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Chen, Tainsong, Tzu-Pei Chen, and Liang Miin Tsai. "Computerized Quantification Analysis of Left Ventricular Wall Motion from Echocardiograms." Ultrasonic Imaging 19, no. 2 (April 1997): 138–44. http://dx.doi.org/10.1177/016173469701900204.
Повний текст джерелаАнотація:
Two-dimensional echocardiography (2-D echo) imaging is a more attractive clinical tool than other modalities that either involve radiation exposure or are too slow to image heart motion in real-time. Computer-aided analysis of left ventricular (LV) wall motion provides quantitative parameters for diagnosis. This study presents a computerized model for quantitative analysis of left ventricular wall motion from two-dimensional echocardiography by the application of image processing algorithms, including automatic threshold estimation, contrast stretching, boundary detection and border smoothing. The wall motion measurements rely primarily on sequential changes from end-diastolic to end-systolic frames in the left ventricular contours of apical four-chamber view echocardiograms. Left ventricular wall motion was analyzed on the 30 segments of 5 patients with acute myocardial infarction. The results from the computerized model were compared to those obtained from qualitative analysis of echocardiograms by an experienced clinical cardiologist who was unaware of the results of quantitative data.
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Yamashita, Mary, Rachel F. Brem, Lauren Baker, Taylor F. Mahoney, Patrick Walker, Rachel M. Treat, and Linda Hovanessian Larsen. "Abstract P3-04-13: Patient experience with automated SoftVue 3D whole breast tomographic ultrasound." Cancer Research 83, no. 5_Supplement (March 1, 2023): P3–04–13—P3–04–13. http://dx.doi.org/10.1158/1538-7445.sabcs22-p3-04-13.
Повний текст джерелаАнотація:
Abstract Authors: Mary Yamashita, MD; Rachel Brem, MD; Lauren Baker, Ph.D; MD; Taylor Mahoney, PhD; Patrick Walker, PharmD, MPH; Rachel Treat, MA; Linda Hovanessian Larsen, MD. Title: Patient experience with automated SoftVue 3D whole breast tomographic ultrasound. Purpose: SoftVue (SV) is an automated, 3D whole breast ultrasound tomographic imaging device which is FDA PMA approved as adjunct to mammography for women with dense breasts. Screening with handheld US is labor intensive and with ABUS is associated with significant patient discomfort. A benefit of SV is that image acquisition is not operator dependent and does not require compression. Because acceptance by patients is crucial to implementation of US screening, we evaluated patients’ experience with SV, specifically, asymptomatic women with BI-RADS c or d density undergoing FFDM. Materials and Methods: As part of a prospective, 10-site study, 7,439 asymptomatic women with BI-RADS density category c or d were screened on the same day with FFDM and SV. Each patient’s experience was assessed for perceived pain, discomfort and anxiety, discretion and modesty, overall satisfaction, and whether they would recommend it to others. The responses were measured on a Likert scale with 5 choices from strongly agree to strongly disagree, then studied by Chi-Squared analysis. Results: The mean age was 53.9 ± 9.7 yo, mostly white women (87.7%). The median BMI was 24.4. Majority had no personal history of breast cancer (97.2%), but 24.8% had a previous biopsy and almost half (46.3%) had a family history of breast cancer. Almost all patients (99.6%) completed the survey. SV was perceived as significantly more comfortable than FFDM (83.7% vs 52.2%, p< 0.001), was painless (94.9% vs 53.1%, p< 0.001), and was associated with less anxiety during the procedure (95.1% vs 79.9, p< 0.001). Lastly, 99.3% felt the experience was private and discreet, and 95% would recommend the SV exam to other women. Conclusion: Pain, fear, anxiety, and modesty concerns are some of the barriers preventing widespread implementation of screening breast US. This data suggests that SV, an FDA PMA approved adjunctive screening exam for women with dense breast tissue, is painless, offers a private and discreet scan that limits anxiety, and is well accepted by patients. Clinical relevance statement: SV is a novel automated US tomographic screening technology that is comfortable, well-accepted, FDA PMA approved, and will likely result in improved implementation of screening breast ultrasound in women with dense breasts. Citation Format: Mary Yamashita, Rachel F. Brem, Lauren Baker, Taylor F. Mahoney, Patrick Walker, Rachel M. Treat, Linda Hovanessian Larsen. Patient experience with automated SoftVue 3D whole breast tomographic ultrasound [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-04-13.
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Frellesen, Claudia, Julian L. Wichmann, Patricia Tischendorf, Jan-Erik Scholtz, Martin Beeres, Thomas J. Vogl, and Ralf W. Bauer. "High-pitch dual-source paranasal sinus CT in agitated patients with maxillofacial trauma: analysis of image quality, motion artifacts, and dose aspects." Acta Radiologica 59, no. 8 (November 6, 2017): 909–16. http://dx.doi.org/10.1177/0284185117740931.
Повний текст джерелаАнотація:
Background Image quality benefits from high-pitch scanning in agitated patients by reducing acquisition time. Purpose To compare image quality and exposure parameters in patients with maxillofacial trauma on second- and third-generation dual-source computed tomography (DSCT). Material and Methods Four groups were compared. Group 1 was examined on second-generation DSCT (120 kV/50 mAs, pitch 3.0). The other three groups were examined on third-generation DSCT. Group 2 was scanned with 120 kV/50 mAs, pitch 2.2. Automated exposure control (AEC) was used in group 3 and group 4 with pitch factors of 2.2 and 3.0, respectively. Images of third-generation DSCT were reconstructed with iterative reconstruction (IR), of second-generation DSCT with filtered back-projection. CTDIvol, acquisition time, and image quality were compared. Results Thirty patients were included in each group. Average CTDIvol (2.76 ± 0.00 mGy, 2.66 ± 0.00 mGy, 0.74 ± 0.23 mGy, and 0.75 ± 0.17 mGy) was significantly lower on third-generation DSCT with AEC ( P < 0.001). Subjective image quality was rated worst in group 4 due to strong high-pitch artifacts, while in the remaining three groups it was rated good or very good with good inter-observer agreement (k > 0.64). Average acquisition time was significantly shorter with third-generation DSCT (0.47 s, 0.36 s, 0.38 s, 0.30 s; P < 0.001). Conclusion Third-generation DSCT yields faster acquisition times and substantial dose reduction with AEC. A pitch of 2.2 should be preferred, as it results in fewer artifacts. If AEC is used, latest IR ensures that diagnostic image quality is guaranteed.
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Fang, W., Y. An, H. Sugimori, S. Kiuch, and T. Kamishima. "POS1391 DEEP LEARNING-BASED PANNUS LOCALIZATION SOFTWARE IN THE HANDS OF INFLAMMATORY ARTHRITIS USING TIME-INTENSITY CURVE (TIC) SHAPE CLASSIFICATION ON DYNAMIC MRI DATASET." Annals of the Rheumatic Diseases 81, Suppl 1 (May 23, 2022): 1036.1–1036. http://dx.doi.org/10.1136/annrheumdis-2022-eular.2196.
Повний текст джерелаАнотація:
BackgroundRheumatoid arthritis (RA) is a chronic inflammatory disease associated with significant functional impairment and disability, linked to inflammatory and structural articular and peri-articular damage [1]. Synovitis is a characteristic feature of RA, and is considered an important factor in disease activity and the best predictive marker of joint damage [2]. Therefore, accurate quantification of synovitis can play an important role in clinical evaluation and treatment serving as a biomarker. Pixel-by-pixel time–intensity curve (TIC) shape analysis is a dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) technique to help visualize differently shaped TICs [3]. Pixels having TIC shape type 4, which is characterized as early enhancement followed by washout phase, were regarded as synovitis pixel [4]. A deep residual network called ResNet-50 model, a convolutional neural network (CNN) that is 50 layers deep, might effectively classify TIC shapes.ObjectivesThis study aimed to develop software that can automatically demonstrate the distribution of enhancing synovial pannus of patients with inflammatory arthritis on DCE-MRI.MethodsModified ResNet-50 was used on MATLAB. Two investigators drew regions of interest (ROIs) of muscle, bone, and synovitis under expert guidance and obtained TICs for each tissue on DCE-MRI of ten rheumatoid patients. Through cross-validation and batch evaluation, we verified the confusion matrices for the performance of the classifier. Then we identified the pixels of enhancing synovial pannus by image classification from the obtained pixel-by-pixel TIC shape and displayed them in color. The software performance was evaluated using a visual assessment on seven hand joints of one patient.Results150 ROIs for muscles, 150 ROIs for bones, and 59 ROIs for synovitis on DCE-MRI of the hand joints were drawn in ten patients and obtained 4049, 3825, and 1041 TIC shape images, respectively. The classifier’s accuracy, precision, sensitivity, and specificity were 99.6%, 99.3%, 98.4%, and 99.7%, respectively. Out of seven joints, four were assessed as good, two as fair, and one as fail.Figure 1.Software performance on contrast enhanced dynamic MRI of the wristConclusionOur classifier showed high accuracy, precision, sensitivity, and specificity. And through the comparison between manual outlining and the result of software, our software had relatively good performance. This automatic software developed using deep learning with CNN might accurately display the enhancing synovial pannus in RA.References[1]Micu MC, Fodor D. Concepts in monitoring the treatment in rheumatoid arthritis- the role of musculoskeletal ultrasound. Part I: synovitis. Med Ultrason. 2015;17(3):367-76.[2]Carotti M, Galeazzi V, Catucci F, Zappia M, Arrigoni F, Barile A, et al. Clinical utility of eco-color-power Doppler ultrasonography and contrast enhanced magnetic resonance imaging for interpretation and quantification of joint synovitis: a review. Acta Biomed. 2018;89(1-s):48-77.[3]Sakashita T, Kamishima T, Kobayashi Y, Sugimori H, Tang M, Sutherland K, et al. Accurate quantitative assessment of synovitis in rheumatoid arthritis using pixel-by-pixel, time-intensity curve shape analysis. Br J Radiol. 2016;89(1061):20151000.[4]Kobayashi Y, Kamishima T, Sugimori H, Ichikawa S, Noguchi A, Kono M, et al. Quantification of hand synovitis in rheumatoid arthritis: Arterial mask subtraction reinforced with mutual information can improve accuracy of pixel-by-pixel time-intensity curve shape analysis in dynamic MRI. J Magn Reson Imaging. 2018.Disclosure of InterestsNone declared
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Kakileti, Siva Teja, Himanshu Madhu, Richa Bansal, Akshita Singh, Sudhakar Sampangi, Bharat Aggarwal, and Geetha Manjunath. "Abstract P3-03-25: An Automated Risk Stratification System for Breast Cancer Screening using Thermalytix." Cancer Research 83, no. 5_Supplement (March 1, 2023): P3–03–25—P3–03–25. http://dx.doi.org/10.1158/1538-7445.sabcs22-p3-03-25.
