69 research outputs found

    Clinical thought-based software for diagnosing developmental dysplasia of the hip on pediatric pelvic radiographs

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    BackgroundThe common methods of radiographic diagnosis of developmental dysplasia of the hip (DDH) include measuring hip parameters and quantifying the degree of hip dislocation. However, clinical thought-based analysis of hip parameters may be a more effective way to achieve expert-like diagnoses of DDH. This study aims to develop a diagnostic strategy-based software for pediatric DDH and validate its clinical feasibility.MethodsIn total, 543 anteroposterior pelvic radiographs were retrospectively collected from January 2017 to December 2021. Two independent clinicians measured four diagnostic indices to compare the diagnoses made by the software and conventional manual method. The diagnostic accuracy was evaluated using the receiver operator characteristic (ROC) curves and confusion matrix, and the consistency of parametric measurements was assessed using Bland-Altman plots.ResultsIn 543 cases (1,086 hips), the area under the curve, accuracy, sensitivity, and specificity of the software for diagnosing DDH were 0.988–0.994, 99.08%–99.72%, 98.07%–100.00%, and 99.59%, respectively. Compared with the expert panel, the Bland-Altman 95% limits of agreement for the acetabular index, as determined by the software, were −2.09°–2.91° (junior orthopedist) and −1.98°–2.72° (intermediate orthopedist). As for the lateral center-edge angle, the 95% limits were −3.68°–5.28° (junior orthopedist) and −2.94°–4.59° (intermediate orthopedist).ConclusionsThe software can provide expert-like analysis of pelvic radiographs and obtain the radiographic diagnosis of pediatric DDH with great consistency and efficiency. Its initial success lays the groundwork for developing a full-intelligent comprehensive diagnostic system of DDH

    Comparative study regarding the stability of a proximal ulnar stump with or without distal oblique bundle reconstruction during the Sauvé‒Kapandji procedure: a finite-element analysis

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    BackgroundThe most common postoperative complication of the Sauvé‒Kapandji (S-K) procedure is proximal ulnar stump instability. The distal oblique bundle (DOB) is a stable tissue used to stabilize the distal radioulnar joint. This study created finite-element models of the distal oblique bundle (DOB) to determine its effect on the proximal ulnar stump instability encountered during the Sauvé‒Kapandji procedure.PurposeWe hypothesized that a proximal ulnar stump with distal oblique bundle reconstruction would provide greater stability than a proximal ulnar stump without distal oblique bundle reconstruction.MethodsDetailed CT imaging data acquired from a pathological specimen of the wrist joint were imported into a finite-element analysis software package, and the regions of interest, including bone, cartilage, ligaments and tendons, were extracted to create a 3-dimensional model. The volar/dorsal and medial/lateral displacements of the proximal ulnar stump and the stress changes exhibited by the bone and distal oblique bundle tendon were measured with and without DOB reconstruction under 60° pronation, neutrality, and 60° supination.ResultsWhen utilizing DOB reconstruction, the displacement of the radius relative to the proximal ulna stump was approximately 17.89 mm in the neutral position. The bone stress values corresponding to the neutral position, 60° pronation and 60° pronation were 1.01, 18.32 and 14.69 MPa, respectively. The stress peaks of the DOB tendon structure corresponding to the neutral position, 60° pronation and 60° pronation were 0.07 MPa, 2.21 and 1.55 MPa, respectively. Without DOB reconstruction, the displacement of the radius relative to the proximal ulna stump was approximately 18.05 mm in the neutral position. Under 60° pronation and 60° supination, the displacement values were approximately 14.62 mm and 16.89 mm, respectively. The peak bone stress values corresponding to the neutral position, 60° pronation and 60° supination were 1.02, 18.29 MPa and 14.41 MPa, respectively. The stress peaks of the tendon structure corresponding to the neutral position, 60° pronation and 60° pronation were 0.03, 0.87 and 0.85 MPa, respectively.ConclusionDOB reconstruction is capable of improving the stability of the proximal ulnar stump during the Sauvé–Kapandji procedure

    Multivisceral resection of nonfunctional pancreatic neuroendocrine neoplasm with nearby organ invasion: a case report

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    Pancreatic neuroendocrine neoplasms (pNENs) are relatively rare epithelial malignancies originating from pancreatic neuroendocrine cells, pathologically classified into well-differentiated pancreatic neuroendocrine tumors (pNETs) and poorly-differentiated pancreatic neuroendocrine carcinoma (pNECs). Although they also fall under the category of pNENs, the almost entirely distinct biological characteristics and survival prognosis have caused debate among surgeons when it comes to the development of surgical intervention options, particularly for locally advanced G3 pNETs and pNECs. We present a case of 66-year-old male with nonfunctional G3 pNET, invasion of five nearby pancreatic organs and type II liver metastases. The patient achieved good outcomes after undergoing multivisceral resection and postoperative adjuvant chemotherapy. This finding helps surgeons better understand locally advanced pNENs, formulate treatment decisions systematically and confidently, and balance patient benefits and risks of surgery

