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Conspectus2D conjugated metal-organic frameworks (2D -MOFs) have emerged as a class of graphene-like materials with fully π-conjugated aromatic structures. Their unique structural characteristics provide abundant physiochemical features, including regular nanochannels, high electrical conductivity, and customizable band gaps. Recent intensive research has significantly advanced this field, yet the exploration of 2D c-MOFs with enhanced features is limited by the availability of organic linkages and topologies. Designing novel ligands is essential for the construction of new 2D c-MOFs with high crystallinity, excellent conductivity, and tailor-made functions.In this Account, we summarize our recent contributions in fine-tuning the topology of 2D c-MOFs through precise ligand design, thereby giving them fantastic structures and tailor-made functions. First, we propose the concept of replacing planar ligands by nonplanar ligands on conductive MOF skeletons. The incorporation of nonplanar ligands improves the solubility of large π-conjugated organic molecules without interfering with the interlayer π-stacking. Our investigation discovered that conjugate polycyclic aromatics-based ligands can be synthesized through in situ Scholl reactions by means of oxidative cyclodehydrogenation of a nonplanar precursor ligand during the solvothermal synthesis process. Hence, fully conjugated 2D c-MOFs can be directly synthesized from nonplanar organic ligands, simplifying and diversifying the preparation of 2D c-MOFs. Accordingly, the design flexibility of the ligands expands the topological structures and pore types. By controlling the synthesis conditions, we can successfully induce either a rhombus or a kagome topology from a nonplanar D2 symmetric ligand. Moreover, by employing a ligand engineering strategy, we incrementally increase the number of coordination functional groups on a twisted hexabenzocoronene core, resulting in the formation of three distinct symmetric hydroxyl ligands. These ligands elicit diverse target topologies and pore sizes, resulting in variances in the coordination node density on the skeletons. This, in turn, leads to differences in electron transfer abilities, ultimately causing variations in the electrical conductivity and mobility. In addition, we employ a straightforward coupling method to incorporate redox components, such as salphen and pyrazine, into nonplanar ligands, facilitating the synthesis of 2D c-MOFs with highly active centers. This strategy confers upon the resulting frameworks substantial capacity for catalysis and energy storage, offering a good platform for elucidating the structure-property relationships at the molecular level. Moreover, the well-defined synthesis of 2D c-MOFs imparts them with specific properties, particularly in the fields of electrical, electrochemical, and spintronic applications. At the end, the primary challenges facing 2D c-MOFs in achieving tailor functions and their practical applications are proposed. This account is expected to evoke new inspirations and innovative research in the field of 2D c-MOFs, especially in emerging interdisciplinary research areas.
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Conductive metal-organic frameworks (c-MOFs) with outstanding electrical conductivities and high charge carrier mobilities are promising candidates for electronics and optoelectronics. However, the poor solubility of planar ligands greatly hinders the synthesis and widespread applications of c-MOFs. Nonplanar ligands with excellent solubility in organic solvents are ideal alternatives to construct c-MOFs. Herein, contorted hexabenzocoronene (c-HBC) derivatives with good solubility are adopted to synthesize c-MOFs. Three c-MOFs (c-HBC-6O-Cu, c-HBC-8O-Cu, and c-HBC-12O-Cu) with substantially different geometries and packing modes have been synthesized using three multitopic catechol-based c-HBC ligands with different symmetries and coordination numbers, respectively. With more metal coordination centers and increased charge transport pathways, c-HBC-12O-Cu exhibits the highest intrinsic electrical conductivity of 3.31 S m-1. Time-resolved terahertz spectroscopy reveals high charge carrier mobilities in c-HBC-based c-MOFs, ranging from 38 to 64 cm2 V-1 s-1. This work provides a systematic and modular approach to fine-tune the structure and enrich the c-MOF family with excellent charge transport properties using nonplanar and highly soluble ligands.
