Cardiomyocyte-specific Peli1 contributes to the pressure overload-induced cardiac fibrosis through miR-494-3p-dependent exosomal communication.

Cardiac fibrosis is an essential pathological process in pressure overload (PO)-induced heart failure. Recently, myocyte-fibroblast communication is proven to be critical in heart failure, in which, pathological growth of cardiomyocytes (CMs) may promote fibrosis via miRNAs-containing exosomes (Exos). Peli1 regulates the activation of NF-κB and AP-1, which has been demonstrated to engage in miRNA transcription in cardiomyocytes. Therefore, we hypothesized that Peli1 in CMs regulates the activation of cardiac fibroblasts (CFs) through an exosomal miRNA-mediated paracrine mechanism, thereby promoting cardiac fibrosis. We found that CM-conditional deletion of Peli1 improved PO-induced cardiac fibrosis. Moreover, Exos from mechanical stretch (MS)-induced WT CMs (WT MS-Exos) promote activation of CFs, Peli1-/- MS-Exos reversed it. Furthermore, miRNA microarray and qPCR analysis showed that miR-494-3p was increased in WT MS-Exos while being down regulated in Peli1-/- MS-Exos. Mechanistically, Peli1 promoted miR-494-3p expression via NF-κB/AP-1 in CMs, and then miR-494-3p induced CFs activation by inhibiting PTEN and amplifying the phosphorylation of AKT, SMAD2/3, and ERK. Collectively, our study suggests that CMs Peli1 contributes to myocardial fibrosis via CMs-derived miR-494-3p-enriched exosomes under PO, and provides a potential exosomal miRNA-based therapy for cardiac fibrosis.

Morphological changes of the thoracic duct and accessory lymphatic channels in patients with chylothorax: detection with unenhanced magnetic resonance imaging.

OBJECTIVES: To characterise the imaging findings of patients with chylothorax and to identify the leak site using unenhanced MRI. METHODS: Seven patients with chylothorax and 30 healthy individuals (as the control group) underwent three-dimensional heavily and routine T2-weighted MRI. Morphological changes and diameters of the thoracic duct, chyloma display, and some dilated accessory lymph channels were evaluated and measured. The differences between patients and the control group were compared. The leak sites of the thoracic duct and parietal pleura were also identified. RESULTS: The patients had a higher display rate of the entire thoracic duct and some accessory lymphatic channels, enlarged diameters and tortuous configuration of the thoracic duct, and existence of chylomas compared with the control group (P < 0.05). Seven leaks of the thoracic duct in five patients and five leaks of the parietal pleura in four patients were identified. Close relationships between the leak of thoracic duct and the chylomas or the meshworks of tiny lymphatics were found (P < 0.05). CONCLUSION: Unenhanced MRI appears reliable in the detection of morphological changes of thoracic lymphatics and in the identification of chyloma and leak sites in patients with chylothorax, which helps appropriate treatment planning and follow-up.

Optimizing the Structure and Electrochemical Properties of Benzoquinone-Embedded COF via Heat Treatment for a High-Energy Organic Cathode.

A benzoquinone-embedded aza-fused covalent organic framework (BQ COF) with the maximum loading of redox-active units per molecule was employed as a cathode for lithium-ion batteries (LIBs) to achieve high energy and power densities. The synthesis was optimized to obtain high crystallinity and improved electrochemical performance. Synthesis at moderate temperature followed by a solid-state reaction was found to be particularly useful for achieving good crystallinity and the activation of the COF. When used as a cathode for LIBs, very high discharge capacities of 513, 365, and 234 mAh g-1 were obtained at 0.1C, 1C, and 10C, respectively, showing a remarkable rate performance. More than 70% of the initial capacity was retained after 1000 cycles when the cathode was investigated for cyclic performance at 2.5C. We demonstrated that a straightforward heat treatment led to enhanced crystallinity, an optimized structure, and favorable morphology, resulting in enhanced electrode kinetics and an improved overall electrochemical behavior. A comparative study was conducted involving an aza-fused COF lacking carbonyl groups (TAB COF) and a small molecule containing phenazine and carbonyl (3BQ), providing useful insights into new material design. A full cell was assembled with graphite as the anode to assess the commercial feasibility of BQ COF, and a discharge capacity of 240 mAh g-1 was obtained at 0.5C. Furthermore, a pouch-type cell with a high discharge capacity and an excellent rate performance was assembled, demonstrating the practical applicability of our designed cathode. Considering the entire mass of the working electrode, a specific energy density of 492 Wh kg-1 and a power density of 492 W kg-1 were achieved at the high current density of 1C, which are comparable to those of commercially available cathodes. These results highlight the promise of organic electrode materials for next-generation lithium-ion batteries. Furthermore, this study provides a systematic approach for simultaneously designing organic materials with high power and energy densities.

