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Two-dimensional Images (two-dimensional + image)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Evaluation by scanning acoustic microscopy (SAM) on glomerular lesion of IgA nephropathy

NEPHROLOGY, Issue 2001
H Kiyomoto
IgA nephropathy (IgAN) is known to commonly cause of end-stage renal failure in Japan. The glomerular lesions of IgAN have histological variations. The determination of prognosis and therapeutic strategy should be carefully done by experts because morphological information from renal biopsies using ordinary optical microscopy is usually qualitative and subjective. Moreover, the histological items for the evaluation of glomerular lesions seems to be unsatisfactory for expression of the disease condition of IgAN. The beneficial properties of scanning acoustic microscopy (SAM) include not only observation of microstructure but also quantitative measurement of acoustic propagation speed (APS), indicating the tissue elasticity. In the present study we compared the APS of glomeruli with the pathological scores that were determined by ordinary light microscopy. We used stocked human renal biopsy specimens diagnosed as IgAN (n = 12) and normal/minimal changes (n = 5). All samples were taken by renal biopsy in Kagawa Medical University Hospital during 1997,2000 under informed consent of the patients. The obtained renal tissue were immersed in 10% formalin and embedded in paraffin. A fixed specimen was consecutively cut into 4 ,m slices. One of the deparaffinized 4 ,m-specimens was directly utilized for SAM without any staining, and the others were stained with haematoxylin-eosin and Masson Trichrome for counting cell number and evaluation of collagen accumulation. For the measurement of glomerular APS, the sample line was set on the equator of the glomerulus and then scanning of the X,Z axis was carried out to obtain the interference fringes that were analysed with a computer imaging software in order to calculate the APS. In light microscopic study, pathological scores were evaluated semiquantitatively by two independent investigators who were unaware of the sample number. Glomerular lesions were scored into five grades and glomerular cell number was also counted in individual glomerulus. The computer-assisted imaging analyser Win ROOF (Mitani, Fukui, Japan) was also used for the determination of glomerular collagen content in specimens stained by Masson Trichrome. A two-dimensional image (C-mode scanning) of SAM enabled imaging of glomerulus in renal biopsy specimen compatible with findings of ordinary light microscopy without staining dye. The glomerular APS in IgAN was significantly higher than in normal/minimal changes. This alteration of glomerular APS in IgAN was positively correlated to both semiquantitative pathological scores and glomerular collagen content determined by light microscopy. However, the cell number of glomelurus did not change between IgAN and normal/minimal change. As a result, we conclude that the glomerular lesion, especially matrix expansion in IgAN, was comparable with the absolute value among specimens. Therefore, it is suggested that SAM method is a novel and useful technique for quantitative evaluation of glomerular lesion in IgAN. [source]

Acute Cardiac Effects of Nicotine in Healthy Young Adults

ECHOCARDIOGRAPHY, Issue 6 2002
Catherine D. Jolma M.D.
Background: Nicotine is known to have many physiologic effects. The influence of nicotine delivered in chewing gum upon cardiac hemodynamics and conduction has not been well-characterized. Methods: We studied the effects of nicotine in nonsmoking adults (6 male, 5 female; ages 23,36 years) using a double-blind, randomized, cross-over study. Subjects chewed nicotine gum (4 mg) or placebo. After 20 minutes (approximate time to peak nicotine levels), echocardiograms and signal-averaged electrocardiograms (SAECG) were obtained. After 40 minutes, subjects were again given nicotine gum or placebo in cross-over fashion. Standard echocardiographic measurements were made from two-dimensional images. We then calculated end-systolic wall stress (ESWS), shortening fraction (SF), systemic vascular resistance (SVR), velocity for circumferential fiber shortening corrected for heart rate (Vcfc), stroke volume, and cardiac output. P wave and QRS duration were measured from SAECG. Results: Significant differences (P < 0.05) from control or placebo were found for ESWS, mean blood pressure, cardiac output, SVR, heart rate, and P wave duration. No significant changes were seen in left ventricular ejection time (LVET), LV dimensions, SF, contractility (Vcfc), or QRS duration. Conclusions: These results suggest that nicotine chewing gum increases afterload and cardiac output. Cardiac contractility does not change acutely in response to nicotine gum. Heart rate and P wave duration are increased by chewing nicotine gum. [source]

