Blotchy Appearance Research Articles

Comparison of image quality between Deep learning image reconstruction and Iterative reconstruction technique for CT Brain- a pilot study.

Non-contrast Computed Tomography (NCCT) plays a pivotal role in assessing central nervous system disorders and is a crucial diagnostic method. Iterative reconstruction (IR) methods have enhanced image quality (IQ) but may result in a blotchy appearance and decreased resolution for subtle contrasts. The deep-learning image reconstruction (DLIR) algorithm, which integrates a convolutional neural network (CNN) into the reconstruction process, generates high-quality images with minimal noise. Hence, the objective of this study was to assess the IQ of the Precise Image (DLIR) and the IR technique (iDose 4) for the NCCT brain. This is a prospective study. Thirty patients who underwent NCCT brain were included. The images were reconstructed using DLIR-standard and iDose 4. Qualitative IQ analysis parameters, such as overall image quality (OQ), subjective image noise (SIN), and artifacts, were measured. Quantitative IQ analysis parameters such as Computed Tomography (CT) attenuation (HU), image noise (IN), posterior fossa index (PFI), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the basal ganglia (BG) and centrum-semiovale (CSO) were measured. Paired t-tests were performed for qualitative and quantitative IQ analyses between the iDose 4 and DLIR-standard. Kappa statistics were used to assess inter-observer agreement for qualitative analysis. Quantitative IQ analysis showed significant differences (p<0.05) in IN, SNR, and CNR between the iDose 4 and DLIR-standard at the BG and CSO levels. IN was reduced (41.8-47.6%), SNR (65-82%), and CNR (68-78.8%) were increased with DLIR-standard. PFI was reduced (27.08%) the DLIR-standard. Qualitative IQ analysis showed significant differences (p<0.05) in OQ, SIN, and artifacts between the DLIR standard and iDose 4. The DLIR standard showed higher qualitative IQ scores than the iDose 4. DLIR standard yielded superior quantitative and qualitative IQ compared to the IR technique (iDose4). The DLIR-standard significantly reduced the IN and artifacts compared to iDose 4 in the NCCT brain.

Evaluation of image resolution and quantification parameters on fdg-pet/ct images in patients with metastatic breast cancer using Q. clear and osem reconstruction techniques

We compared the 2-[18F]FDG-PET/CT scans performed for response monitoring in patients with metastatic breast cancer in a prospective setting using the ordered subset expectation maximization (OSEM) algorithm and the bayesian penalized likelihood reconstruction algorithm (Q.Clear) and the image quality and quantification parameters. 35 patients with metastatic breast cancer who were treated and followed up with 2-[18F]FDG-PET/CT were included. A total of 150 scans were evaluated on a five-point scale for the image quality parameters of noise, sharpness, contrast, diagnostic confidence, artefact, and blotchy look while being blinded to the Q.Clear and OSEM reconstruction algorithms. In scans with detectable disease, the lesion with the highest volume of interest was chosen, taking into account both reconstruction techniques' interest levels. For the same heated lesion, SULpeak (g/mL) and SUVmax (g/mL) were contrasted. The OSEM reconstruction had significantly less blotchy appearance than the Q.Clear reconstruction, while there was no significant difference between the two methods in terms of noise, diagnostic confidence, or artefact. Q.Clear had significantly better sharpness (p &amp;#60; 0.002) and contrast (p &amp;#60; 0.002) than the OSEM reconstruction. Quantitative examination of 75/150 scans revealed that Q.Clear reconstruction considerably outperformed OSEM reconstruction in terms of SULpeak (6.33 ± 1.8 vs. 5.85 ± 1.5, p &amp;#60; 0.002) and SUVmax (7.27 ± 5.8 vs. 3.90 ± 2.8, p 0.002). In conclusion, OSEM reconstruction was less blotchy, but Q.Clear reconstruction showed superior sharpness, better contrast, higher SUVmax, and higher SULpeak.

Comparison of Image Quality and Quantification Parameters between Q.Clear and OSEM Reconstruction Methods on FDG-PET/CT Images in Patients with Metastatic Breast Cancer.