Повний текст джерелаАнотація:
Abstract Background: As opposed to conventional age-based population-level breast screening strategies, risk-stratified breast screening programs are emerging as a new approach to balanced population screening methodology where the screening frequency and choice of modality (mammography/tomosynthesis or magnetic resonance imaging) is determined based on accurate personalized estimation of an individual’s risk score. A woman identified with low risk can now be screened less frequently, avoiding repeated mammography screening where radiation risk outweighs the benefits in that particular individual. The standard questionnaire based risk stratification is found to be less reliable and imaging based risk stratification mechanisms are being explored in recent years. In this study, we evaluate the performance of a new computer-aided image analysis technique called Thermalytix that automatically generates a personalized risk score using a combination of imaging and questionnaire information for risk stratification of women. Methodology: Thermalytix is an artificial intelligence system that uses thermal imaging and questionnaire data for predicting the risk of breast cancer. Thermalytix analyzes spatio-thermal signatures and vascular patterns in the breast region along with patients’ complaints and age to generate a score called B-Score (or BHARATI Score) which ranges from 1 to 5. B-Score of 1 indicates low risk of malignancy and a B-Score of 5 indicates the highest risk of malignancy. To evaluate the effectiveness of risk stratification using B-Scores, we performed retrospective analysis of thermal and participants’ data acquired from two registered clinical studies. One study (CTRI/2017/10/0 10 115) is a multi-site study conducted in Bangalore, India, and the other study (NCT04688086) is a single site study conducted in Delhi, India. Both these study sites are geographically distant with 2000 KM apart from each other and comprise a diversified population from India. Results: In total, 717 eligible women were considered in this study with age varying from 18 years to 80 years. Reports from standard of care procedures involving mammography, ultrasound and biopsy (as needed), were collectively considered by a radiologist to determine the ground truth for malignancy. Out of 717 women, 85 women were thus concluded as malignant. When used in a blinded fashion, Thermalytix graded 275 women as B-Score 1 (lowest risk), 225 women as B-Score 2, 44 women as B-Score 3, 137 women as B-Score 4 and 36 women as B-Score 5 (highest risk). The fraction of malignancies in the cohorts corresponding to B-Score categories from 1 to 5 were found to be progressively higher (0.36%, 1.33%, 29.55%, 33.58% and 61.11%, respectively) - showing the correctness of the proposed personalized risk scoring methodology. Conclusion: Thermalytix test, a low-cost, radiation-free, contactless and privacy aware test was used as a technique to determine the breast cancer risk of a woman.. The results obtained in the study show that a high B-score of 5 indicates a high risk for malignancy with 61.11% chance of breast cancer. Likewise the lowest B-Score of 1 indicates low risk for malignancy with just 0.36% percentage of women in the cohort found with malignancy. These results combined with other experiential benefits of Thermalytix test makes it a promising risk stratification mechanism enabling differential frequency of screening while balancing the cost and risk versus benefit. Large scale studies, however, need to be conducted to see the ground benefits of the proposed approach in a screening program implementation. Distribution of study population in different risk cohorts Higher risk correlates with higher malignancy rate Citation Format: Siva Teja Kakileti, Himanshu Madhu, Richa Bansal, Akshita Singh, Sudhakar Sampangi, Bharat Aggarwal, Geetha Manjunath. An Automated Risk Stratification System for Breast Cancer Screening using Thermalytix [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-03-25.
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Roysam, Badrinath, Hakan Ancin, Douglas E. Becker, Robert W. Mackin, Matthew M. Chestnut, Gregg M. Ridder, Thomas E. Dufresne, Donald H. Szarowski, and James N. Turner. "Going Beyond 3-D Imaging: Automated 3-D Montaged image Analysis of Cytological Specimens." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 282–83. http://dx.doi.org/10.1017/s0424820100163873.
Повний текст джерелаАнотація:
This paper summarizes recent advances made by this group in the automated three-dimensional (3-D) image analysis of cytological specimens that are much thicker than the depth of field, and much wider than the field of view of the microscope. The imaging of thick samples is motivated by the need to sample large volumes of tissue rapidly, make more accurate measurements than possible with 2-D sampling, and also to perform analysis in a manner that preserves the relative locations and 3-D structures of the cells. The motivation to study specimens much wider than the field of view arises when measurements and insights at the tissue, rather than the cell level are needed.The term “analysis” indicates a activities ranging from cell counting, neuron tracing, cell morphometry, measurement of tracers, through characterization of large populations of cells with regard to higher-level tissue organization by detecting patterns such as 3-D spatial clustering, the presence of subpopulations, and their relationships to each other. Of even more interest are changes in these parameters as a function of development, and as a reaction to external stimuli. There is a widespread need to measure structural changes in tissue caused by toxins, physiologic states, biochemicals, aging, development, and electrochemical or physical stimuli. These agents could affect the number of cells per unit volume of tissue, cell volume and shape, and cause structural changes in individual cells, inter-connections, or subtle changes in higher-level tissue architecture. It is important to process large intact volumes of tissue to achieve adequate sampling and sensitivity to subtle changes. It is desirable to perform such studies rapidly, with utmost automation, and at minimal cost. Automated 3-D image analysis methods offer unique advantages and opportunities, without making simplifying assumptions of tissue uniformity, unlike random sampling methods such as stereology.12 Although stereological methods are known to be statistically unbiased, they may not be statistically efficient. Another disadvantage of sampling methods is the lack of full visual confirmation - an attractive feature of image analysis based methods.
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Clendenen, Steven R. "Needle Placement for Piriformis Injection Using 3-D Imaging." May 2013 3;16, no. 3;5 (May 14, 2013): E301—E310. http://dx.doi.org/10.36076/ppj.2013/16/e301.
Повний текст джерелаАнотація:
Piriformis syndrome is a pain syndrome originating in the buttock and is attributed to 6% – 8% of patients referred for the treatment of back and leg pain. The treatment for piriformis syndrome using fluoroscopy, computed tomography (CT), electromyography (EMG), and ultrasound (US) has become standard practice. The treatment of Piriformis Syndrome has evolved to include fluoroscopy and EMG with CT guidance. We present a case study of 5 successful piriformis injections using 3-D computer-assisted electromagnet needle tracking coupled with ultrasound. A 6-degree of freedom electromagnetic position tracker was attached to the ultrasound probe that allowed the system to detect the position and orientation of the probe in the magnetic field. The tracked ultrasound probe was used to find the posterior superior iliac spine. Subsequently, 3 points were captured to register the ultrasound image with the CT or magnetic resonance image scan. Moreover, after the registration was obtained, the navigation system visualized the tracked needle relative to the CT scan in real-time using 2 orthogonal multi-planar reconstructions centered at the tracked needle tip. Conversely, a recent study revealed that fluoroscopically guided injections had 30% accuracy compared to ultrasound guided injections, which tripled the accuracy percentage. This novel technique exhibited an accurate needle guidance injection precision of 98% while advancing to the piriformis muscle and avoiding the sciatic nerve. The mean (± SD) procedure time was 19.08 (± 4.9) minutes. This technique allows for electromagnetic instrument tip tracking with realtime 3-D guidance to the selected target. As with any new technique, a learning curve is expected; however, this technique could offer an alternative, minimizing radiation exposure. Key words: Piriformis, electromagnetic, ultrasound, fluoroscopy, injection, 3-D imaging.
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van der Hulst, J. M., D. Punzo, and J. B. T. M. Roerdink. "3-D interactive visualisation tools for Hispectral line imaging." Proceedings of the International Astronomical Union 12, S325 (October 2016): 305–10. http://dx.doi.org/10.1017/s174392131700134x.
Повний текст джерелаАнотація:
AbstractUpcoming HI surveys will deliver such large datasets that automated processing using the full 3-D information to find and characterize HI objects is unavoidable. Full 3-D visualization is an essential tool for enabling qualitative and quantitative inspection and analysis of the 3-D data, which is often complex in nature. Here we presentSlicerAstro, an open-source extension of3DSlicer, a multi-platform open source software package for visualization and medical image processing, which we developed for the inspection and analysis of HI spectral line data. We describe its initial capabilities, including 3-D filtering, 3-D selection and comparative modelling.
