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artifact on section tissue

Ramón Casero, Urszula Siedlecka, Elizabeth S Jones, Lena Gruscheski, Matthew Gibb, Jürgen E Schneider, Peter Kohl, Vicente Grau
Traditional histology is the gold standard for tissue studies, but it is intrinsically reliant on two-dimensional (2D) images. Study of volumetric tissue samples such as whole hearts produces a stack of misaligned and distorted 2D images that need to be reconstructed to recover a congruent volume with the original sample's shape. In this paper, we develop a mathematical framework called Transformation Diffusion (TD) for stack alignment refinement as a solution to the heat diffusion equation. This general framework does not require contour segmentation, is independent of the registration method used, and is trivially parallelizable...
March 23, 2017: Medical Image Analysis
Monika Pawłowska, Diana Legutko, Marzena Stefaniuk
One of the biggest challenges in neuroscience is to understand how brain operates. For this, it would be the best to image the whole brain with at least cellular resolution, preserving the three-dimensional structure in order to capture the connections between different areas. Most currently available high-resolution imaging techniques are based on preparing thin brain sections that are next photographed one by one and subsequently bigger structures are reconstructed. These techniques are laborious and create artifacts...
2017: Postepy Biochemii
Lu Ding, Xose Luis Dean Ben, Neal C Burton, Robert W Sobol, Vasilis Ntziachristos, Daniel Razansky
Accurate extraction of physical and biochemical parameters from optoacoustic images is often impeded due to the use of unrigorous inversion schemes, incomplete tomographic detection coverage or other experimental factors that cannot be readily accounted for during the image acquisition and reconstruction process. For instance, inaccurate assumptions in the physical forward model may lead to negative optical absorption values in the reconstructed images. Any artifacts present in the single wavelength optoacoustic images can be significantly aggravated when performing a two-step reconstruction consisting in acoustic inversion and spectral unmixing aimed at rendering the distributions of spectrally-distinct absorbers...
March 22, 2017: IEEE Transactions on Medical Imaging
Esther Bär, Arthur Lalonde, Gary Royle, Hsiao-Ming Lu, Hugo Bouchard
PURPOSE: Dual-energy CT (DECT) promises improvements in estimating stopping power ratios (SPRs) for proton therapy treatment planning. Although several comparable mathematical formalisms have been proposed in literature, the optimal techniques to characterize human tissue SPRs with DECT in a clinical environment are not fully established. The aim of this work is to compare the most robust DECT methods against conventional single-energy CT (SECT) in conditions reproducing a clinical environment, where CT artifacts and noise play a major role on the accuracy of these techniques...
March 15, 2017: Medical Physics
Jeave Reserva, Zachary Kozel, Cindy Krol, Jodi Speiser, William Adams, Rebecca Tung
Processing of adipose-rich Mohs micrographic surgery (MMS) specimens poses challenges that may preclude complete margin evaluation. In this setting, the value of additional freezing methods using various cooling agents has not been previously investigated. The aim of this study is to compare the frozen section quality of high-adipose Mohs specimens processed without additional cooling treatments versus those pretreated with 1,1,1,2-tetrafluoroethane (TFE) or liquid nitrogen (LN2). A set of 3 sections were each taken from 24 adipose-rich Mohs micrographic surgery specimens...
January 26, 2017: American Journal of Dermatopathology
Marie Albéric, Mason N Dean, Aurélien Gourrier, Wolfgang Wagermaier, John W C Dunlop, Andreas Staude, Peter Fratzl, Ina Reiche
Macroscopic, periodic, dark and bright patterns are observed on sections of elephant tusk, in the dentin part (ivory). The motifs-also called Schreger pattern-vary depending on the orientation in the tusk: on sections perpendicular to the tusk axis, a checkerboard pattern is present whereas on sections longitudinal to it, alternating stripes are observed. This pattern has been used to identify elephant and mammoth ivory in archeological artifacts and informs on the continuous tissue growth mechanisms of tusk...
2017: PloS One
Yang Chen, Adam Budde, Ke Li, Yinsheng Li, Jiang Hsieh, Guang-Hong Chen
PURPOSE: When the scan field of view (SFOV) of a CT system is not large enough to enclose the entire cross-section of the patient, or the patient needs to be positioned partially outside the SFOV for certain clinical applications, truncation artifacts often appear in the reconstructed CT images. Many truncation artifact correction methods perform extrapolations of the truncated projection data based on certain a priori assumptions. The purpose of this work was to develop a novel CT truncation artifact reduction method that directly operates on DICOM images...
