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1.
Zhongguo Zhong Yao Za Zhi ; 49(6): 1683-1689, 2024 Mar.
Artículo en Zh | MEDLINE | ID: mdl-38621952

RESUMEN

The purpose of this study was to evaluate the economics of Annao Pills combined with antihypertensive drugs in the treatment of primary hypertension in the Chinese medical setting. TreeAge pro 2018 was used for cost-effect analysis and sensitivity analysis of the two treatment regimens. The intervention time of the simulation model was 2 weeks. The cost parameters were derived from Yaozhi.com, and the effect parameters were based on Meta-analysis of randomized controlled trial(RCT) involving Annao Pills. The experimental group was treated with Annao Pills combined with anti-hypertensive drugs(nifedipine controlled-release tablets + losartan potassium tablets), and the control group was treated with anti-hypertensive drugs(nifedipine controlled-release tablets + losartan potassium tablets). The basic analysis showed that the incremental cost-effect ratio(ICER) of the two groups was 2 678.67 yuan, which was less than 7.26% of the per capita disposable income in 2022. That is, compared with anti-hypertensive drugs alone, Annao Pills combined with antihypertensive drugs cost 2 678.67 yuan more for each additional patient with primary hypertension. The results of sensitivity analysis verified the robustness of the basic analysis results. The probability sensitivity results showed that when the patient's personal willingness to pay the price was higher than 2 650 yuan, the probability of the regimen in the experimental group was higher, which was consistent with the results of the basic analysis. In conclusion, when the price was higher than 2 650 yuan, Annao Pills combined with anti-hypertensive drugs was more economical than anti-hypertensive drugs alone in terms of improving the response rate of the patients with primary hypertension.


Asunto(s)
Antihipertensivos , Nifedipino , Humanos , Antihipertensivos/uso terapéutico , Análisis Costo-Beneficio , Árboles de Decisión , Preparaciones de Acción Retardada , Hipertensión Esencial , Losartán/uso terapéutico
2.
Angew Chem Int Ed Engl ; 63(15): e202319871, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38289019

RESUMEN

The combination of achiral Cp*Rh(III) with chiral carboxylic acids (CCAs) represents an efficient catalytic system in transition metal-catalyzed enantioselective C-H activation. However, this hybrid catalysis is limited to redox-neutral C-H activation reactions and the adopt to oxidative enantioselective C-H activation remains elusive and pose a significant challenge. Herein, we describe the development of an electrochemical Cp*Rh(III)-catalyzed enantioselective C-H annulation of sulfoximines with alkynes enabled by chiral carboxylic acid (CCA) in an operationally friendly undivided cell at room temperature. A broad range of enantioenriched 1,2-benzothiazines are obtained in high yields with excellent enantioselectivities (up to 99 % yield and 98 : 2 er). The practicality of this method is demonstrated by scale-up reaction in a batch reactor with external circulation. A crucial chiral Cp*Rh(III) intermediate is isolated, characterized, and transformed, providing rational support for a Rh(III)/Rh(I) electrocatalytic cycle.

3.
Pharm Biol ; 61(1): 1474-1483, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37855412

RESUMEN

CONTEXT: Berberine is a potential drug that can effectively treat cardiovascular diseases, including premature ventricular contractions (PVCs). OBJECTIVE: This study was conducted to assess the efficacy and safety of berberine for PVCs. METHODS: The literature was searched using PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), Wanfang, and Chinese Biomedical Literature Database (CBM) for randomized controlled trials (RCTs) from inception to October 1, 2022. The risk of bias was assessed using the Revised Cochrane risk-of-bias tool for randomized trials, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was adopted to assess the quality of evidence. RESULTS: Ten RCTs with 896 participants were included in the meta-analysis. The results showed that compared to antiarrhythmic drugs (AD), berberine (BE) combined with AD had a higher effective rate (RR = 1.26; 95% CI:1.12, 1.42; p = 0.0001) with no significant incidence of adverse reactions (RR = 0.93; 95% CI:0.33, 2.57; p = 0.88), and BE alone had no significant difference in effective rate (RR = 0.91; 95% CI:0.77, 1.07; p = 0.23), and a lower incidence of adverse reactions (RR = 0.38; 95% CI:0.15, 0.97; p = 0.04) and recurrence rate (RR = 0.40; 95% CI:0.18, 0.88; p = 0.02). CONCLUSIONS: The results suggest that BE is an effective and safe adjunctive method for PVCs. In addition, BE is recommended for patients with PVCs who had severe adverse reactions after administrating AD as an alternative therapy.