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Awad, Samer I., and Jesse T. Yen. "3D Strain Imaging Using a Rectilinear 2D Array." Ultrasonic Imaging 29, no. 4 (October 2007): 220–30. http://dx.doi.org/10.1177/016173460702900403.
Повний текст джерелаАнотація:
Under mechanical compression, tissue movements are inherently three-dimensional. 2-D strain imaging can suffer from decorrelation noise caused by out-of-plane tissue movement in elevation. With 3-D strain imaging, all tissue movements can be estimated and compensated, hence minimizing out-of-plane decorrelation noise. Promising 3-D strain imaging results have been shown using 1 -D arrays with mechanical translation in elevation. However, the relatively large slice thickness and mechanical translation can degrade image quality. Using 2-D arrays, an improved elevational resolution can be achieved with electronic focusing. Furthermore, scanning with 2-D arrays is also done electronically, which eliminates the need for mechanical translation. In this paper, we demonstrate the feasibility of 3-D strain imaging using a 4 cm × 4 cm ultrasonic sparse rectilinear 2-D array operating at 5MHz. The signal processing combinations of 2-D or 3-D beamforming followed by 2-D or 3-D strain imaging are studied and compared to each other to evaluate the performance of our 3-D strain imaging system. 3-D beamforming followed by 3-D strain imaging showed best performance in all experiments.
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Sasaki, Katsunari, Kohji Kakefuda, Kenji Masuda, Ging-Ho Hsiue, and Chain-Shu Hsu. "Application of Imaging Plate for Polymer Analysis." Advances in X-ray Analysis 36 (1992): 387–96. http://dx.doi.org/10.1154/s0376030800019005.
Повний текст джерелаАнотація:
AbstractThe Fuji Imaging Plate (IP) is a 2-Dimensional X-ray detector on which a latent X-ray image is stored as a distribution of color centers in a photo-stimulable phosphor(BaFBr:Eu) screen. It has excellent characteristics such as a wide dynamic range of five or more digits and an order of magnitude higher sensitivity than X-ray film. Thus it has been actively used in the field of X-ray single crystal structure analysis.For polymer studies, 2-D information is useful to analyse a sample's orientation or periodic structure, and some system such as 2-D position sensitive detector (PSD) are widely used. But in spite of the superior performance of the IP which will give significant advantages in various measurements, few applications have been reported in this field, because most conventional IP based systems are specialized for the single crystal structure analysis,Therefore we developed the R-AXIS II D (Rigaku Automated X-ray Imaging System II D), an IP reader for general X-ray diffractometry which has a removable IP in order for exposure with external X-ray optics, and software which converts 2-D data to conventional 2theta-intensity or beta-intensity data for analysis of crystallinity or orientation. In this paper, we report the performance of R-AXIS II D and its applications to polymer studies and thin film analyses.
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Turner, J. N., W. hain, D. H. Szarowski, S. Lasek, L. Kam, A. Can, K. Al-Kofahi, and B. Roysam. "Three Dimensional Light Microscopy: Imaging & Corrections for Quantitative Analysis." Microscopy and Microanalysis 5, S2 (August 1999): 522–23. http://dx.doi.org/10.1017/s1431927600015932.
Повний текст джерелаАнотація:
There are several forms of three-dimensional (3-D) light microscopy but all utilize the principle of optical section recording, i.e. the 3-D image is a sequence of two-dimensional (2-D) images called optical sections. The optical sections are particular focal planes formed within the thick specimen and usually correspond to the conventional image projections recorded in a light microscope, referred to as x,y projections. The optical sections are recorded for a sequence of focus- or z-positions. This “stack” of 2-D images is the data set for the 3-D image. If quantitative analysis is to be performed on the 3-D images, the choice of the z-dimension increment between 2-D images is especially important, and its value may be more or less critical depending on the analysis algorithm used. A reasonable starting value for this dimension is the depth-of-field of the objective lens, but the actual value may have to be smaller to optimize the image analysis or larger to decrease the influence of photobleaching. The most photostable dyes should be selected and the specimen should be mounted in index-of-refraction matching media with an antioxidant.The image resolution in all three-dimensions is determined by the 3-D point-spread-function (psf), and as a rough rule of thumb the z-resolution is degraded by a factor of 3 relative to the x,y resolution. To achieve or at least approach isotropic resolution the 3-D image can be deconvolved. Figure 1 shows the 2-D maximum value projection of a 3-D image of a cultured glial cell dual labeled for actin and vinculin before and after deconvolution. The actin fibers and vinculin focal contacts are more clearly resolved after deconvolution. Although a single cultured cell might traditionally be considered a thin object, it is really a thick object if the desired spatial resolution is less than the thickness of the cell. It is desirable to image as deep into a thick object as possible to maximize the tissue volume sampled. However, it has been shown that the image signal decreases with depth into the specimen. Figure 2 demonstrates this effect in a 3-D image of the nuclei of the rat hippocampus that have been labeled with the fluorescent Schiffs reagent acriflavine. In the x,y projection, it is not clear why some nuclei are dimmer than others, but the x,z projection shows that the dimmer ones tend to be deeper in the section. It has been shown that this depth dependent signal attenuation follows the form of an exponential function.
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Mackin, Robert W. "High-speed brightfield 3-D imaging and 3-D image analysis of thick and overlapped cell clusters in cytological preparations." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 218–19. http://dx.doi.org/10.1017/s0424820100168827.
Повний текст джерелаАнотація:
This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.
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Becker, D. E., H. Ancin, B. Roysam, and J. N. Turner. "Fast automated mosaic synthesis method for 2-D/3-D image analysis of specimens much wider than the field of view." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 224–25. http://dx.doi.org/10.1017/s0424820100168852.
Повний текст джерелаАнотація:
We present an efficient, robust, and widely-applicable technique for computational synthesis of wide-area images from a series of overlapping partial views. The synthesized image is the set union of the areas covered by the partial views, and is called the “mosaic”. One application is the laser-scanning confocal microscopy of specimens that are much wider than the field of view of the microscope. Another is imaging of the retinal periphery using a standard fundus imager. This technique can also be used to combine the results of various forms of image analysis, such as cell counting and neuron tracing, to generate large representations that are equivalent to processing the total mosaic, rather than the individual partial views.The synthesis begins by computing a concise set of landmark points for each partial view. The type of landmarks used can vary greatly depending on the application. For instance, in the retinal imaging application, the vascular branching and crossover points are a natural choice. Likewise, the locations of cells in Figs. 1 and 2 provide a natural set of landmarks for joining these images.
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Chen, Jeon-Hor, Yan-Wei Lee, Si-Wa Chan, Dah-Cherng Yeh, and Ruey-Feng Chang. "Breast Density Analysis with Automated Whole-Breast Ultrasound: Comparison with 3-D Magnetic Resonance Imaging." Ultrasound in Medicine & Biology 42, no. 5 (May 2016): 1211–20. http://dx.doi.org/10.1016/j.ultrasmedbio.2015.12.015.
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Hossack, J. A., T. S. Sumanaweera, S. Napel, and J. S. Ha. "Quantitative 3-D diagnostic ultrasound imaging using a modified transducer array and an automated image tracking technique." IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 49, no. 8 (August 2002): 1029–38. http://dx.doi.org/10.1109/tuffc.2002.1026015.
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Margolis, Ryan, Junjie Li, Lokesh Basavarajappa, and Kenneth Hoyt. "Abstract 2469: Image-guided focused ultrasound-mediated drug delivery for improved cancer treatment." Cancer Research 82, no. 12_Supplement (June 15, 2022): 2469. http://dx.doi.org/10.1158/1538-7445.am2022-2469.
Повний текст джерелаАнотація:
Abstract Introduction: The first option for cancer treatment is often chemotherapy. However, studies have shown that only 1% of the injected dose reaches the target cancer as the tumor microenvironment presents a physical barrier for optimal drug delivery. Focused ultrasound (FUS) in combination with microbubble (MB) contrast agents is an emerging therapy to improve drug delivery by temporarily increasing microvascular permeability. This research details the development and testing of a novel ultrasound (US) image-guided FUS system and method for enhancing drug delivery to tumor tissue and volume space with comparison to a 2-dimensional (2-D) US therapeutic technology. Methods: Real-time US therapy was implemented on a programmable US system (Vantage 256, Verasonics Inc) equipped with a dual US transducer configuration for interleaved anatomical imaging and volumetric treatment delivery (HIFU-Plex, Sonic Concepts Inc). Both US imaging and therapeutic transducers are co-registered 128 element arrays with center frequencies of 3.5 and 2.0 MHz, respectively. The latter is a concentric array that enables beam steering in 3-dimensional (3-D) space. US treatment was performed at a peak negative pressure of 0.7 MPa (mechanical index, MI of 0.45), pulse repetition frequency of 10 Hz, and duty cycle of 10%. BALB/c mice (N = 22, Charles River Laboratory) were implanted with 2.0 × 105 breast cancer cells (4T1, ATCC). Once tumors reached 0.6 cm in size, mice were randomly divided into a 3-D or 2-D US therapy group or sham control. US therapy was performed following an intravascular injection of microbubbles (Definity, Lantheus Medical Imaging) and IR-780 dye. Note microbubbles function as a therapeutic mediator whereas the fluorescent dye represents a surrogate small molecule drug. Live animal fluorescent imaging was performed at baseline before US therapy (0 h) and again at 1, 24, and 48 h. Following the 48 h timepoint, animals were euthanized and tumors surgically excised for ex vivo analysis. Results: 3-D US-mediated therapy improved molecular delivery to tumor tissue by 150 and 180% at 24 and 48 h, respectively, when compared to our previously established 2-D US therapeutic approach (p = 0.22) or sham therapy (p = 0.07). A similar trend was observed during ex vivo imaging of excised tumor samples treated with 3-D US therapy as compared to the 2-D US therapeutic approach (p = 0.41) or sham therapy (p = 0.04). Dye extraction further confirmed these observations (p > 0.12). Conclusions: 3-D US therapy improved molecular delivery to the tumor volume compared to our previously established 2-D US-based method as confirmed by a series of optical imaging studies. Citation Format: Ryan Margolis, Junjie Li, Lokesh Basavarajappa, Kenneth Hoyt. Image-guided focused ultrasound-mediated drug delivery for improved cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2469.
