scholarly journals Noninvasive Temperature Estimation Based on Texture Features of Ultrasound Images for RFA

2021 ◽  
Author(s):  
Ming Chen ◽  
Xingqun Zhao ◽  
Linfang Yao
Keyword(s):  
Wavelet Transform ◽  
Linear Correlation ◽  
Estimation Method ◽  
Texture Features ◽  
Temperature Monitoring ◽  
Rabbit Kidney ◽  
Ultrasound Images ◽  
Temperature Estimation

Abstract BackgroundHyperthermia is one of the most common therapy for tumor， in which temperature monitoring is essential. Invasive temperature monitoring is mostly used in clinic at present, which leads to limited points under monitoring and extra hurt to patients. Therefore, noninvasive temperature estimation is a key and tough problem in hyperthermia. In this paper, a noninvasive temperature estimation method for hyperthermia based on B-mode ultrasonic image with wavelet transform and texture analysis is proposed.MethodsAnimal tissue both in vitro and in vivo(pig kidneys in vitro and rabbit kidney in vivo) were taken as experimental materials. Ultrasound images and temperature data were collected from radio frequency ablation experiment under approved protocol. Image subtraction and wavelet transform were performed on the ultrasound images to enhance the change during ablation, after which texture features were extracted to analyze the relationship with temperature.ResultsTexture features hybrid entropy and energy extracted from gray-level gradient co-occurrence matrix of ultrasound images processed had higher linear correlation with temperature than traditional gray value method. From in vitro and in vivo experiments, the linear correlation coefficients obtained between hybrid entropy and temperature were 0.979±0.028 and -0.935±0.037, respectively, and those between energy and temperature were 0.932±0.056 and -0.915±0.034, respectively. In addition, the slopes of linear model obtained in vitro were relatively consistent, while those under in vivo condition had certain individual differences.ConclusionsThe results demonstrated that texture features hybrid entropy and energy of ultrasound image processed with the method proposed in this paper can be used for temperature estimation with a smaller error because of high linear correlation with temperature both in vitro and in vivo. Compared with most previous research which only based on biomaterial in vitro, the in vivo experiment conducted in this paper verified the feasibility of the noninvasive temperature estimation method proposed in practice.

scholarly journals In Vitro and In Vivo Digestibility of Native Maize Starch Granules Varying in Amylose Contents

2007 ◽  
Vol 90 (6) ◽  
pp. 1628-1634 ◽  
Author(s):  
Tatsuya Morita ◽  
Yusuke Ito ◽  
Ian Lewis Brown ◽  
Ryuichi Ando ◽  
Shuhachi Kiriyama
Keyword(s):  
Surface Area ◽  
Linear Correlation ◽  
Resistant Starch ◽  
Amylose Content ◽  
Starch Granules ◽  
Gelatinization Temperature ◽  
Maize Starch ◽  
Positive Linear Correlation

Abstract Digestibility of maize starch granules with different amylose content (AL-0, 22, 54, 68, 80, or 90) was investigated. Measurement of the in vivo resistant starch (RS) content of the starches was performed using surgically prepared ileorectostomized rats. The rats were fed a purified diet containing one of the starches at 652.5 g/kg diet. The in vivo RS content was determined based on the fecal starch excretion. The dietary fiber (DF) value increased as a function of the amylose content in the starch and showed a positive linear correlation with the gelatinization temperature of the granules. In contrast, the in vitro RS content was likely to depend on both the surface area and amylose contents of the starch granules. The maximum in vitro RS content was obtained with AL-68 (54.4). In vivo RS content showed a significant correlation with the amount of in vitro RS but not in respect to the DF detected. The in vivo RS content of AL-68 (43.4) was higher than that found in AL-90 (37.8). A profound gap was observed for AL-54 between the amount of DF (6.4) and RS (in vitro = 46.6 and in vivo = 40.9) present. The results suggest that both in vitro and in vivo digestibility of maize starch is affected by the amylose content and surface area of the granules. The current evaluation suggests that the physiological occurrence of RS from maize starch might be predictable by reference to the in vitro RS value.

scholarly journals A Robust Automatic Ultrasound Spectral Envelope Estimation

Information ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 199 ◽  
Author(s):  
Jinkai Li ◽  
Yi Zhang ◽  
Xin Liu ◽  
Paul Liu ◽  
Hao Yin ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Carotid Artery ◽  
Power Spectrum ◽  
Estimation Method ◽  
Maximum Velocity ◽  
Speckle Noise ◽  
Spectral Envelope ◽  
Accurate Estimation ◽  
Ultrasound Images

Accurate estimation of ultrasound Doppler spectrogram envelope is essential for clinical pathological diagnosis of various cardiovascular diseases. However, due to intrinsic spectral broadening in the power spectrum and speckle noise existing in ultrasound images, it is difficult to obtain the accurate maximum velocity. Each of the standard existing methods has their own limitations and does not work well in complicated recordings. This paper proposes a robust automatic spectral envelope estimation method that is more accurate in phantom recordings and various in-vivo recordings than the currently used methods. Comparisons were performed on phantom recordings of the carotid artery with varying noise and additional in-vivo recordings. The accuracy of the proposed method was on average 8% greater than the existing methods. The experimental results demonstrate the wide applicability under different blood conditions and the robustness of the proposed algorithm.