We compared the image quality and quantification parameters through bayesian penalized likelihood reconstruction algorithm (Q.Clear) and ordered subset expectation maximization (OSEM) algorithm for 2-[18F]FDG-PET/CT scans performed for response monitoring in patients with metastatic breast cancer in prospective setting. We included 37 metastatic breast cancer patients diagnosed and monitored with 2-[18F]FDG-PET/CT at Odense University Hospital (Denmark). A total of 100 scans were analyzed blinded toward Q.Clear and OSEM reconstruction algorithms regarding image quality parameters (noise, sharpness, contrast, diagnostic confidence, artefacts, and blotchy appearance) using a five-point scale. The hottest lesion was selected in scans with measurable disease, considering the same volume of interest in both reconstruction methods. SULpeak (g/mL) and SUVmax (g/mL) were compared for the same hottest lesion. There was no significant difference regarding noise, diagnostic confidence, and artefacts within reconstruction methods; Q.Clear had significantly better sharpness (p < 0.001) and contrast (p = 0.001) than the OSEM reconstruction, while the OSEM reconstruction had significantly less blotchy appearance compared with Q.Clear reconstruction (p < 0.001). Quantitative analysis on 75/100 scans indicated that Q.Clear reconstruction had significantly higher SULpeak (5.33 ± 2.8 vs. 4.85 ± 2.5, p < 0.001) and SUVmax (8.27 ± 4.8 vs. 6.90 ± 3.8, p < 0.001) compared with OSEM reconstruction. In conclusion, Q.Clear reconstruction revealed better sharpness, better contrast, higher SUVmax, and higher SULpeak, while OSEM reconstruction had less blotchy appearance.

A Clustering Approach to Improve IntraVoxel Incoherent Motion Maps from DW-MRI Using Conditional Auto-Regressive Bayesian Model

The Intra-Voxel Incoherent Motion (IVIM) model allows to estimate water diffusion and perfusion-related coefficients in biological tissues using diffusion weighted MR images. Among the available approaches to fit the IVIM bi-exponential decay, a segmented Bayesian algorithm with a Conditional Auto-Regressive (CAR) prior spatial regularization has been recently proposed to produce more reliable coefficient estimation. However, the CAR spatial regularization can generate inaccurate coefficient estimation, especially at the interfaces between different tissues. To overcome this problem, the segmented CAR model was coupled in this work with a k-means clustering approach, to separate different tissues and exclude voxels from other regions in the CAR prior specification. The proposed approach was compared with the original Bayesian CAR method without clustering and with a state-of-the-art Bayesian approach without CAR. The approaches were tested and compared on simulated images by calculating the estimation error and the coefficient of variation (CV). Furthermore, the proposed method was applied to some illustrative real images of oncologic patients. On simulated images, the proposed innovation reduced the average error of 47%, 21% and 58% for D, f and D*, respectively, compared to the state-of-the-art Bayesian approach, and of 48% and 34% for D and f, respectively, compared to the original CAR, while it achieved the same error for D*. The clustering approach was also able to consistently reduce the CV for each coefficient. On real images, the novel approach did not alter the IVIM maps obtained by the original CAR method, with the advantage of reducing their typical blotchy appearance at the boundaries. The proposed approach represents a valuable improvement over the state-of-the-art Bayesian CAR method and provides more reliable IVIM coefficient estimation, and is less sensitive to bias and inconsistency at tissue/tissue and tissue/background interfaces.

A questionnaire-based assessment of Safe Eye Examination (SEE) technique.

