3-dimensional Measurement Research Articles

Hausdorff Dimension of Julia Sets in the Logistic Family

A closed interval and circle are the only smooth Julia sets in polynomial dynamics. D. Ruelle proved that the Hausdorff dimension of unicritical Julia sets close to the circle depends analytically on the parameter. Near the tip of the Mandelbrot set \({{\mathcal {M}}}\), the Hausdorff dimension is generally discontinuous. Answering a question of J-C. Yoccoz in the conformal setting, we observe that the Hausdorff dimension of quadratic Julia sets depends continuously on c and find explicit bounds at the tip of \({{\mathcal {M}}}\) for most real parameters in the the sense of 1-dimensional Lebesgue measure.

Impacts of first- and second-order optimization in deep learning of turbulent fluctuations from gas puff imaging

Following the results of [1], which demonstrates a novel method to translate 2-dimensional measurements of HeI line radiation on turbulent scale into local plasma fluctuations via an integrated deep learning framework, this manuscript investigates the results when applying two separate techniques for optimization: Adam and L-BFGS. Fundamentally, the two approaches apply the same set of constraints and loss functions that combine neutral transport physics and collisional radiative theory for the 33D − 23P (587.6 nm line) transition in atomic helium whilst training the networks. The impact of these first- and second-order optimization techniques are investigated to examine their influence on numerical convergence and stability when seeking to analyze turbulent dynamics via gas puff imaging in experimental plasmas.

Quantitative thermography: a powerful but simple tool to assess the fatigue strength of metals in a one-specimen test–capabilities and limitations in the test setup

PurposeThe aim of the study is the question, that is, which evaluation method for the measured temperature profile is more suitable and feasible for quantitative thermometry (QT): A simple measurement setup based on 3-point temperature sensing by means of semiconductor sensors (NTCs) or thermographic methods which offer 2-dimensional (2D) temperature measurements of the sample with good spatial resolution but an inferior temperature sensitivity. What experimental effort is required to adjust the test setup to satisfy the boundary conditions of the underlying thermodynamic equations?Design/methodology/approachIn this paper results of both methods are contrasted and the error of QT measurement is assessed by finite element analysis (FEA) in this follow-up.FindingsThe low-cost NTC method allows a straightforward determination of a lower estimate of the fatigue strength with only a very small measurement error. Even asymmetries in the thermal boundary conditions of the test setup are broadly tolerated, as well as a lack of thermal isolation.Practical implicationsThe method is restricted to metallic materials without phase transitions during fatigue in the fatigue strength regime.Originality/valueQT is not a new method. The assessment of the methods proposed in the literature regarding their practicability in terms of accuracy is innovative focus of this work. Nevertheless, highly accurate thermometric measurements can be performed by using simple commercial sensors in combination with a standard digital multimeter.

Application of concentration and 2-dimensional stable isotope measurements of methane to constrain sources and sinks in a seasonally stratified freshwater lake

Methane (CH4) emissions from aquatic systems have recently been comprised to account for up to 50% of global CH4 emissions, with lakes representing one of the largest CH4 sources within this pool. However, there is large uncertainty associated with CH4 emissions from freshwater environments to the atmosphere, because of a lack of understanding in the spatial and temporal dynamics of CH4 sources and sinks, as well as underlying mechanisms and processes. In this study, we investigated the concentrations and stable carbon (δ13C-CH4) and hydrogen (δ2H-CH4) isotope composition of CH4 in a small eutrophic lake (Lake Willersinnweiher) with seasonal stratification and its spatial and temporal variation. We found that while supersaturation of CH4 in the entire water column was present throughout the whole year, the isotopic composition of CH4 in sediment and water column varied depending on lake stratification, physiochemical conditions, and lake depth. During the stratification period, isotopic characteristics of pelagic surface water CH4 differed from littoral and sedimentary CH4, suggesting likely mixing of CH4 from different sources including vertical and lateral input as well as groundwater input and potentially oxic methane production in the mixed surface water layer. Aerobic CH4 oxidation indicated by a strong increase in both δ13C-CH4 and δ2H-CH4 values at the bottom of the oxycline was found to significantly reduce upward migrating CH4 released at the sediment-water interface. In the sediment, stable isotope characteristics of CH4 showed an increasing dominance of the acetoclastic CH4 formation pathway from the pelagic towards the littoral area. Furthermore, the occurrence of sulfate-dependent anaerobic methane oxidation in the sediment was suggested by an increase in δ13C-CH4 and δ2H-CH4 values. During the mixing period, the isotopic CH4 composition of the water column was distinctively less negative than during the stratification period potentially resulting from a greater impact of groundwater CH4 input compared to the stratification period. Our findings implicate that the application of concentrations and dual isotope measurements of CH4 is a promising approach for constraining CH4 sinks and sources in Lake Willersinnweiher and potentially other small lakes to clearly disentangle the complex CH4 dynamics in lakes both spatially and seasonally.