Asunto(s)
Berberina , Medicamentos Herbarios Chinos , Humanos , Medicamentos Herbarios Chinos/uso terapéutico , Berberina/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto , China
4.
Small ; 18(41): e2203264, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36070429

RESUMEN

Superhydrophobic surfaces with the "lotus effect" have wide applications in daily life and industry, such as self-cleaning, anti-freezing, and anti-corrosion. However, it is difficult to reliably predict whether a designed superhydrophobic surface has the "lotus effect" by traditional theoretical models due to complex surface topographies. Here, a reliable machine learning (ML) model to accurately predict the "lotus effect" of solid surfaces by designing a set of descriptors about nano-scale roughness and micro-scale topographies in addition to the surface hydrophobic modification is demonstrated. Geometrical and mathematical descriptors combined with gray level cooccurrence matrices (GLCM) offer a feasible solution to the puzzle of accurate descriptions of complex topographies. Furthermore, the "black box" is opened by feature importance and Shapley-additive-explanations (SHAP) analysis to extract waterdrop adhesion trends on superhydrophobic surfaces. The accurate prediction on as-fabricated superhydrophobic surfaces strongly affirms the extensionality of the ML model. This approach can be easily generalized to screen solid surfaces with other properties.


Asunto(s)
Aprendizaje Automático , Modelos Teóricos , Interacciones Hidrofóbicas e Hidrofílicas , Propiedades de Superficie
5.
Langmuir ; 38(41): 12530-12538, 2022 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-36201865

RESUMEN

Intrinsically poor conductivity and sluggish ion-transfer kinetics limit the further development of electrochemical storage of mesoporous manganese dioxide. In order to overcome the challenge, defect engineering is an effective way to improve electrochemical capability by regulating electronic configuration at the atomic level of manganese dioxide. Herein, we demonstrate effective construction of defects on mesoporous α-MnO2 through simply controlling the degree of redox reaction process, which could obtain a balance between Mn3+/Mn4+ ratio and oxygen vacancy concentration for efficient supercapacitors. The different structures of α-MnO2 including the morphology, specific surface area, and composition are successfully constructed by tuning the mole ratio of KMnO4 to Na2SO3. The electrode materials of α-MnO2-0.25 with an appropriate Mn3+/Mn4+ ratio and abundant oxygen vacancy showed an outstanding specific capacitance of 324 F g-1 at 0.5 A g-1, beyond most reported MnO2-based materials. The asymmetric supercapacitors formed from α-MnO2-0.25 and activated carbon can present an energy density as high as of 36.33 W h kg-1 at 200 W kg-1 and also exhibited good cycle stability over a wide voltage range from 0 to 2.0 voltage (kept at approximately 98% after 10 000 cycles in galvanostatic cycling tests) and nearly 100% Coulombic efficiency. Our strategy lays a foundation for fine regulation of defects to improve charge-transfer kinetics.

6.
Rheumatol Int ; 35(8): 1351-60, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26007152

RESUMEN

Background Vascular endothelial growth factor (VEGF) is an important angiogenic factor and may be connected with chronic immune-mediated inflammatory diseases (IMIDs) to some extent. However, previous researches about the relationship between the +405G>C (dbSNP: rs2010963) polymorphism in VEGF gene and the risk of IMIDs are controversial and inconsistent. So we conducted this meta-analysis to assess whether the relationship between the +405G>C polymorphism in the 5'-UTR region of VEGF gene and IMID susceptibility exists. Methods Our literature search was conducted on the PubMed, Embase, Web of science, Chinese National Knowledge Infrastructure, and Chinese Biomedical databases to retrieve for eligible studies. Odds ratios as well as their 95 % confidence intervals were utilized to deduce the possible relationship. Results A total number of 5175 patients with IMIDs and 7069 healthy controls from 27 case-control studies were included. For the overall eligible data collected in our meta-analysis, there was no marked relationship between +405G>C polymorphism and the risk of IMIDs. However, subgroup analysis by ethnicity suggested that +405C allele could be a protective factor for IMIDs in Asians, whereas an opposite conclusion was drawn in Caucasians. Conclusion Thus, we may come to the conclusion that the VEGF +405G>C polymorphism could be associated with IMIDs, and the correlation might vary with ethnic groups.


