Plant Adaptation to Flooding Stress under Changing Climate Conditions: Ongoing Breakthroughs and Future Challenges.

Climate-change-induced variations in temperature and rainfall patterns are a serious threat across the globe. Flooding is the foremost challenge to agricultural productivity, and it is believed to become more intense under a changing climate. Flooding is a serious form of stress that significantly reduces crop yields, and future climatic anomalies are predicted to make the problem even worse in many areas of the world. To cope with the prevailing flooding stress, plants have developed different morphological and anatomical adaptations in their roots, aerenchyma cells, and leaves. Therefore, researchers are paying more attention to identifying developed and adopted molecular-based plant mechanisms with the objective of obtaining flooding-resistant cultivars. In this review, we discuss the various physiological, anatomical, and morphological adaptations (aerenchyma cells, ROL barriers (redial O2 loss), and adventitious roots) and the phytohormonal regulation in plants under flooding stress. This review comprises ongoing innovations and strategies to mitigate flooding stress, and it also provides new insights into how this knowledge can be used to improve productivity in the scenario of a rapidly changing climate and increasing flood intensity.

Soil acidification and salinity: the importance of biochar application to agricultural soils.

Soil acidity is a serious problem in agricultural lands as it directly affects the soil, crop production, and human health. Soil acidification in agricultural lands occurs due to the release of protons (H+) from the transforming reactions of various carbon, nitrogen, and sulfur-containing compounds. The use of biochar (BC) has emerged as an excellent tool to manage soil acidity owing to its alkaline nature and its appreciable ability to improve the soil's physical, chemical, and biological properties. The application of BC to acidic soils improves soil pH, soil organic matter (SOM), cation exchange capacity (CEC), nutrient uptake, microbial activity and diversity, and enzyme activities which mitigate the adverse impacts of acidity on plants. Further, BC application also reduce the concentration of H+ and Al3+ ions and other toxic metals which mitigate the soil acidity and supports plant growth. Similarly, soil salinity (SS) is also a serious concern across the globe and it has a direct impact on global production and food security. Due to its appreciable liming potential BC is also an important amendment to mitigate the adverse impacts of SS. The addition of BC to saline soils improves nutrient homeostasis, nutrient uptake, SOM, CEC, soil microbial activity, enzymatic activity, and water uptake and reduces the accumulation of toxic ions sodium (Na+ and chloride (Cl-). All these BC-mediated changes support plant growth by improving antioxidant activity, photosynthesis efficiency, stomata working, and decrease oxidative damage in plants. Thus, in the present review, we discussed the various mechanisms through which BC improves the soil properties and microbial and enzymatic activities to counter acidity and salinity problems. The present review will increase the existing knowledge about the role of BC to mitigate soil acidity and salinity problems. This will also provide new suggestions to readers on how this knowledge can be used to ameliorate acidic and saline soils.

[Application and practice of multidimensional teaching method in "Cell Engineering"].

In order to improve the teaching quality of engineering courses, we introduced a multi-dimensional teaching method into the teaching reform of biology majors in colleges based on the portfolio assessment in the curriculum of Cell Engineering. We reformed the knowledge system, teaching form and implementation scheme of this course. By combining the reform of online teaching, interactive teaching, case teaching and other teaching modes, the students mastered the relevant professional knowledge and the scientific and technological frontier of Cell Engineering. Moreover, their learning interest and enthusiasm, ability of analyzing and solving professional problems related to Cell Engineering also improved. The implementation of teaching reform of this course provides a reference for other similar professional courses in colleges.

How Does Zinc Improve Salinity Tolerance? Mechanisms and Future Prospects.