Target-free 3D tiny structural vibration measurement based on deep learning and motion magnification

• A novel target-free tiny vibration displacement measurement approach is proposed. • It is based on deep learning and motion magnification techniques. • Binocular vision system is used for measuring 3D vibration measurement. • Deep learning techniques are used for key-points detection, matching and tracking. • Experimental and in-field studies are conducted to validate the accuracy. In the field of structural health monitoring (SHM), computer vision based methods have been usually developed for 2-dimensional (2D) vibration displacement measurement and crack identification of civil engineering structures. However, the accurate measurement of tiny 3-dimensional (3D) vibrations for real civil engineering structures remains a very difficult task. To overcome this challenge, this paper proposes a target-free full-field 3D tiny vibration measurement approach for civil engineering structures by using a binocular vision system. The proposed approach is based on deep learning and motion magnification. A phase-based video motion magnification algorithm is employed to achieve a high measurement accuracy of tiny vibrations at the submillimeter level. The advanced key point detection, matching and tracking algorithms via deep learning techniques are employed to achieve target-free tiny vibration displacement measurement. The accuracy and performance of the proposed approach are evaluated through experimental tests on a steel cantilever beam in the laboratory. In-field experimental tests are conducted on a pedestrian bridge on a university campus to investigate the accuracy of the proposed approach in practical applications. The measured 3D tiny vibration displacement from the proposed approach is compared with those measured by laser displacement sensors, and the derived acceleration responses are compared with those measured from the installed accelerometers on the testing structures. The results demonstrate that the 3D tiny vibration measurements are obtained accurately by the proposed approach.

Evaluation of Cardiac Function in Uncomplicated COVID-19 Survivors by 2-Dimensional Speckle Tracking Imaging.

COVID-19 is a multi-systemic infectious disease. Nearly 20%-30% of hospitalized patients have evidence of acute myocardial involvement, portending a poorer prognosis. However, information about the long-term effects of the disease on cardiac functions is sparse. As a result, there is a growing concern about the cardiac sequelae of COVID-19 among survivors. This study aimed to investigate the effects of prior mild-moderate COVID-19 infection on cardiac functions, using speckle tracking echocardiography. Patients who have been diagnosed with COVID-19 within the previous 6 months and age-, sex-, and risk factor-matched healthy adults were included. All patients underwent a comprehensive echocardiographic examination. Both conventional and 2-dimensional speckle tracking echocardiographic measurements were performed. Serum cardiac biomarkers were also obtained on the day of the echocardiographic study. Compared with healthy controls, COVID-19 survivors had similar left and right ventricular longitudinal strain values at 6 months. Also, left and right atrial peak systolic strain values did not differ between the groups. Our study is valuable in putting forth the unaffected ventricular and atrial functions on long term in uncomplicated COVID-19 cases and may decrease the survivors' anxiety and the number of unnecessary applications to cardiology clinics.

Wide-viewing-zone Light-field Capturing Using Turtleback Convex Reflector

Light field cameras have been used for 3-dimensional geometrical measurement or refocusing of captured photo. In this paper, we propose the light field acquiring method using a spherical mirror array. By employing a mirror array and two cameras, a virtual camera array that captures an object from around it can be generated. Since large number of virtual cameras can be constructed from two real cameras, an affordable high-density camera array can be achieved using this method. Furthermore, the spherical mirrors enable the capturing of large objects as compared to the previous methods. We conducted simulations to capture the light field, and synthesized arbitrary viewpoint images of the object with observation from 360 degrees around it. The ability of this system to refocus assuming a large aperture is also confirmed. We have also built a prototype which approximates the proposal to conduct a capturing experiment in order to ensure the system’s feasibility.