Asunto(s)
Enfermedades Autoinmunes/genética , Factor A de Crecimiento Endotelial Vascular/genética , Alelos , Artritis Reumatoide/genética , Pueblo Asiatico/genética , Síndrome de Behçet/genética , Diabetes Mellitus Tipo 1/genética , Predisposición Genética a la Enfermedad , Arteritis de Células Gigantes/genética , Enfermedad de Graves/genética , Humanos , Lupus Eritematoso Sistémico/genética , Síndrome Mucocutáneo Linfonodular/genética , Oportunidad Relativa , Polimorfismo de Nucleótido Simple , Psoriasis/genética , Esclerodermia Sistémica/genética , Población Blanca/genética
7.
iScience ; 27(8): 110446, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39108728

RESUMEN

Soft tissues experience strain under mechanical stresses, storing energy as residual stresses and strain energy. However, the specific impact of such strain on cell migration and its molecular mechanisms remains unclear. In this study, we investigated this by using polydimethylsiloxane (PDMS) membranes with varying prestrain levels but constant stiffness to mimic tissue-like conditions. Results showed that higher prestrain levels enhanced 3T3 fibroblast adhesion and reduced filopodia formation. Elevated prestrain also increased integrin and vinculin expression, which was associated with lower cell migration rates. Notably, both 3T3 fibroblasts and primary rat airway smooth muscle cells migrated faster toward higher prestrain areas on substrates with strain gradients. Knockdown of integrin or vinculin inhibited 3T3 cell migration directionality, highlighting their critical role. This research reveals a mechanobiological pathway where strain gradients direct cell migration, providing insight into a common mechanotransduction pathway influencing cellular responses to both stiffness and strain-related mechanical cues.

8.
Chin Med J (Engl) ; 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38711358

RESUMEN

BACKGROUND: Molecular subtyping is an essential complementarity after pathological analyses for targeted therapy. This study aimed to investigate the consistency of next-generation sequencing (NGS) results between circulating tumor DNA (ctDNA)-based and tissue-based in non-small cell lung cancer (NSCLC) and identify the patient characteristics that favor ctDNA testing. METHODS: Patients who diagnosed with NSCLC and received both ctDNA- and cancer tissue-based NGS before surgery or systemic treatment in Lung Cancer Center, Sichuan University West China Hospital between December 2017 and August 2022 were enrolled. A 425-cancer panel with a HiSeq 4000 NGS platform was used for NGS. The unweighted Cohen's kappa coefficient was employed to discriminate the high-concordance group from the low-concordance group with a cutoff value of 0.6. Six machine learning models were used to identify patient characteristics that relate to high concordance between ctDNA-based and tissue-based NGS. RESULTS: A total of 85 patients were enrolled, of which 22.4% (19/85) had stage III disease and 56.5% had stage IV disease. Forty-four patients (51.8%) showed consistent gene mutation types between ctDNA-based and tissue-based NGS, while one patient (1.2%) tested negative in both approaches. Advanced diseases and metastases to other organs would be fit for the ctDNA-based NGS, and the generalized linear model showed that T stage, M stage, and tumor mutation burden were the critical discriminators to predict the consistency of results between ctDNA-based and tissue-based NGS. CONCLUSION: ctDNA-based NGS showed comparable detection performance in the targeted gene mutations compared with tissue-based NGS, and it could be considered in advanced or metastatic NSCLC.

9.
Eur J Clin Nutr ; 78(3): 171-179, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38093096

RESUMEN

A dramatic shift in the global food system is occurring with the rapid growth of ultra-processed foods (UPFs) consumption, which poses potentially serious health risks. Systematic review (SR) method has been used to summarise the association between UPF consumption and multiple health outcomes; however, a suboptimal-quality SR may mislead the decision-making in clinical practices and health policies. Therefore, a methodological review was conducted to identify the areas that can be improved regarding the risk of bias and reporting quality of relevant SRs. Systematic searches to collect SRs with meta-analyses of UPFs were performed using four databases from their inception to April 14, 2023. The risk of bias and reporting quality were evaluated using ROBIS and PRISMA 2020, respectively. The key characteristics of the included SRs were summarised descriptively. Excel 2019 and R 4.2.3 were used to analyse the data and draw graphs. Finally, 16 relevant SRs written in English and published between 2020 and 2023 in 12 academic journals were included. Only one SR was rated as low risk of bias, and the others were rated as higher risk of bias mainly because the risk of bias in the original studies was not explicitly addressed when synthesising the evidence. The reporting was required to be advanced significantly, involving amendments of registration and protocol, data and analytic code statement, and lists of excluded studies with justifications. The reviews' results could improve the quality, strengthen future relevant SRs' robustness, and further underpin the evidence base for supporting clinical decisions and health policies.


