scholarly journals Two simple criteria to estimate an objective’s performance when imaging in non design tissue clearing solutions

2019 ◽  
Author(s):  
Sabrina Asteriti ◽  
Valeria Ricci ◽  
Lorenzo Cangiano
Keyword(s):  
Image Quality ◽  
High Refractive Index ◽  
Optimal Conditions ◽  
Point Spread Functions ◽  
Tissue Clearing ◽  
Fluorescent Microscope ◽  
Immersion Medium ◽  
Quality Degradation ◽  
Point Spread ◽  
The Impact

ABSTRACTTissue clearing techniques are undergoing a renaissance motivated by the need to image fluorescence deep in biological samples without physical sectioning. Optical transparency is achieved by equilibrating tissues with high refractive index (RI) solutions, which require expensive optimized objectives to avoid aberrations. One may thus need to assess whether an available objective is suitable for a specific clearing solution, or the impact on imaging of small mismatches between cleared sample and objective design RIs. We derived closed form approximations for image quality degradation versus RI mismatch and other parameters available to the microscopist. We validated them with computed (and experimentally confirmed) aberrated point spread functions, and by imaging fluorescent neurons in high RI solutions. Crucially, we propose two simple numerical criteria to establish: (i) the degradation in image quality (brightness and resolution) from optimal conditions of any clearing solution/objective combination; (ii) which objective, among several, achieves the highest resolution in a given immersion medium. These criteria apply directly to the widefield fluorescent microscope but are also closely relevant to more advanced microscopes.

scholarly journals Single scan parameterization of space-variant point spread functions in image space via a printed array: the impact for two PET/CT scanners

2011 ◽  
Vol 56 (10) ◽  
pp. 2917-2942 ◽  
Author(s):  
F A Kotasidis ◽  
J C Matthews ◽  
G I Angelis ◽  
P J Noonan ◽  
A Jackson ◽  
...  
Keyword(s):  
Image Space ◽  
Point Spread Functions ◽  
Point Spread ◽  
Pet Ct ◽  
Ct Scanners ◽  
The Impact ◽  
Space Variant

scholarly journals Some Thoughts on Point Spread Functions, Resolution and Image Quality

2018 ◽  
Vol 24 (S1) ◽  
pp. 600-601
Author(s):  
Eric Lifshin ◽  
Matthew D. Zotta ◽  
Richard K. Hailstone ◽  
Mandy C. Nevins
Keyword(s):  
Image Quality ◽  
Point Spread Functions ◽  
Point Spread

Gradient Delay Correction for FSE-MRI

2013 ◽  
Vol 718-720 ◽  
pp. 641-644
Author(s):  
Rui Peng Ning ◽  
Guang Yang
Keyword(s):  
Image Quality ◽  
Correction Method ◽  
Total Delay ◽  
Quality Degradation ◽  
Imaging Sequence ◽  
Gradient Waveform ◽  
The Impact ◽  
Delay Correction

In this paper, the impact of the gradient delay and its anisotropy on FSE-MRI was studied. It is shown by experiments that FSE imaging sequence is sensitive to uncorrected gradient delay. A simple correction method of this problem is proposed, in which the delay of the gradient waveform is compensated by shifting the gradient waveform directly. We have demonstrated that the proposed method is effective to overcome the image quality degradation cause by the gradient delay. The correction does not depend on specific samples or subjects and total delay can be used without recalibrating in each scan.

scholarly journals P‐13.5: The impact of Gate Loading on Image Quality for large & middle size AM‐OLED display devices

2021 ◽  
Vol 52 (S1) ◽  
pp. 643-646
Author(s):  
Yang Guobo ◽  
Qiu Haijun ◽  
Huang Weiyun ◽  
Yang Yuqing ◽  
Long Yue ◽  
...  
Keyword(s):  
Image Quality ◽  
Display Devices ◽  
The Impact ◽  
Oled Display

scholarly journals Modeling and image quality enhancement for dynamic compressive imaging system

2021 ◽  
Vol 15 ◽  
pp. 174830262110080
Author(s):  
Changjun Zha* ◽  
Qian Zhang* ◽  
Huimin Duan
Keyword(s):  
Image Quality ◽  
Imaging System ◽  
Quality Enhancement ◽  
Target Image ◽  
Compressive Imaging ◽  
Image Quality Enhancement ◽  
System A ◽  
Single Column ◽  
The Impact