A prediction model for major adverse cardiovascular events in patients with heart failure based on high-throughput echocardiographic data.

Heart failure (HF) is a serious end-stage condition of various heart diseases with increasing frequency. Few studies have combined clinical features with high-throughput echocardiographic data to assess the risk of major cardiovascular events (MACE) in patients with heart failure. In this study, we assessed the relationship between these factors and heart failure to develop a practical and accurate prognostic dynamic nomogram model to identify high-risk groups of heart failure and ultimately provide tailored treatment options. We conducted a prospective study of 468 patients with heart failure and established a clinical predictive model. Modeling to predict risk of MACE in heart failure patients within 6 months after discharge obtained 320 features including general clinical data, laboratory examination, 2-dimensional and Doppler measurements, left ventricular (LV) and left atrial (LA) speckle tracking echocardiography (STE), and left ventricular vector flow mapping (VFM) data, were obtained by building a model to predict the risk of MACE within 6 months of discharge for patients with heart failure. In addition, the addition of machine learning models also confirmed the necessity of increasing the STE and VFM parameters. Through regular follow-up 6 months after discharge, MACE occurred in 156 patients (33.3%). The prediction model showed good discrimination C-statistic value, 0.876 (p < 0.05), which indicated good identical calibration and clinical efficacy. In multiple datasets, through machine learning multi-model comparison, we found that the area under curve (AUC) of the model with VFM and STE parameters was higher, which was more significant with the XGboost model. In this study, we developed a prediction model and nomogram to estimate the risk of MACE within 6 months of discharge among patients with heart failure. The results of this study can provide a reference for clinical physicians for detection of the risk of MACE in terms of clinical characteristics, cardiac structure and function, hemodynamics, and enable its prompt management, which is a convenient, practical and effective clinical decision-making tool for providing accurate prognosis.

Dimension and measure of sums of planar sets and curves

Considerable attention has been given to the study of the arithmetic sum of two planar sets. We focus on understanding the measure and dimension of A + Γ : = { a + v : a ∈ A , v ∈ Γ } $A+\Gamma :=\lbrace a+v:a\in A, v\in \Gamma \rbrace$ when A ⊂ R 2 $A\subset \mathbb {R}^2$ and Γ is a piecewise C 2 $\mathcal {C}^2$ curve. Assuming Γ has non-vanishing curvature, we verify that: (a): if dim H A ⩽ 1 $\dim _{\rm H} A \leqslant 1$ , then dim H ( A + Γ ) = dim H A + 1 $\dim _{\rm H} (A+\Gamma )=\dim _{\rm H} A +1$ ; (b): if dim H A > 1 $\dim _{\rm H} A>1$ , then L 2 ( A + Γ ) > 0 $\mathcal {L}_2(A+\Gamma )>0$ ; (c): if dim H A = 1 $\dim _{\rm H} A=1$ and H 1 ( A ) < ∞ $\mathcal {H}^1(A) < \infty$ , then L 2 ( A + Γ ) = 0 $\mathcal {L}_2(A+\Gamma )=0$ if and only if A is an irregular (purely unrectifiable) 1-set. In this article, we develop an approach using nonlinear projection theory which gives new proofs of (a) and (b) and the first proof of (c). Item (c) has a number of consequences: if a circle is thrown randomly on the plane, it will almost surely not intersect the four corner Cantor set. Moreover, the pinned distance set of an irregular 1-set has 1-dimensional Lebesgue measure equal to zero at almost every pin t ∈ R 2 $t\in \mathbb {R}^2$ .

A 3-Dimensional Measurements of Bone and Airway Variables After Le Fort I Distraction Osteogenesis in Patients With Cleft Lip and/or Palate-Induced Midface Hypoplasia: A Retrospective Study.