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Ewing's sarcoma in the cervix is characterized by extremely rare occurrence,high degree of malignancy,and rapid progression.The diagnosis of this disease is based on pathology and immunohistochemistry. The main image of the case reported in this paper showed the cervical cyst with solid mass,large volume,and uneven density and signal,and the solid part can be strengthened in enhanced scanning.Because of the rapid growth,the lesion is prone to liquefaction necrosis and bleeding.Since the metastasis occurs early,timely diagnosis is essential.
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Tumores Neuroectodérmicos Primitivos Periféricos , Sarcoma de Ewing , Neoplasias do Colo do Útero , Colo do Útero/patologia , Feminino , Humanos , Imuno-Histoquímica , Tumores Neuroectodérmicos Primitivos Periféricos/patologia , Sarcoma de Ewing/diagnóstico , Sarcoma de Ewing/patologiaRESUMO
INTRODUCTION: Blue rubber bleb nevus syndrome (BRBNS) is a rare systemic venous malformation (VM) disease. The characteristic gastrointestinal (GI) bleeding from multiple VM lesions causes severe chronic anemia which renders most patients depend on lifelong blood transfusion and frequent endoscopic treatment with dismayed outcomes. Although recent case reports suggest that oral sirolimus (rapamycin) is effective, a comprehensive evaluation of its efficacy and safety is in need. METHODS: A prospective study was conducted for both pediatric and adult BRBNS patients with administration of sirolimus at the dose of 1.0 mg/m2 to maintain a trough concentration of 3-10 ng/mL. Laboratory tests including complete blood count, biochemical profile, D-dimer, and whole-body magnetic resonance imaging were performed at baseline and 3, 6, and 12 months after treatment. Clinical indicators such as hemoglobin level, lesion size, and transfusion need were evaluated. Adverse effects were recorded regularly. RESULTS: A total of 11 patients (4 males and 7 females) with median age of 14 (range, 5-49) years were recruited. The average lesion size was reduced by 7.4% (P < 0.001), 9.3% (P < 0.001), and 13.0% (P < 0.05) at 3, 6, and 12 months of sirolimus treatment, respectively. Hemoglobin increased significantly after 6- and 12-month treatment (P = 0.006 and 0.019, respectively). Only 1 patient received blood transfusion once during the study. Patients' quality of life and coagulation function were improved. Grade 1-2 adverse effects including oral ulcers (81.8%), acne (27.3%), transient elevation of liver enzymes (18.2%), and hair loss (9.1%) were observed. DISCUSSION: Sirolimus reduces the size of VMs, alleviates GI bleeding, and eliminates transfusion dependence of patients with BRBNS. The drug-related adverse effects are mild and mostly self-limited. These findings support sirolimus as a first-line treatment for GI and cutaneous VMs of BRBNS (see Visual abstract, Supplementary Digital Content, http://links.lww.com/AJG/B819).
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Antibióticos Antineoplásicos/uso terapêutico , Neoplasias Gastrointestinais/tratamento farmacológico , Nevo Azul/tratamento farmacológico , Sirolimo/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Adolescente , Adulto , Transfusão de Componentes Sanguíneos/estatística & dados numéricos , Criança , Pré-Escolar , China , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Hemorragia Gastrointestinal/diagnóstico por imagem , Hemorragia Gastrointestinal/prevenção & controle , Neoplasias Gastrointestinais/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Nevo Azul/diagnóstico por imagem , Estudos Prospectivos , Neoplasias Cutâneas/diagnóstico por imagem , Imagem Corporal TotalRESUMO
Due to the tunable skeletons, variable pore environments, and predesignable structures, covalent organic frameworks (COFs) can be served as a versatile platform to tailor redox activities for efficient energy storage. Redox-active COFs with specific functional groups can not only promote high-speed mass transport in the permanently open channels, but also provide dense active sites for reversible redox reactions so as to efficiently adsorb the electrolyte ions, thus becoming emerging and promising electroactive materials. This review summarizes the design principles and synthetic methods of redox-active COFs, with a focus on surveying the representative advances in supercapacitors. The key progress, major challenges, and future directions in this promising field are highlighted as well.