Purpose:This study aims to assess the novel and innovative method of Safe Eye Examination (SEE) technique using the model eye for the purpose of teaching, training, and resident examination.Methods:A questionnaire-based study (Descriptive Data) with 53 participants, including ophthalmology residents, fellows in various subspecialties, and trainee optometrists was used. In our study, we used the Reti Eye model, but instead of the usual retina template sheet, we used prominent pathological fundus photographs loaded into the model eye. The study participants were asked to view prominent pathological fundus images printed on a matte finish paper. A circular image was cut and was placed in the Reti Eye model. The candidates were made to perform indirect ophthalmoscopy with a + 20D lens and to fill up a Google image assessment scale questionnaire with characteristics, including pixelation, sharpness, contrast, reflexes, blotchy appearance, and diagnostic confidence, which were then analyzed and depicted. Association between categorical variables was analyzed using Fisher exact test and Chi-square test. A P value of less than 0.05 was considered statistically significant. All data were analyzed with a statistical software package (SPSS, Version 16.0 for Windows).Results:The number of positive responses (>90%) obtained for the pixelation, sharpness, contrast, reflexes, blotchy appearance, and diagnostic confidence of the image viewed were statistically more significant than the negative responses (P < 0.05).Conclusion:The SEE technique of using the model eye can be incorporated for teaching, training, and skill assessment in the examinations in these difficult times of COVID-19 (coronavirus disease 2019) pandemic.

Noise Texture Deviation: A Measure for Quantifying Artifacts in Computed Tomography Images With Iterative Reconstructions.

The aims of this study were to introduce the measure noise texture deviation as quantitative parameter for evaluating iterative reconstruction (IR)-specific artifacts in computed tomography (CT) images and to test whether IR-specific artifacts, quantified through this measure, are reduced in advanced modeled IR (ADMIRE) as compared with sinogram-affirmed IR (SAFIRE) images of the liver ex vivo and in patients with hypodense liver lesions. In the ex vivo study part, an abdominal phantom was used. In the institutional review board-approved in vivo study part, 40 consecutive patients (mean age, 63 years) with hypodense liver lesions undergoing abdominal CT in the portal-venous phase were included. Images were reconstructed with filtered back projection, with the second-generation IR algorithm SAFIRE and with the third-generation IR algorithm ADMIRE. Noise power spectra and noise texture deviation were calculated in the phantom; image noise was measured in the phantom and in patients. Two blinded readers evaluated all image data regarding IR-specific artifacts (plastic-like, blotchy appearance); patient data were evaluated regarding conspicuity and confidence for detecting hypodense liver lesions. Image noise was significantly reduced at increasing IR levels (P < 0.001) with both algorithms, with no significant differences between corresponding strength levels of SAFIRE and ADMIRE (all, P > 0.05). Noise power spectra were similar at corresponding strength levels of SAFIRE and ADMIRE (all, P > 0.05). Noise texture deviation in ADMIRE was reduced compared with corresponding strength levels of SAFIRE (all, P < 0.001) and strongly correlated with subjective IR-specific artifacts (r = 0.88, P < 0.001). Iterative reconstruction-specific artifacts were significantly reduced in ADMIRE compared with that in SAFIRE images at strength levels 3 or greater, both ex vivo and in vivo (all, P < 0.001). There were no significant differences in the readers' ratings of lesion conspicuity and lesion confidence in detecting hypodense liver lesions between SAFIRE and ADMIRE (P > 0.05). Only lesion conspicuity was superior with SAFIRE and ADMIRE compared with filtered back projection (all, P < 0.001). Noise texture deviation is a quantitative measure reflecting IR-specific artifacts and is reduced in CT images with ADMIRE compared with SAFIRE.

Iterative reconstruction techniques for computed tomography Part 1: Technical principles

To explain the technical principles of and differences between commercially available iterative reconstruction (IR) algorithms for computed tomography (CT) in non-mathematical terms for radiologists and clinicians. Technical details of the different proprietary IR techniques were distilled from available scientific articles and manufacturers' white papers and were verified by the manufacturers. Clinical results were obtained from a literature search spanning January 2006 to January 2012, including only original research papers concerning IR for CT. IR for CT iteratively reduces noise and artefacts in either image space or raw data, or both. Reported dose reductions ranged from 23 % to 76 % compared to locally used default filtered back-projection (FBP) settings, with similar noise, artefacts, subjective, and objective image quality. IR has the potential to allow reducing the radiation dose while preserving image quality. Disadvantages of IR include blotchy image appearance and longer computational time. Future studies need to address differences between IR algorithms for clinical low-dose CT. • Iterative reconstruction technology for CT is presented in non-mathematical terms. • IR reduces noise and artefacts compared to filtered back-projection. • IR can improve image quality in routine-dose CT and lower the radiation dose. • IR's disadvantages include longer computation and blotchy appearance of some images.