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Romijn, R. L., B. J. Oosterveld, and J. M. Thijssen. "Phase-Derivative Imaging I: Methods and Stabilization Analysis." Ultrasonic Imaging 9, no. 3 (July 1987): 147–61. http://dx.doi.org/10.1177/016173468700900301.
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The potential of using the phase derivative (PD) for echographic imaging was investigated. The PD data were calculated by four methods: zero crossing (ZCS) with squelch addition, analytic signal either with squelch addition (ASS) or with employment of a Wiener kernel (ASW), and unwrapped phase (UWP). The large peaks which occur in an unprocessed PD signal were “stabilized” by some kind of smoothing algorithm. The effects of the amplitude of the squelch signal and of the degree of smoothing were systematically investigated for experimental and simulated 1-D and 2-D rf echograms. The optimal pictures obtained for all four PD estimation methods were compared to the amplitude modulated (AM) image obtained from the same rf data. It is concluded that three different PD images can be derived: AM dominated (ZCS, ASS), mixed AM-PD (ASW) and pure PD (UWP) images. Some preliminary conclusions regarding the potential of PD imaging for medical diagnostics were drawn. These conclusions were based on quantitative 1st order statistics and on a qualitative assessment of 2nd order statistics of the PD image texture.
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Alanen, A., S. Bondestam, and M. Komu. "Artifacts in MR Imaging Caused by Small Quantities of Powdered Iron." Acta Radiologica 36, no. 1 (January 1995): 92–95. http://dx.doi.org/10.1177/028418519503600117.
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The MR image artifacts caused by minute metallic particles were investigated by imaging small powdered iron quantities from 0.01 mg to 1.7 mg in water phantoms. Images with T1-weighted GRE 3-D and T2-weighted SE 2-D sequences were reconstructed with 5 MR imagers: at 0.04 T., 0.1 T (2 scanners), 1.0 T and 1.5 T. In GRE 3-D images the artifacts were round, clearly demarcated black areas, whereas in SE 2-D images artifact areas were elliptic and surrounded by a bright irregular rim with ghost veils in the direction of frequency encoding. The area of the artifact increased slightly up to 0.1 mg of iron, but grew clearly with larger samples. It appeared to behave independently on the MR imager system for all iron samples. This study shows that even microscopic magnetic particles cause a notable distortion in the MR image independently of the MR equipment used.
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Wertheim, D., G. Gillmore, L. Brown, and N. Petford. "3-D imaging of particle tracks in solid state nuclear track detectors." Natural Hazards and Earth System Sciences 10, no. 5 (May 20, 2010): 1033–36. http://dx.doi.org/10.5194/nhess-10-1033-2010.
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Abstract. It has been suggested that 3 to 5% of total lung cancer deaths in the UK may be associated with elevated radon concentration. Radon gas levels can be assessed using CR-39 plastic detectors which are often assessed by 2-D image analysis of surface images. 3-D analysis has the potential to provide information relating to the angle at which alpha particles impinge on the detector. In this study we used a "LEXT" OLS3100 confocal laser scanning microscope (Olympus Corporation, Tokyo, Japan) to image tracks on five CR-39 detectors. We were able to identify several patterns of single and coalescing tracks from 3-D visualisation. Thus this method may provide a means of detailed 3-D analysis of Solid State Nuclear Track Detectors.
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Wang, Xingwei, Xiaodong Chen, Yuhua Li, Hong Liu, Shibo Li, Roy R. Zhang, and Bin Zheng. "FluorescenceIn SituHybridization (FISH) Signal Analysis Using Automated Generated Projection Images." Analytical Cellular Pathology 35, no. 5-6 (2012): 395–405. http://dx.doi.org/10.1155/2012/248158.
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Fluorescencein situhybridization (FISH) tests provide promising molecular imaging biomarkers to more accurately and reliably detect and diagnose cancers and genetic disorders. Since current manual FISH signal analysis is low-efficient and inconsistent, which limits its clinical utility, developing automated FISH image scanning systems and computer-aided detection (CAD) schemes has been attracting research interests. To acquire high-resolution FISH images in a multi-spectral scanning mode, a huge amount of image data with the stack of the multiple three-dimensional (3-D) image slices is generated from a single specimen. Automated preprocessing these scanned images to eliminate the non-useful and redundant data is important to make the automated FISH tests acceptable in clinical applications. In this study, a dual-detector fluorescence image scanning system was applied to scan four specimen slides with FISH-probed chromosome X. A CAD scheme was developed to detect analyzable interphase cells and map the multiple imaging slices recorded FISH-probed signals into the 2-D projection images. CAD scheme was then applied to each projection image to detect analyzable interphase cells using an adaptive multiple-threshold algorithm, identify FISH-probed signals using a top-hat transform, and compute the ratios between the normal and abnormal cells. To assess CAD performance, the FISH-probed signals were also independently visually detected by an observer. The Kappa coefficients for agreement between CAD and observer ranged from 0.69 to 1.0 in detecting/counting FISH signal spots in four testing samples. The study demonstrated the feasibility of automated FISH signal analysis that applying a CAD scheme to the automated generated 2-D projection images.
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Hartov, Alexander, Symma D. Eisner, W. Roberts, Keith D. Paulsen, Leah A. Platenik, and Michael I. Miga. "Error analysis for a free-hand three-dimensional ultrasound system for neuronavigation." Neurosurgical Focus 6, no. 3 (March 1999): E7. http://dx.doi.org/10.3171/foc.1999.6.3.8.
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Image-guided neurosurgery that is directed by a preoperative imaging study, such as magnetic resonance (MR) imaging or computerized tomography (CT) scanning, can be very accurate provided no significant changes occur during surgery. A variety of factors known to affect brain tissue movement are not reflected in the preoperative images used for guidance. To update the information on which neuronavigation is based, the authors propose the use of three-dimensional (3-D) ultrasound images in conjunction with a finite-element computational model of the deformation of the brain. The 3-D ultrasound system will provide real-time information on the displacement of deep structures to guide the mathematical model. This paper has two goals: first, to present an outline of steps necessary to compute the location of a feature appearing in an ultrasound image in an arbitrary coordinate system; and second, to present an extensive evaluation of this system's accuracy. The authors have found that by using a stylus rigidly coupled to the 3-D tracker's sensor, they were able to locate a point with an overall error of 1.36 ± 1.67 mm (based on 39 points). When coupling the tracker to an ultrasound scanhead, they found that they could locate features appearing on ultrasound images with an error of 2.96 ± 1.85 mm (total 58 features). They also found that when registering a skull phantom to coordinates that were defined by MR imaging or CT scanning, they could do so with an error of 0.86 ± 0.61 mm (based on 20 coordinates). Based on their previous finding of brain shifts on the order of 1 cm during surgery, the accuracy of their system warrants its use in updating neuronavigation imaging data.
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Aach, T., H. Witte, and T. M. Lehmann. "Sensor, Signal and Image Informatics." Yearbook of Medical Informatics 15, no. 01 (August 2006): 57–67. http://dx.doi.org/10.1055/s-0038-1638479.
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SummaryThe number of articles published annually in the fields of biomedical signal and image acquisition and processing is increasing. Based on selected examples, this survey aims at comprehensively demonstrating the recent trends and developments.Four articles are selected for biomedical data acquisition covering topics such as dose saving in CT, C-arm X-ray imaging systems for volume imaging, and the replacement of dose-intensive CTbased diagnostic with harmonic ultrasound imaging. Regarding biomedical signal analysis (BSA), the four selected articles discuss the equivalence of different time-frequency approaches for signal analysis, an application to Cochlea implants, where time-frequency analysis is applied for controlling the replacement system, recent trends for fusion of different modalities, and the role of BSA as part of a brain machine interfaces. To cover the broad spectrum of publications in the field of biomedical image processing, six papers are focused. Important topics are content-based image retrieval in medical applications, automatic classification of tongue photographs from traditional Chinese medicine, brain perfusion analysis in single photon emission computed tomography (SPECT), model-based visualization of vascular trees, and virtual surgery, where enhanced visualization and haptic feedback techniques are combined with a sphere-filled model of the organ.The selected papers emphasize the five fields forming the chain of biomedical data processing: (1) data acquisition, (2) data reconstruction and pre-processing, (3) data handling, (4) data analysis, and (5) data visualization. Fields 1 and 2 form the sensor informatics, while fields 2 to 5 form signal or image informatics with respect to the nature of the data considered.Biomedical data acquisition and pre-processing, as well as data handling, analysis and visualization aims at providing reliable tools for decision support that improve the quality of health care. Comprehensive evaluation of the processing methods and their reliable integration in routine applications are future challenges in the field of sensor, signal and image informatics.