Asunto(s)
Alimentos Procesados , Proyectos de Investigación , Humanos , Sesgo
10.
Chem Commun (Camb) ; 60(12): 1623-1626, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38230709

RESUMEN

P-Stereogenic phosphorus compounds are important structural elements in chiral ligands or organocatalysts. Herein, we report a Pd(II)-catalyzed enantioselective C-H olefination toward the synthesis of P-stereogenic phosphinamides using cheap commercially available L-pGlu-OH as a chiral ligand. A broad range of P-stereogenic phosphinamides were gained in good yields with high enantioselectivities (33 examples, up to 77% yield, 99% ee) via desymmetrization and kinetic resolution.

11.
Thorac Cancer ; 14(30): 3063-3066, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37658846

RESUMEN

Malignant pleural mesothelioma (MPM) is associated with previous asbestos exposure, while more clinical insights into this disease have come from other case studies. Maximal cytoreduction is critical in disease control and might help to improve the prognosis. Here, a 41-year-old female presented with a 6-month history of a mass detected in the chest wall following resection of a right pleural mesothelioma 2 years previously. A fluorodeoxyglucose positron emission tomography/computed tomography scan showed a right chest wall mass with a blurred boundary 8.9 cm × 3.7 cm in size. The patient had received one cycle of bevacizumab, carboplatin, and pemetrexed, and two cycles of nivolumab, ipilimumab, and gemcitabine 5 months before admission. We subsequently resected the tumor, the involved diaphragm, and the fifth and sixth ribs, and titanium mesh and continuous suture were used to close the thoracic cage. The fixed paraffin-embedded tissues showed epithelioid pleural mesothelioma. The patient received nivolumab and ipilimumab postoperatively, and no recurrence was detected 16 months after surgery. En bloc resection with reconstructive surgery effectively removed the locally advanced malignancy and restored the biological function of the thorax with a favorable prognosis. Neoadjuvant immunotherapy might therefore be conducive to radical resection and perioperative immunotherapy might improve the prognosis.


Asunto(s)
Mesotelioma Maligno , Mesotelioma , Neoplasias Pleurales , Pared Torácica , Femenino , Humanos , Adulto , Mesotelioma Maligno/patología , Pared Torácica/cirugía , Pared Torácica/patología , Nivolumab , Ipilimumab , Mesotelioma/cirugía , Mesotelioma/patología , Neoplasias Pleurales/cirugía , Neoplasias Pleurales/patología , Inmunoterapia
12.
Org Lett ; 25(31): 5724-5729, 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37498884

RESUMEN

P-Stereogenic phosphinamides represent important structural elements in chiral organocatalysts and bioactive compounds. Herein, we report Pd(II)-catalyzed enantioselective C-H alkynylation using cheap commercially available l-pyroglutamic acid as a chiral ligand. A range of structurally diverse P-stereogenic phosphinamides was prepared in good yields with high enantioselectivities via desymmetrization and kinetic resolution. A tailor-made congested directing group, N-ethyl-N-(3-methylpyridin-2-yl)amino, was crucial for the reactivity.

13.
Front Cardiovasc Med ; 9: 1032736, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36684565

RESUMEN

Patients with atrial fibrillation (AF) suffer from a high risk of thrombosis. Currently, the CHA2DS2-VASc score is the most widely used tool for risk stratification in patients with AF, but it has disappointing accuracy and limited predictive value, especially in those with low scores. Thrombi in patients with AF mostly grow in their left atrial appendages (LAA), which is directly related to the abnormal morphology of the LAA or the left atrium and the unusual hemodynamic state around LAA, which may sensitively evaluate the risk of thrombosis complications in patients with AF and bring bases to clinical plans of medication and operation. Therefore, we investigated the research progress of hemodynamic and morphological studies about the predictive value of thrombosis risk in patients with AF, intending to discuss the prediction potential of morphological and hemodynamic indexes when compared with the presently used CHA2DS2-VASc system and how to build a more precise thromboembolic event prediction model for patients with AF.