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Two-dimensional conductive metal-organic frameworks (2D c-MOFs) as an emerging class of multifunctional materials have attracted extensive attention due to their predictable and diverse structures, intrinsic permanent porosity, high charge mobility, and excellent electrical conductivity. Such unique characteristics render them as a promising new platform for electrical related devices. This Minireview highlights the recent key progress of 2D c-MOFs with emphasis on the design strategies, unique electrical properties, and potential applications in electrochemical energy storage. The thorough elucidation of structure-function correlations may offer a guidance for the development of 2D c-MOFs based next-generation energy storage devices.
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The development of new linkages is one of the most efficient strategies to enrich the diversity of covalent organic frameworks (COFs). Particularly, functional linkages can endow COFs with additional tailored properties besides the building units, which further diversify COFs with desirable functions. Herein, we have developed a new arylamine linkage for the construction of COFs. Two new arylamine-linked COFs (AAm-TPB and AAm-Py) were prepared by condensing cost-effective dimethyl succinyl succinate (DMSS) with corresponding multitopic amines (TPB-NH2 and Py-NH2 ). Due to the abundant electroactive diphenylamine moieties in the COF skeletons resembling that of polyaniline (PANI), a state-of-the-art conductive polymer, the pseudocapacitive energy storage performance of AAm-TPB was further investigated. Remarkably, the AAm-TPB electrode exhibits a high capacitance of 271â F g-1 with a three-electrode setup at a discharge rate of 1â A g-1 , which represents one of the highest capacitances among the reported COF-based electrode materials.
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2D conductive metal-organic frameworks (2D c-MOFs) are promising candidates for efficient electrocatalysts for the CO2 reduction reaction (CO2 RR). A nitrogen-rich tricycloquinazoline (TQ) based multitopic catechol ligand was used to coordinate with transition-metal ions (Cu2+ and Ni2+ ), which formed 2D graphene-like porous sheets: M3 (HHTQ)2 (M=Cu, Ni; HHTQ=2,3,7,8,12,13-Hexahydroxytricycloquinazoline). M3 (HHTQ)2 can be regarded as a single-atom catalyst where Cu or Ni centers are uniformly distributed in the hexagonal lattices. Cu3 (HHTQ)2 exhibited superior catalytic activity towards CO2 RR in which CH3 OH is the sole product. The Faradic efficiency of CH3 OH reached up to 53.6 % at a small over-potential of -0.4â V. Cu3 (HHTQ)2 exhibited larger CO2 adsorption energies and higher activities over the isostructural Ni3 (HHTQ)2 and the reported archetypical Cu3 (HHTP)2 . There is a strong dependence of both metal centers and the N-rich ligands on the electrocatalytic performance.
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OBJECTIVE: The purpose of the study was to investigate the role of CT radiomics for the preoperative distinction of intestinal-type gastric adenocarcinomas. MATERIALS AND METHODS: A total of 187 consecutive patients with preoperative contrast CT examination and pathologically proven gastric adenocarcinoma were retrospectively collected. Patients were divided into a training set (n = 150) and a test set (n = 37). Arterial phase (AP), portal phase (PP), and delay phase (DP) images were retrieved for analysis. A dedicated postprocessing software was used to segment the lesions and extract radiomics features. Random forest (RF) algorithm was applied to construct the classifier models. A nomogram was developed by incorporating multiphase radiomics scores. Receiver operating characteristic (ROC) curves were used to evaluate the performance of the radiomics model and nomogram in both sets. RESULTS: The radiomics model showed a favorable capability in the distinction of intestinal-type gastric adenocarcinomas. The areas under curves (AUCs) of the AP, PP, and DP radiomics models were 0.754 (95% CI: 0.676, 0.820), 0.815 (95% CI: 0.744, 0.874), and 0.764 (95% CI: 0.688, 0.829) in the training set, respectively, which were confirmed in the test set with AUCs of 0.742 (95% CI: 0.572, 0.872), 0.775 (95% CI: 0.608, 0.895), and 0.857 (95% CI: 0.703, 0.950), respectively. The nomogram yielded excellent performance for distinguishing intestinal-type adenocarcinomas in both sets, with AUCs of 0.928 (95%: 0.875, 0.964) and 0.904 (95% CI: 0.761, 0.976). CONCLUSIONS: The multiphase CT radiomics nomogram holds promise for the individual preoperative discrimination of intestinal-type gastric adenocarcinoma. KEY POINTS: ⢠CT radiomics has a potential role in the distinction of intestinal-type gastric adenocarcinomas. ⢠Single-phase enhanced CT-based radiomics showed favorable capability in distinguishing intestinal-type tumors. ⢠The nomogram which incorporates the multiphase radiomics scores could facilitate the individual prediction of intestinal-type lesions.