Salinity stress (SS) is a serious abiotic stress and a major constraint to agricultural productivity across the globe. High SS negatively affects plant growth and yield by altering soil physio-chemical properties and plant physiological, biochemical, and molecular processes. The application of micronutrients is considered an important practice to mitigate the adverse effects of SS. Zinc (Zn) is an important nutrient that plays an imperative role in plant growth, and it could also help alleviate the effects of salt stress. Zn application improves seed germination, seedling growth, water uptake, plant water relations, nutrient uptake, and nutrient homeostasis, therefore improving plant performance and saline conditions. Zn application also protects the photosynthetic apparatus from salinity-induced oxidative stress and improves stomata movement, chlorophyll synthesis, carbon fixation, and osmolytes and hormone accumulation. Moreover, Zn application also increases the synthesis of secondary metabolites and the expression of stress responsive genes and stimulates antioxidant activities to counter the toxic effects of salt stress. Therefore, to better understand the role of Zn in plants under SS, we have discussed the various mechanisms by which Zn induces salinity tolerance in plants. We have also identified diverse research gaps that must be filled in future research programs. The present review article will fill the knowledge gaps on the role of Zn in mitigating salinity stress. This review will also help readers to learn more about the role of Zn and will provide new suggestions on how this knowledge can be used to develop salt tolerance in plants by using Zn.

Hyperglycemia-Suppressed SMARCA5 Disrupts Transcriptional Homeostasis to Facilitate Endothelial Dysfunction in Diabetes.

BACKGROUND: Dysfunction of vascular endothelial cells (ECs) plays a central role in the pathogenesis of cardiovascular complications in diabetes. SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 5 (SMARCA5) is a key regulator of chromatin structure and DNA repair, but its role in ECs remains surprisingly unexplored. The current study was designed to elucidate the regulated expression and function of SMARCA5 in diabetic ECs. METHODS: SMARCA5 expression was evaluated in ECs from diabetic mouse and human circulating CD34+ cells using quantitative reverse transcription polymerase chain reaction and Western blot. Effects of SMARCA5 manipulation on ECs function were evaluated using cell migration, in vitro tube formation and in vivo wound healing assays. Interaction among oxidative stress, SMARCA5 and transcriptional reprogramming was elucidated using luciferase reporter assay, electrophoretic mobility shift assay and chromatin immunoprecipitation. RESULTS: Endothelial SMARCA5 expression was significantly decreased in diabetic rodents and humans. Hyperglycemia-suppressed SMARCA5 impaired EC migration and tube formation in vitro, and blunted vasculogenesis in vivo. Contrarily, overexpression of SMARCA5 in situ by a SMARCA5 adenovirus-incorporated hydrogel effectively promoted the rate of wound healing in a dorsal skin punch injury model of diabetic mice. Mechanistically, hyperglycemia-elicited oxidative stress suppressed SMARCA5 transactivation in a signal transducer and activator of transcription 3 (STAT3)-dependent manner. Moreover, SMARCA5 maintained transcriptional homeostasis of several pro-angiogenic factors through both direct and indirect chromatin-remodeling mechanisms. In contrast, depletion of SMARCA5 disrupted transcriptional homeostasis to render ECs unresponsive to established angiogenic factors, which ultimately resulted in endothelial dysfunction in diabetes. CONCLUSION: Suppression of endothelial SMARCA5 contributes to, at least in part, multiple aspects of endothelial dysfunction, which may thereby exacerbate cardiovascular complications in diabetes.

Study on the inhibition mechanism of eucalyptus tannins against Microcystis aeruginosa.