14.
Nutrition ; 90: 111345, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34166897

RESUMEN

OBJECTIVES: Sarcopenia is commonly encountered in patients with advanced cancer, but the role of sarcopenia in predicting prognosis in this group of patients receiving immune checkpoint inhibitors (ICIs) remains undetermined. The aim of this study was to performed the first meta-analysis focusing on the prognostic value of sarcopenia in patients with advanced cancer who were treated with ICIs comprehensively. METHODS: A systematic search for relevant studies in the Web of Science, PubMed, and Embase was conducted on August 19, 2020. Outcomes including response rate, 1-y progression-free survival (PFS) rate, 1-y overall survival (OS) rate, and hazard ratios (HRs) of PFS and OS were extracted. Meta-analysis was performed by using the STATA version 12 software package. RESULTS: Nine cohort studies consisting of 740 patients with advanced cancer receiving ICIs were finally included for analysis. Our meta-analysis found that patients with sarcopenia tended to have a lower response rate than those without the disease (30.5 versus 15.9%; P = 0.095). Furthermore, patients with sarcopenia yielded a significantly shorter 1-y PFS rate (32 versus 10.8%; risk ratio [RR], 1.31; P < 0.001) and 1-y OS rate (66 versus 43%; RR, 1.71; P < 0.001) than patients without sarcopenia. Moreover, sarcopenia was found to be an independent, unfavorable prognostic factor of PFS (HR, 1.79; P < 0.001) and OS (HR, 2.11; P < 0.001) in patients with advanced cancer receiving ICIs. Subgroup analysis further confirmed the unfavorable predictive value of sarcopenia in patients with advanced non-small cell lung cancer and those with melanoma receiving ICIs. CONCLUSIONS: Sarcopenia proved to be an independent, unfavorable prognostic factor in patients with advanced cancer receiving ICIs. Routine assessment of sarcopenia status and correction of sarcopenic status should be emphasized for patients treated with ICIs. Further research with sufficient adjustments for confounding factors are warranted to better elucidate the prognostic value of sarcopenia in these patients.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Sarcopenia , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Humanos , Inhibidores de Puntos de Control Inmunológico , Neoplasias Pulmonares/tratamiento farmacológico , Pronóstico , Sarcopenia/diagnóstico , Sarcopenia/etiología
15.
Comput Math Methods Med ; 2016: 5836410, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27066107

RESUMEN

Limited-angle computed tomography (CT) has great impact in some clinical applications. Existing iterative reconstruction algorithms could not reconstruct high-quality images, leading to severe artifacts nearby edges. Optimal selection of initial image would influence the iterative reconstruction performance but has not been studied deeply yet. In this work, we proposed to generate optimized initial image followed by total variation (TV) based iterative reconstruction considering the feature of image symmetry. The simulated data and real data reconstruction results indicate that the proposed method effectively removes the artifacts nearby edges.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Algoritmos , Artefactos , Gráficos por Computador , Simulación por Computador , Humanos , Imagenología Tridimensional , Modelos Estadísticos , Fantasmas de Imagen , Rayos X
16.
Phys Med ; 32(10): 1276-1283, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27289353

RESUMEN

PURPOSE: Non-local means (NLM) based reconstruction method is a promising algorithm for few-view computed tomography (CT) reconstruction, but often suffers from over-smoothed image edges. To address this problem, an adaptive NLM reconstruction method based on rotational invariance (ART-RIANLM) is proposed. METHODS: The method consists of four steps: 1) Initializing parameters; 2) ART reconstruction using raw data; 3) Positivity constraint of the reconstructed image; 4) Image updating by RIANLM filtering. In RIANLM, two kinds of rotational invariance measures which are average gradient (AG) and region homogeneity (RH) are proposed to calculate the distance between two patches and a novel NLM filter is developed to avoid over-smoothed image. Moreover, the parameter h in RIANLM which controls the decay of the weights is adaptive to avoid over-smoothness, while it is constant in NLM during the whole reconstruction process. The proposed method is validated on two digital phantoms and real projection data. RESULTS: In our experiments, the searching neighborhood size is set as 15×15 and the similarity window is set as 3×3. For the simulated case of Shepp-Logan phantom, ART-RIANLM produces higher SNR (36.23dB>24.00dB) and lower MAE (0.0006<0.0024) reconstructed images than ART-NLM. The visual inspection demonstrated that the proposed method could suppress artifacts or noises more effectively and recover image edges better. The result of real data case is also consistent with the simulation result. CONCLUSIONS: A RIANLM based reconstruction method for few-view CT is presented. Compared to the traditional ART-NLM method, SNR and MAE from ART-RIANLM increases 51% and decreases 75%, respectively.


