Dynamic Optical Coherence Tomography Research Articles

Label-free intratissue activity imaging of alveolar organoids with dynamic optical coherence tomography.

An organoid is a three-dimensional (3D) in vitro cell culture emulating human organs. We applied 3D dynamic optical coherence tomography (DOCT) to visualize the intratissue and intracellular activities of human induced pluripotent stem cells (hiPSCs)-derived alveolar organoids in normal and fibrosis models. 3D DOCT data were acquired with an 840-nm spectral domain optical coherence tomography with axial and lateral resolutions of 3.8 µm (in tissue) and 4.9 µm, respectively. The DOCT images were obtained by the logarithmic-intensity-variance (LIV) algorithm, which is sensitive to the signal fluctuation magnitude. The LIV images revealed cystic structures surrounded by high-LIV borders and mesh-like structures with low LIV. The former may be alveoli with a highly dynamics epithelium, while the latter may be fibroblasts. The LIV images also demonstrated the abnormal repair of the alveolar epithelium.

1618 Simulated solar radiation (SSR) induced skin inflammation across skin types measured by dynamic optical coherence tomography and laser doppler

1618 Simulated solar radiation (SSR) induced skin inflammation across skin types measured by dynamic optical coherence tomography and laser doppler

Advantages of Optical Coherence Tomography as a High Dynamic Range Imaging Modality in Subretinal Hyperreflective Material.

We aim to describe the utility of high dynamic range optical coherence tomography (OCT) imaging to study subretinal hyperreflective material (SHRM) in patients with age-related macular degeneration (AMD). We retrospectively reviewed clinical information including visual acuity (VA) and OCT images (Heidelberg Engineering Inc., Germany) of patients undergoing antiangiogenic treatment for neovascular AMD and showing SHRM at baseline. We increased contrast between strong signal structures (high dynamic range image) re-classifying SHRM as hyperreflective, isoreflective and hyporeflective. We evaluated the patients at baseline, 3, 6 and 12-months follow-up. Forty-four eyes were classified as 15 hyperreflective (34.1%); 21 as isoreflective (47.7%); and 8 as hyporeflective (18.2%). During follow-up, hyporeflective SHRM disappeared in all cases, isoreflective SHRM faded in 16 cases (76,2%); hyperreflective SHRM remained in all cases. Hyporreflective SHRM showed a greater VA improvement than hyperreflective SHRM group (p=0,033). After 12-month follow-up only the hyporeflective and isoreflective groups significantly reduced the presence of fluid in 37,5% (p=0,250) and 46,62% (p=0,006) of the patients respectively; and outer retinal layers were disrupted more frequently in the presence of hyperreflective SHRM (ellipsoid zone, p=0,16; external limiting membrane, p=0,007). Contrast-enhanced OCT images enabled us to classify SHRM according to its reflectivity showing groups with different disappearance rates, visual acuity improvement and outer retinal layer disruption. This easy to access tool may be helpful as a prognostic factor in neovascular AMD cases.

Visualizing enteric nervous system activity through dye-free dynamic full-field optical coherence tomography

Major advances have been achieved in imaging technologies but most methodological approaches currently used to study the enteric neuronal functions rely on exogenous contrast dyes that can interfere with cellular functions or survival. In the present paper, we investigated whether full-field optical coherence tomography (FFOCT), could be used to visualize and analyze the cells of the enteric nervous system. Experimental work on whole-mount preparations of unfixed mouse colons showed that FFOCT enables the visualization of the myenteric plexus network whereas dynamic FFOCT enables to visualize and identify in situ individual cells in the myenteric ganglia. Analyzes also showed that dynamic FFOCT signal could be modified by external stimuli such veratridine or changes in osmolarity. These data suggest that dynamic FFOCT could be of great interest to detect changes in the functions of enteric neurons and glia in normal and disease conditions.

Adaptive dynamic analysis-based optical coherence tomography angiography for blood vessel projection artifact suppression.

Optical coherence tomography angiography (OCTA) for blood vessel 3-D structure imaging suffers from blood vessel projection artifacts/tail artifacts when using a long decorrelation time (e.g., repeat B-scan acquisition in regular OCTA) or loss of micro vessel signal when using a short decorrelation time. In this work, we developed an adaptive first-order field autocorrelation function (g1) analysis-based technique to suppress the projection artifacts under macro vessels while enhancing the dynamic signal of micro vessels. The proposed method is based on the differences of the decorrelation rate and the phase variations of g1 between the vessel voxels and the artifacts regions. A short or long decorrelation time was applied to obtain the dynamic index of the projection artifacts region or the blood vessel region, respectively. Compared to the slab subtraction-based post-image processing-based techniques, the proposed approach addresses this problem on a physical basis and shows the ability to suppress the projection artifacts while enhancing the detection of the micro vessels.