Microcystis aeruginosa is the competitively dominant algal species in eutrophic waters and poses a serious threat to the aquatic ecological environment. To investigate the effects of eucalyptus tannins (TFL) and black water in eucalyptus plantations on M. aeruginosa, this study exposed M. aeruginosa to different concentrations (0 (control), 20, 50, 80, 110, and 140 mg L-1) of tannic acid (TA; hydrolyzed tannins, HT; reagent tannin), epigallocatechin gallate (EGCG; condensed tannins, CT; reagent tannin), eucalyptus tannins (TFL, complex tannin) and mixed TFL + Fe3+ solution (tannin: Fe3+ molar ratio = 1:10). The cell density, chlorophyll-a (Chl-a) content, superoxide dismutase (SOD) activity, malondialdehyde (MDA) and soluble protein (SP) contents of algae under tannin stress were determined, and the algal cell density treated with under the combination of TFL and Fe3+ was determined. The results showed a reduction in the Chl-a content of algal cells, which inhibited photosynthesis; leading to membrane lipid peroxidation; and the complexation of soluble proteins resulting in blocked protein synthesis were the main mechanisms by which tannins inhibited the growth of M. aeruginosa. TFL achieved the same inhibition of algal cells as the tannin reagent at the same concentration. At 4 d, TFL at 80 mg L-1 and above could achieve more than 54.87 % algal density inhibition. The inhibition rate of 80 mg L-1 and above TFL + Fe3+ on algal density was more than 75 %, indicating that TFL + Fe3+ had a stronger inhibitory effect on algal density. The results may facilitate the resource utilization of eucalyptus harvesting residues, explorations of the potential application of eucalyptus tannins in the control of M. aeruginosa, and provide new ideas for ecological algal inhibition in eucalyptus plantations.

Versatile roles of polyamines in improving abiotic stress tolerance of plants.

In recent years, extreme environmental cues such as abiotic stresses, including frequent droughts with irregular precipitation, salinity, metal contamination, and temperature fluctuations, have been escalating the damage to plants' optimal productivity worldwide. Therefore, yield maintenance under extreme events needs improvement in multiple mechanisms that can minimize the influence of abiotic stresses. Polyamines (PAs) are pivotally necessary for a defensive purpose under adverse abiotic conditions, but their molecular interplay in this remains speculative. The PAs' accretion is one of the most notable metabolic responses of plants under stress challenges. Recent studies reported the beneficial roles of PAs in plant development, including metabolic and physiological processes, unveiling their potential for inducing tolerance against adverse conditions. This review presents an overview of research about the most illustrious and remarkable achievements in strengthening plant tolerance to drought, salt, and temperature stresses by the exogenous application of PAs. The knowledge of underlying processes associated with stress tolerance and PA signaling pathways was also summarized, focusing on up-to-date evidence regarding the metabolic and physiological role of PAs with exogenous applications that protect plants under unfavorable climatic conditions. Conclusively, the literature proposes that PAs impart an imperative role in abiotic stress tolerance in plants. This implies potentially important feedback on PAs and plants' stress tolerance under unfavorable cues.

Management Strategies to Mitigate N2O Emissions in Agriculture.

The concentration of greenhouse gases (GHGs) in the atmosphere has been increasing since the beginning of the industrial revolution. Nitrous oxide (N2O) is one of the mightiest GHGs, and agriculture is one of the main sources of N2O emissions. In this paper, we reviewed the mechanisms triggering N2O emissions and the role of agricultural practices in their mitigation. The amount of N2O produced from the soil through the combined processes of nitrification and denitrification is profoundly influenced by temperature, moisture, carbon, nitrogen and oxygen contents. These factors can be manipulated to a significant extent through field management practices, influencing N2O emission. The relationships between N2O occurrence and factors regulating it are an important premise for devising mitigation strategies. Here, we evaluated various options in the literature and found that N2O emissions can be effectively reduced by intervening on time and through the method of N supply (30-40%, with peaks up to 80%), tillage and irrigation practices (both in non-univocal way), use of amendments, such as biochar and lime (up to 80%), use of slow-release fertilizers and/or nitrification inhibitors (up to 50%), plant treatment with arbuscular mycorrhizal fungi (up to 75%), appropriate crop rotations and schemes (up to 50%), and integrated nutrient management (in a non-univocal way). In conclusion, acting on N supply (fertilizer type, dose, time, method, etc.) is the most straightforward way to achieve significant N2O reductions without compromising crop yields. However, tuning the rest of crop management (tillage, irrigation, rotation, etc.) to principles of good agricultural practices is also advisable, as it can fetch significant N2O abatement vs. the risk of unexpected rise, which can be incurred by unwary management.

