scholarly journals DETERMINATION OF THE OPTIMAL SCANNING STEP FOR EVALUATION OF IMAGE RECONSTRUCTION QUALITY IN MAGNETOACOUSTIC TOMOGRAPHY WITH MAGNETIC INDUCTION

2019 ◽  
Vol 9 (4) ◽  
pp. 38-42
Author(s):  
Adam Ryszard Żywica ◽  
Marcin Ziółkowski
Keyword(s):  
Image Reconstruction ◽  
Magnetic Induction ◽  
Imaging Modality ◽  
Biological Tissues ◽  
Non Invasive ◽  
Scanning Step ◽  
Reconstruction Quality ◽  
Complex Shapes

Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) is a new hybrid imaging modality especially dedicated for non-invasive electrical conductivity imaging of low-conductivity objects such as e.g. biological tissues. The purpose of the present paper is to determine the optimal scanning step assuring the best quality of image reconstruction. In order to resolve this problem a special image reconstruction quality indicator based on binarization has been applied. Taking into account different numbers of measuring points and various image processing algorithms, the conditions allowing successful image reconstruction have been provided in the paper. Finally, the image reconstruction examples for objects’ complex shapes have been analyzed.

scholarly journals Detailed Analytical Approach to Solve the Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) Problem for Three-Layer Objects

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6515
Author(s):  
Adam Ryszard Zywica ◽  
Marcin Ziolkowski ◽  
Stanislaw Gratkowski
Keyword(s):  
Image Reconstruction ◽  
Magnetic Induction ◽  
Analytical Approach ◽  
Numerical Solutions ◽  
Separation Of Variables ◽  
Radiation Theory ◽  
Reconstruction Quality ◽  
Complex Shapes ◽  
Analytical Formulas ◽  
Analytical Expressions

This paper is devoted to an analytical approach to the magnetoacoustic tomography with magnetic induction (MAT-MI) problem for three-layer low-conductivity objects. For each layer, we determined closed-form analytical expressions for the eddy current density and Lorentz force vectors based on the separation of variables method. Next, the analytical formulas were validated with numerical solutions obtained with the help of the finite element method (FEM). Based on the acoustic dipole radiation theory, the influence of the transducer reception pattern on MAT-MI was investigated. To obtain acoustic wave patterns, as a system transfer function we proposed the Morlet wavelet. Finally, image reconstruction examples for objects of more complex shapes are presented, and the influence of the MAT-MI scanning resolution and the presence of the noise on the image reconstruction quality was studied in detail.

scholarly journals Metal artifacts in intraoperative O-arm CBCT scans

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juha I. Peltonen ◽  
Touko Kaasalainen ◽  
Mika Kortesniemi
Keyword(s):  
Image Quality ◽  
Imaging Modality ◽  
Nonlinear Effects ◽  
Exposure Level ◽  
Metal Artifacts ◽  
Imaging Protocol ◽  
Metal Implants ◽  
Comprehensive Determination

Abstract Background Cone-beam computed tomography (CBCT) has become an increasingly important medical imaging modality in orthopedic operating rooms. Metal implants and related image artifacts create challenges for image quality optimization in CBCT. The purpose of this study was to develop a robust and quantitative method for the comprehensive determination of metal artifacts in novel CBCT applications. Methods The image quality of an O-arm CBCT device was assessed with an anthropomorphic pelvis phantom in the presence of metal implants. Three different kilovoltage and two different exposure settings were used to scan the phantom both with and without the presence of metal rods. Results The amount of metal artifact was related to the applied CBCT imaging protocol parameters. The size of the artifact was moderate with all imaging settings. The highest applied kilovoltage and exposure level distinctly increased artifact severity. Conclusions The developed method offers a practical and robust way to quantify metal artifacts in CBCT. Changes in imaging parameters may have nonlinear effects on image quality which are not anticipated based on physics.

Adaptive Dual Conjudate Gradient Projection Algorithm for Compressed Sensing Image Reconstruction

2013 ◽  
Vol 347-350 ◽  
pp. 2600-2604
Author(s):  
Hai Xia Yan ◽  
Yan Jun Liu
Keyword(s):  
Image Reconstruction ◽  
Compressed Sensing ◽  
Gradient Projection ◽  
Projection Algorithm ◽  
Sparse Reconstruction ◽  
Reconstruction Method ◽  
Reconstruction Accuracy ◽  
Reconstruction Quality ◽  
Dual Gradient

In order to improve the quality of noise signals reconstruction method, an algorithm of adaptive dual gradient projection for sparse reconstruction of compressed sensing theory is proposed. In ADGPSR algorithm, the pursuit direction is updated in two conjudate directions, the better original signals estimated value is computed by conjudate coefficient. Thus the reconstruction quality is improved. Experiment results show that, compared with the GPSR algorithm, the ADGPSR algorithm improves the signals reconstruction accuracy, improves PSNR of reconstruction signals, and exhibits higher robustness under different noise intensities.

scholarly journals CLINICAL AND X-RAY FEATURES OF PERIODONTIC TISSUES IN PATIENTS WITH GINGIVAL RECESSION

2020 ◽  
Vol 16 (1) ◽  
pp. 81-86
Author(s):  
Rushana Farkhshatova ◽  
Larisa Gerasimova ◽  
Irina Usmanova
Keyword(s):  
Oral Hygiene ◽  
Gingival Recession ◽  
Class I ◽  
Periodontal Tissues ◽  
Non Invasive ◽  
Radiological Data ◽  
Apical Direction ◽  
Number Of Patients