The authors retrospectively analyzed the effects of Le Fort I advancement with distraction osteogenesis on skeletal and airway variables in patients with midfacial hypoplasia induced by cleft lip and/or palate using 3-dimensional computed tomography reconstructions. The authors enrolled 23 subjects with moderate-to-severe midface hypoplasia induced by cleft lip and palate who were treated with Le Fort I distraction osteogenesis (mean age, 19.22±3.48y; male/female ratio, 20/3); computed tomography images (1 before distraction and another at completion of distraction) were acquired. A 3-dimensional craniometric findings and airway volumes for the nasal cavity, nasopharynx, velopharynx, and upper and lower oropharynx were compared before and after distraction. The relationships between craniofacial morphology and changes in airway volume were also assessed ( P <0.05 was considered significant). Significant increases were observed in airway volumes for the nasal cavity (13.85%), nasopharynx (50.82%), velopharynx (29.57%), and upper oropharynx (36.92%) ( P =0.007, P <0.001, P =0.023, and P <0.001, respectively), whereas no significant changes were observed for the lower oropharynx ( P =0.117). Maxillary horizontal advancement was positively correlated with the airway volumes of the nasopharynx and upper oropharynx after distraction osteogenesis ( rs =+0.451, P =0.031; rs =+0.548, P =0.007); however, no significant correlations were observed for the nasal cavity and velopharynx. The authors' finding indicate that despite rotation of the mandible along with the maxilla, this change does not impact airway volume at the mandibular level. Le Fort I distraction osteogenesis can be feasible for patients with cleft lip and palate-induced midface hypoplasia, with satisfactory appearance and occlusion. Long-term detailed follow-up of the patients postdistraction osteogenesis is warranted.

Response assessment in pediatric craniopharyngioma: recommendations from the Response Assessment in Pediatric Neuro-Oncology (RAPNO) Working Group.

Craniopharyngioma is a histologically benign tumor of the suprasellar region for which survival is excellent but quality of life is often poor secondary to functional deficits from tumor and treatment. Standard therapy consists of maximal safe resection with or without radiation therapy. Few prospective trials have been performed, and response assessment has not been standardized. The Response Assessment in Pediatric Neuro-Oncology (RAPNO) committee devised consensus guidelines to assess craniopharyngioma response prospectively. Magnetic resonance imaging is the recommended radiologic modality for baseline and follow-up assessments. Radiologic response is defined by 2-dimensional measurements of both solid and cystic tumor components. In certain clinical contexts, response to solid and cystic disease may be differentially considered based on their unique natural histories and responses to treatment. Importantly, the committee incorporated functional endpoints related to neuro-endocrine and visual assessments into craniopharyngioma response definitions. In most circumstances, the cystic disease should be considered progressive only if growth is associated with acute, new-onset or progressive functional impairment. Craniopharyngioma is a common pediatric central nervous system tumor for which standardized response parameters have not been defined. A RAPNO committee devised guidelines for craniopharyngioma assessment to uniformly define response in future prospective trials.

Rhinoplasty with Simultaneous Autologous Full-Face Fat Transfer for Asian Facial Contouring Balance: A Retrospective Study.

The aesthetic facial contouring procedures have gained an increasing popularity in the Asian population. Nevertheless, currently, there are few specific literature assessments and studies on the outcomes of rhinoplasty combined with full-face fat graft contouring. To conduct an objective evaluation of the efficacy of Asian rhinoplasty combined with autologous facial fat transfer in terms of 3-dimensional measurement and patient-reported outcomes. Patients who underwent rhinoplasty combined with full-face fat transfer for facial contouring between January 2016 and July 2019 were recruited in the study. The preoperative and postoperative clinical variables and 3-dimensional measurement of patients were also collected. The satisfaction outcome of surgeons and patients was assessed. Twenty patients completed rhinoplasty with full-face fat transfer. The average postoperative follow-up was 10.2 months (range 6-24 months). The nasal length, and the nasal protrusion rate were significantly increased (p<0.05) after surgery, and the median number of nasolabial angles decreased from 106° to 101°, which was closer to the aesthetic standard of 90°-100°. The topographical projection images of whole face indicated that the volume of frontal, temporal, inner cheek and chin regions were increased obviously. All cases received satisfaction outcome based on surgeons' satisfaction scale, ROE scale, FACE-Q overall facial satisfaction scale, and FACE-Q Rhinoplasty scale. Additionally, no patients had intraoperative or postoperative complications. Rhinoplasty combined with full-face fat transfer is a reliable and effective method of augmenting and contouring the facial convexity in the Asian populations. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Cardiac function unchanged following reanimation with normothermic regional perfusion in donation after circulatory death.