[Value of 3T magnetic resonance dynamic contrast-enhanced and diffusion-weighted imaging in differential diagnosis of musculoskeletal tumors].

OBJECTIVE: To evaluate the value of magnetic resonance dynamic contrast-enhanced (MR-DCE) and magnetic resonance diffusion-weighted imaging (MR-DWI) in the differentiation of benign and malignant musculoskeletal tumors. METHODS: Sixty-three patients with pathologically confirmed musculoskeletal tumors were examined with MR-DCE and MR-DWI. Using single shot spin echo planar imaging sequence and different b values of 400, 600, 800 and 1000 s/mm(2), we obtained the apparent diffusion coefficient (ADC) of the lesions. ADC values were measured before and after MR-DCE, with a b value of 600 s/mm(2). The 3D fast acquired multiple phase enhanced fast spoiled gradient recalled echo sequence was obtained for multi-slice of the entire lesion. The time-signal intensity curve (TIC), dynamic contrast-enhanced parameters, maximum slope of increase (MSI), positive enhancement integral, signal enhancement ratio, and time to peak (T(peak)) were also recorded. RESULTS: ADC showed no significant difference between benign and malignant tumors when the b value was 400, 600, 800, or 1000 s/mm(2), and it was not significantly different between benign and malignant tumors in both pre-MR-DCE and post-MR-DCE with b value of 600 s/mm(2). TIC were classified into four types type1 showed rapid progression and gradual drainage; type2 showed rapid progression but had no or slight progression; type 3 showed gradual progression; and type 4 had no or slight progression. Most lesions of type1 or type2 were malignant, whereas most lesions of type 3 or type 4 were benign. When using type1 and type 2 as the standards of malignancy, the diagnostic sensitivity and specificity was 87.23% and 50.00%, respectively. The types of TIC showed significant difference between benign and malignant musculoskeletal tumors(χ(2)=17.009,P=0.001). When using MSI 366.62 ± 174.84 as the standard of malignancy, the diagnostic sensitivity and specificity was 86.78% and 78.67%, respectively. When using T(peak)≤70s as the standard of malignancy, the diagnostic sensitivity and specificity was 82.89%and 85.78%, respectively. Positive enhancement integral and signal enhancement ratio showed no significant difference between benign and malignant musculoskeletal tumors. CONCLUSIONS: TIC, MSI and T(peak) of MR-DCE are valuable in differentiating benign from malignant musculoskeletal tumors. T(peak) has the highest diagnostic specificity, and TIC has the highest diagnostic sensitivity. The mean ADC value are no significant difference between benign and malignant tumors.

Detection of hemorrhagic hypointense foci in radiation injury region using susceptibility-weighted imaging.

BACKGROUND: Susceptibility-weighted imaging (SWI), a novel, highly sensitive 3D gradient echo MR imaging technique, is used to detect hemorrhage. PURPOSE: To evaluate SWI at 3.0T for detection and visualization of hemorrhage at radiation injury region after radiotherapy for brain glioma. MATERIAL AND METHODS: In 16 patients who had radiation injury in the vicinity of the previously resected and irradiated high-grade brain glioma, SWI examinations were performed on a 3T MR scanner. The presence of intralesional hypointense foci on SWI was evaluated by two neuroradiologists. Frequency of these foci on SWI was assessed and the number of these foci was counted. Diagnosis of radiation injury was assigned by means of histopathology or follow-up MR image. RESULTS: In all 16 cases with cerebral radiation injury, nine were verified by means of histopathologic examination, seven by follow-up image. While in one patient quality of SWI was poor, in all remaining patients diagnostic-quality SWI was obtained. The intralesional hypointense foci were detected in 12 of 15 patients. These hypointense foci were nodular, angular, or tubular regions of low signal intensity on SWI. The distribution of these foci was diffusive (n=5) or scattered (n=7). Number of these foci per cm(2) on SWI was 7.25 ± 3.67. CONCLUSION: SWI is a novel and promising technique for evaluation of hemorrhage at radiation injury regions in the vicinity of the previously treated gliomas.