Sinogram-Affirmed Iterative Reconstruction of Low-Dose Chest CT: Effect on Image Quality and Radiation Dose

OBJECTIVE. The purpose of this study is to compare sinogram-affirmed iterative reconstruction (SAFIRE) and filtered back projection (FBP) reconstruction of chest CT acquired with 65% radiation dose reduction. MATERIALS AND METHODS. In this prospective study involving 24 patients (11 women and 13 men; mean [± SD] age, 66 ± 10 years), two scan series were acquired using 100 and 40 Quality Reference mAs over a 10-cm scan length in the chest with a 128-MDCT scanner. The 40 Quality Reference mAs CT projection data were reconstructed with FBP and four settings of SAFIRE (S1, S2, S3, and S4). Six image datasets (FBP with 100 and 40 Quality Reference mAs, and S1, S2, S3, S4 with 40 Quality Reference mAs) were displayed on a DICOM-compliant 55-inch 2-megapixel monitor for blinded evaluation by two thoracic radiologists for number and location of lesions, lesion size, lesion margins, visibility of small structures and fissures, and diagnostic confidence. Objective noise and CT values were measured in thoracic aorta for each image series, and the noise power spectrum was assessed. Data were analyzed with analysis of variance and Wilcoxon signed rank tests. RESULTS. All 186 lesions were seen on 40 Quality Reference mAs SAFIRE images. Diagnostic confidence on SAFIRE images was higher than that for FBP images. Except for the minor blotchy appearance on SAFIRE settings S3 and S4, no significant artifacts were noted. Objective noise with 40 Quality Reference mAs S1 images (21.1 ± 6.1 SD of HU) was significantly lower than that for 40 Quality Reference mAs FBP images (28.5 ± 8.1 SD of HU) (p < 0.001). Noise power spectra were identical for SAFIRE and FBP with progressive noise reduction with higher iteration SAFIRE settings. CONCLUSION. Iterative reconstruction (SAFIRE) allows reducing the radiation exposure by approximately 65% without losing diagnostic information in chest CT.

Desempenho de híbridos de tomate de crescimento indeterminado em função de sistemas de condução de plantas

O presente trabalho teve como objetivo avaliar dois sistemas de tutoramento e condução de plantas na produtividade e seus componentes em híbridos de tomateiro dos segmentos Salada Longa Vida e Santa Cruz de crescimento indeterminado, visando ao consumo in natura. Adotou-se o delineamento em blocos ao acaso com os tratamentos em esquema fatorial 5x2, quatro repetições, sendo avaliados cinco híbridos comerciais, três pertencentes ao grupo Salada Longa Vida ('Alambra', 'Paron' e 'Forty') e dois do grupo Santa Cruz ('Débora Pto' e 'Ellus'), em dois sistemas de condução de plantas (bambu e fitilho). O experimento foi conduzido em condições de campo, em Itatiba (SP), de julho de 2007 a janeiro de 2008. Foram consideradas todas as plantas de cada parcela e avaliaram-se a produtividade total, produtividade comercial, produção por planta, massa média de frutos, número total de frutos, número de frutos comercializáveis, número de frutos das classes '3A', '2A' e '1A', número de frutos manchado e com lóculo aberto. Não houve interação entre cultivar e sistema de condução de planta para maioria das características avaliadas, exceto número total de frutos, número de frutos comercializáveis e número de frutos da classe '2A'. O sistema de condução de plantas com uma haste tutorada com fitilho proporcionou incremento na massa média de frutos e número de frutos da classe '3A', e decréscimo do número de frutos da classe '1A', sem reduzir a produtividade total e comercial quando comparado ao método de condução tradicional no bambu com duas hastes por planta.