ObjectivesTo determine whether hearts reanimated with normothermic regional perfusion (NRP) have clinically detectable changes in function using echocardiography comparing the prearrest and post-NRP imaging. As heart transplantation from donation after circulatory death (DCD) continues to increase, preliminary results suggest outcomes comparable with donation after brain death. It is unknown whether the obligatory period of warm ischemia experienced during DCD withdrawal process causes immediate changes in cardiac allograft function following in situ reanimation.MethodsWe retrospectively reviewed and compared predonation with postreanimation echocardiographic findings in all DCD donors at our institution from January to October 2021. All DCD donor organs were reanimated with in situ thoracoabdominal NRP after circulatory death. Echocardiographic assessment included (1) 2-dimensional and speckle-tracking measures of chamber size and function; (2) ejection fraction; (3) fractional area change; and (4) global longitudinal strain.ResultsAltogether, 4 DCD heart donations were performed during the study period. Basic demographics and withdrawal ischemic time periods are reported. There were no changes in left ventricular ejection fraction and right ventricular fractional area change when comparing the predonation and the postreanimation echocardiogram. There was a minimal, nonstatistically significant decrease in left ventricular global longitudinal strain and right ventricular free-wall systolic strain in 3 of the 4 donors following reanimation.ConclusionsDCD cardiac allografts reanimated with NRP demonstrated no change in echocardiographic parameters used for a standard predonation donor heart evaluation. Findings suggest cardiac function of DCD allografts reanimated with thoracoabdominal NRP is not adversely impacted by limited period of warm ischemia following circulatory arrest.

Comparison between Automatic and Semiautomatic System for the 3D Echocardiographic Multiparametric Evaluation of RV Function and Dimension.

Background: The right ventricle (RV) plays a pivotal role in cardiovascular diseases and 3-dimensional echocardiography (3DE) has gained acceptance for the evaluation of RV volumes and function. Recently, a new artificial intelligence (AI)–based automated 3DE software for RV evaluation has been proposed and validated against cardiac magnetic resonance. The aims of this study were three-fold: (i) feasibility of the AI-based 3DE RV quantification, (ii) comparison with the semi-automatic 3DE method and (iii) assessment of 2-dimensional echocardiography (2DE) and strain measurements obtained automatically. Methods: A total of 203 subject (122 normal and 81 patients) underwent a 2DE and both the semi-automatic and automatic 3DE methods for Doppler standard, RV volumes and ejection fraction (RVEF) measurements. Results: The automatic 3DE method was highly feasible, faster than 2DE and semi-automatic 3DE and data obtained were comparable with traditional measurements. Both in normal subjects and patients, the RVEF was similar to the two 3DE methods and 2DE and strain measurements obtained by the automated system correlated very well with the standard 2DE and strain ones. Conclusions: results showed that rapid analysis and excellent reproducibility of AI-based 3DE RV analysis supported the routine adoption of this automated method in the daily clinical workflow.

Artificial intelligence (AI)-based decision support improves reproducibility of tumor response assessment in neuro-oncology: An international multi-reader study.