January 2017: Medical Physics
Jumpei Kawamura, Shingo Kamoshida, Takaaki Shimakata, Yurie Hayashi, Kuniko Sakamaki, Tamami Denda, Kenji Kawai, Sadahito Kuwao
BACKGROUND: Intraoperative diagnosis of central nervous system (CNS) tumors provides critical guidance to surgeons in the determination of surgical resection margins and treatment. The techniques and preparations used for the intraoperative diagnosis of CNS tumors include frozen sectioning and cytologic methods (squash smear and touch imprint). Cytologic specimens, which do not have freezing artifacts, are important as an adjuvant tool to frozen sections. However, if the amount of submitted tissue samples is limited, then it is difficult to prepare both frozen sections and squash smears or touch imprint specimens from a single sample at the same time...
April 2017: Cancer
Marie-Theres Weil, Torben Ruhwedel, Wiebke Möbius, Mikael Simons
Intracerebral injections are an invasive method to bypass the blood brain barrier and are widely used to study molecular and cellular mechanisms of the central nervous system. The administered substances are injected directly at the site of interest, executing their effect locally. By combining injections in the rat brain with state-of-the-art electron microscopy, subtle changes in ultrastructure of the nervous tissue can be detected prior to overt damage or disease. The protocol presented here involves stereotactic injection into the corpus callosum of Lewis rats and the cryopreparation of freshly dissected tissue for electron microscopy...
January 3, 2017: Current Protocols in Neuroscience
Young-Min Kwon, Sariah Khormaee, Ming Han Lincoln Liow, Tsung-Yuan Tsai, Andrew A Freiberg, Harry E Rubash
BACKGROUND: Modularity in total hip arthroplasty facilitates intraoperative restoration of patient anatomy. Although dual-taper modular total hip arthroplasty offers potential advantages for optimizing the hip center of rotation, it has been associated with modular taper corrosion. This corrosion has led to adverse local tissue reactions (pseudotumors) at the neck-stem junction and elevated metal-ion levels. However, the occurrence of taper-corrosion-related pseudotumors in patients who remain asymptomatic following total hip arthroplasty with a dual-taper modular femoral stem remains largely unknown...
October 19, 2016: Journal of Bone and Joint Surgery. American Volume
Amberly L Nunez, Giovanna A Giannico, Faisal Mukhtar, Virginia Dailey, Rizk El-Galley, Omar Hameed
The utility of routine frozen section (FS) analysis for margin evaluation during radical prostatectomy (RP) remains controversial. A retrospective search was conducted to identify RPs evaluated by FS over a 5-year period. The potential of FS to discriminate between benign and malignant tissue and to predict final margins was evaluated. During the study period, 71 (12.3%) of 575 cases underwent FS evaluation of margins, generating 192 individual FSs. There were 8 FSs diagnosed as atypical/indeterminate because of significant freezing, crushing, and/or thermal artifacts; 11 as positive for carcinoma; and 173 as benign...
October 2016: Annals of Diagnostic Pathology
Euphemia W Mu, Jesse M Lewin, Mary L Stevenson, Shane A Meehan, John A Carucci, Daniel S Gareau
Importance: Confocal microscopy has the potential to provide rapid bedside pathologic analysis, but clinical adoption has been limited in part by the need for physician retraining to interpret grayscale images. Digitally stained confocal mosaics (DSCMs) mimic the colors of routine histologic specimens and may increase adaptability of this technology. Objective: To evaluate the accuracy and precision of 3 physicians using DSCMs before and after training to detect basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in Mohs micrographic surgery fresh-tissue specimens...
December 1, 2016: JAMA Dermatology
Young-Min Kwon
Although dual taper modular-neck total hip arthroplasty (THA) design with additional neck-stem modularity has the potential to optimize hip biomechanical parameters by facilitating adjustments of leg length, femoral neck version and offset, there is increasing concern regarding this stem design as a result of the growing numbers of adverse local tissue reactions due to fretting and corrosion at the neck-stem taper junction. Implant factors such as taper cone angle, taper surface roughness, taper contact area, modular neck taper metallurgy, and femoral head size play important roles in influencing extent of taper corrosion...
July 2016: Journal of Arthroplasty
Pramod K Jali, Mandana Donoghue, Mohsin Gadiwan
BACKGROUND: Surgical pathology is an integral part of diagnosis and management planning in patient care. In the absence of widespread automation, many small laboratories are unable to provide this service due to lack of time. Currently, the shortest processing schedule for formalin-fixed paraffin-embedded tissues is 16 working hours; most small laboratories cannot complete the rapid schedules within the average 8-9 working hours. Thus, the availability of an 8-9 h processing schedule that provide satisfactory results can help many small laboratories in routinely providing surgical pathology services...