Principles of Highly Resolved Determination of Texture and Microstructure using High-Energy Synchrotron Radiation,

ADVANCED ENGINEERING MATERIALS, Issue 6 2009
Helmut Klein
Abstract Diffraction imaging with hard X-rays (high-energy synchrotron radiation) using the detector sweeping techniques allows measurement of the texture and microstructure of polycrystalline materials with high orientation- and location-resolution. These techniques provide continuous two-dimensional images of different sections and projections of the six-dimensional "orientation-location" space. For the high orientation resolution case, it is possible to measure the orientation and location coordinates of up to 105 individual grains simultaneously. From these parameters, the grain size and shape can also be obtained, yielding the complete orientation stereology of the polycrystalline aggregate, which is required for its complete characterization. For the high location resolution case, the intensity at any point of the diagrams corresponds to a pole density as a function of the orientation-location space. [source]

Interpreting three-dimensional structures from two-dimensional images: a web-based interactive 3D teaching model of surgical liver anatomy

HPB, Issue 6 2009
Jodi L. Crossingham
Abstract Background:, Given the increasing number of indications for liver surgery and the growing complexity of operations, many trainees in surgical, imaging and related subspecialties require a good working knowledge of the complex intrahepatic anatomy. Computed tomography (CT), the most commonly used liver imaging modality, enhances our understanding of liver anatomy, but comprises a two-dimensional (2D) representation of a complex 3D organ. It is challenging for trainees to acquire the necessary skills for converting these 2D images into 3D mental reconstructions because learning opportunities are limited and internal hepatic anatomy is complicated, asymmetrical and variable. We have created a website that uses interactive 3D models of the liver to assist trainees in understanding the complex spatial anatomy of the liver and to help them create a 3D mental interpretation of this anatomy when viewing CT scans. Methods:, Computed tomography scans were imported into DICOM imaging software (OsiriXÔ) to obtain 3D surface renderings of the liver and its internal structures. Using these 3D renderings as a reference, 3D models of the liver surface and the intrahepatic structures, portal veins, hepatic veins, hepatic arteries and the biliary system were created using 3D modelling software (Cinema 4DÔ). Results:, Using current best practices for creating multimedia tools, a unique, freely available, online learning resource has been developed, entitled Visual Interactive Resource for Teaching, Understanding And Learning Liver Anatomy (VIRTUAL Liver) (http://pie.med.utoronto.ca/VLiver). This website uses interactive 3D models to provide trainees with a constructive resource for learning common liver anatomy and liver segmentation, and facilitates the development of the skills required to mentally reconstruct a 3D version of this anatomy from 2D CT scans. Discussion:, Although the intended audience for VIRTUAL Liver consists of residents in various medical and surgical specialties, the website will also be useful for other health care professionals (i.e. radiologists, nurses, hepatologists, radiation oncologists, family doctors) and educators because it provides a comprehensive resource for teaching liver anatomy. [source]

Sliding multislice MRI for abdominal staging of patients with pelvic malignancies: A pilot study

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2008
Gregor Sommer MS
Abstract Purpose To integrate SMS (sliding multislice imaging technique for acquiring axial images during continuous table motion) into a high-resolution pelvic MRI protocol for additional staging of the entire abdomen within one examination. Materials and Methods Axial two-dimensional images were acquired during continuous table motion using a fat-saturated contrast-enhanced T1-weighted gradient echo sequence. Patients held their breath during the first 20 s of the examination and breathed normally afterward while data acquisition continued. Measurement parameters were adjusted to optimize image quality throughout the total field of view. The method was investigated in 22 patients with pelvic malignancies. Two readers independently compared SMS image quality to conventional abdominal MR images, generated by a stationary multi-breath-hold gradient echo sequence. Results Qualitative evaluation yielded high diagnostic value of SMS data in body regions with no or minor breathing motion, and in those acquired during the initial breath-hold. Image quality in the upper abdomen, retroperitoneum, and pelvis is reproducible and equivalent to stationary MRI. Interfering artifacts are related to the intestine in the mid-abdomen. Conclusion SMS is a promising technique that may have the potential for a first-line abdominal staging tool in patients with pelvic malignancies. J. Magn. Reson. Imaging 2008;27:666,672. © 2008 Wiley-Liss, Inc. [source]