Dynamic Optical Coherence Tomography: A Non-Invasive Imaging Tool for the Distinction of Nevi and Melanomas

Along with the rising melanoma incidence in recent decades and bad prognoses resulting from late diagnoses, distinguishing between benign and malignant melanocytic lesions has become essential. Unclear cases may require the aid of non-invasive imaging to reduce unnecessary biopsies. This multicentric, case-control study evaluated the potential of dynamic optical coherence tomography (D-OCT) to identify distinguishing microvascular features in nevi. A total of 167 nevi, including dysplastic ones, on 130 participants of all ages and sexes were examined by D-OCT and dermoscopy with a histological reference. Three blinded analyzers evaluated the lesions. Then, we compared the features to those in 159 melanomas of a prior D-OCT study and determined if a differential diagnosis was possible. We identified specific microvascular features in nevi and a differential diagnosis of melanomas and nevi was achieved with excellent predictive values. We conclude that D-OCT overcomes OCT´s inability to distinguish melanocytic lesions based on its focus on microvascularization. To determine if an addition to the gold standard of a clinical-dermoscopic examination improves the diagnosis of unclear lesions, further studies, including a larger sample of dysplastic nevi and artificial intelligence, should be conducted.

Iris Color Matters-A Contractility Analysis With Dynamic Volume-Rendered Optical Coherence Tomography Pupillometry.

To analyze natural variability in pupillary contractility with dynamic volume-rendered optical coherence tomography (OCT) pupillometry regarding iris color, age, and sex in healthy Caucasian participants. The intrapupillary spaces (IPSs) derived from anterior segment swept-source OCT of 71 healthy eyes were retrospectively analyzed. Baseline scotopic and photopic volumes and the functional parameters of pupillary ejection fraction (PEF), three-dimensional (3D) contractility, and relative light response (RLR) were measured on the swept-source OCT volumes. The effect on these parameters of iris color (brown, green, and blue), age, and sex was assessed. More pigmented irises were more contractile than less pigmented irises. Iris color significantly affected scotopic baseline IPSs (brown, 10.39 ± 4.86 mm3; green, 9.68 ± 3.31 mm3; blue, 6.75 ± 4.27 mm3; P = 0.018), PEF (brown, 90.8% ± 2.7%; green, 89.1% ± 2.5%; blue, 85.0% ± 9.3%; P = 0.010), 3D contractility (brown, 9.52 ± 4.59 mm3; green, 8.66 ± 3.07 mm3; blue, 6.44 ± 4.87 mm3; P = 0.016), and RLR (brown, 11.90 ± 4.03; green, 9.75 ± 2.73; blue, 8.52 ± 3.88; P = 0.026). Absolute scotopic volume (P = 0.022) and 3D contractility (P = 0.024) decreased with age. Sex showed no correlations. The natural variability of pupillary contractility can be analyzed with dynamic OCT pupillometry. Iris color and age can impact pupillary response with this method. Iris contractility parameters can be measured using a commercially available OCT system, allowing for quantification of the aqueous humor volume inside the pupil.

Dynamic full-field optical coherence tomography as complementary tool in fungal diagnostics

Histopathology and microscopic examination of infected tissue are the gold standards to prove the diagnosis of invasive fungal infection (IFI). Yet, they suffer from essential limitations that hamper rapid diagnosis and require the future development of new imaging tools dedicated to fungal diagnostics. To this end, the present work introduces the first use of dynamic full-field optical coherence tomography (D-FF-OCT) for the visualization of microscopic filamentous fungi. Data collected from the observation of three different fungal species (Nannizzia gypsea, Aspergillus fumigatus and Rhizopus arrhizus) confirm the ability of D-FF-OCT to visualize not only the main structures of all selected fungal species (hyphae, spores, conidia, sporulating structures), but also the metabolic activity of the organisms, which could provide additional help in the future to better characterize the signature of each fungal structure. These results demonstrate how D-FF-OCT could serve as potential complementary tool for rapid diagnosis of IFI in both intensive and non-intensive care units.

