360 Hz to sample a maximum field of view of 1.3 mm. OCT images of a human finger as well as visualization of microvasculature of the human palm are presented both in two and three dimensions. The combination of morphological tissue contrast with qualitative dynamic blood flow information within this endoscopic imaging approach potentially enables improved early diagnostic capabilities of internal organs for diseases such as bladder cancer.
Subject(s)
Angiography/instrumentation , Endoscopy/instrumentation , Tomography, Optical Coherence/instrumentation , Artifacts , Fingers/diagnostic imaging , Humans , MovementABSTRACT
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
ABSTRACT
Imaging of the human retina with high resolution is an essential step towards improved diagnosis and treatment control. In this paper, we introduce a compact, clinically user-friendly instrument based on swept source optical coherence tomography (SS-OCT). A key feature of the system is the realization of two different operation modes. The first operation mode is similar to conventional OCT imaging and provides large field of view (FoV) images (up to 45° × 30°) of the human retina and choroid with standard resolution. The second operation mode enables it to optically zoom into regions of interest with high transverse resolution using adaptive optics (AO). The FoV of this second operation mode (AO-OCT mode) is 3.0° × 2.8° and enables the visualization of individual retinal cells such as cone photoreceptors or choriocapillaris. The OCT engine is based on an akinetic swept source at 1060 nm and provides an A-scan rate of 200 kHz. Structural as well as angiographic information can be retrieved from the retina and choroid in both operational modes. The capabilities of the prototype are demonstrated in healthy and diseased eyes.
ABSTRACT
The cutaneous vasculature is involved in many diseases. Current clinical examination techniques, however, cannot resolve the human vasculature with all plexus in a non-invasive manner. By combining an optical coherence tomography system with angiography extension and an all optical photoacoustic tomography system, we can resolve in 3D the blood vessels in human skin for all plexus non-invasively. With a customized imaging unit that permits access to various parts of patients' bodies, we applied our multimodality imaging system to investigate several different types of skin conditions. Quantitative vascular analysis is given for each of the dermatological conditions to show the potential diagnostic value of our system in non-invasive examination of diseases and physiological processes. Improved performance of our system over its previous generation is also demonstrated with an updated characterization.
Subject(s)
Photoacoustic Techniques/methods , Skin/diagnostic imaging , Tomography, Optical Coherence/methods , Humans , Imaging, Three-Dimensional/instrumentation , Imaging, Three-Dimensional/methods , Photoacoustic Techniques/instrumentation , Skin/anatomy & histology , Skin/blood supply , Tomography, Optical Coherence/instrumentationABSTRACT
Studies have proven the relationship between cutaneous vasculature abnormalities and dermatological disorders, but to image vasculature noninvasively