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Mitchell, Drew, Samantha Buszek, Benjamin Tran, Maguy Farhat, Jodi Goldman, Lily Erickson, Brandon Curl, et al. "Managing the effect of magnetic resonance imaging pulse sequence on radiomic feature reproducibility in the study of brain metastases." F1000Research 11 (August 4, 2022): 892. http://dx.doi.org/10.12688/f1000research.122871.1.
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Background: Despite the promise of radiomics studies, their limited reproducibility has hindered meaningful clinical translation. Variability in study designs as well as image acquisition and processing contribute to unreproducible radiomic results. This work’s purpose was to (i) quantitatively compare variability of radiomic features extracted from 2-D spin echo (SE) and 3-D spoiled gradient echo (SPGR) T1-weighted post-contrast magnetic resonance (MR) images of brain metastases acquired within the same patient in a single imaging session, and (ii) provide a framework to inform data acquisition for reproducible radiomics studies. Methods: A retrospective cohort of 29 patients with pathologically-confirmed brain metastases and contrast-enhanced T1-weighted MR images acquired using 2-D SE and 3-D SPGR sequences within one exam was identified. Metastases were segmented twice by different physicians using semi-automated methods. Radiomic features were extracted using PyRadiomics for 264 preprocessing variable combinations. Lin’s concordance correlation coefficient (CCC) was computed between features extracted from images acquired by both pulse sequences and different tumor segmentations. Results: We provided general recommendations to improve MR-based radiomic feature reproducibility by clustering and identifying low-concordance features and processing variables. Median CCC between 2-D SE and 3-D SPGR (measuring feature agreement between pulse sequences) was greater for fixed bin count intensity discretization (0.76 versus 0.63) and specific high-concordance features (0.74 versus 0.53). Applying all recommendations improved median CCC from 0.51 to 0.79. Median CCC between contours (measuring feature sensitivity to inter-observer variability) was higher for 2-D SE (0.93 versus 0.86) but improved to 0.93 for 3-D SPGR after low-concordance feature exclusion. Conclusions: The following recommendations are proposed to improve reproducibility: 1) Fixed bin count intensity discretization for all studies, 2) for studies with 2-D and 3-D datasets, excluding high-variability features from downstream analyses, 3) when segmentation is manual or semi-automated, using only 2-D SE images or excluding features susceptible to segmentation variability.
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Liu, Weiping, John W. Sedat, and David A. Agard. "EMCAT: An automatic image-processing system for electron-microscopic tomography." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 418–19. http://dx.doi.org/10.1017/s0424820100169821.
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Any real world object is three-dimensional. The principle of tomography, which reconstructs the 3-D structure of an object from its 2-D projections of different view angles has found application in many disciplines. Electron Microscopic (EM) tomography on non-ordered structures (e.g., subcellular structures in biology and non-crystalline structures in material science) has been exercised sporadically in the last twenty years or so. As vital as is the 3-D structural information and with no existing alternative 3-D imaging technique to compete in its high resolution range, the technique to date remains the kingdom of a brave few. Its tedious tasks have been preventing it from being a routine tool. One keyword in promoting its popularity is automation: The data collection has been automated in our lab, which can routinely yield a data set of over 100 projections in the matter of a few hours. Now the image processing part is also automated. Such automations finish the job easier, faster and better.
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Remeijer, Peter, Erik Geerlof, Lennert Ploeger, Kenneth Gilhuijs, Marcel van Herk, and Joos V. Lebesque. "3-D portal image analysis in clinical practice: an evaluation of 2-D and 3-D analysis techniques as applied to 30 prostate cancer patients." International Journal of Radiation Oncology*Biology*Physics 46, no. 5 (March 2000): 1281–90. http://dx.doi.org/10.1016/s0360-3016(99)00468-x.
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Maurer, Hansruedi, and Christian Hauck. "Geophysical imaging of alpine rock glaciers." Journal of Glaciology 53, no. 180 (2007): 110–20. http://dx.doi.org/10.3189/172756507781833893.
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AbstractSlope instabilities caused by the disappearance of ice within alpine rock glaciers are an issue of increasing concern. Design of suitable counter-measures requires detailed knowledge of the internal structures of rock glaciers, which can be obtained using geophysical methods. We examine benefits and limitations of diffusive electromagnetics, geoelectrics, seismics and ground-penetrating radar (georadar) for determining the depth and lateral variability of the active layer, the distributions of ice and water, the occurrence of shear horizons and the bedrock topography. In particular, we highlight new developments in data acquisition and data analysis that allow 2-D or even 3-D structures within rock glaciers to be imaged. After describing peculiarities associated with acquiring appropriate geophysical datasets across rock glaciers and emphasizing the importance of state-of-the-art tomographic inversion algorithms, we demonstrate the applicability of 2-D imaging techniques using two case studies of rock glaciers in the eastern Swiss Alps. We present joint interpretations of geoelectric, seismic and georadar data, appropriately constrained by information extracted from boreholes. A key conclusion of our study is that the different geophysical images are largely complementary, with each image resolving a different suite of subsurface features. Based on our results, we propose a general template for the cost-effective and reliable geophysical characterization of mountain permafrost.
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Munkvold, Bodil Karoline Ravn, Hans Kristian Bø, Asgeir Store Jakola, Ingerid Reinertsen, Erik Magnus Berntsen, Geirmund Unsgård, Sverre Helge Torp, and Ole Solheim. "Tumor Volume Assessment in Low-Grade Gliomas: A Comparison of Preoperative Magnetic Resonance Imaging to Coregistered Intraoperative 3-Dimensional Ultrasound Recordings." Neurosurgery 83, no. 2 (August 10, 2017): 288–96. http://dx.doi.org/10.1093/neuros/nyx392.
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Abstract BACKGROUND Image guidance based on magnetic resonance imaging (MRI) and/or ultrasound (US) is widely used to aid decision making in glioma surgery, but tumor delineation based on these 2 modalities does not always correspond. OBJECTIVE To analyze volumes of diffuse low-grade gliomas (LGGs) based on preoperative 3-D FLAIR MRIs compared to intraoperative 3-D US image recordings to quantitatively assess potential discrepancies between the 2 imaging modalities. METHODS Twenty-three patients with supratentorial WHO grade II gliomas undergoing primary surgery guided by neuronavigation based on preoperative FLAIR MRI and navigated 3-D US were included. Manual volume segmentation was performed twice in 3-D Slicer version 4.0.0 to assess intrarater variabilities and compare modalities with regard to tumor volume. Factors possibly related to correspondence between MRI and US were also explored. RESULTS In 20 out of 23 patients (87%), the LGG tumor volume segmented from intraoperative US data was smaller than the tumor volume segmented from the preoperative 3-D FLAIR MRI. The median difference between MRI and US volumes was 7.4 mL (range: −4.9-58.7 mL, P < .001) with US LGG volumes corresponding to a median of 74% (range: 42%-183%) of the MRI LGG volumes. However, there was considerable intraobserver variability for US volumes. The correspondence between MRI and US data was higher for astrocytomas (92%). CONCLUSION The tumor volumes of LGGs segmented from intraoperative US images were most often smaller than the tumor volumes segmented from preoperative MRIs. There was a much better match between the 2 modalities in astrocytomas.
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Shima, Hiromasa. "2-D and 3-D resistivity image reconstruction using crosshole data." GEOPHYSICS 57, no. 10 (October 1992): 1270–81. http://dx.doi.org/10.1190/1.1443195.
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Theoretical changes in the distribution of electrical potential near subsurface resistivity anomalies have been studied using two resistivity models. The results suggest that the greatest response from such anomalies can be observed with buried electrodes, and that the resistivity model of a volume between boreholes can be accurately reconstructed by using crosshole data. The distributive properties of crosshole electrical potential data obtained by the pole‐pole array method have also been examined using the calculated partial derivative of the observed apparent resistivity with respect to a small cell within a given volume. The results show that for optimum two‐dimensional (2-D) and three‐dimensional (3-D) target imaging, in‐line data and crossline data should be combined, and an area outside the zone of exploration should be included in the analysis. In this paper, the 2-D and 3-D resistivity images presented are reconstructed from crosshole data by the combination of two inversion algorithms. The first algorithm uses the alpha center method for forward modeling and reconstructs a resistivity model by a nonlinear least‐squares inversion. Alpha centers express a continuously varying resistivity model, and the distribution of the electrical potential from the model can be calculated quickly. An initial general model is determined by the resistivity backprojection technique (RBPT) prior to the first inversion step. The second process uses finite elements and a linear inversion algorithm to improve the resolution of the resistivity model created by the first step. Simple 2-D and 3-D numerical models are discussed to illustrate the inversion method used in processing. Data from several field studies are also presented to demonstrate the capabilities of using crosshole resistivity exploration techniques. The numerical experiments show that by using the combined reconstruction algorithm, thin conductive layers can be imaged with good resolution for 2-D and 3-D cases. The integration of finite‐element computations is shown to improve the image obtained by the alpha center inversion process for 3-D applications. The first field test uses horizontal galleries to evaluate complex 2-D features of a zinc mine. The second field test illustrates the use of three boreholes at a dam site to investigate base rock features and define the distribution of an altered zone in three dimensions.
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Liu, Weiping, Jennifer Fung, W. J. de Ruijter, Hans Chen, John W. Sedat, and David A. Agard. "Automated electron tomography: from data collection to image processing." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 26–27. http://dx.doi.org/10.1017/s0424820100136507.