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Adenocarcinoma/diagnóstico por imagem , Neoplasias Gástricas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Área Sob a Curva , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nomogramas , Período Pré-Operatório , Curva ROC , Estudos Retrospectivos , Software , Adulto JovemRESUMO
PURPOSE: To investigate the role of computed tomography (CT) radiomics for the preoperative prediction of lymph node (LN) metastasis in gastric cancer. MATERIALS AND METHODS: This retrospective study included 247 consecutive patients (training cohort, 197 patients; test cohort, 50 patients) with surgically proven gastric cancer. Dedicated radiomics prototype software was used to segment lesions on preoperative arterial phase (AP) CT images and extract features. A radiomics model was constructed to predict the LN metastasis by using a random forest (RF) algorithm. Finally, a nomogram was built incorporating the radiomics scores and selected clinical predictors. Receiver operating characteristic (ROC) curves were used to validate the capability of the radiomics model and nomogram on both the training and test cohorts. RESULTS: The radiomics model showed a favorable discriminatory ability in the training cohort with an area under the curve (AUC) of 0.844 (95% CI, 0.759 to 0.909), which was confirmed in the test cohort with an AUC of 0.837 (95% CI, 0.705 to 0.926). The nomogram consisted of radiomics scores and the CT-reported LN status showed excellent discrimination in the training and test cohorts with AUCs of 0.886 (95% CI, 0.808 to 0.941) and 0.881 (95% CI, 0.759 to 0.956), respectively. CONCLUSIONS: The CT-based radiomics nomogram holds promise for use as a noninvasive tool in the individual prediction of LN metastasis in gastric cancer. KEY POINTS: ⢠CT radiomics showed a favorable performance for the prediction of LN metastasis in gastric cancer. ⢠Radiomics model outperformed the routine CT in predicting LN metastasis in gastric cancer. ⢠The radiomics nomogram holds potential in the individualized prediction of LN metastasis in gastric cancer.
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Metástase Linfática/diagnóstico por imagem , Nomogramas , Neoplasias Gástricas/diagnóstico por imagem , Adulto , Idoso , Algoritmos , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Cuidados Pré-Operatórios/métodos , Curva ROC , Estudos Retrospectivos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios X/métodosRESUMO
A conjugated copper(II) catecholate based metal-organic framework (namely Cu-DBC) was prepared using a D2 -symmetric redox-active ligand in a copper bis(dihydroxy) coordination geometry. The π-d conjugated framework exhibits typical semiconducting behavior with a high electrical conductivity of ca. 1.0â S m-1 at room temperature. Benefiting from the good electrical conductivity and the excellent redox reversibility of both ligand and copper centers, Cu-DBC electrode features superior capacitor performances with gravimetric capacitance up to 479â F g-1 at a discharge rate of 0.2â A g-1 . Moreover, the symmetric solid-state supercapacitor of Cu-DBC exhibits high areal (879â mF cm-2 ) and volumetric (22â F cm-3 ) capacitances, as well as good rate capability. These metrics are superior to most reported MOF-based supercapacitors, demonstrating promising applications in energy-storage devices.
