Imaging Of Cellular Structures Research Articles

In Vivo Imaging of the Biliary (BD) and Pancreatic Duct (PD) with Optical Coherence Tomography (OCT) During ERCP Accurately Identifies Dysplastic Cellular Changes

Background: Pancreatic adenocarcinomas and cholangiocarcinomas likely arise from dysplastic PD and BD epithelium, respectively. Current imaging techniques are unable to detect these early microscopic changes. OCT has the potential to identify dysplastic ductal lesions by imaging cellular and subcellular epithelial structures. Aims: (1) to image the BD and PD in vivo with OCT in diseased and normal states and (2) to correlate high resolution endoscopic OCT imaging with histopathologic changes of PD and BD epithelium.

In vivo imaging of cellular structures in Caenorhabditis elegans by combined TPEF, SHG and THG microscopy

In this study, we use combined two-photon excitation fluorescence (TPEF), second-harmonic generation (SHG) and third-harmonic generation (THG) measurements to image cellular structures of the nematode Caenorhabditis elegans, in vivo. To our knowledge, this is the first time that a THG modality is employed to image live C. elegans specimens. Femtosecond laser pulses (1028 nm) were utilized for excitation. Detailed and specific structural and anatomical features can be visualized, by recording THG signals. Thus, the combination of three image-contrast modes (TPEF-SHG-THG) in a single instrument has the potential to provide unique and complementary information about the structure and function of tissues and individual cells of live biological specimens.

In Vivo Imaging of the Biliary (BD) and Pancreatic Duct (PD) with Optical Coherence Tomography (OCT) During ERCP

Background: Pancreatic adenocarcinomas and cholangiocarcinomas likely arise from dysplastic PD and BD epithelium, respectively. Current imaging techniques are unable to detect these dysplastic lesions because these changes occur at the microscopic level. OCT has the potential to image cellular and subcellular structures. Aims: (1) to image the BD and PD in vivo with OCT in diseased and normal states and (2) to correlate high resolution endoscopic OCT imaging with histopathologic changes of the PD and BD epithelium. Methods: Patients age ≥18 years undergoing ERCP for the evaluation of biliary or pancreatic disease were eligible. After fluoroscopic evaluation of the BD or PD, but prior to any endoscopic stent placement, a 2.4 mm diameter radial scanning OCT probe was passed over a guidewire using a monorail type system. Digitized images of the entire OCT examination with a corresponding fluoroscopic image identifying the location of the OCT probe and the distance of the probe from the major papilla were recorded during probe withdrawal. Histologic analysis of brush cytology, biopsy, EUS-FNA, and/or surgical resection specimens from the corresponding area of interest in the BD or PD was reviewed in blinded fashion. OCT features characterized on the basis of our previous experience in dogs and reported in humans (reflectance pattern, intensity, and structural organization) were compared to the fluoroscopic and histologic features of normal epithelium, inflammation, dysplasia, and cancer. Results: 11 patients (6 men; 5 women; mean age 67, range 35-89) were enrolled with BD OCT imaging in 9 pts [2 normal and 7 strictures - 1 extrinsic Hodgkin's lymphoma, 2 pancreatic cancer, 2 benign PSC-dominant strictures, 1 autoimmune pancreatitis (AIP), and 1 cholangiocarcinoma] and PD OCT imaging in 2 pts [1 chronic pancreatitis stricture and 1 pancreatic cancer]. Average fluoro time for OCT imaging was 12 seconds (range 3-34). Low light scattering and loss of organizational structure on OCT correlated with dysplasia and cancer in all patients with cancer. In patients with inflammation, a heterogenous reflectance pattern and wall thickening was noted in 3 of 4 with a homogenous low reflectance pattern in the AIP patient. No complications occurred. Conclusions: In this pilot study, in vivo intraductal OCT of the BD and PD was both feasible and safe. Intraductal OCT appears to have the potential for identifying dysplastic cellular changes or cancer in the PD or BD epithelium during ERCP.

An Informational Technology for Description and Morphometric Analysis of Images of Microobjects

A procedure for generalized description and parameterization of the images of cellular structures of the medico-biological microobjects with the aim of formalizing knowledge of physicians and automating morphometric analysis, classification, and identification of cells computer-aided systems was proposed. Structural and parameterized models for generalized description of the images of normal and pathologically changed cells of blood and sperm were presented by way of example.

Atomic force microscopy imaging of living cells: progress, problems and prospects.

Recent development of atomic force microscopy (AFM) applications in imaging living cells is reviewed, focusing on technical progress and application advancements made in the following major areas: (i) high-resolution imaging of cellular structures, (ii) real-time monitoring of cellular dynamic processes, and (iii) detecting micromechanical properties of the cell. Technical and experimental difficulties frequently encountered in AFM applications in above areas are presented and possible strategies for overcoming these obstacles are discussed. Significant advances in the AFM study of living cells can be achieved from further development of AFM technology, sample preparation, and innovative applications.

2D-CELL: image processing software for extraction and analysis of 2-dimensional cellular structures

2D-CELL is a software package for the processing and analyzing of photographic images of cellular structures in a largely interactive way. Starting from a binary digitized image, the programs extract the line network (skeleton) of the structure and determine the graph representation that best models it. Provision is made for manually correcting defects such as incorrect node positions or dangling bonds. Then a suitable algorithm retrieves polygonal contours which define individual cells — local boundary curvatures are neglected for simplicity. Using elementary analytical geometry relations, a range of metric and topological parameters describing the population are then computed, organized into statistical distributions and graphically displayed.

Contact x-ray microscopy. A new technique for imaging cellular fine structure

Contact x-ray microscopy potentially allows living, wet cells to be visualized at a resolution of up to 100 A. Furthermore, differential absorption by specific elements permits the study of the distribution of those elements in biological specimens. In contact x-ray microscopy, soft x-rays (10 A to 100 A) pass through a biological sample and expose an underlying x-ray sensitive polymer (resist), producing an image that reflects the photon absorbance within the specimen. The high penetrating power of soft x-ray enables images to be obtained from specimens up to several microns thick. In this paper, the technique is described, some of the areas currently under study are considered, and biological examples of the use of contact x-ray microscopy are given.