Ultrastructure of BHK-21 cells treated with dopamine

The ultrastructure of a suspension or of adhered BHK-21 cells exposed to dopamine has been studied. It was found that ultrastructural modifications were observed mainly in cellular regions enriched in actin, including in intercellular desmosome-like contacts, microvilli, and under the membrane cortical layer. Desmosome-like contacts are hypertrophied with increased electron density and fibrillar bridges that appear in specialized contacts. Microvilli fused with each other and with plasma membrane of neighboring cells or were split up and penetrated by fibrils. The cytoplasm is filled with randomly arranged F-actin filaments and has a blotchy appearance. The effect of dopamine is more pronounced in nonattached cells with undifferentiated actin cytoskeletons than in spread cells with stress fibers. The blockage of the D2 receptor with haloperidol does not affect the ultrastructure of BHK-21 or dopamine induced modifications. The data obtained suggest direct interactions between dopamine and the actin cytoskeleton.

Effective platform for the generation of aerosol droplets and application in evaluating the effectiveness of a MEMS-based nanoparticle trapping device

The purpose of this study is two-fold: firstly, the development of a cheap, easy-to-construct and effective nanoparticle generator for testing nanoparticle sensors; secondly, the use of such a generator to test the effectiveness of a sensor device in trapping aerosolised nanoparticles. In this study, we have constructed an effective aerosol generator platform, based on aerosol-assisted chemical vapour deposition technology. Under well-controlled experimental conditions, this platform is capable of depositing aerosolised sodium chloride particles homogeneously on a substrate very effectively. Deposited aerosol droplets were subsequently dried and shown to form nanosized cubic crystals that are free from impurities. This platform was employed to test the effectiveness of a MEMS comb device in the electrostatic trapping of nanoparticles. Upon applying a DC bias (0.5 V) to the MEMS device, results showed an increase in nanoparticle deposition on the surface of the device, due to electrostatic precipitation. The presence of an electric field was shown to affect crystal formation upon drying of the aerosol droplets on the substrate; this caused a blotchy appearance on the SEM image, which was not observed in the absence of electric field.

Structural Aging: The Facial Recurve Concept

Cutaneous facial aging is responsible for the increasingly wrinkled and blotchy appearance of the skin, whereas aging of the facial structures is attributed primarily to gravity. This article purports to show, however, that the primary etiology of structural facial aging relates instead to repeated contractions of certain facial mimetic muscles, the age marker fascicules, whereas gravity only secondarily abets an aging process begun by these muscle contractions. Magnetic resonance imaging (MRI) has allowed us to study the contrasts in the contour of the facial mimetic muscles and their associated deep and superficial fat pads in patients of different ages. The MRI model shows that the facial mimetic muscles in youth have a curvilinear contour presenting an anterior surface convexity. This curve reflects an underlying fat pad lying deep to these muscles, which acts as an effective mechanical sliding plane. The muscle's anterior surface convexity constitutes the key evidence supporting the authors' new aging theory. It is this youthful convexity that dictates a specific characteristic to the muscle contractions conveyed outwardly as youthful facial expression, a specificity of both direction and amplitude of facial mimetic movement. With age, the facial mimetic muscles (specifically, the age marker fascicules), as seen on MRI, gradually straighten and shorten. The authors relate this radiologic end point to multiple repeated muscle contractions over years that both expel underlying deep fat from beneath the muscle plane and increase the muscle resting tone. Hence, over time, structural aging becomes more evident as the facial appearance becomes more rigid.