[Promoting teaching quality by portfolio assessment in Cell Engineering classroom].

We introduce the portfolio assessment into the classroom teaching reform in the curriculum of Cell Engineering, a specialty course in bioengineering & biotechnology. We established a complete classroom evaluation system that was divided the classroom assessment system of portfolio into four stages including the preparation stage, training stage, implementation stage and exhibition stage. We also discuss the feasibility and necessity of implementing the portfolio evaluation method in the course of cell engineering, the construction of evaluation system, and the key points and matters needing attention in the implementation process. The classroom reform is very productive, not only the classroom atmosphere has been activated, students' learning initiative and autonomy has been enhanced, but also the students' ability to analyze and solve professional problems related to cell engineering technology has been improved. The implementation of classroom teaching reform of this course can provide reference for other similar professional courses in colleges and universities.

Electrochemical Sensors and Biosensors for the Analysis of Tea Components: A Bibliometric Review.

Tea is a popular beverage all around the world. Tea composition, quality monitoring, and tea identification have all been the subject of extensive research due to concerns about the nutritional value and safety of tea intake. In the last 2 decades, research into tea employing electrochemical biosensing technologies has received a lot of interest. Despite the fact that electrochemical biosensing is not yet the most widely utilized approach for tea analysis, it has emerged as a promising technology due to its high sensitivity, speed, and low cost. Through bibliometric analysis, we give a systematic survey of the literature on electrochemical analysis of tea from 1994 to 2021 in this study. Electrochemical analysis in the study of tea can be split into three distinct stages, according to the bibliometric analysis. After chromatographic separation of materials, electrochemical techniques were initially used only as a detection tool. Many key components of tea, including as tea polyphenols, gallic acid, caffeic acid, and others, have electrochemical activity, and their electrochemical behavior is being investigated. High-performance electrochemical sensors have steadily become a hot research issue as materials science, particularly nanomaterials, and has progressed. This review not only highlights these processes, but also analyzes and contrasts the relevant literature. This evaluation also provides future views in this area based on the bibliometric findings.

Evaluating the Significance of Viscoelasticity in Diagnosing Early-Stage Liver Fibrosis with Transient Elastography.

Transient elastography quantifies the propagation of a mechanically generated shear wave within a soft tissue, which can be used to characterize the elasticity and viscosity parameters of the tissue. The aim of our study was to combine numerical simulation and clinical assessment to define a viscoelastic index of liver tissue to improve the quality of early diagnosis of liver fibrosis. This is clinically relevant, as early fibrosis is reversible. We developed an idealized two-dimensional axisymmetric finite element model of the liver to evaluate the effects of different viscoelastic values on the propagation characteristics of the shear wave. The diagnostic value of the identified viscoelastic index was verified against the clinical data of 99 patients who had undergone biopsy and routine blood tests for staging of liver disease resulting from chronic hepatitis B infection. Liver stiffness measurement (LSM) and the shear wave attenuation fitting coefficient (AFC) were calculated from the ultrasound data obtained by performing transient elastography. Receiver operating curve analysis was used to evaluate the reliability and diagnostic accuracy of LSM and AFC. Compared to LSM, the AFC provided a higher diagnostic accuracy to differentiate early stages of liver fibrosis, namely F1 and F2 stages, with an overall specificity of 81.48%, sensitivity of 83.33% and diagnostic accuracy of 81.82%. AFC was influenced by the level of LSM, ALT. However, there are no correlation between AFC and Age, BMI, TBIL or DBIL. Quantification of the viscoelasticity of liver tissue provides reliable measurement to identify and differentiate early stages of liver fibrosis.

High frame rate and high line density ultrasound imaging for local pulse wave velocity estimation using motion matching: A feasibility study on vessel phantoms.