Label-free metabolic imaging of non-alcoholic-fatty-liver-disease (NAFLD) liver by volumetric dynamic optical coherence tomography.

Label-free metabolic imaging of non-alcoholic fatty liver disease (NAFLD) mouse liver is demonstrated ex vivo by dynamic optical coherence tomography (OCT). The NAFLD mouse is a methionine choline-deficient (MCD)-diet model, and two mice fed the MCD diet for 1 and 2 weeks are involved in addition to a normal-diet mouse. The dynamic OCT is based on repeating raster scan and logarithmic intensity variance (LIV) analysis that enables volumetric metabolic imaging with a standard-speed (50,000 A-lines/s) OCT system. Metabolic domains associated with lipid droplet accumulation and inflammation are clearly visualized three-dimensionally. Particularly, the normal-diet liver exhibits highly metabolic vessel-like structures of peri-vascular hepatic zones. The 1-week MCD-diet liver shows ring-shaped highly metabolic structures formed with lipid droplets. The 2-week MCD-diet liver exhibits fragmented vessel-like structures associated with inflammation. These results imply that volumetric LIV imaging is useful for visualizing and assessing NAFLD abnormalities.

Dynamic full-field optical coherence tomography allows live imaging of retinal pigment epithelium stress model

Retinal degenerative diseases lead to the blindness of millions of people around the world. In case of age-related macular degeneration (AMD), the atrophy of retinal pigment epithelium (RPE) precedes neural dystrophy. But as crucial as understanding both healthy and pathological RPE cell physiology is for those diseases, no current technique allows subcellular in vivo or in vitro live observation of this critical cell layer. To fill this gap, we propose dynamic full-field OCT (D-FFOCT) as a candidate for live observation of in vitro RPE phenotype. In this way, we monitored primary porcine and human stem cell-derived RPE cells in stress model conditions by performing scratch assays. In this study, we quantified wound healing parameters on the stressed RPE, and observed different cell phenotypes, displayed by the D-FFOCT signal. In order to decipher the subcellular contributions to these dynamic profiles, we performed immunohistochemistry to identify which organelles generate the signal and found mitochondria to be the main contributor to D-FFOCT contrast. Altogether, D-FFOCT appears to be an innovative method to follow degenerative disease evolution and could be an appreciated method in the future for live patient diagnostics and to direct treatment choice.

Dynamic inverse SNR-decorrelation OCT angiography with GPU acceleration.

Dynamic OCT angiography (OCTA) is an attractive approach for monitoring stimulus-evoked hemodynamics; however, a 4D (3D space and time) dataset requires a long acquisition time and has a large data size, thereby posing a great challenge to data processing. This study proposed a GPU-based real-time data processing pipeline for dynamic inverse SNR-decorrelation OCTA (ID-OCTA), offering a measured line-process rate of 133 kHz for displaying OCT and OCTA cross-sections in real time. Real-time processing enabled automatic optimization of angiogram quality, which improved the vessel SNR, contrast-to-noise ratio, and connectivity by 14.37, 14.08, and 9.76%, respectively. Furthermore, motion-contrast 4D angiographic imaging of stimulus-evoked hemodynamics was achieved within a single trail in the mouse retina. Consequently, a flicker light stimulus evoked an apparent dilation of the retinal arterioles and venules and an elevation of the decorrelation value in the retinal plexuses. Therefore, GPU ID-OCTA enables real-time and high-quality angiographic imaging and is particularly suitable for hemodynamic studies.

Dynamic microscopic optical coherence tomography to visualize the morphological and functional micro-anatomy of the airways.

In the imaging of airway tissue, optical coherence tomography (OCT) provides cross-sectional images of tissue structures, shows cilia movement and mucus secretion, but does not provide sufficient contrast to differentiate individual cells. By using fast sequences of microscopic resolution OCT (mOCT) images, OCT can use small signal fluctuations to overcome lack in contrast and speckle noise. In this way, OCT visualizes airway morphology on a cellular level and allows the tracking of the dynamic behavior of immune cells, as well as mucus transport and secretion. Here, we demonstrate that mOCT, by using temporal tissue fluctuation as contrast (dynamic mOCT), provides the possibility to study physiological and pathological tissue processes in vivo.

Identification of Peripheral Anterior Synechia by Corneal Deformation Using Air-Puff Dynamic Anterior Segment Optical Coherence Tomography.