[Application value of 3T 1H-magnetic resonance spectroscopy in diagnosing tumors of bone and soft tissue].

OBJECTIVE: To study benign and malignant bone and soft tissue tumors with 1H-magnetic resonance spectroscopy (1H-MRS) at 3 Tesla MR scanner and assess the value of 1H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors. METHODS; Totally 49 patients with clinically and pathologically confirmed bone and soft tissue tumors were enrolled in this study. 1H-MRS was performed before treatment with point-resolved spectroscopy sequence. The imaging characteristics of 1H-MRS for bone and soft tissue tumors were observed and the possible differences between benign and malignant tumors was compared. Since spectra were directly found under single-voxel proton MRS brain examination, the peak height of choline containing compounds (Cho) opposite to the creatine (Cr) and the Cho peak were observed, and then the malignancies of the tumors were judged. Cho/Cr value was calculated and used to distinguishing benign tumors from malignancies. RESULTS: 1H-MRS spectra of bone and soft tissue tumors were different from those of the normal muscles, and such difference also existed between benign and malignant tumors. The Cho peak disappeared or was extremely low among benign tumors. The Cho/Cr values of malignant tumors and benign tumors were 3.13 +/- 0.9 and 1.34 +/- 1.02, respectively (P = 0.02). Using 1.79 as the threshold value, the Cho/Cr value had sensitivity, specificity, and accuracy of 94%, 80%, and 90%, respectively, in diagnosing malignancies. CONCLUSIONS: The increased Cho level, as measured by 1H-MRS, is related with the bone and soft tissue malignant tumor. Cho/Cr value is useful in distinguishing benign tumors from malignancies. 1H-MRS can be an important supplement to the conventional magnetic resonance imaging.

Morphological features and clinical feasibility of thoracic duct: detection with nonenhanced magnetic resonance imaging at 3.0 T.

PURPOSE: To evaluate the detection of the thoracic duct using nonenhanced magnetic resonance imaging (MRI) and to determine the influence of some related disorders on the lymphatic duct. MATERIALS AND METHODS: Highly fluid-sensitive sequence and fat-suppressed T2-weighted imaging (FS-T2WI) were performed in a total of 139 cases. The axial and coronal images were used to locate the thoracic duct and the measurement and evaluation of its dimensions were performed using a 3D maximum intensity projection (MIP) reconstruction image. The differences in the dimensions among control, portal hypertension, and common bile duct obstruction groups were compared using one-way analysis of variance. RESULTS: The cisterna chyli was shown in 91% of cases on FS-T2WI, while the thoracic duct appeared in 70% of the MIP images. The common configuration of the cisterna chyli was tubular or saccular in 73%. Eighty thoracic ducts had a slight turn declining to the left at the level of T8-10. There was a significant difference in the transverse diameter of the thoracic duct between the portal hypertension group and other groups (F = 5.638, P = 0.005). CONCLUSION: Nonenhanced MRI is feasible for locating and depicting the morphological features of the thoracic duct. Portal hypertension may influence the dimension of the thoracic duct.

[Evaluation of blood oxygen level in hepatocellular carcinoma with noninvasive magnetic resonance multi-echo R2* technique and its clinical significance].

OBJECTIVE: To probe the relationship of clinical and pathological features of hepatocellular carcinoma (HCC) with the blood oxygen level by the technique of noninvasive magnetic resonance multi-echo R2*. METHODS: Multi-echo R2* sequence was carried out pre-operatively in a total of 46 patients with pathologically proved HCC. The T2* and R2* values of HCC, liver, spleen and paraspinous muscle on T2* and R2* maps and the ratios of HCC to liver (H/L), spleen (H/S) and muscle (H/M) were calculated. Different groups were defined according to such clinical parameters as the serum AFP level, lesion dimension, Edmondson's grade, ascites, capsula, liver cirrhosis, intrahepatic daughter foci or tumor-emboli in portal vein respectively. The differences in T2* and R2* values and the ratios between different groups were analyzed. RESULTS: In contrast with T2* value, the R2* value of HCC was less than that of liver or spleen (P < 0.05). Difference in R2* ratio of H/M (0.81 +/- 0.26 vs. 1.23 +/- 0.39) was found between positive and negative groups of AFP (P = 0.047, t = 2.248). And so was the same difference (0.83 +/- 0.24 vs. 1.23 +/- 0.43) between the lesions with or without capsula (P = 0.046, t = 2.257). The R2* ratio of H/S in hepatic cirrhosis group (1.01 +/- 0.58) was higher than that in noncirrhosis one (0.53 +/- 0.17) (P = 0.035, t = 2.247) whereas the T2* ratio of H/S was reversed (1.42 +/- 0.92 vs. 2.64 +/- 1.15) (P = 0.036, t = 2.230). The differences in T2* ratio of H/M in the group with or without intrahepatic daughter foci (1.18 +/- 0.47 vs. 2.24 +/- 1.71) (P = 0.048, t = 2.115), and in T2* value in the group with or without tumor-emboli in portal vein (27.24 +/- 11.90 ms vs. 46.70 +/- 38.40 ms) (P = 0.049, t = 2.046) were shown to be significant. However, no differences in MR parameters between other groups were observed (P > 0.05). CONCLUSION: The blood oxygen level parameters, R2* and T2* values and the ratios are related to some clinical and pathological features of HCC. And the blood oxygen level is affected by multiple factors.