Hydrogen Peroxide and Calcium Chloride Added to Irrigation Water as a Strategy to Reduce Bacterial Populations and Improve Quality of Fresh Mushrooms

ABSTRACTThe quality and value of fresh mushrooms are often diminished by the presence of high bacterial populations that cause a brown, blotchy appearance. The objective of the present research was to evaluate the addition of hydrogen peroxide and/or calcium chloride to irrigation water as a means to reduce total bacterial populations on fresh mushrooms. Crops were grown using commercial mushroom growing practices except for the addition of 0.75% hydrogen peroxide and/or 0.3% calcium chloride irrigation water added to the crop starting 11 d after the casing layer was applied on top of mushroom compost. Irrigation water without the added treatments acted as the control. Mushrooms were aseptically sampled from the production beds for enumerating bacterial counts. Total aerobic bacterial populations were determined by standard microbiological plating procedures. Mushroom whiteness (L‐value) and color (delta E) after harvest and postharvest storage were measured using a Minolta chromameter. Harvested mushrooms were separated by treatment and weighed to record yield. Mushrooms irrigated with water (control) had 7.3 log colony‐forming units (CFU) of aerobic bacterial populations per gram of fresh mushroom tissue. Compared with the control, irrigation with 0.75% hydrogen peroxide and 0.3% calcium chloride reduced the bacterial populations on fresh mushrooms by 87% (6.4 log CFU/g). Irrigation with hydrogen peroxide and calcium chloride significantly enhanced mushroom whiteness after harvest as well as after 6 d of postharvest storage at 12 °C. The irrigation treatments did not have a significant effect on crop yields; hence, the addition of hydrogen peroxide and calcium chloride to irrigation water was demonstrated to have good potential as a practical strategy to reduce bacterial populations and to improve the quality of fresh mushrooms.

Antifungal Activity and Studies on Mode of Action of Novel Xanthoxyline‐Derived Chalcones

Chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensation of appropriate aldehydes and xanthoxyline, were tested for antifungal properties against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the agar dilution assay. Results indicate that neither the sole presence of a "xanthoxyline-like" substitution pattern nor a 2'-OH substituent on ring A are sufficient for these compounds to have antifungal properties. The chalcone 3-(2-chlorophenyl)-1-(2'-hydroxy-4',6'-dimethoxyphenyl)prop-2-en-1-one, with a Cl atom in the ortho position of benzene ring B showed the best antifungal activity against standardized strains of Trichophyton rubrum (MIC = 12.5 microg/mL) and inhibited all of the ten clinical isolates of T. rubrum tested (MIC at which 50 % [MIC(50)] and 90 % [MIC(90)] of the isolates were inhibited = 12.5 and 25 microg/mL). Regarding its mode of action, the Neurospora crassa assay showed a blotchy appearance in the inhibition halo produced by this chalcone, strongly suggesting that it could act by inhibiting the fungal cell wall. This chalcone seems to be an hyphal malformation inducer, since a clear curling of the hypha was observed in this hazy zone at a magnification of x 400. This work strongly contributes to the knowledge of the antifungal properties of hydroxy-chalcones.

Effect of Two Polymeric Coatings on Fruit Quality of ‘Bartlett’ and ‘d’Anjou’ Pears

Abstract ‘Bartlett’ and ‘d’Anjou’ pears (Pyrus communis L.) coated with either Pro-long or Nutri-Save, two proprietary fruit-coating materials, were firmer, higher in titratable acidity, and greener in skin color than noncoated fruit stored in air at 0°C. Coated fruit were, in most instances, comparable to noncoated fruit stored in controlled atmospheres (CA). The incidence of core breakdown in ‘Bartlett’ pears and superficial scald in ‘d’Anjou’ pears were lower in coated fruit than in noncoated fruit kept in air storage. The incidence of scald in CA-stored noncoated fruit was usually comparable to and sometimes lower than in the air-stored coated fruit. Normal fruit ripening, however, was adversely affected by the coating compounds, particularly in ‘Bartlett’ pears. Coated ‘Bartlett’ pears tended to develop a blotchy appearance of green interspersed with yellow when held at ripening temperatures.

Elimination of stacking-fault formation in silicon by preoxidation annealing in N2/HCl/O2 mixtures

The formation of oxidation-induced stacking faults in the surface regions of silicon wafers can be eliminated by a short-period anneal in a dry nitrogen atmosphere containing small concentrations of HCl and oxygen in the same furnace where subsequent oxidation will be carried out. This preoxidation anneal results in the prevention of fault nucleation without causing any problem like a nitridation reaction, an etch-pit formation, and a blotchy appearance on the silicon surface.