Indentation gonioscopy is commonly used in the clinic to evaluate peripheral anterior synechia (PAS) of angle closure glaucoma (ACG). The examination requires contacting with the cornea, resulting in an uncomfortable feeling for patients, and it only provides qualitative outcomes which may be affected by subjective judgment of the clinicians. Previous studies had reported to identify the presence of PAS by measuring the changes of morphological parameters of the anterior chamber angle (ACA) under the pupillary light reflex, by anterior segment optical coherence tomography (AS-OCT). However, this method was invalid for some subjects who had low sensitiveness to light. This article describes an air-puff dynamic anterior segment optical coherence tomography (DAS-OCT) system that can evaluate the presence of PAS in a non-contact approach. The peripheral cornea is deformed by an air puff jetted from the DAS-OCT, causing a transfer of force to the ACA, just as how indentation gonioscopy works. The dynamic changes of the ACA before and after the air puff are recorded by OCT. Ten eyes of normal subjects were enrolled in this study to validate the repeatability and availability of the measurements. Then, ten samples of the ACA from five subjects with ACG were recruited and were assigned into two groups, the non PAS group (NPAS) and PAS group, according to the results of gonioscopy. The ACA structural parameters including the angle opening distance at 750 μm to the scleral spur (AOD750) and the trabecular-iris space area at 750 μm anterior to the scleral spur (TISA750) were then calculated automatically by a custom-written algorithm. The intraclass correlation coefficient (ICC) of measured parameters was all above 0.85 for normal subjects, exhibiting good repeatability. For patients, both parameters showed significant differences between the two groups after the air puff, while no differences were observed before the air puff. AOD750dif and TISA750dif between two groups showed more significant differences, indicating that they could be used as indicators to identify the presence of PAS. In conclusion, the DAS-OCT system proposed in this study is demonstrated effective to identify the presence of PAS by measuring the changes of the ACA via a noncontact approach. It shows great potential for applications in guidance for diagnosis of angle closure glaucoma.

Hidradenitis suppurativa: Morphologic and vascular study of nodular inflammatory lesions by means of optical coherence tomography.

Hidradenitis suppurativa (HS) is an inflammatory disease characterized by a recurrent-remission trend and clinical lesions that range from asymptomatic to inflamed, deep-seated nodules with scarring and suppuration. The aim of our study was to identify morphologic and vascular features of HS nodules by means of dynamic optical coherence tomography (D-OCT) and to define if they are correlated to patient endotype and risk of disease progression. A set of standardized clinical pictures and D-OCT images were acquired from 57 inflammatory nodules of 40 patients affected by HS. A set of 20 clinical and D-OCT images were acquired from 20 healthy volunteers as a control group. The comparison of D-OCT features among HS and control group was analysed. The correlation between HS patient endotype and D-OCT features of the lesions was calculated. D-OCT enabled to identify vascular and morphological aspects characterizing HS nodular inflammatory lesions. In addition, several D-OCT features were significantly different among distinct disease endotypes. The characterization of HS nodular inflammatory lesions through D-OCT, corresponding to blood vessel dilation and inflammatory associated hyper-vascularization, may have important clinical consequences in the assessment of HS risk of progression, therapeutic decisions and treatment efficacy monitoring.

Identification of venular capillary remodelling: a possible link to the development of periodontitis?

PurposeThe present study measured changes in arteriolar and venular capillary flow and structure in the gingival tissues during the development of plaque-induced gingival inflammation by combining dynamic optical coherence tomography (OCT), laser perfusion, and capillaroscopic video imaging.MethodsGingival inflammation was induced in 21 healthy volunteers over a 3-week period. Gingival blood flow and capillary morphology were measured by dynamic OCT, laser perfusion imaging, and capillaroscopy, including a baseline assessment of capillary glycocalyx thickness. Venular capillary flow was estimated by analysis of the perfusion images and mean blood velocity/acceleration in the capillaroscopic images. Readings were recorded at baseline and weekly over the 3 weeks of plaque accumulation and 2 weeks after brushing was resumed.ResultsPerfusion imaging demonstrated a significant reduction of gingival blood flow after 1 and 2 weeks of plaque accumulation (P<0.05), but by 3 weeks of plaque accumulation there was a more mixed picture, with reduced flow in some participants and increased flow in others. Participants with reduced flux at 3 weeks also demonstrated venular-type flow as determined by perfusion images and evidence of the development of venular capillaries as assessed by the velocity/acceleration ratio in capillaroscopic images. After brushing resumed, these venular capillaries were broken down and replaced by arteriolar capillaries.ConclusionsAfter 3 weeks of plaque accumulation, there was wide variation in microvascular reactions between the participants. Reduced capillary flow was associated with the development of venular capillaries in some individuals. This is noteworthy, as an early increase in venous capillaries is a key vascular feature of cardiovascular disease, psoriasis, Sjögren syndrome, and rheumatoid arthritis—diseases with a significant association with the development of severe gingival inflammation, which leads to periodontitis. Future investigations of microvascular changes in gingival inflammation might benefit from accurate capillary flow velocity measurements to assess the development of venular capillaries.