[Changes of 3-tesla 31P-MR spectroscopy of bone and soft tissue tumors].

OBJECTIVE: To study the characteristic changes of 31P-MR spectroscopy of bone and soft tissue tumors. METHODS: 41 patients were examined by phosphorus surface coil of 3 tesla MR machine, including 18 benign tumor foci and 28 malignant foci, and adjacent normal muscles. The areas under the peaks of various metabolites in the spectra were measured, including phosphomonoester (PME), inorganic phosphours (Pi), phosphodiester (PDE), phosphocreatine (Pcr), adenosine triphosphate (ATP) gamma, alpha, beta. The ratios of the metabolites to beta-ATP, NTP and Pcr were calculated. Intracellular pH was calculated according to the chemical shift change of Pi relative to Pcr. RESULTS: The ratios of Pcr/PME and PME/NTP in benign and malignant tumor groups were significantly different from those of the normal group (P<0.05). Between benign and malignant tumor groups, the ratios of PME/beta-ATP and PME/NTP were significantly different (P<0.05). CONCLUSION: Pcr/PME and PME/NTP are potential diagnostic indexes of bone and soft tissue tumors. PME/beta-ATP and PME/NTP are potential indexes of differential diagnosis of bone and soft tissue tumors.

[Angiogenesis and its maturation of hepatocellular carcinoma and its correlation with the deoxyhemoglobin parameters R2 * and T2 * values by using noninvasive magnetic resonance imaging].

OBJECTIVE: To explore the angiogenesis and its maturation of hepatocellular carcinoma (HCC) and its correlation with deoxyhemoglobin parameters R2 * and T2 * values and the lesion/muscle R2*, T2 * ratio by using noninvasive magnetic resonance imaging (MRI). METHODS: T2 *, R2 * values and the lesion/muscle R2 *, T2 * ratio in tumor periphery and center were calculated via series T2 * images in a total of 31 patients with surgically and pathologically confirmed HCC. After surgery, all sections were obtained from the specimen periphery in accordance with the MR analyzed areas. Continuous slices of each lesion were stained with hematoxylin-eosin (HE), and immunohistochemical staining was performed in vascular endothelial growth factor (VEGF), Flk-1, proliferating cell nuclear antigen (PCNA), CD34, and alpha smooth muscle actin (SMA). The expressions of VEGF, Flk-1, and PCNA index (PI) were evaluated. According to CD34 and SMA, some vascular parameters, including number, mean vessel area, total vessel area, circumference, diameter, distance between adjacent vessels, and variety index of microvessel and mature vessel, were calculated with a computed analysis system. The amounts of arterioles and veinlets, mature vessel index, and mean perfused fraction (mPF) were also recorded. All vessel parameters were compared with the calculated values of MRI. RESULTS: R2 * value or lesion/muscle R2 * ratio decreased and T2 * value or the lesion/muscle T2 * ratio increased in HCC when compared with hepatic parenchyma (P < 0.05); however, those values between lesion periphery and center and among different pathological grades were not significantly different (P > 0.05). T2 * value and the lesion/muscle T2 * ratio significantly decreased when the expression of VEGF was positive (P < 0.05). T2 * value was negatively correlated with microvessel amount (P = 0.047, r = - 0.639), while T2 * value and the lesion/muscle T2 * ratio were positively correlated with mPF (P = 0.040, r = 0.655; P = 0.048, r = 0.40, respectively). R2 * value was also positively correlated with mean area (P = 0.028, r = 0.688), total area (P = 0.021, r = 0.712) or circumference (P = 0.037, r = 0.663) of microvessel, and negatively correlated with mPF (P = 0.024, r = - 0.702). Meanwhile, the lesion/muscle R2 * ratio was positively correlated with mean area (P = 0.043, r = 0.647) and circumference (P = 0.026, r = 0.694) of microvessels. CONCLUSION: R2 * or T2 * value may be influenced by the variation of deoxyhemoglobin caused by the heterogeneity of angiogenesis.