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Electron tomography is a technique where many projections of an object are collected from the transmission electron microscope (TEM), and are then used to reconstruct the object in its entirety, allowing internal structure to be viewed. As vital as is the 3-D structural information and with no other 3-D imaging technique to compete in its resolution range, electron tomography of amorphous structures has been exercised only sporadically over the last ten years. Its general lack of popularity can be attributed to the tediousness of the entire process starting from the data collection, image processing for reconstruction, and extending to the 3-D image analysis. We have been investing effort to automate all aspects of electron tomography. Our systems of data collection and tomographic image processing will be briefly described.To date, we have developed a second generation automated data collection system based on an SGI workstation (Fig. 1) (The previous version used a micro VAX). The computer takes full control of the microscope operations with its graphical menu driven environment. This is made possible by the direct digital recording of images using the CCD camera.
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Russ, J. Christian, and John C. Russ. "3-D image analysis of serial focal sections from confocal scanning laser microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 152–53. http://dx.doi.org/10.1017/s0424820100152732.
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The Confocal Scanning Laser Microscope (CSLM) is used in two quite different imaging modes: reflection and transmission. Most instruments maintain their confocal optics only when operated in reflection mode, in which light reflected or emitted from points in the sample or on its surface, lying in the focal plane of the microscope, is detected to form an image. Point elevations can be measured by scanning through a range of focal distances. Recording in memory the maximum brightness at each pixel forms an image containing the “in-focus” information for the entire irregular surface or object (Figure 1). These are powerful capabilities and account for much of the current use of confocal microscopes for metrology of rough surfaces, and for use with fluorescent dyes.True transmission confocal imaging can be achieved by passing the light from the source through the specimen to a mirror, reflecting it back through the specimen again (maintaining the focus in the same plane), and thence to the detector. This is shown schematically in Figure 2. This is only possible with monochromatic light, because of sample-induced chromatic aberrations.
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Roysam, Badrinath, Anoop K. Bhattacharjya, Hakan Ancin, Andrew R. Cohen, Robert W. Mackin, Douglas E. Becker, and Carlos Rodriguez. "Intelligent computational 3-D microscopy: New results in segmentation, noise removal, cell counting, and automated neuron tracing." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 160–61. http://dx.doi.org/10.1017/s0424820100146643.
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This paper presents a review of recent advances made by us in the broad area of intelligent computational 3-D microscopy. This research involves the development and application of automated pattern recognition, computer vision and image interpretation algorithms to problems in 3-D biological microscopy. The broad goal of this work is to develop computational tools for rapid, unsupervised, flexible, quantitative and unbiased analysis of large sets of complex 3-D images of thick biological specimens. The imaging modalities used in this work have thus far involved laser-scanning confocal microscopy (LSCM) and 3-D brightfield microscopy. The specimens of interest have been thick slices of brain tissue, large selectively-stained neurons, indocyanin green and fluorescein retinal angiograms, and duck overlapping cell clusters in cytological preparations such as Papanicolaou smears.Image segmentation is an essential first step for most forms of analysis. This task is straightforward when the image data is isotropic, has uniform high contrast, and is free of noise.
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Savioli, Nicoló, Enrico Grisan, Silvia Visentin, Erich Cosmi, Giovanni Montana, and Pablo Lamata. "Real-time diameter of the fetal aorta from ultrasound." Neural Computing and Applications 32, no. 11 (December 18, 2019): 6735–44. http://dx.doi.org/10.1007/s00521-019-04646-3.
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AbstractThe automatic analysis of ultrasound sequences can substantially improve the efficiency of clinical diagnosis. This article presents an attempt to automate the challenging task of measuring the vascular diameter of the fetal abdominal aorta from ultrasound images. We propose a neural network architecture consisting of three blocks: a convolutional neural network (CNN) for the extraction of imaging features, a convolution gated recurrent unit (C-GRU) for exploiting the temporal redundancy of the signal, and a regularized loss function, called CyclicLoss, to impose our prior knowledge about the periodicity of the observed signal. The solution is investigated with a cohort of 25 ultrasound sequences acquired during the third-trimester pregnancy check, and with 1000 synthetic sequences. In the extraction of features, it is shown that a shallow CNN outperforms two other deep CNNs with both the real and synthetic cohorts, suggesting that echocardiographic features are optimally captured by a reduced number of CNN layers. The proposed architecture, working with the shallow CNN, reaches an accuracy substantially superior to previously reported methods, providing an average reduction of the mean squared error from 0.31 (state-of-the-art) to 0.09 $$\mathrm{mm}^2$$mm2, and a relative error reduction from 8.1 to 5.3%. The mean execution speed of the proposed approach of 289 frames per second makes it suitable for real-time clinical use.
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Patil, Smitha, and Savita Choudhary. "Deep convolutional neural network for chronic kidney disease prediction using ultrasound imaging." Bio-Algorithms and Med-Systems 17, no. 2 (April 22, 2021): 137–63. http://dx.doi.org/10.1515/bams-2020-0068.
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Abstract Objectives Chronic kidney disease (CKD) is a common disease and it is related to a higher risk of cardiovascular disease and end-stage renal disease that can be prevented by the earlier recognition and diagnosis of individuals at risk. Even though risk factors for CKD have been recognized, the effectiveness of CKD risk classification via prediction models remains uncertain. This paper intends to introduce a new predictive model for CKD using US image. Methods The proposed model includes three main phases “(1) preprocessing, (2) feature extraction, (3) and classification.” In the first phase, the input image is subjected to preprocessing, which deploys image inpainting and median filtering processes. After preprocessing, feature extraction takes place under four cases; (a) texture analysis to detect the characteristics of texture, (b) proposed high-level feature enabled local binary pattern (LBP) extraction, (c) area based feature extraction, and (d) mean intensity based feature extraction. These extracted features are then subjected for classification, where “optimized deep convolutional neural network (DCNN)” is used. In order to make the prediction more accurate, the weight and the activation function of DCNN are optimally chosen by a new hybrid model termed as diversity maintained hybrid whale moth flame optimization (DM-HWM) model. Results The accuracy of adopted model at 40th training percentage was 44.72, 11.02, 5.59, 3.92, 3.92, 3.57, 2.59, 1.71, 1.68, and 0.42% superior to traditional artificial neural networks (ANN), support vector machine (SVM), NB, J48, NB-tree, LR, composite hypercube on iterated random projection (CHIRP), CNN, moth flame optimization (MFO), and whale optimization algorithm (WOA) models. Conclusions Finally, the superiority of the adopted scheme is validated over other conventional models in terms of various measures.
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He, Wenyun, Thomas A. Hamilton, Andrew R. Cohen, Timothy J. Holmes, Christopher Pace, Donald H. Szarowski, James N. Turner, and Badrinath Roysam. "Automated Three-Dimensional Tracing of Neurons in Confocal and Brightfield Images." Microscopy and Microanalysis 9, no. 4 (August 2003): 296–310. http://dx.doi.org/10.1017/s143192760303040x.
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Automated three-dimensional (3-D) image analysis methods are presented for tracing of dye-injected neurons imaged by fluorescence confocal microscopy and HRP-stained neurons imaged by transmitted-light brightfield microscopy. An improved algorithm for adaptive 3-D skeletonization of noisy images enables the tracing. This algorithm operates by performing connectivity testing over large N × N × N voxel neighborhoods exploiting the sparseness of the structures of interest, robust surface detection that improves upon classical vacant neighbor schemes, improved handling of process ends or tips based on shape collapse prevention, and thickness-adaptive thinning. The confocal image stacks were skeletonized directly. The brightfield stacks required 3-D deconvolution. The results of skeletonization were analyzed to extract a graph representation. Topological and metric analyses can be carried out using this representation. A semiautomatic method was developed for reconnection of dendritic fragments that are disconnected due to insufficient dye penetration, an imaging deficiency, or skeletonization errors.
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Ikizyan, Ike A., Stefan Burde, and James F. Leary. "Interactive 3-D image analysis and visualization techniques for FISH-labelled chromosomes in interphase nuclei." Bioimaging 2, no. 1 (March 1994): 41–56. http://dx.doi.org/10.1002/1361-6374(199403)2:1<41::aid-bio4>3.0.co;2-z.
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Ikizyan, Ike A., Stefan Burde, and James F. Leary. "Interactive 3‐D image analysis and visualization techniques for FISH‐labelled chromosomes in interphase nuclei." Bioimaging 2, no. 1 (March 1994): 41–56. http://dx.doi.org/10.1002/1361-6374(199403)2:1<41::aid-bio4>3.3.co;2-q.
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Chauhan, Swarup, Kathleen Sell, Wolfram Rühaak, Thorsten Wille, and Ingo Sass. "CobWeb 1.0: machine learning toolbox for tomographic imaging." Geoscientific Model Development 13, no. 1 (January 31, 2020): 315–34. http://dx.doi.org/10.5194/gmd-13-315-2020.
Повний текст джерелаАнотація:
Abstract. Despite the availability of both commercial and open-source software, an ideal tool for digital rock physics analysis for accurate automatic image analysis at ambient computational performance is difficult to pinpoint. More often, image segmentation is driven manually, where the performance remains limited to two phases. Discrepancies due to artefacts cause inaccuracies in image analysis. To overcome these problems, we have developed CobWeb 1.0, which is automated and explicitly tailored for accurate greyscale (multiphase) image segmentation using unsupervised and supervised machine learning techniques. In this study, we demonstrate image segmentation using unsupervised machine learning techniques. The simple and intuitive layout of the graphical user interface enables easy access to perform image enhancement and image segmentation, and further to obtain the accuracy of different segmented classes. The graphical user interface enables not only processing of a full 3-D digital rock dataset but also provides a quick and easy region-of-interest selection, where a representative elementary volume can be extracted and processed. The CobWeb software package covers image processing and machine learning libraries of MATLAB® used for image enhancement and image segmentation operations, which are compiled into series of Windows-executable binaries. Segmentation can be performed using unsupervised, supervised and ensemble classification tools. Additionally, based on the segmented phases, geometrical parameters such as pore size distribution, relative porosity trends and volume fraction can be calculated and visualized. The CobWeb software allows the export of data to various formats such as ParaView (.vtk), DSI Studio (.fib) for visualization and animation, and Microsoft® Excel and MATLAB® for numerical calculation and simulations. The capability of this new software is verified using high-resolution synchrotron tomography datasets, as well as lab-based (cone-beam) X-ray microtomography datasets. Regardless of the high spatial resolution (submicrometre), the synchrotron dataset contained edge enhancement artefacts which were eliminated using a novel dual filtering and dual segmentation procedure.