Pulse wave imaging (PWI) is an ultrasound-based method to visualize the propagation of pulse wave and to quantitatively estimate regional pulse wave velocity (PWV) of the arteries within the imaging field of view (FOV). To guarantee the reliability of PWV measurement, high frame rate imaging is required, which can be achieved by reducing the line density of ultrasound imaging or transmitting plane wave at the expense of spatial resolution and/or signal-to-noise ratio (SNR). In this study, a composite, full-view imaging method using motion matching was proposed with both high temporal and spatial resolution. Ultrasound radiofrequency (RF) data of 4 sub-sectors, each with 34 beams, including a common beam, were acquired successively to achieve a frame rate of ∼507 Hz at an imaging depth of 35 mm. The acceleration profiles of the vessel wall estimated from the common beam were used to reconstruct the full-view (38-mm width, 128-beam) image sequence. The feasibility of mapping local PWV variation along the artery using PWI technique was preliminarily validated on both homogeneous and inhomogeneous polyvinyl alcohol (PVA) cryogel vessel phantoms. Regional PWVs for the three homogeneous phantoms measured by the proposed method were in accordance with the sparse imaging method (38-mm width, 32-beam) and plane wave imaging method. Local PWV was estimated using the above-mentioned three methods on 3 inhomogeneous phantoms, and good agreement was obtained in both the softer (1.91±0.24 m/s, 1.97±0.27 m/s and 1.78±0.28 m/s) and the stiffer region (4.17±0.46 m/s, 3.99±0.53 m/s and 4.27±0.49 m/s) of the phantoms. In addition to the improved spatial resolution, higher precision of local PWV estimation in low SNR circumstances was also obtained by the proposed method as compared with the sparse imaging method. The proposed method might be helpful in disease detections through mapping the local PWV of the vascular wall.

[Correlation between liver hardness testing results obtained by FibroTouch and FibroScan and liver pathological stage].

OBJECTIVE: To evaluate the correlation of liver hardness testing RESULTS: obtained by FibroTouch and FibroScan and the liver pathological stage. METHODS: Seventy-five patients with chronic hepatitis B who presented to our clinic between January 2011 and April 2013 were examined with FibroTouch and FibroScan to evaluate the degree of liver fibrosis. Forty-six of those patients also underwent liver biopsy examination. THE RESULTS: from technology-based testing and histopathological evaluation of the biopsy were compared by statistical analysis to determine the consistency of FibroTouch and FibroScan in regard to histological stage. RESULTS: Analysis by paired t-test showed that the RESULTS: from FibroTouch and FibroScan were not significantly different (t = -0.17, P =0.8616), and the correlation coefficient from Pearson's correlation analysis was 0.9949 (P less than 0.05), suggesting that the two technologies' RESULTS: are correlated. Based on the histopathology RESULTS: for liver fibrosis stage, the FibroTouch diagnosis of liver fibrosis more than or equal to S 1 had a receiver operating characteristic (ROC) area under the curve (AUC) of 0.889, diagnosis of liver fibrosis more than or equal to S2 had a ROC AUC of 0.941, diagnosis of liver fibrosis more than or equal to S3 had a ROC AUC of 0.908, and diagnosis of liver fibrosis more than or equal to S4 had a ROC AUC of 0.911. CONCLUSION: Compared to FibroScan, FibroTouch has a better ability for detecting liver fibrosis and a better consistency with liver pathological stage determined by histopathological analysis.

A regularization-free Young's modulus reconstruction algorithm for ultrasound elasticity imaging.

Ultrasound elasticity imaging aims to reconstruct the distribution of elastic modulus (e.g., Young's modulus) within biological tissues, since the value of elastic modulus is often related to pathological changes. Currently, most elasticity imaging algorithms face a challenge of choosing the value of the regularization constant. We propose a more applicable algorithm without the need of any regularization. This algorithm is not only simple to use, but has a relatively high accuracy. Our method comprises of a nonrigid registration technique and tissue incompressibility assumption to estimate the two-dimensional (2D) displacement field, and finite element method (FEM) to reconstruct the Young's modulus distribution. Simulation and phantom experiments are performed to evaluate the algorithm. Simulation and phantom results showed that the proposed algorithm can reconstruct the Young's modulus with an accuracy of 63∼85%.