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Metal-organic framework cathodes usually exhibit low capacity and poor electrochemical performance for Li-ion storage owing to intrinsic low conductivity and inferior redox activity. Now a redox-active 2D copper-benzoquinoid (Cu-THQ) MOF has been synthesized by a simple solvothermal method. The abundant porosity and intrinsic redox character endow the 2D Cu-THQ MOF with promising electrochemical activity. Superior performance is achieved as a Li-ion battery cathode with a high reversible capacity (387â mA h g-1 ), large specific energy density (775â Wh kg-1 ), and good cycling stability. The reaction mechanism is unveiled by comprehensive spectroscopic techniques: a three-electron redox reaction per coordination unit and one-electron redox reaction per copper ion mechanism is demonstrated. This elucidatory understanding sheds new light on future rational design of high-performance MOF-based cathode materials for efficient energy storage and conversion.
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We herein develop a two-in-one molecular design strategy for facile synthesis of 2D imine based covalent organic frameworks (COFs). The integration of two different functional groups (i.e., formyl and amino groups) in one simple pyrene molecule affords a bifunctional building block: 1,6-bis(4-formylphenyl)-3,8-bis(4-aminophenyl)pyrene (BFBAPy). Highly crystalline and porous Py-COFs can be easily prepared by the self-condensation of BFBAPy in various solvents, such as CH2Cl2, CHCl3, tetrahydrofuran, methanol, ethanol, acetonitrile, and dimethylacetamide, etc. The current work, to the best of our knowledge, is a rare case of COF synthesis that exhibits excellent solvent adaptability. Highly crystalline Py-COF thin films have been facilely fabricated on various substrates and exhibit potential applications in hole transporting layers for perovskite solar cells. Furthermore, the versatility of this two-in-one strategy was also verified by two additional examples. The current work dramatically reduces the difficulty of COF synthesis, and such two-in-one strategy is anticipated to be applicable for the synthesis of other COFs constructed by different building blocks and linkages.
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A new metal-organic framework (MOF), [Zn6 L4 (Me2 NH2 + )4 â 3 H2 O] (1) was constructed based on [9, 9'-biscarbazole]-3, 3', 6, 6'-tetracarboxylic acid (H4 L) and Zn2+ ions. The porous framework and intense blue fluorescence of the MOF based on the biscarbazole moiety of the ligand could facilitate efficient host to guest energy transfer, which makes it an ideal platform for the tuning of luminescence.
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A unique three-dimensional luminescent metal-organic framework (Cd-MOFs), [Cd(tpbpc)2]·2H2O·DMF (Htpbpc = 4'-[4,2';6',4â³]-terpyridin-4'-yl-biphenyl-4-carboxylic acid; DMF = dimethylformamide), was synthesized and structurally characterized; it exhibits excellent luminescent property and structural stability in aqueous solutions. Interestingly, an unparalleled luminescence-silent system CrO42-@Cd-MOFs was successfully fabricated by postsynthetic modification of metal-organic frameworks. This luminescence-silent system represents a highly selective and sensitive turn-on luminescent responding to ascorbic acid. First, this advanced fluorescent sensor displays excellent performance for CrO42- ions with a quenching of fluorescence intensity originating from fluorescence resonance energy transfer (FRET) mechanism. What's more, the fluorescent intensity of CrO42-@Cd-MOFs system can be recovered (turn-on) for sensing ascorbic acid because of the elimination of FRET process. Such a novel fabrication strategy should offer the guidance to develop various MOFs-implicated luminescence-silent systems as "turn-on" sensors for detection of specific chemicals.