Advances in optical coherence tomography

Optical coherence tomography (OCT) has been able to establish itself in recent years not only in academic-scientific, but also in everyday dermatological practice. Its focus lies on epithelial tumors of the skin, which can be diagnosed intuitively and within afew seconds. Thus, basal cell carcinomas, actinic keratoses, and different stages of field cancerization can be diagnosed and monitored for response to therapy or possible recurrence. This often helps to avoid invasive sample extraction. Recently, the field of OCT and its latest advancement, dynamic OCT (D-OCT), has been expanded to include non-oncologic dermatological diseases. This encompasses inflammatory dermatoses and the analysis of physiological skin parameters such as hydration. Thanks to automated vascular imaging and the measurement of objective parameters such as epidermal thickness, blood flow at depth, optical attenuation coefficient, and skin roughness, more and more characteristics of the skin can be studied in anoninvasive and standardized way. New potential areas of application are eczema, contact allergic dermatitis, psoriasis, rosacea, telangiectasia, acute and chronic wounds, melasma and nevus flammeus but also melanocytic lesions.

Enhanced medical diagnosis for dOCTors: a perspective of optical coherence tomography.

.Significance: After three decades, more than 75,000 publications, tens of companies being involved in its commercialization, and a global market perspective of about USD 1.5 billion in 2023, optical coherence tomography (OCT) has become one of the fastest successfully translated imaging techniques with substantial clinical and economic impacts and acceptance.Aim: Our perspective focuses on disruptive forward-looking innovations and key technologies to further boost OCT performance and therefore enable significantly enhanced medical diagnosis.Approach: A comprehensive review of state-of-the-art accomplishments in OCT has been performed.Results: The most disruptive future OCT innovations include imaging resolution and speed (single-beam raster scanning versus parallelization) improvement, new implementations for dual modality or even multimodality systems, and using endogenous or exogenous contrast in these hybrid OCT systems targeting molecular and metabolic imaging. Aside from OCT angiography, no other functional or contrast enhancing OCT extension has accomplished comparable clinical and commercial impacts. Some more recently developed extensions, e.g., optical coherence elastography, dynamic contrast OCT, optoretinography, and artificial intelligence enhanced OCT are also considered with high potential for the future. In addition, OCT miniaturization for portable, compact, handheld, and/or cost-effective capsule-based OCT applications, home-OCT, and self-OCT systems based on micro-optic assemblies or photonic integrated circuits will revolutionize new applications and availability in the near future. Finally, clinical translation of OCT including medical device regulatory challenges will continue to be absolutely essential.Conclusions: With its exquisite non-invasive, micrometer resolution depth sectioning capability, OCT has especially revolutionized ophthalmic diagnosis and hence is the fastest adopted imaging technology in the history of ophthalmology. Nonetheless, OCT has not been completely exploited and has substantial growth potential—in academics as well as in industry. This applies not only to the ophthalmic application field, but also especially to the original motivation of OCT to enable optical biopsy, i.e., the in situ imaging of tissue microstructure with a resolution approaching that of histology but without the need for tissue excision.

Frequency and predictors of thin-cap fibroatheroma progression: a comprehensive and dynamic in-vivo OCT study