[Algorithm of brain pathology detection based on statistical atlas of attribute vectors].

To detect lesions of brain CT automatically, a statistical atlas of attribute vectors (SAAV) was designed and created to describe the multiple features of medical images. By comparing the features of study image with those of SAAV, we successfully detected various kinds of brain lesion. It was demonstrated that the algorithm is effective in detecting various kinds of lesions found on brain CT images. Further studies are needed to make the algorithm more acceptable.

[A method to enhance user experience of EMR based on mining association rules of incremental updating data].

The user experience (EX) of current Electronic Medical Record systems (EMR) is needed to improve. This paper proposed a new method to enhance EX of EMR. Firstly, system template and text characterization are used to make the EMR data structured. Then, the structured date are mined based on mining the association rules of incremental updating data to find the association of the elements of template of EMR and the values of elements. Finally, with the help of mined results, the users of EMR are able to input data effectively and quickly.

[A new algorithm for ultrasound image speckle suppression].

Ultrasound image has a lot of speckle noise, which brings great difficulties to the feature extraction, recognition and analysis. Especially in the edge extraction, the conventional extraction algorithms are difficult to achieve the desired results because of the speckle noise. To solve this problem, an algorithm based on the anisotropic diffusion equation is presented. The new algorithm combines the robust estimation and considers the characteristic of the speckle noise, so it can suppress the speckle noise effectively and be more robust, thus the edge details of the ultrasound image can be preserved even enhanced, which can provide effective safeguard for the following edge extraction. Furthermore, the paper proposes a new method to compute speckle scale coefficients automatically, which reduces the influence of the human beings, and enhances the stability of the algorithm.

[Application of fingerprint identification technology in EMR system].

Based on the deep analysis of existing fingerprint identification algorithms, this article proposes an integrative solution to adopt the fingerprint identification technology into EMRS Electronic Medical Records System. It may improve the security of EMRS and raise the working efficiency of physicians effectively.

[Effect of acupuncture and moxibustion on brain functional connectivity network in patients with refractory facial paralysis].

OBJECTIVE: To observe the effects of acupuncture on resting-state functional connectivity (rs-FC) in patients with refractory peripheral facial paralysis, and to preliminarily explore the central mechanism of acupuncture for this disease. METHODS: Twenty patients with refractory peripheral facial paralysis were selected as subject and treated with acupuncture at Qianzheng (EX-HN 16), Fengchi (GB 20), Cuanzhu (BL 2), Dicang (ST 4), Jiache (ST 6), Shuigou (GV 26), Chengjiang (CV 24), Yifeng (TE 17), Touwei (ST 8), Sibai (ST 2), Yingxiang (LI 20) and Hegu (LI 4), once every other day, three times a week, 15 times as a course of treatment. The 1-course treatment was given. The score of Sunnybrook (Toronto) facial grading system was used to evaluate the clinical efficacy before and after the treatment. In addition, 20 healthy volunteers were selected as control. For patients, the resting-state functional magnetic resonance imaging (rs-fMRI) scans were performed before and after treatment, for healthy volunteers, the scans were performed when they were recruited. The brain magnetic resonance images were analyzed with left primary motor area (LMⅠ) and right primary motor area (RMⅠ) as regions of interest. The differences of rs-FC between patients with refractory peripheral facial paralysis before and after treatment and healthy volunteers were compared. RESULTS: Compared before treatment, the Sunnybrook score was increased after the treatment (P<0.05). Compared with healthy volunteers, the functional connection between bilateral primary motor areas (MⅠ) and multiple brain areas were enhanced in patients before treatment, and most of brain areas were located in the anterior motor area (middle frontal gyrus, superior frontal gyrus), posterior central gyrus, anterior cuneiform lobe, middle temporal gyrus, inferior temporal gyrus and cerebellum lobe. Compared before treatment, the left inferior frontal gyrus was the strong functional connection area between LMⅠ and whole brain after acupuncture treatment, and there was no significant difference between RMⅠ and resting-state whole brain. Compared with healthy volunteers, the functional connections between bilateral MⅠ and multiple brain regions were enhanced after acupuncture, and most of the main brain regions were consistent with those before treatment. CONCLUSION: (1) Acupuncture could effectively improve the clinical symptoms of refractory peripheral facial paralysis. (2) The brain function of patients with refractory peripheral facial paralysis has been changed before acupuncture, which may be caused by the reactive compensation of the brain. (3) Acupuncture could enhance the functional connection between LMⅠ and left inferior frontal gyrus to promote the compensatory response, which may be one of the central mechanisms of acupuncture for refractory peripheral facial paralysis.

