Optical Coherence Tomography Imaging Technology Research Articles

Advances in Optical Coherence Tomography Imaging Technology and Techniques for Choroidal and Retinal Disorders.

Optical coherence tomography (OCT) imaging has played a pivotal role in the field of retina. This light-based, non-invasive imaging modality provides high-quality, cross-sectional analysis of the retina and has revolutionized the diagnosis and management of retinal and choroidal diseases. Since its introduction in the early 1990s, OCT technology has continued to advance to provide quicker acquisition times and higher resolution. In this manuscript, we discuss some of the most recent advances in OCT technology and techniques for choroidal and retinal diseases. The emerging innovations discussed include wide-field OCT, adaptive optics OCT, polarization sensitive OCT, full-field OCT, hand-held OCT, intraoperative OCT, at-home OCT, and more. The applications of these rising OCT systems and techniques will allow for a closer monitoring of chorioretinal diseases and treatment response, more robust analysis in basic science research, and further insights into surgical management. In addition, these innovations to optimize visualization of the choroid and retina offer a promising future for advancing our understanding of the pathophysiology of chorioretinal diseases.

Research progress on the application of optical coherence tomography in the field of oncology.

Optical coherence tomography (OCT) is a non-invasive imaging technique which has become the “gold standard” for diagnosis in the field of ophthalmology. However, in contrast to the eye, nontransparent tissues exhibit a high degree of optical scattering and absorption, resulting in a limited OCT imaging depth. And the progress made in the past decade in OCT technology have made it possible to image nontransparent tissues with high spatial resolution at large (up to 2mm) imaging depth. On the one hand, OCT can be used in a rapid, noninvasive way to detect diseased tissues, organs, blood vessels or glands. On the other hand, it can also identify the optical characteristics of suspicious parts in the early stage of the disease, which is of great significance for the early diagnosis of tumor diseases. Furthermore, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This review summarizes the recent advances in the OCT area, which application in oncological diagnosis and treatment in different types: (1) superficial tumors:OCT could detect microscopic information on the skin’s surface at high resolution and has been demonstrated to help diagnose common skin cancers; (2) gastrointestinal tumors: OCT can be integrated into small probes and catheters to image the structure of the stomach wall, enabling the diagnosis and differentiation of gastrointestinal tumors and inflammation; (3) deep tumors: with the rapid development of OCT imaging technology, it has shown great potential in the diagnosis of deep tumors such in brain tumors, breast cancer, bladder cancer, and lung cancer.

Application of Intravascular Imaging in Forensic Autopsy.

With the emergence of new technologies and devices including minimally invasive catheters and rotary couplers, the application of imaging technology such as traditional ultrasound and optical coherence tomography （OCT） is gradually expanded. In recent years, intravascular ultrasound （IVUS） and OCT have become increasingly mature as coronary intravascular imaging techniques, and therefore become an important complementary means of coronary angiography. Although studies on feasibility of clinical applications of IVUS and OCT have been confirmed in the evaluation of previous cadaver studies, these techniques have been neglected in forensic autopsy. This paper reviews the application value of IVUS and OCT in forensic autopsy, especially in the adjuvant evaluation of coronary artery disease. Including the characteristics of IVUS and OCT imaging technology, the problems of coronary examination in traditional autopsy and the specific application of new intravascular imaging technology in forensic autopsy.

Current Advances in COPD Imaging

To review the recent advances in available technologies for imaging COPD and present the novel optical coherence tomography (OCT) airway imaging technology. This is an unstructured review of published evidence of available pulmonary imaging technologies along with a demonstration of state-of-the-art OCT imaging technology of in vivo human and animal airways. Advanced imaging techniques such as Magnetic Resonance (MR) imaging using hyperoloarized noble gases, micro-Computed Tomography (micro-CT), and OCT aim to further our understanding of COPD. Lung densitometry can aid in identifying an exacerbation prone phenotype which may have implications for targeting specific therapies to these individuals. MR ventilation scans have the ability to provide a functional and regional distribution of airflow obstruction offering insight into the airway and parenchymal changes induced by COPD. Micro-CT gives a near microscopic view of the terminal bronchioles and alveoli permitting study of the microarchitecture of the lung ex vivo. Optical coherence tomography can visualize the microstructure of the airway walls (epithelium, smooth muscle, blood vessels, cartilage) permitting real time in vivo as well as longitudinal evaluation of airway changes in patients with COPD. Advanced imaging techniques play a vital role in expanding our current understanding of COPD.