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Lontoc-Roy, Melinda, Pierre Dutilleul, Shiv O. Prasher, Liwen Han, and Donald L. Smith. "Computed tomography scanning for three-dimensional imaging and complexity analysis of developing root systems." Canadian Journal of Botany 83, no. 11 (November 2005): 1434–42. http://dx.doi.org/10.1139/b05-118.
Повний текст джерелаАнотація:
To improve our understanding of the role of root systems in soil-based resource acquisition by plants and eventually model it completely, root system complexity must be quantified, in addition to other morphometric traits. In this note, we introduce a new approach in which computed tomography (CT) scan data are collected on crop root systems in three-dimensional (3-D) space nondestructively and noninvasively, thus allowing for repeated measurements and a relevant complexity analysis of root systems. The experimental crop is maize ( Zea mays L.). Four potted seedlings were CT scanned under wet soil conditions on the day of emergence, and each of the two following days. Specifically, a high-resolution X-ray CT scanner formerly used for medical purposes produced 3 × 500 CT images of 0.1 mm thick cross-sections for each seedling. The fractal dimension of each root system on each day was estimated on a skeletonized 3-D image reconstructed from CT scan data. We found that the mean fractal dimension value was not significantly greater than 1 on day 1 (1.015 ± 0.015), contrary to days 2 and 3 (1.037 ± 0.015, 1.065 ± 0.016). Our results, including original 3-D images, provide support for a novel type of root system studies based on the collection and advanced analysis of CT scan data.
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Segedin, Barbara, Jasenka Gugic, and Primoz Petric. "Uterine perforation – 5-year experience in 3-D image guided gynaecological brachytherapy at Institute of Oncology Ljubljana." Radiology and Oncology 47, no. 2 (June 1, 2013): 154–60. http://dx.doi.org/10.2478/raon-2013-0030.
Повний текст джерелаАнотація:
Background. Accurate applicator placement is a precondition for the success of gynaecological brachytherapy (BT). Unrecognized uterine perforation can lead to bleeding, infection, high doses to pelvic organs and underdosage of the target volume, resulting in acute morbidity, long-term complications and reduced chance of cure. We aimed to assess the incidence and clinical characteristics of our cases with uterine perforation, review their management and impact on the treatment course. Patients and methods. In all patients, treated with utero-vaginal image guided BT for gynaecological cancer between January 2006 and December 2011, the CT/MR images with the applicator in place were reviewed. The incidence of uterine perforations was recorded. Clinical factors that may have predisposed to increased risk of perforation were recorded. Management of perforations and their impact on treatment course was assessed. Results. 219 patients (428 applications) were suitable for analysis. Uterine perforation was found in 13 (3.0%) applications in 10 (4.6%) patients. The most frequent perforation site was posterior uterine wall (n = 9), followed by anterior wall (n = 2) and fundus (n = 2). All cases were managed conservatively, without complications. Prophylactic antibiotics were administered in 8 cases. In 4 patients, abdominal and/or transrectal ultrasound (US) guidance was used on subsequent applications for applicator insertion; adequate applicator placement was achieved and treatment completed as planned in all cases. Conclusions. 3D imaging for BT planning enables accurate identification of uterine perforations. The incidence of perforations at our department is one of the lowest reported in the literature. US guidance of applicator insertion is useful and feasible, allowing to complete the planned treatment even in challenging cases.
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NILSSON, OLA, MARTIN REIMERS, KEN MUSETH, and ANDERS BRUN. "A NEW ALGORITHM FOR COMPUTING RIEMANNIAN GEODESIC DISTANCE IN RECTANGULAR 2-D AND 3-D GRIDS." International Journal on Artificial Intelligence Tools 22, no. 06 (December 2013): 1360020. http://dx.doi.org/10.1142/s0218213013600208.
Повний текст джерелаАнотація:
We present a novel way to efficiently compute Riemannian geodesic distance over a two- or three-dimensional domain. It is based on a previously presented method for computation of geodesic distances on surface meshes. Our method is adapted for rectangular grids, equipped with a variable anisotropic metric tensor. Processing and visualization of such tensor fields is common in certain applications, for instance structure tensor fields in image analysis and diffusion tensor fields in medical imaging. The included benchmark study shows that our method provides significantly better results in anisotropic regions in 2-D and 3-D and is faster than current stat-of-the-art solvers in 2-D grids. Additionally, our method is straightforward to code; the test implementation is less than 150 lines of C++ code. The paper is an extension of a previously presented conference paper and includes new sections on 3-D grids in particular.
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Brenan, Colin J. H., Ian W. Hunter, and Michael J. Korenberg. "Volumetric Raman Spectral Imaging With a Confocal Raman Microscope: Image Modalities and Applications." Microscopy and Microanalysis 3, S2 (August 1997): 819–20. http://dx.doi.org/10.1017/s1431927600010989.
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Confocal Raman microscopy is an invaluable tool for non-invasive three-dimensional (3-D) analysis and visualization of chemically heterogeneous samples. The confocal Raman microscope (CRM) combines focused laser illumination with spatially filtered detection to define in the sample a localized volume element (voxel) from which scattered or reflected light is detected. Attenuation of light from outside the voxel by the pinhole spatial filter increases image contrast and results in voxel sizes typically <10−18 m3. Moving the specimen relative to the voxel and recording the scattered light Raman spectrum at each scan position generates a Raman spectrally-encoded 3-D sample image for non-invasive in situ differentiation between optically similar yet chemically distinct materials.The motivation for the present work stems from our application of continuum modeling techniques as the mathematical framework for development of physiologically realistic biosystem models. A Type 2 correlation-based confocal scanning laser microscope (CSLM) integrated with a high performance, parallel-drive micro-motion robot (MR-1) was built for spatially-distributed acquisition of optical and mechanical data within a < 1 mm3 workspace volume.
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Ganesh, K. J., M. Kawasaki, J. P. Zhou, and P. J. Ferreira. "D-STEM: A Parallel Electron Diffraction Technique Applied to Nanomaterials." Microscopy and Microanalysis 16, no. 5 (August 31, 2010): 614–21. http://dx.doi.org/10.1017/s1431927610000334.
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AbstractAn electron diffraction technique called D-STEM has been developed in a transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) instrument to obtain spot electron diffraction patterns from nanostructures, as small as ∼3 nm. The electron ray path achieved by configuring the pre- and postspecimen illumination lenses enables the formation of a 1–2 nm near-parallel probe, which is used to obtain bright-field/dark-field STEM images. Under these conditions, the beam can be controlled and accurately positioned on the STEM image, at the nanostructure of interest, while sharp spot diffraction patterns can be simultaneously recorded on the charge-coupled device camera. When integrated with softwares such as GatanTMSTEM diffraction imaging and Automated Crystallography for TEM or DigistarTM, NanoMEGAS, the D-STEM technique is very powerful for obtaining automated orientation and phase maps based on diffraction information acquired on a pixel by pixel basis. The versatility of the D-STEM technique is demonstrated by applying this technique to nanoparticles, nanowires, and nano interconnect structures.
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Dajani, Khalil F., Sergio Salles-Cunha, and Hugh G. Beebe. "Abdominal Aortic Aneurysm Volume Measurement with Three-Dimensional Ultrasound—A Feasibility Study." Journal for Vascular Ultrasound 27, no. 1 (March 2003): 20–25. http://dx.doi.org/10.1177/154431670302700104.
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Introduction Endoluminal stent grafts are replacing conventional abdominal aortic aneurysm (AAA) surgery in an increasing number of patients in an attempt to minimize morbidity and mortality. Long-term follow-up of endograft-treated AAA demands image-based surveillance to detect endoleak, graft migration, and morphology change in the excluded AAA. AAA diameter is a traditional but simplistic measurement that has inherent flaws and has been shown to be insensitive to changes in AAA sac morphology. Volume measurement, performed by CT data acquisition and computerized postprocessing, has been proposed as the most sensitive index of successful AAA stent graft exclusion. We evaluated two ultrasound (US) volume measuring techniques for AAA volume determination: Virtual Organ Computer-aided AnaLysis (VOCAL) and Multi-Plane Area Summation (MPAS). Methods US images of an endograft-treated AAA were obtained with a commercially available three-dimensional (3-D) scanner. A fast rotating motor inside the probe allowed registration of multiple two-dimensional (2-D) images in real time. Data from these images were assembled in a 3-D dataset. With VOCAL, the 3-D AAA boundaries were identified, and volume was calculated. The operator traced AAA boundaries in six virtual planes selected by the software. With MPAS, aneurysm boundaries were traced in 2-D virtual images perpendicular to the longitudinal axis of the aneurysm obtained every 1 mm. AAA area was calculated and multiplied by this 1-mm step to obtain incremental volumes that were summed to obtain the AAA volume. VOCAL and MPAS volumes were calculated 10 times each for one AAA scan. Results Average AAA volumes were 86.7 ± 3.7 cm3 with VOCAL and 87.6 ± 3.1 cm3 with MPAS. These averages were not statistically significantly different by t test ( p = 0.54). Standard deviation (SD) to average ratio was 4.3% for VOCAL and 3.5% for MPAS. Conclusion Volume of an endograft-treated AAA was successfully measured multiple times with two 3-D US techniques. Volumes obtained were comparable, demonstrating feasible reproducibility.