Estimating elastogram series of different resolutions using a multiresolution strain computation method.

The techniques used to estimate axial elastogram usually present a trade-off between elastogram resolution and noise level. It is advantageous to format a series of elastograms of various resolutions because each can provide different information about tissue stiffness. This goal is traditionally achieved by generating displacement fields using various window lengths, which increases computation load significantly. In this study, we achieve the same goal by using a multiresolution strain computation method based on Savitzky-Golay digital differentiators of different lengths, which requires calculating the displacement field only once. Simulation and experimental results show that the elastograms estimated by the proposed method are comparable to those estimated by traditional methods in terms of resolution, elastographic signal-to-noise ratio, and elastographic contrast-to-noise ratio, but the proposed method requires significantly less computational time.

A snake-based method for segmentation of intravascular ultrasound images and its in vivo validation.

Image segmentation for detection of vessel walls is necessary for quantitative assessment of vessel diseases by intravascular ultrasound. A new segmentation method based on gradient vector flow (GVF) snake model is proposed in this paper. The main characteristics of the proposed method include two aspects: one is that nonlinear filtering is performed on GVF field to reduce the critical points, change the morphological structure of the parallel curves and extend the capture range; the other is that balloon snake is combined with the model. Thus, the improved GVF and balloon snake can be automatically initialized and overcome the problem caused by local energy minima. Results of 20 in vivo cases validated the accuracy and stability of the segmentation method for intravascular ultrasound images.

New noninvasive assessment of liver fibrosis in chronic hepatitis B: maximal accumulative respiration strain.

OBJECTIVE: A novel parameter acquired from conventional B-mode sonographic videos was introduced in this study, and its diagnostic accuracy for evaluation of hepatic fibrosis was investigated. METHODS: Twenty-eight patients with chronic hepatitis B and 8 patients with hepatic cysts in the right lobe (controls) were enrolled. B-mode sonographic videos of hepatic motion under the ensisternum in the sagittal plane were captured during peaceful breathing. Maximal accumulative respiration strain (MARS) values of hepatic tissue were obtained after image analysis. METAVIR scoring after liver biopsy was considered the standard. First, the relationship between MARS and the fibrotic stage was studied; and second, receiver operating characteristic (ROC) curves were used to assess the accuracy of MARS for evaluation of the fibrotic stage. RESULTS: When the transducer was placed in the sagittal imaging plane under the ensisternum during the whole respiratory period, the hepatic tissue motion was almost in the same plane. The MARS values (mean +/- SD) were 29.44% +/- 10.44% in the F0 group (no fibrosis; n = 8), 19.30% +/- 9.10% in the F1 group (portal fibrosis without septa; n = 8), 18.09% +/- 7.36% in the F2-F3 group (portal fibrosis with few septa or numerous septa without cirrhosis; n = 12), and 14.16% +/- 4.18% in the F4 group (cirrhosis; n = 8). The Spearman correlation coefficient between MARS and the fibrotic stage was 0.516 (P = .001). The diagnostic accuracy rates, expressed as areas under the ROC curves, were 0.87 for mild fibrosis (F >or= 1), 0.72 for substantial fibrosis (F >or= 2), and 0.75 for cirrhosis (F = 4). CONCLUSIONS: Maximal accumulative respiration strain attained from B-mode sonographic videos of hepatic tissue is a new, convenient, economical, and promising noninvasive parameter for assessment of hepatic fibrosis in patients with chronic hepatitis B.

Ultrasound elastography of ethanol-induced hepatic lesions: in vitro study.