To assess whether artificial intelligence (AI)-based decision support allows more reproducible and standardized assessment of treatment response on MRI in neuro-oncology as compared to manual 2-dimensional measurements of tumor burden using the Response Assessment in Neuro-Oncology (RANO) criteria. A series of 30 patients (15 lower-grade gliomas, 15 glioblastoma) with availability of consecutive MRI scans was selected. The time to progression (TTP) on MRI was separately evaluated for each patient by 15 investigators over two rounds. In the first round the TTP was evaluated based on the RANO criteria, whereas in the second round the TTP was evaluated by incorporating additional information from AI-enhanced MRI sequences depicting the longitudinal changes in tumor volumes. The agreement of the TTP measurements between investigators was evaluated using concordance correlation coefficients (CCC) with confidence intervals (CI) and P-values obtained using bootstrap resampling. The CCC of TTP-measurements between investigators was 0.77 (95% CI=0.69,0.88) with RANO alone and increased to 0.91 (95% CI=0.82,0.95) with AI-based decision support (P=.005). This effect was significantly greater (P=.008) for patients with lower-grade gliomas (CCC=0.70 [95% CI=0.56,0.85] without vs. 0.90 [95% CI=0.76,0.95] with AI-based decision support) as compared to glioblastoma (CCC=0.83 [95% CI=0.75,0.92] without vs. 0.86 [95% CI=0.78,0.93] with AI-based decision support). Investigators with less years of experience judged the AI-based decision as more helpful (P=.02). AI-based decision support has the potential to yield more reproducible and standardized assessment of treatment response in neuro-oncology as compared to manual 2-dimensional measurements of tumor burden, particularly in patients with lower-grade gliomas. Afully-functional version of this AI-based processing pipeline is provided as open-source (https://github.com/NeuroAI-HD/HD-GLIO-XNAT).

Bony Cartilaginous Graft in Unilateral Cleft Lip Rhinoplasty.

Cleft rhinoplasty is a challenging form of nasal correction of both esthetic and functional deformities. The septal cartilage in many Asian patients are not sufficient and weak. Does a combination of the septal cartilage and the bony septum have both esthetic and functional benefits to secondary unilateral cleft rhinoplasty? Thirty patients with a unilateral cleft lip palate underwent open rhinoplasty from October 2018 to January 2021. After preserving a 10mm L-strut, the posterior cartilaginous and bony septum were harvested as an integrative unit. The osteocartilaginous graft was used as a caudal septal extension graft and an extended spreader graft. Correcting the asymmetry of the tip and tip projection followed. The intraoperative harvested composite graft was analyzed. Acoustic rhinometry and the 3-dimensional anthropometric measurements of the external nose were assessed before and after surgery. The osteocartilaginous unit was much larger than the cartilaginous part of this unit. The mean nasal tip height and the nasolabial angle increased significantly after surgery. The measurement of cross-sectional areas and volumes by acoustic rhinometry revealed that septorhinoplasty provided a significant increase in the function of both nasal cavities. This septal bony cartilaginous graft is effective for cleft lip nasal deformity when correcting the deviated septum, creating a supporting frame to correct the nasal tip asymmetry, improving function.

272 Adiposis dolorosa and deoxycholic acid: An alternative therapeutic method

Dercum disease, or adiposis dolorosa, is a rare disorder characterized by multiple painful lipomas distributed throughout the body. There are currently no approved treatments for Dercum disease and excision is often not feasible due to tumor burden and extent of disease. Here we present the use of deoxycholic acid (DCA) to reduce the size of lipomas associated with Dercum disease. Ultrasound was used to obtain 3-dimensional measurements of painful lipomas in three patients. Lesions were identified for treatment with patient and radiology input based on larger size, troublesome symptoms, and feasibility of location (e.g.

Supramalleolar Osteotomy for Ankle Varus Deformity Alters Subtalar Joint Alignment

Although correction of ankle and hindfoot deformity after supramalleolar osteotomy has been investigated extensively, the specific effect on the subtalar joint alignment remains elusive. This can be attributed to the limitations of 2-dimensional measurements, which impede an exact quantification of the 3-dimensional subtalar joint alignment. Therefore, we determined both the ankle, hindfoot, and subtalar joint alignment before and after supramalleolar osteotomy using autogenerated 3-dimensional measurements based on weightbearing CT imaging. Twenty-nine patients with a mean age of 50.4±10.6 years were retrospectively analyzed in a pre-post study design using weightbearing CT. Inclusion criteria were correction of ankle varus deformity by an opening wedge (n = 22) or dome osteotomy (n = 7). Exclusion criteria consisted of an additional inframalleolar arthrodesis or osteotomy. Corresponding 3-dimensional bone models were reconstructed to compute following autogenerated measurements of the ankle- and hindfoot alignment: tibial anterior surface (TAS), tibiotalar surface (TTS), talar tilt (TT) angle, hindfoot angle (HA). In addition, the talocalcaneal angle (TCA) in the axial (TCAax), sagittal (TCAsag), and coronal (TCAcor) plane were measured to assess the subtalar joint alignment. The preoperative radiographic parameters of the ankle joint alignment (TAS=88±4 degrees, TTS=82±7 degrees, TT=5.8±4.9 degrees) improved significantly relative to their postoperative equivalents (TAS = 93±5 degrees, TTS = 88±7 degrees, TT=4.2±4.5 degrees; P < .05). The following radiographic parameters of the hindfoot and subtalar joint alignment improved significantly from preoperatively (8.7±8.9 degrees, TCAax = 41±10 degrees, TCAsag = 48±10 degrees) to postoperatively (HA=4.5±8.6 degrees, TCAax = 38±9 degrees, TCAsag = 44±11 degrees; P < .05). No significant differences could be detected in the coronal plane alignment of the subtalar joint (TCAcor) pre- compared to postoperatively (P > .05). This study quantified the 3-dimensional ankle, hindfoot, and subtalar joint alignment after a solitary supramalleolar osteotomy. We found alterations in the subtalar joint alignment, which occurred by 2 to 3 degrees in each anatomic plane. However, before recommendations can be given related to inframalleolar procedures in conjunction to supramalleolar osteotomies, further studies on the variation of subtalar joint alignment change are needed.