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BACKGROUND: The aim of this study was to evaluate the early anti-tumor efficiency of different therapeutic agents with a combination of multi-b-value DWI, DCE-MRI and texture analysis. METHODS: Eighteen 4 T1 homograft tumor models were divided into control, paclitaxel monotherapy and paclitaxel and bevacizumab combination therapy groups (n = 6) that underwent multi-b-value DWI, DCE-MRI and texture analysis before and 15 days after treatment. RESULTS: After treatment, the tumors in the control group were significantly larger than those in the combination group (P = 0.018). In multi-b-value DWI, the ADCslow obviously increased in the combination group compared to that in the others (P < 0.01). The f increased in the control and paclitaxel groups, but the combination group showed a significant decrease versus the others (P < 0.02). Additionally, in DCE-MRI, the decreasing Ktrans showed an evident difference between the combination and control groups (P = 0.003) due to the latter's increasing Ktrans. The intra-group comparisons of tumor texture in pre-, mid- and post-treatments showed that the entropy had all significantly increased in all groups (P < 0.01, SSF = 0-6), though the MPP, mean and SD increased only in the combination group (PMPP,mean,SD < 0.05, SSF = 4-6). Moreover, the inter-group comparisons revealed that the mean and MPP exhibited significant differences after treatment (Pmean,MPP < 0.05, SSF = 0-3). CONCLUSION: All these results suggest some strong correlations among DWI, DCE and texture analysis, which are beneficial for further study and clinical research.
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Neoplasias da Mama/tratamento farmacológico , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Mamárias Animais/diagnóstico por imagem , Neoplasias Mamárias Animais/tratamento farmacológico , Aloenxertos , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bevacizumab/administração & dosagem , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Meios de Contraste/uso terapêutico , Modelos Animais de Doenças , Feminino , Humanos , Neoplasias Mamárias Animais/patologia , Camundongos , Paclitaxel/administração & dosagem , Resultado do TratamentoRESUMO
A unique metal-organic complex (MOC) with formula [Eu2(tpbpc)4·CO3·4H2O]·DMF·solvent (Htpbpc = 4'-[4,2';6',4â³]-terpyridin-4'-yl-biphenyl-4-carboxylic acid) has been successfully constructed under solvothermal conditions. The Eu complex, as proved by structural analysis, exhibits a fascinating 1D linear-type chain structure which is further extended to a 3D H-bonded supramolecular framework. The luminescent investigations confirm that the emission behavior of the Eu complex possesses excellent water stability and pH stability, and it is the first example of a MOC-based fluorescent probe with high selectivity, high sensitivity, and low detection limit, targeting Cr(III) and Cr(VI) (CrO42-/Cr2O72-) ions in aqueous solution. Importantly, the luminescence can be fast and simple, regenerated in detecting CrO42- and Cr2O72- ions. Furthermore, the simple fluorescent-based test paper was successfully prepared and provided a reliable and visual detection of Cr3+, CrO42-, and Cr2O72- ions in daily applications.
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Intravoxel incoherent motion model-based diffusion weighted imaging can distinguish the microcirculation reperfusion and true diffusion of water molecules,which can quantitatively or semi-quantitatively reflect the functional state and microstructure features of tissues.Thus,this technique has increasingly been used in breast tumor,especially in the differential diagnosis,pathological classification,and curative effect monitoring of breast cancer.