Preliminary Research on Bubble Characteristics of Ancient Glaze Using OCT Technology

The bubble is one of the most common feature in ancient glaze. The size and distribution of bubbles are closely associated with recipes of the raw materials for the body and glaze and the making process. To characterize the bubbles is essential for the study of ceramic production process, production places, times characteristics and so on. In order to explore the possibility of using the optical coherence tomography (OCT) imaging technology to characterize the bubbles and the bubble distribution characteristic in glaze of ancient porcelain, sweep frequency OCT imaging system is used to detect five different types ancient porcelain chips. According to the two dimensional sectional images and three dimensional tomographic images of the transparent layer of glaze obtained by the OCT imaging system, the two dimensional sectional images characteristics and three dimensional slices characteristics of the bubbles in glaze are studied. The bubble characteristics in the glaze and its possible causes that gases in the body of the ceramic overflow to the glaze layer in the firing process are comprehensively analyzed. Meantime, the size of bubble is calculated according to the two dimensional sectional images based on pixel, and the result is compared with the traditional microscopic test result. The bubble size, two dimensional sectional characteristics and three dimensional tomographic image characteristics of opaque glaze are also studied. Experimental results show that the bubble characteristics in glaze of different ancient porcelain chips are obvious difference, the result of the bubble size calculated based on pixel coincides with the result of the bubble size observed by traditional microscope with ten times magnification, slices of the body near the body-glaze binding region based on OCT imaging technology three dimensional tomography can effectively reflect the bubble characteristics in glaze. The measurement of using OCT imaging technology to characterize bubble characteristics of the glaze is proposed, and the feasibility and the validity of the measurement are certified, and the nondestructive detection of bubble characteristics in ancient porcelain glaze is realized. Especially for the analysis of bubble characteristics of opaque glaze, the OCT imaging technology overcomes the limitations of using the traditional microscope technology to study the distribution of bubble in glaze in the past, and provides a novel, reliable analysis method for the analysis of ceramic glaze bubble characteristics.

基于标定臂的低噪声光学相干层析成像技术

基于标定臂的低噪声光学相干层析成像技术

Changes in the Expression of the Alzheimers Disease-Associated Presenilin Gene in Drosophila Heart Leads to Cardiac Dysfunction

Mutations in the presenilin genes cause the majority of early-onset familial Alzheimer’s disease. Recently, presenilin mutations have been identified in patients with dilated cardiomyopathy (DCM), a common cause of heart failure and the most prevalent diagnosis in cardiac transplantation patients. However, the molecular mechanisms, by which presenilin mutations lead to either AD or DCM, are not yet understood. We have employed transgenic Drosophila models and optical coherence tomography imaging technology to analyze cardiac function in live adult Drosophila. Silencing of Drosophila ortholog of presenilins (dPsn) led to significantly reduced heart rate and remarkably age-dependent increase in end-diastolic vertical dimensions. In contrast, overexpression of dPsn increased heart rate. Either overexpression or silencing of dPsn resulted in irregular heartbeat rhythms accompanied by cardiomyofibril defects and mitochondrial impairment. The calcium channel receptor activities in cardiac cells were quantitatively determined via real-time RT-PCR. Silencing of dPsn elevated dIP3R expression, and reduced dSERCA expression; overexprerssion of dPsn led to reduced dRyR expression. Moreover, overexpression of dPsn in wing disc resulted in loss of wing phenotype and reduced expression of wingless. Our data provide novel evidence that changes in presenilin level leads to cardiac dysfunction, owing to aberrant calcium channel receptor activities and disrupted Wnt signaling transduction, indicating a pathogenic role for presenilin mutations in DCM pathogenesis.

Optical coherence tomography in unprotected left main coronary artery stenting

Delayed or incomplete stent endothelisation and stent malapposition may predispose to DES thrombosis that can be a catastrophic event in the left main coronary artery (LMCA). OCT can accurately identify stent struts and arterial tissue, but is limited by the need of vessel blood clearance and penetration; also no data exist on its use in LMCA. We sought to verify whether optical coherence tomography (OCT) can accurately assess arterial wall response after drug eluting stent (DES) implantation in the LMCA.OCT images were obtained in 15 patients (mean age 70.7 + or - 8.0 years) six months after LMCA DES implantation. Acquisitions were performed without proximal balloon occlusion during isoosmolar contrast injection through a 6 Fr guiding catheter without side holes at a speed of 2-3 mL/sec. Offline image analyses were performed to evaluate assessable stent area (all slices), strut coverage, apposition, and abnormal tissue responses for every three slices (= every 0.45 mm). All OCT images were obtained without periprocedural complications. Overall, 69 + or - 20% of the stent inner area was analysable; this corresponded to 2.7 + or - 0.8 analysable quadrants per slice. Out of 1,281 struts, 1,136 (88.7%) were well apposed and fully covered, 101 (7.8%) were uncovered; and 45 (3.5%) were malapposed although nine of the malapposed struts (20%) were covered by some tissue. In five patients OCT detected abnormal intraluminal tissue, and in two cases this finding was related to uncovered struts.OCT assessment of vascular response after LMCA DES implantation is safe and feasible. Further development of OCT imaging technology will be necessary for complete evaluation of LMCA stents.