Metabolite concentration ratios in thalami of patients with migraine and trigeminal neuralgia measured with 1H-MRS.

OBJECTIVE: To investigate the metabolite concentration ratios including N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine plus phosphocreatine (Cr) in thalami of patients with migraine without aura, patients with trigeminal neuralgia and healthy comparison subjects using multi-voxel proton magnetic resonance spectroscopy (1H-MRS). METHODS: 1H-MRS was performed with a 3.0 T MR system on the thalamus bilaterally in 20 patients with migraine without aura, 16 patients with trigeminal neuralgia and 14 healthy control subjects. RESULTS: In the patients with trigeminal neuralgia, metabolite concentration ratios except for Cho/Cr in thalami were different from those of healthy subjects (p>0.05). In migraine group, only NAA/Cho is low in the left thalamus (p>0.05). Comparing the metabolite concentration ratios of affected and contralateral sides in migraine and trigeminal neuralgia groups, only NAA/Cr showed a significant difference (p>0.05). CONCLUSION: It was proved that migraine and trigeminal neuralgia seemed to be associated with an abnormal balance of the neural activity in the thalamus using 1H-MRS. There was some significant difference between metabolite concentration ratios in two diseases. 1H-MRS may serve as a useful non-invasive tool for evaluating thalamic neural activity and therapy effect in clinical performance of patients with migraine without aura.

[An algorithm of nodule detection based on high resolution CT images].

Combining the speed of two-dimensional detection with the precision of three-dimensional detection, an automatic algorithm based on high resolution CT images is proposed to identify nodules in this paper. Nodule candidates are extracted by a two-dimensional convergence index (CI) filter, then a three-dimensional Hessian matrix detection filter is introduced to reduce false positive lung nodules, Experiments show that the algorithm is effective with a sensitivity of 90% and the false positive lung nodules per slice is 0.33.

[Diagnosis of prostate cancer using SVM-based ultrasound images].

This paper presents a computer-aided diagnosis method for prostate cancer detection using Trans-rectal ultrasound(TRUS) images. Firstly, statistical texture analysis is implemented in every ROI in segmented prostate images. From each ROI, grey level difference vector features, edge-frequency features and texture features in frequency domain are constructed. Then, the number of features is reduced using ANOVA statistics to select the optimal feature subset. Finally, SVM is applied to the selected subset for detecting the cancer regions. Experimental results show that the proposed algorithm can recognize and detect the cancer images effectively so as to supply essential information for a diagnosis.

[Three domains filtering for medical ultrasound images denoising].

A filtering algorithm is proposed to deal with the medical ultrasonic image series in video format, which uses the relativity in spatial domain, gray value domain and temporal domain simultaneously. For each frame image, the relativity in spatial domain and gray value domain is utilized to construct the adaptive neighborhood first. Then the spatial weighted and gray value weighted filtering is performed in this neighborhood. Finally, the temporal relativity between the adjacent frames is used to perform the temporal weighted filtering. All the weighted filtering in the three domains uses Gaussian kernel, thus the filtering sensitivity resulting from the threshold selection is reduced, and the stability of the algorithm is enhanced. As it can be seen from the experimental results, the three-domains filtering algorithm can suppress the noise effectively, and the edge details can be reserved well. So it is useful for the feature extraction, recognition and analysis.

[Segmentation of the prostate ultrasound image based on an improved geodesic active contour model].

In this paper, we propose that, the need of the costly re-initialization procedure can be completely eliminated by using the variation formulation, thus increasing the speed of computing operations. The edge detecting function in the geodesic active contour model is improved by incorporating a prior knowledge. The accuracy of the segmentation algorithm can be enhanced by using the minimal variance. Experimental results show that the proposed algorithm can segment the prostate ultrasound images effectively and avoid the problem of contour leakage.