Asunto(s)
Algoritmos , Tomografía Computarizada por Rayos X/métodos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Artefactos , Fenómenos Biofísicos , Simulación por Computador , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Modelos Estadísticos , Fantasmas de Imagen , Dosis de Radiación , Relación Señal-Ruido , Tomografía Computarizada por Rayos X/efectos adversos
17.
Phys Med ; 32(9): 1041-51, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27501875

RESUMEN

PURPOSE: Limited-angle CT imaging is an effective technique to reduce radiation. However, existing image reconstruction methods can effectively reduce streak artifacts but fail to suppress those artifacts around edges due to incomplete projection data. Thus, a modified NLM (mNLM) based reconstruction method is proposed. METHODS: Since the artifacts around edges mainly exist in local position, it is possible to restore the true pixels in artifacts using pixels located in artifacts-free regions. In each iteration, mNLM is performed on image reconstructed by ART followed by positivity constraint. To solve the problem caused by ART-mNLM that there is undesirable information that may appear in the image, ART-TV is then utilized in the following iterative process after ART-mNLM iterates for a number of iterations. The proposed algorithm is named as ART-mNLM/TV. RESULTS: Simulation experiments are performed to validate the feasibility of algorithm. When the scanning range is [0, 150°], our algorithm outperforms the ART-NLM and ART-TV with more than 40% and 29% improvement in terms of SNR and with more than 58% and 49% reduction in terms of MAE. Consistently, reconstructed images from real projection data also demonstrate the effectiveness of presented algorithm. CONCLUSION: This paper uses mNLM which benefits from redundancy of information across the whole image, to recover the true value of pixels in artifacts region by utilizing pixels from artifact-free regions, and artifacts around the edges can be mitigated effectively. Experiments show that the proposed ART-mNLM/TV is able to achieve better performances compared to traditional methods.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X , Algoritmos , Artefactos , Simulación por Computador , Humanos , Modelos Estadísticos , Fantasmas de Imagen , Reproducibilidad de los Resultados , Relación Señal-Ruido
18.
Comput Math Methods Med ; 2015: 354869, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26089962

RESUMEN

Radiation dose reduction without losing CT image quality has been an increasing concern. Reducing the number of X-ray projections to reconstruct CT images, which is also called sparse-projection reconstruction, can potentially avoid excessive dose delivered to patients in CT examination. To overcome the disadvantages of total variation (TV) minimization method, in this work we introduce a novel adaptive TpV regularization into sparse-projection image reconstruction and use FISTA technique to accelerate iterative convergence. The numerical experiments demonstrate that the proposed method suppresses noise and artifacts more efficiently, and preserves structure information better than other existing reconstruction methods.


Asunto(s)
Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Algoritmos , Biología Computacional , Humanos , Modelos Estadísticos , Fantasmas de Imagen , Dosis de Radiación
19.
Biomed Mater Eng ; 26 Suppl 1: S1389-98, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26405900

RESUMEN

Low-dose computed tomography reconstruction is an important issue in the medical imaging domain. Sparse-view has been widely studied as a potential strategy. Compressed sensing (CS) method has shown great potential to reconstruct high-quality CT images from sparse-view projection data. Nonetheless, low-contrast structures tend to be blurred by the total variation (TV, L1-norm of the gradient image) regularization. Moreover, TV will produce blocky effects on smooth and edge regions. To overcome this limitation, this study has proposed an iterative image reconstruction algorithm by combining L1 regularization and smoothed L0 (SL0) regularization. SL0 is a smooth approximation of L0 norm and can solve the problem of L0 norm being sensitive to noise. To evaluate the proposed method, both qualitative and quantitative studies were conducted on a digital Shepp-Logan phantom and a real head phantom. Experimental comparative results have indicated that the proposed L1/SL0-POCS algorithm can effectively suppress noise and artifacts, as well as preserve more structural information compared to other existing methods.


Asunto(s)
Algoritmos , Artefactos , Encéfalo/anatomía & histología , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Humanos , Fantasmas de Imagen , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Relación Señal-Ruido , Tomografía Computarizada por Rayos X/instrumentación
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