OBJECTIVE: To study the value of ultrasound elastography in evaluation of ethanol-induced lesions of liver. METHODS: Alcohol with a dose of 2 ml was injected into a fresh porcine liver under ultrasound guidance to create stiff necrosis. Then freehand elastography of the lesion from the identical scan plane was obtained with SONOLINE Antares system using VF10-5 probe at about every 30 seconds till 6 minutes later. The original high quality radiofrequency data were acquired through an ultrasound research interface which was provided by the ultrasound system. Then, corresponding elastograms were produced offline using cross-correlation technique and compared with gross pathology findings. RESULTS: Gray-scale sonogram showed a hyperechoic area with acoustic shadow below appeared immediately after alcohol injection. The hyperechoic area tended to be diffuse and its boundary to be illegible with time. On the contrary, the ethanol-induced lesion in elastogram appeared as a low strain hard region surrounded by high strain soft hepatic tissues, with clear but irregular boundaries. Sequential elastograms with the sketched lesion boundaries showed that the lesion area increased in the first 3 minutes after ethanol injection, and then reached a plateau which corresponding to gross specimen. CONCLUSION: Ultrasound elastography is capable of detecting and evaluating the diffusion of ethanol-induced hepatic lesion, and more sensitive and accurate than routine sonography.

A 2D strain estimator with numerical optimization method for soft-tissue elastography.

Elastography is a bioelasticity-based imaging modality which has been proved to be a potential evaluation tool to detect the tissue abnormalities. Conventional method for elastography is to estimate the displacement based on cross-correlation technique firstly, then strain profile is calculated as the gradient of the displacement. The main problem of this method arises from the fact that the cross-correlation between pre- and post-compression signals will be decreased because of the signal's compression-to-deformation. It may constrain the estimation of the displacement. Numerical optimization, as an efficient tool to estimate the non-rigid deformation in image registration, has its potential to achieve the elastogram. This paper incorporates the idea of image registration into elastography and proposes a radio frequency (RF) signal registration strain estimator based on the minimization of a cost function using numerical optimization method with Powell algorithm (NOMPA). To evaluate the proposed scheme, the simulation data with a hard inclusion embedded in the homogeneous background is produced for analysis. NOMPA can obtain the displacement profiles and strain profiles simultaneously. When compared with the cross-correlation based method, NOMPA presents better signal-to-noise ratio (SNR, 32.6+/-1.5 dB vs. 23.8+/-1.1 dB) and contrast-to-noise ratio (CNR, 28.8+/-1.8 dB vs. 21.7+/-0.9 dB) in axial normal strain estimation. The in vitro experiment of porcine liver with ethanol-induced lesion is also studied. The statistic results of SNR and CNR indicate that strain profiles by NOMPA performs better anti-noise and target detectability than that by cross-correlation based method. Though NOMPA carry a heavier computational burden than cross-correlation based method, it may be an useful method to obtain 2D strains in elastography.

Subtraction elastography for the evaluation of ablation-induced lesions: a feasibility study.

Different noninvasive or minimally invasive therapeutic ablation procedures can produce tissue necrosis associated with local-stiffness increase. Although elastography has been proved as a potential evaluation tool for many kinds of ablation-induced lesions, the application of subtraction technique in elastography to enhance the visualization of the ablation lesions has rarely been reported. In this paper, subtraction elastography is proposed to evaluate the ablation-induced lesions. Three models are constructed to simulate different kinds of ablated inclusions. The simulation results showed that subtraction elastography is superior to conventional elastography in detecting the ablation-induced lesions with higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The artifacts induced by elastographic signal processing algorithms can be largely reduced in subtraction elastography. In addition, subtraction elastography is less influenced by the stiff background and can provide more reliable boundary information about the lesion than conventional elastography. Furthermore, the feasibility of subtraction elastography is validated by an in vitro experiment of ethanol-induced hepatic lesions. The preliminary results of this work suggest that subtraction elastography may be a good option for the evaluation of ablationinduced lesions.