Measuring esophageal distension by high-frequency intraluminal ultrasound probe

2002 ◽  
Vol 283 (4) ◽  
pp. G886-G892 ◽  
Author(s):  
Poong-Lyul Rhee ◽  
Jianmin Liu ◽  
James L. Puckett ◽  
Ravinder K. Mittal
Keyword(s):  
High Frequency ◽  
Healthy Subjects ◽  
Normal Subjects ◽  
Ultrasound Images ◽  
Agarose Gel ◽  
Ultrasound Probe ◽  
Cross Sectional ◽  
Esophageal Sphincter

Distension of the esophagus can cause heartburn and chest pain; however, none of the available techniques to study the esophagus measure esophageal distension. We evaluated the technique of high-frequency intraluminal ultrasound probe (HFIUS) to measure the esophageal cross-sectional area (CSA) during gastroesophageal reflux (GER). The following methods were used: 1) the CSA of agarose gel tubes of known dimensions were measured using ultrasound probes; 2) seven normal subjects were studied to evaluate the esophageal CSA during different bolus volumes (1, 5, 10, 15, and 20 ml) of water swallows (WS); and 3) simultaneous pressures, pH, and ultrasound images of the esophagus were recorded in healthy subjects. In vitro studies showed that the HFIUS measured the CSA of the tubes accurately. The maximal CSA of the distal esophagus during WS with boluses of 1, 5, 10, 15, and 20 ml were 54, 101, 175, 235, and 246 mm2, respectively. Esophageal contents during 62 episodes of transient lower esophageal sphincter relaxations, 29 pH positive, and 33 pH negative GER episodes revealed that reflux of air into the esophagus occurred more frequently than liquid. The median CSA and estimated diameter of the esophagus during liquid GER was 44.1 mm2 and 7.5 mm, respectively. We conclude that HFIUS is a valid technique to measure the CSA of the esophagus in vivo during GER. Distension of the esophagus during physiological GER is relatively small.

22 IN VITRO FERTILITY ESTIMATES USING SPERM KINETICS VARIABLES AND CONCEPTION RATES IN BEEF HEIFERS

2010 ◽  
Vol 22 (1) ◽  
pp. 169
Author(s):  
M. V. C. Ferraz Jr ◽  
R. S. Macedo ◽  
J. B. Barreto Filho ◽  
T. F. Silva ◽  
R. A. Braga Jr ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Ultrasound Images ◽  
Beef Heifers ◽  
Fast Evaluation ◽  
Spermatozoa Motility ◽  
Frozen Semen ◽  
Conception Rates ◽  
Inertial Moment

Sperm motility is a physical parameter evaluated in semen samples of the bull and is thought to be related to the fertility in the male. Despite being a characteristic of simple and fast evaluation, motility estimates involve subjective components when analyzed by light microscopy (LM) that might restrain their evaluation in some conditions. Moreover, in some species, poor correlations were observed between spermatozoa motility and semen fertility. The incidence of coherent light in a semen sample generates a phenomenon called biospeckle (BSL) that is capable of measuring the kinetics activity of the spermatozoa. In this work the relationship among sperm kinetics variables evaluated by LM and BSL and conception rates in beef heifers was investigated, with the purpose to predict frozen semen fertility when laser light is used. Sixty semen samples of 6 mature AI donor bulls (Bos taurus indicus) herein named A, B, C, D, E, and F were thawed at 37°C for 30 s in a water bath and evaluated by LM and BSL. In LM evaluation, an index (IND) was proposed to group together, in a single mean estimate, the spermatozoa motility (M: % scale) and velocity (V: 1 to 5 scale) according to the equation IND = [V × 20 + M]/2. In the BSL evaluation, each sample was illuminated (n = 10 per bull) by a laser beam (He-Ne, 632 nm and 10 MW) for 40 s and a mean inertial moment (IM) was obtained for each donor bull. These semen samples were used in an AI program of beef heifers (n = 166) clinically examined for reproductive health, body condition, and weight. Pregnancy diagnosis was done by ultrasound images (Falco 100, 6 MHz, Pie Medical, Crawley, UK) 28 days after insemination. Fertility estimates were done by the generalized linear model using logistic regression (stepwise methodology), generating an equation to predict the conception rate of the semen, the variables of which were IM and IND. Results of the predicted conception rates (pCR) using IM and IND and the observed conception rates (oCR) were A (0.5490; 0.57), B (0.6483; 0.68), C (0.7108; 0.71), D (0.4552; 0.28), E (0.4797; 0.54), F (0.3825; 0.47), respectively. Positive correlations (P < 0.05) were observed between pCR and oCR (r = 0.79) showing a similar behavior between in vitro and in vivo estimates. Results of this work showed that there is a high correlation between spermatozoa kinetics and semen fertility in the bull and that BSL motility analysis could be used as an approach to evaluate the fertility of semen samples. Financial support: FAPEMIG grant EDT 94/07, CNPq.