    A CsI hodoscope on CSHINE for Bremsstrahlung {\gamma}-rays in Heavy Ion Reactions

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    Bremsstrahlung γ\gamma production in heavy ion reactions at Fermi energies carries important physical information including the nuclear symmetry energy at supra-saturation densities. In order to detect the high energy Bremsstrahlung γ\gamma rays, a hodoscope consisting of 15 CsI(Tl) crystal read out by photo multiplier tubes has been built, tested and operated in experiment. The resolution, efficiency and linear response of the units to γ\gamma rays have been studied using radioactive source and (p,γ)({\rm p},\gamma) reactions. The inherent energy resolution of 1.6%+2%/Eγ1/21.6\%+2\%/E_{\gamma}^{1/2} is obtained. Reconstruction method has been established through Geant 4 simulations, reproducing the experimental results where comparison can be made. Using the reconstruction method developed, the whole efficiency of the hodoscope is about 2.6×1042.6\times 10^{-4} against the 4π4\pi emissions at the target position, exhibiting insignificant dependence on the energy of incident γ\gamma rays above 20 MeV. The hodoscope is operated in the experiment of 86^{86}Kr + 124^{124}Sn at 25 MeV/u, and a full γ\gamma energy spectrum up to 80 MeV has been obtained.Comment: 9 pages, 19 figure

    The Spatial and Temporal Evolution Pattern and Transformation of Urban–Rural Construction Land in Karst Mountainous Areas: Qixingguan District of Guizhou, Southwest China

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    Studying the temporal and spatial evolution pattern and transformation rule of urban–rural construction land in karst mountainous areas has important guiding significance for urban development boundary planning, red lines for ecological protection, and cultivated land protection. The present study took 46 townships (streets) in Qixingguan District of Guizhou Province, southwest China, as the research area; collected the current status of four-phase land use data in 2009, 2013, 2017, and 2020; and used GIS spatial analysis models and geographical detectors to analyze the temporal and spatial evolution pattern characteristics and influencing factors of urban–rural construction. The results showed the following: (1) Since 2009, the total area of urban–rural construction land has continued to increase; the largest area is rural residential land, followed by urban land and transportation land, with relatively little urban industrial and mining land, scenic spots, and special land. The growth rate of land used for transport increased rapidly, and urban land grew faster than rural residential land. (2) More than 57.72% of the newly increased urban–rural construction land came from cultivated land, but the transformation of cultivated land for construction gradually slowed down; 57.48% of urban–rural construction land was transferred for reclamation as cultivated land. During the study period, the transformation of cultivated land to construction land was more intense (the transfer out of cultivated land was greater than the transfer in by 9541.94 hm2). (3) There are strong spatial differences in the density of urban–rural construction land, showing scattered agglomeration distribution, and the degree of aggregation in medium-high- and high- density areas is further strengthened, expanding to the east and southwest. (4) The growth of urban–rural construction land has been controlled by a variety of complex factors, the most influential of which are the completion of fixed asset investment in society as a whole and the total fiscal revenue, with explanatory power (PD) values of 0.819 and 0.607, respectively. Interactions between detection factors have a greater impact on the spatial differentiation of urban–rural construction land than single factors. The results of this study can provide basic research data and support the control and high-quality development of urban–rural construction land in Qixingguan District and karst mountain areas

    Contactless surface tension measurement of molten oxides using oscillating drop method in an aerodynamic levitator

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    Aerodynamic levitation stands as a contactless method for thermophysical property measurement of molten oxides at high temperatures, offering the advantage of eliminating sample contamination and enabling surface tension measurement through the oscillating drop method. However, the presence of oscillation mode splitting results in an underestimation of surface tension. By improving levitation stability and optimizing the acoustic excitation method for the levitated drops, this study successfully eliminates oscillation mode splitting for the first time. The l = 2 resonance frequency is directly measured, which is used to calculate surface tension according to the Rayleigh equation. Taking Al2O3 as a representative of oxides, this study demonstrates the accurate surface tension measurement during the frequency scan process when oscillation mode splitting is absent. Additionally, combining damped oscillation analysis with the frequency scan reduces measurement uncertainty from 2.8 % to 1.5 %. Within the temperature range of 2336K–2923K, the surface tension of molten Al2O3 is determined to be γ = −(4.071 ± 2.688) × 10−5 (T-2327)+(0.7465 ± 0.074) N/m. Underestimation of surface tension is prevented when the l = 2 resonance frequency is used for surface tension calculations. The frequency crossover method which is used for surface tension measurement is also found to be affected by oscillation mode splitting
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