September 2015: Journal of Oral and Maxillofacial Pathology: JOMFP
Michal Franek, Jana Suchánková, Petra Sehnalová, Jana Krejčí, Soňa Legartová, Stanislav Kozubek, Josef Večeřa, Dmitry V Sorokin, Eva Bártová
Studies on fixed samples or genome-wide analyses of nuclear processes are useful for generating snapshots of a cell population at a particular time point. However, these experimental approaches do not provide information at the single-cell level. Genome-wide studies cannot assess variability between individual cells that are cultured in vitro or originate from different pathological stages. Immunohistochemistry and immunofluorescence are fundamental experimental approaches in clinical laboratories and are also widely used in basic research...
April 2016: Microscopy and Microanalysis
Jeffrey M Goldstein, Thomas K Fehring, Keith A Fehring
BACKGROUND: The presence of pain as a harbinger of bearing-related problems has recently been challenged. Adverse local tissue reactions (ALTRs) have been noted on cross-sectional imaging even in asymptomatic patients. The purpose of this study was to determine the natural history of such lesions in asymptomatic patients. METHODS: Eighty-three asymptomatic patients with modular metal-on-metal total hip arthroplasties underwent metal ion reports and metal artifact reduction sequence magnetic resonance imaging (MARS MRI)...
July 2016: Journal of Arthroplasty
Young-Min Kwon, Dimitris Dimitriou, Ming Han Lincoln Liow, Tsung-Yuan Tsai, Guoan Li
BACKGROUND: Current guidelines recommend longitudinal monitoring of at-risk metal-on-metal (MoM) arthroplasty patients with cross-sectional imaging such as metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) or ultrasound. During follow-up evaluations, the clinical focus is on the relative interval changes in symptoms, radiographs, laboratory tests, and cross-sectional imaging modalities. Although MRI has the capacity for the detection of adverse local soft tissue reactions (ALTRs), the potential disadvantages of MARS MRI include the obscuration of periprosthetic tissues by metal artifacts and the cost...
August 2016: Journal of Arthroplasty
Kevin Lindgren, Mike B Anderson, Christopher L Peters, Christopher E Pelt, Jeremy M Gililland
BACKGROUND: We sought to assess the prevalence of soft tissue changes seen on magnetic resonance imaging (MRI) after metal-on-metal (MOM) total hip arthroplasty (THA) and determine if the presence of pseudotumors was associated with metal ion levels, acetabular cup position, outcomes scores, and femoral head size. METHODS: After receiving an institutional review board exemption for secondary data analysis, we performed a cross-sectional study identifying 55 patients (55 hips) that underwent primary THA with a MOM articulation and had subsequent MRI imaging between February 2013 and February 2014 at a single academic medical center...
July 2016: Journal of Arthroplasty
Jianguo Zhang, Gang Ji, Xiaojun Huang, Wei Xu, Fei Sun
Cryo-electron tomography (cryo-ET) provides great insights into the ultrastructure of cells and tissues in their native state and provides a promising way to study the in situ 3D structures of macromolecular complexes. However, this technique has been limited on the very thin specimen, which is not applicable for most cells and tissues. Besides cryo-sectioning approach, cryo focused ion beam (cryo-FIB) appeared recently to achieve 'artifact-free' thin frozen hydrated lamella via fabrication. Considering that the current cryo-FIB methods need modified holders or cartridges, here, with a "D-shaped" molybdenum grid and a specific shutter system, we developed a simple cryo-FIB approach for thin frozen hydrated lamella fabrication, which fits both standard transmission cryo-electron microscopes with side-entry cryo-holders and state-of-the-art ones with AutoGrids...
May 2016: Journal of Structural Biology
Fabien Forest, Gilles Thuret, Philippe Gain, Jean-Marc Dumollard, Michel Peoc'h, Chantal Perrache, Zhiguo He
PURPOSE: In the literature, immunohistochemistry on cross sections is the main technique used to study protein expression in corneal endothelial cells (ECs), even though this method allows visualization of few ECs, without clear subcellular localization, and is subject to the staining artifacts frequently encountered at tissue borders. We previously proposed several protocols, using fixation in 0.5% paraformaldehyde (PFA) or in methanol, allowing immunostaining on flatmounted corneas for proteins of different cell compartments...
2015: Molecular Vision
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