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Neoplasias da Mama/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Humanos , Microcirculação , Movimento (Física)RESUMO
Objective To prospectively investigate the radiation dose and image quality of pediatric chest CT using Sn100 kV on a third-generation dual-source CT (DSCT)in comparison to standard 100 kV chest CT. Methods From December 12,2015 to June 30,2016,45 consecutive pediatric patients referred for non-contrast chest CT scan in Peking Union Medical College Hospital were prospectively enrolled as study group. They were examined at 100 kV with a dedicated tin filter on a third-generation DSCT. These patients were retrospectively matched with 45 patients who were examined on a second-generation DSCT at 100 kV without tin filter. The radiation dose as well as the lung and mediastinal window image quality(IQ)of the two groups were compared and analyzed statistically. IQ was evaluated using a five-point scale (1=unevaluable,5=excellent). Differences of radiation dose and noise between the two groups were determined with variance analysis and t test,IQ with Mann-Whitney U test,and the consistency of diagnosis with Kappa test. Results The average CT dose index volume of the study group was (0.24±0.11)mGy,which was decreased by 92% compared with the control group [(3.10+1.18)mGy] (t=16.287,P=0.000). Mean dose-length product and mean effective dose for study group were significantly lower than those of control group [(7.13±4.72)mGy·cm vs. (84.78±46.78)mGy·cm,t=11.077,P=0.000;(0.11±0.06)mSv vs.(1.23±0.61)mSv,t=12.334,P=0.000]. There was no significant difference between the two groups in terms of image noise (t=-0.003,P=0.397)and contrast to noise ratio (t=0.545,P=0.488). There was no significant difference between the two groups in lung window IQ (doctor 1:U=796.000,P=0.055;doctor 2:U=889.500,P=0.277),while significant difference was seen concerning of the mediastinal window IQ (doctor 1:U=305.000,P=0.000;doctor 2:U=276.500,P=0.000). Referring to the lung window,the median IQ for the study group and control group was 4 (3-5)and 4 (3-5),respectively. All imaging findings had acceptable IQ. The breath motion artifacts (χ2=13.846,P=0.001)and heart beat artifacts (χ2=53.519,P=0.000)of the study group were significantly lower than those of the control group. Conclusion Compared with standard 100 kV chest CT,the use of tin-filtered Sn100 kV on a third-generation DSCT provided 92% dose reduction in pediatric chest CT examinations while maintaining diagnostically acceptable lung window images.
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Interpretação de Imagem Radiográfica Assistida por Computador , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Artefatos , Criança , Estudos de Viabilidade , Humanos , Pulmão/diagnóstico por imagem , Doses de Radiação , Estudos RetrospectivosRESUMO
Objective To explore the feasibility of reducing radiation dose of CT colonography (CTC) while preserving image quality using the third-generation dual-source CT at 70 kV tube voltage with advanced modeled iterative reconstruction (ADMIRE). Methods This prospective study consecutively included 53 patients. All patients underwent CTC at 120 kV in supine position with filtered back projection reconstruction and at 70 kV in prone position with ADMIRE with the same scan range. Radiation dose and image quality were compared between these two protocols. Results CT dose index volume,dose-length product,and effective dose of 70 kV were (1.47±0.23)mGy,(68.85±13.82)mGy·cm,and (1.03±0.21)mSv,respectively,which were significantly lower than 120 kV mode [(2.96±0.61)mGy (t=25.356,P=0.000),(136.97±32.77)mGy·cm (t=22.246,P=0.000),and (2.05±0.49)mSv (t=22.293,P=0.000)]. Signal to noise ratio of 70 kV with ADMIRE was 3.60±0.58,which was obviously higher than that of 120 kV as 2.34±0.47 (t=-18.036,P=0.000). Noise of 70 kV with ADMIRE was (11.81±1.93)HU,which was obviously lower than that of 120 kV as (14.39±2.57)HU (t=7.856,P=0.000). The κ value of two radiologists' overall subjective image score was 0.843 (P=0.000). For 2D images,the noise score of 70 kV with ADMIRE was significantly lower (Z=325.000,P=0.000) and the overall image quality was significantly higher (Z=78.000,P=0.001) compared with 120 kV;however,the sharpness had no significant difference. All scores ranged from 4 to 5. For 3D virtual endoscopy,the overall image quality of 70 kV with ADMIRE and 120 kV was not significantly different (Z=4.000,P=0.059),and all scores ranged from 4 to 5. Conclusion CTC at 70 kV tube voltage combined with ADMIRE can remarkably reduce the radiation dose while maintaining imaging quality than 120 kV at third-generation dual-source CT.