Traditional single-pixel imaging systems are aimed mainly at relatively static or slowly changing targets. When there is relative motion between the imaging system and the target, sizable deviations between the measurement values and the real values can occur and result in poor image quality of the reconstructed target. To solve this problem, a novel dynamic compressive imaging system is proposed. In this system, a single-column digital micro-mirror device is used to modulate the target image, and the compressive measurement values are obtained for each column of the image. Based on analysis of the measurement values, a new recovery model of dynamic compressive imaging is given. Differing from traditional reconstruction results, the measurement values of any column of vectors in the target image can be used to reconstruct the vectors of two adjacent columns at the same time. Contingent upon characteristics of the results, a method of image quality enhancement based on an overlapping average algorithm is proposed. Simulation experiments and analysis show that the proposed dynamic compressive imaging can effectively reconstruct the target image; and that when the moving speed of the system changes within a certain range, the system reconstructs a better original image. The system overcomes the impact of dynamically changing speeds, and affords significantly better performance than traditional compressive imaging.

scholarly journals Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2047
Author(s):  
Nor Azura Muhammad ◽  
Zunaide Kayun ◽  
Hasyma Abu Hassan ◽  
Jeannie Hsiu Ding Wong ◽  
Kwan Hoong Ng ◽  
...  
Keyword(s):  
Image Quality ◽  
Multidetector Ct ◽  
Organ Dose ◽  
Quality Metrics ◽  
Ct Scanner ◽  
Image Quality Metrics ◽  
Tube Current ◽  
Significant Difference ◽  
Noise Ratio ◽  
The Impact

The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p > 0.05) observed between the protocols and image metrics.

The impact of acid hydrolysis conditions on carbohydrate determination in lignocellulosic materials: a case study with Eucalyptus globulus bark

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ricardo Jorge Oliveira ◽  
Bruna Santos ◽  
Maria J. Mota ◽  
Susana R. Pereira ◽  
Pedro C. Branco ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Eucalyptus Globulus ◽  
Industrial Processes ◽  
Lignocellulosic Materials ◽  
Optimal Conditions ◽  
Hydrolysis Conditions ◽  
The Impact ◽  
Eucalyptus Bark

Abstract Lignocellulosic biomass represents a suitable feedstock for production of biofuels and bioproducts. Its chemical composition depends on many aspects (e.g. plant source, pre-processing) and it has impact on productivity of industrial bioprocesses. Numerous methodologies can be applied for biomass characterisation, with acid hydrolysis being a particularly relevant step. This study intended to assess the most suitable procedures for acid hydrolysis, taking Eucalyptus globulus bark as a case study. For that purpose, variation of temperature (90–120 °C) was evaluated over time (0–5 h), through monosaccharides and oligosaccharides contents and degradation. For glucose, the optimal conditions were 100 °C for 2.5 h, reaching a content of 48.6 wt.%. For xylose, the highest content (15.2 wt.%) was achieved at 90 °C for 2 h, or 120 °C for 0.5 h. Maximum concentrations of mannose and galactose (1.0 and 1.7 wt.%, respectively) were achieved at 90 and 100 °C (2–3.5 h) or at 120 °C (0.5–1 h). These results revealed that different hydrolysis conditions should be applied for different sugars. Using this approach, total sugar quantification in eucalyptus bark was increased by 4.3%, which would represent a 5% increase in the ethanol volume produced, considering a hypothetical bioethanol production yield. This reflects the importance of feedstock characterization on determination of economic viability of industrial processes.

scholarly journals Raman scattering in high-refractive-index nanostructures

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Søren Raza ◽  
Anders Kristensen
Keyword(s):  
Raman Spectroscopy ◽  
Refractive Index ◽  
Raman Scattering ◽  
Bound States ◽  
Stimulated Raman Scattering ◽  
Dielectric Materials ◽  
High Refractive Index ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Enhancement ◽  
The Impact

AbstractThe advent of resonant dielectric nanomaterials has provided a new path for concentrating and manipulating light on the nanoscale. Such high-refractive-index materials support a diverse set of low-loss optical resonances, including Mie resonances, anapole states, and bound states in the continuum. Through these resonances, high-refractive-index materials can be used to engineer the optical near field, both inside and outside the nanostructures, which opens up new opportunities for Raman spectroscopy. In this review, we discuss the impact of high-refractive-index nano-optics on Raman spectroscopy. In particular, we consider the intrinsic Raman enhancement produced by different dielectric resonances and their theoretical description. Using the optical reciprocity theorem, we derive an expression which links the Raman enhancement to the enhancement of the stored electric energy. We also address recent results on surface-enhanced Raman spectroscopy based on high-refractive-index dielectric materials along with applications in stimulated Raman scattering and nanothermometry. Finally, we discuss the potential of Raman spectroscopy as a tool for detecting the optical near-fields produced by dielectric resonances, complementing reflection and transmission measurements.

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