Subject. Gingival recession refers to a form of periodontal disease, which is characterized by a decrease in the free gum without signs of chronic inflammation in the apical direction of the gum and periodontal tissues. The goal is to determine the clinical and radiological features of periodontal tissues in patients with gum recession. Methodology. A comprehensive diagnostic examination was conducted according to a specially developed algorithm of 47 patients aged 20 to 45 years old with a diagnosis of gum recession, which included the collection of anamnestic data, special questionnaires, clinical, radiological and ultrasound examinations of periodontal tissues. Results. According to clinical and radiological data, the diagnosis of gum recession was confirmed in all patients: in 31 (62 %) ― Miller's class I gum recession, in 11 (25 %) ― II, in 5 (11 %) ― III and in 1 (2 %) ― IV. The dependence of the gum recession on the quality of oral hygiene was determined: with satisfactory oral hygiene (OHI-S <2.6), the depth of the gum recession was 1-1.5 mm, with poor (OHI-S> 2.6) ― more than 1,5 mm. In 14 (42.8 %) patients, a concomitant diagnosis of chronic generalized catarrhal gingivitis was established, in 57.2 % of patients with chronic generalized periodontitis. Of the total number of patients, a thin biotype was determined in 30 (63.8 %) patients, and a thick biotype was identified in 17 (36.2 %). A combination of a thin biotype with a small vestibule of the oral cavity, the presence of anomalies of the frenum and strands of the mucous membrane in 23.4 % was revealed. Conclusions. Miller class I gingival recessions have the highest frequency of occurrence (62 %). The ultrasonic research method allowed non-invasive determination of the gingival biotype and gum thickness. A thin biotype of the gum was diagnosed in 63.8 % of patients, which must be taken into account when planning surgical treatment.

Non-invasive determination of the quality of pomegranate fruit

2018 ◽  
Vol 136 ◽  
pp. 74-79 ◽  
Author(s):  
Lisa Czieczor ◽  
Camilla Bentkamp ◽  
Lutz Damerow ◽  
Michael Blanke
Keyword(s):  
Non Invasive ◽  
Pomegranate Fruit

scholarly journals Correcting the infrared images of soft biological tissues

2019 ◽  
Vol 55 (1) ◽  
pp. 110-117
Author(s):  
A. P. Ivanov
Keyword(s):  
Soft Tissues ◽  
Thermal Power ◽  
Spherical Shape ◽  
Biological Tissues ◽  
Thermal Source ◽  
Near Surface ◽  
Non Invasive ◽  
Calculation Results ◽  
Heat Transfer Parameter

Non-invasive (remote) thermographic methods based on IR images are being actively implemented. Using the calculation results of the temperature increment that occurs when a pathological source exists in the person’s skin, a number of ways of solving “inverse problems” are proposed. These include the determination of the depth of the thermal source by measuring the mono or polychrome increment of the normalized brightness of the tissue surface at one point; the source depth and heat transfer parameter by measuring the poly or monochrome one of the normalized brightness (or temperature) at two points; the thermal power of the source by measuring the increment of absolute brightness or temperature at one point; the depth of the thermal source and its size in the near-surface layer by measuring the increment of the normalized brightness at two points. In order to solve these problems, the thermophysical and optical properties of the soft tissues of the biological organism are indicated. Analytical solutions are given for describing the temperature and the glow that arises under its influence from the sources of cylindrical and spherical shape.

scholarly journals Improving Multiphoton Microscopy by Combining Spherical Aberration Patterns and Variable Axicons

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 573
Author(s):  
Juan M. Bueno ◽  
Geovanni Hernández ◽  
Martin Skorsetz ◽  
Pablo Artal
Keyword(s):  
High Resolution ◽  
Spherical Aberration ◽  
Multiphoton Microscopy ◽  
Biological Tissues ◽  
Optical Sectioning ◽  
Established Method ◽  
Non Invasive ◽  
Microscopy Images ◽  
Better Than

Multiphoton (MP) microscopy is a well-established method for the non-invasive imaging of biological tissues. However, its optical sectioning capabilities are reduced due to specimen-induced aberrations. Both the manipulation of spherical aberration (SA) and the use of axicons have been reported to be useful techniques to bypass this limitation. We propose the combination of SA patterns and variable axicons to further improve the quality of MP microscopy images. This approach provides enhanced images at different depth locations whose quality is better than those corresponding to the use of SA or axicons separately. Thus, the procedure proposed herein facilitates the visualization of details and increases the depth observable at high resolution.

Improving the image reconstruction quality of compressed ultrafast photography via an augmented Lagrangian algorithm

2019 ◽  
Vol 21 (3) ◽  
pp. 035703 ◽  
Author(s):  
Chengshuai Yang ◽  
Dalong Qi ◽  
Fengyan Cao ◽  
Yilin He ◽  
Xing Wang ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Augmented Lagrangian ◽  
Reconstruction Quality

scholarly journals Non-invasive depth determination of inclusion in biological tissues using spatially offset Raman spectroscopy with external calibration

The Analyst ◽  
2020 ◽  
Vol 145 (23) ◽  
pp. 7623-7629 ◽  
Author(s):  
Sara Mosca ◽  
Priyanka Dey ◽  
Marzieh Salimi ◽  
Francesca Palombo ◽  
Nick Stone ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Biological Tissues ◽  
Disease Diagnosis ◽  
Early Disease ◽  
External Calibration ◽  
Non Invasive ◽  
Depth Determination

Spatially Offset Raman Spectroscopy (SORS) allows chemical characterisation of biological tissues at depths enabling in vivo localization of biomarkers for early disease diagnosis.

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