Abstract Purpose To assess the evolution of thin-cap fibroatheroma (TCFA) and to explore predictors for its progression by using optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS). Methods We enrolled ACS patients with non-culprit TCFA at baseline and corresponding OCT images at follow-up of 9 to 15 months. Clinical, angiographic and OCT data were collected and analyzed according to established methods. TCFA was defined as a lipid plaque with maximum lipid arc &amp;gt;90° and fibrous cap thickness &amp;lt;65μm. Considering the resolution of OCT, the regression of TCFA was defined as an increase of fibrous cap thickness &amp;gt;10μm. Inversely, TCFA progression was defined as a decrease, constant or ≤10μm increase of fibrous cap thickness. Results 41 patients with 55 non-culprit TCFAs were taken into final analysis. 17 patients (41.5%) had patient-level progression and 22 TCFAs (40.0%) progressed at plaque-level with a median follow-up duration of 371 days. 11 (20.0%) of the 55 TCFAs happened subclinical rupture at follow-up, including 10 with the formation a new layer and 1 without the detection of the new layer. Besides, another patient suffered re-myocardial infarction because of the rupture of TCFA induced acute thrombosis and lumen occlusion during follow-up. The baseline clinical and angiographic characteristics were similar between the two cohorts. The progression group had a significantly higher prevalence of macrophage infiltration and vasa vasorum at baseline than the non-progression group (Figure 1). Multivariate analysis identified macrophage infiltration (odds ratio [OR]: 5.30; 95% confidence interval [CI]: 1.01 to 27.91; p=0.049]) as the independent predictor of TCFA progression. When it came to the evolution of lesion morphology and lipid components, the progression cohort had a higher percent change of lumen stenosis and lipid length (Figure 2). Conclusions About 40% of non-culprit TCFAs in ACS patients progressed in fibrous cap thickness at a median interval of 1 year. Macrophage infiltration was the independent predictor of non-culprit TCFA progression. The progression of fibrous cap thickness was usually accompanied with an aggressive evolution of other lesion characteristics. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): the National Key R&amp;D Program of China Baseline OCT characteristicsPercent change of lesion morphology

Nailfold Microvascular Imaging by Dynamic Optical Coherence Tomography in Systemic Sclerosis: A Case-Controlled Pilot Study

In systemic sclerosis, outcome measures of skin microvasculopathy are needed for both clinical trials and practice. The aim of this study was to determine whether dynamic-optical coherence tomography (D-OCT) is able to provide information on microvasculopathy compared with the current gold standard, nailfold videocapillaroscopy (NVC), in patients with systemic sclerosis. This case-controlled study included (i) 40 patients with systemic sclerosis, classified by NVC pattern in four age- and sex-matched groups (normal/nonspecific, early, active, late); (ii) a fifth group of 10 age- and sex-matched healthy controls. All participants underwent NVC and D-OCT. D-OCT images were compared with the corresponding NVC images. Reliability was assessed. D-OCT images visualized the corresponding NVC patterns. D-OCT microvascular flow density was different across the five NVC pattern groups (P= 0.0114) with a significant trend test (P= 0.0006). Microvascular flow density correlated with the NVC semiquantitative score (r=-0.7, P < 0.0001), number of abnormal shapes/mm (r= ‒0.3, P= 0.0264), and number of capillaries/mm (r= 0.6, P < 0.0001). Reliability was excellent (intraclass correlation coefficient > 0.9). In conclusion, in patients with systemic sclerosis, D-OCT provided qualitative and quantitative information on nailfold microvasculopathy, showing a correlation between microvascular flow density and NVC scores. The development of D-OCT as a standardized imaging technique could provide a quantitative outcome measure in clinical trials and practice.

Microscopic optical coherence tomography (mOCT) at 600 kHz for 4D volumetric imaging and dynamic contrast.

Volumetric imaging of dynamic processes with microscopic resolution holds a huge potential in biomedical research and clinical diagnosis. Using supercontinuum light sources and high numerical aperture (NA) objectives, optical coherence tomography (OCT) achieves microscopic resolution and is well suited for imaging cellular and subcellular structures of biological tissues. Currently, the imaging speed of microscopic OCT (mOCT) is limited by the line-scan rate of the spectrometer camera and ranges from 30 to 250 kHz. This is not fast enough for volumetric imaging of dynamic processes in vivo and limits endoscopic application. Using a novel CMOS camera, we demonstrate fast 3-dimensional OCT imaging with 600,000 A-scans/s at 1.8µm axial and 1.1 µm lateral resolution. The improved speed is used for imaging of ciliary motion and particle transport in ex vivo mouse trachea. Furthermore, we demonstrate dynamic contrast OCT by evaluating the recorded volumes rather than en face planes or B-scans. High-speed volumetric mOCT will enable the correction of global tissue motion and is a prerequisite for applying dynamic contrast mOCT in vivo. With further increase in imaging speed and integration in flexible endoscopes, volumetric mOCT may be used to complement or partly replace biopsies.