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Zhang, Tong, Ichirou Yamaguchi, and Hywel Morgan. "Digital Holographic Microscopy." Microscopy and Microanalysis 5, S2 (August 1999): 362–63. http://dx.doi.org/10.1017/s1431927600015130.
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We applied phase-shifting digital holography to microscopy in this paper. At first lensless microscopy is proposed, in which no optical adjustment is necessary. Then, the method is applied to relax the limitation of focal depth in traditional optical microscopy. A theory for image formation and experimental verification using a few specimens are described.keywords: microscopy, digital holography, phase shiftingDue to the finite focal depth of an imaging lens, a limitation to normal optical microscopy-is that, only the 2-dimensional (2-D) information of an object can be obtained at one time. Besides, it is not convenient for quantitative analysis the observed image. Optical sectioning microscopy (OSM) and scanning confocal microscopy (SCM) which use opto-electronic detection have been proposed for quantitative analysis of a 3-D object. However, the former requires critical mechanical adjustment, while the latter uses timeconsuming mechanical 3-D scanning. Holographic microscopy can solve these problems because it can record 3-D information at one time. But, the chemical processing of holograms and the mechanical focusing at the reconstructed images cause more or less trouble. A 3-D imaging technique without use of photographic recording called optical scanning holography has recently been reported. However, there are also some trouble owing to the twin-image noise.
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Bron, Cph, Ph Gremillet, D. Launay, M. Jourliny, HP Gautschi, Th Bächi, and J. Schüpbach. "Scanning Transmission and Computer-Aided Volumic Electron Microscopy: 3D Modeling of Entire Cells by Electronic Imaging." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 468–69. http://dx.doi.org/10.1017/s0424820100181099.
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The digital processing of electron microscopic images from serial sections containing laser-induced topographical references allows a 3-D reconstruction at a depth resolution of 30 to 40 nm of entire cells by the use of image analysis methods, as already demonstrated for Transmission Electron Microscopy (TEM) coupled with a video camera. (Cf ref)We decided to use a Scanning Transmission Electron Microscope (STEM) to get higher contrast and better resolution at medium magnification. The scanning of our specimens at video frequencies is an attractive and easy way to link a STEM with an image processing system (see Fig 1) but the hysteresis of the electronic spools responsible for the magnetic deviation of the scanning electron beam induces deformations of images which have to be modelized and corrected before registration. Computer algorithms developed for image analysis and treatment correct the artifacts caused by the use of STEM and by serial sectioning to automatically reconstruct the third dimension of the cells.(see Figs 2 and 3) They permit the normalization of the images through logarithmic processing of the original grey level information. The automatic extraction of cell limits allows to link the image analysis and treatments with image synthesis methods by minimal human intervention. The surface representation and the registered images provide an ultrastructural data base from which quantitative 3-D morphological parameters, as well as otherwise impossible visualizations, can be computed.
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Li, Meng Jie, Shui Fa Sun, Fang Min Dong, Hong Hai Liu, Yong Hong Shao, and Bruce Z. Gao. "TPEF Cardiomyocyte Image 3-D Cutting and Volume Measuring Based on ImageJ." Advanced Engineering Forum 6-7 (September 2012): 327–32. http://dx.doi.org/10.4028/www.scientific.net/aef.6-7.327.
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ImageJ is an open source image processing and analysis platform developed with Java. It can be applied to the analysis of clinical and scientific image effectively. A group of adult SD rat cardiac myocytes image using two-photon excitation fluorescence (TPEF) polarization imaging system is processed with ImageJ: 1)To achieve a panoramic display of the cardiomyocytes, we adopt 3D Viewer plugin to construct the 3D model; 2)Then, cutting the myocardial cell in any directions allows ones to observe the cell’s internal structure; 3) With the following image processing, contrast enhancement, noise reduction, threshold segmentation, clear boundary of the object is presented; 4) Region of interest (ROI) of each slice is then calculated. The entire volume of the myocardial cell is accumulation of the product of area and scan step. The physical volume of the myocardial cell can be calculated with the relationship of physical unit and image pixel, such as pixels-per-inch (ppi).
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McLaughlin, K. L., J. R. Murphy, and B. W. Barker. "A lithospheric velocity anomaly beneath the Shagan river Test Site. Part 2. Imaging and inversion with amplitude transmission tomography." Bulletin of the Seismological Society of America 82, no. 2 (April 1, 1992): 999–1017. http://dx.doi.org/10.1785/bssa0820020999.
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Abstract A linear inversion procedure is introduced that images weak velocity anomalies using amplitudes of transmitted seismic waves. Using projection operators from geometrical ray theory, an image of an anomaly is constructed from amplitudes recorded at arrays of receivers using arrays of sources. The image is related to the velocity anomaly by a second-order partial-differential equation that is inverted using 2-D discrete Fourier transforms. As an example of the inversion procedure, magnitude residuals for European stations recording Shagan River explosions are used to image the deep lithospheric anomaly beneath the Shagan River test site described in Part 1. This formal inversion analysis confirms the existence of a small-scale lateral heterogeneity located 50 km west-northwest of the test site at a probable depth between 80 and 100 km and indicates that it is consistent with a deterministic 1.5% peak-to-peak (or 0.5% rms) velocity anomaly with a scale length of about 3 km. 3-D dynamic raytracing is then used to verify that the inferred laterally varying structure produces amplitude fluctuations consistent with observations.
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Linton, Richard W. "Direct Imaging of Trace Elements, Isotopes, and Molecules Using Mass Spectrometry." Microscopy and Microanalysis 4, S2 (July 1998): 124–25. http://dx.doi.org/10.1017/s1431927600020742.
Повний текст джерелаАнотація:
Secondary ion mass spectrometry (SIMS) is based upon the energetic ion bombardment of surfaces resulting in in the emission of sputtered particles, including both atomic and molecular ions. The use of mass spectrometric detection provides a highly versatile and sensitive tool for surface and thin film microanalysis. The scope of the technique includes a diversity of analysis modes including:1.Elemental Depth Profiling (dynamic SIMS),2.Laterally Resolved Imaging (ion microprobe or ion microscope analysis),3.Image Depth Profiling (combination of modes 1 and 2 providing 3-D images),4.Molecular Monolayer Analysis and Imaging (static SIMS),5.Sputtered Neutral Mass Spectrometry (post-ionization).Much of the early work in dynamic SIMS centered on depth profiling and imaging techniques, with an emphasis on applications to electronic materials. SIMS has made extensive contributions to semiconductor materials science since the 1960's, including the development of new devices and processes, and in failure analysis.
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Adrov, Victor N., and Victor V. Chernomordik. "Simulation of Two-Dimensional Ultrasonic Imaging of Biological Tissues in the Presence of Phase Aberrations." Ultrasonic Imaging 17, no. 1 (January 1995): 27–43. http://dx.doi.org/10.1177/016173469501700102.
Повний текст джерелаАнотація:
A simulator of phase aberrations for mathematical modeling of two-dimensional (2-D) ultrasonic medical imaging is developed. Principal characteristics of expected phase aberrations were put into the model to investigate the distorting influence of intervening tissues on the quality of conventional medical B-scan images. Information necessary for numerical simulations, including the form of the phase correlation function, correlation length and distortion magnitude, was obtained from analysis of known experimental data on abdominal and breast imaging in vivo. Examples of simulated acoustical images of some simple phantoms are presented. Improvement of image quality due to one simple phase adaptation algorithm is also presented.
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Das, Biswajit, R. Palit, R. Donthi, A. Kundu, S. R. Laskar, P. Dey, D. Negi, et al. "Development of a position-sensitive fast scintillator (LaBr3(Ce)) detector setup for gamma-ray imaging application." EPJ Web of Conferences 253 (2021): 11005. http://dx.doi.org/10.1051/epjconf/202125311005.
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We have characterized a Cerium doped Lanthanum Bromide (LaBr3(Ce) ) crystal coupled with the position-sensitive photo-multiplier system for the gamma-ray imaging application. One can use this detector set-up for the scanning of high purity germanium detectors for pulse shape analysis in gamma-ray spectroscopy experiments and the image formation of an object by Compton back-scattering . The sensor has been tested for energy, timing and position information of the gamma-rays interacting within the detector crystal. The GEANT4 simulation results are consistent with the experimental results. We have reconstructed the image of irradiation spots in different positions throughout the detector crystal. Position resolution is found to be around 3.5 mm with the 2 mm collimated gamma-rays. The 2-d image of hexagonal Bismuth Germanate (BGO) crystal and a cylindrical LaBr3(Ce) crystal have been reconstructed in coincidence technique. The performance of the detector for imaging application has been investigated by coincidence technique in GEANT4 simulation and compared with the experimental data. We have reconstructed the 2-d images of objects with various geometrical shapes by Compton back-scattered events of the gamma-rays. This position-sensitive detector can be used as an absorber of a Compton camera for the image reconstruction of an extended radioactive source. One can also use this kind of set-up as in radiation imaging and many other applications where the energy and source position of the gamma-ray is the main interest.