Protease effects on adenylate cyclase in potassium-depleted rabbit kidney

1988 ◽  
Vol 255 (5) ◽  
pp. F1033-F1039
Author(s):  
K. H. Raymond ◽  
S. D. Holland ◽  
T. K. Hymer ◽  
T. D. McKinney ◽  
M. S. Katz
Keyword(s):  
Adenylate Cyclase ◽  
Proteolytic Enzymes ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Rabbit Kidney ◽  
Potassium Depletion ◽  
Collecting Tubules ◽  
And Control

Potassium depletion in rabbits induces a renal concentrating defect in vivo and decreased hydrosmotic response to arginine vasopressin (AVP) in isolated cortical collecting tubules (CCT) perfused in vitro. The molecular basis of the AVP resistance in potassium depletion was investigated by comparing AVP-responsive adenylate cyclase activities in CCT from potassium-depleted and control rabbits. Vasopressin-responsive enzyme activity was impaired in CCT dissected from kidneys of potassium-depleted rabbits but not when kidneys were treated with collagenase to improve microdissection conditions. Potassium depletion also depressed parathyroid hormone (PTH)-stimulated adenylate cyclase activity in proximal straight tubules (PST) dissected from untreated but not collagenase-treated kidneys. Commercially available collagenase, which also contains other proteolytic enzymes, increased AVP-sensitive adenylate cyclase activity in control CCT, and trypsin treatment of CCT dissected without collagenase abolished the decrease in AVP-sensitive activity induced by potassium depletion. Inclusion of trypsin inhibitor during collagenase treatment of kidneys lowered AVP response in CCT from potassium-depleted rabbits. These results demonstrate that potassium depletion impairs hormone-sensitive adenylate cyclase of CCT (and PST) by a protease-sensitive mechanism.

Differential effects of selenium compounds on glucose synthesis in rabbit kidney-cortex tubules and hepatocytes. In vitro and in vivo studies

2007 ◽  
Vol 101 (3) ◽  
pp. 493-505 ◽  
Author(s):  
Anna Kiersztan ◽  
Izabela Lukasinska ◽  
Anna Baranska ◽  
Magdalena Lebiedzinska ◽  
Andrzej Nagalski ◽  
...  
Keyword(s):  
In Vivo Studies ◽  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Selenium Compounds ◽  
Differential Effects ◽  
Glucose Synthesis

scholarly journals Ultrasonic biomechanics method for vortex and wall motion of left ventricle: a phantom and in vivo study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aohua Zhang ◽  
Min Pan ◽  
Long Meng ◽  
Fengshu Zhang ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Wall Motion ◽  
Elasticity Modulus ◽  
Critical Role ◽  
In Vivo Study ◽  
Lv Function ◽  
Ultrasound Images ◽  
Lv Dysfunction

Abstract Background The non-invasive quantitative evaluation of left ventricle (LV) function plays a critical role in clinical cardiology. This study proposes a novel ultrasonic biomechanics method by integrating both LV vortex and wall motion to fully assess and understand the LV structure and function. The purpose of this study was to validate the ultrasonic biomechanics method as a quantifiable approach to evaluate LV function. Methods Firstly, B-mode ultrasound images were acquired and processed, which were utilized to implement parameters for quantifying the LV vortex and wall motion respectively. Next, the parameters were compared in polyvinyl alcohol cryogen (PVA) phantoms with different degree of stiffness corresponding to different freezing and thawing cycles in vitro. Finally, the parameters were computed in vivo during one cardiac cycle to assess the LV function in normal and abnormal subjects in vivo. Results In vitro study, the velocity field of PVA phantom differed with stiffness (varied elasticity modulus). The peak of strain for wall motion decreases with the increase of elasticity modulus, and periodically changed values. Statistical analysis for parameters of vortex dynamics (energy dissipation index, DI; kinetic energy fluctuations, KEF; relative strength, RS; and vorticity, W) based on different elasticity (E) of phantom depicted the good viability of this algorithm. In vivo study, the results confirmed that subjects with LV dysfunction had lower vorticity and strain (S) compared to the normal group. Conclusion Ultrasonic biomechanics method can obtain the vortex and wall motion of left ventricle. The method may have potential clinical value in evaluation of LV dysfunction.

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