Changes in Facial Soft Tissues After Mandibular Angle Ostectomy Based on 3-Dimensional Measurement: A Clinical Study

A limited number of clinical studies have focused on the changing trends of facial soft tissue after mandibular angle ostectomy. We conducted this study to investigate the changes in facial muscles and facial soft tissue appearance before and after mandibular angle ostectomy. A single-center retrospective cohort study was conducted on female patients admitted to our hospital for mandibular angle ostectomy between 2019 and 2020. The primary predictor variable was time (preoperative vs 6 months postoperative). The primary outcome variables were surface area and total volume of the manually delineated region of interest (ROI) for the masseter and temporalis muscles. We utilized computed tomography data to reconstruct 3-dimensional models to delineate muscle ROI and then measure them computationally. Secondary outcome variables were indicators of mandible appearance in soft tissue including bilateral mandibular angle distance, mandibular ramus height, and mandibular angle value. Age, preoperative body mass index, and ostectomy volume were chosen as covariates for correlation analysis with outcome variables. Paired t tests and Pearson correlation analysis were conducted, and P values < .05 were considered statistically significant. A total of 29 female patients (mean age, 26years; range, 18 to 37years) who underwent mandibular angle ostectomy in our hospital were included. The surface area and total volume of the masseter muscle ROI were reduced by 2,541.2±1,925.0mm2 (12.8%; P < .05) and 16,242.4±12,646.8mm3 (18.4%; P < .05), respectively, 6months after surgery. In contrast, the surface area and total volume of the temporalis muscle ROI increased by 6,081.6±6,169.4mm2 (12.0%; P < .05) and 19,273.3±21,666.2mm3 (10.7%; P < .05), respectively. The ostectomy volume showed a correlation coefficient of 0.59 with postoperative masseter ROI change (P < .05). We observed statistically significant levels of atrophy of the masseter muscle ROI and expansion of the temporalis muscle ROI 6months after mandibular angle ostectomy, which may account for appearance changes after surgery. Besides, ostectomy volume positively correlates with postoperative masseter ROI changes. In summary, our study provided empirical evidence illustrating soft tissue alterations in patients who have undergone mandibular angle ostectomy.

Can Location of Stiffness Measurement Impact Spleen 2-Dimensional Shear Wave Elastography Measurement?

Ultrasound-based spleen elastography is a promising surrogate to predict portal hypertension noninvasively. In contrast to defined standards for liver stiffness measurement, the standardized examination procedures for 2-dimensional (2D) shear wave elastography spleen elastography have not been established yet. The aim was to investigate the impact of location of stiffness measurement on 2D shear wave elastography spleen stiffness measurement (SSM). Patients with splenomegaly were enrolled. Both B-mode ultrasound and elastography of spleen were performed. For SSM, 3 regions were chosen for spleen measurement: lower pole region, central region, and the region between lower pole and center. Mean SSM value, success rate, and reliability predicators (standard deviation, standard deviation/mean, size of region of interest) were assessed. A total of 124 patients were included. For mean SSM value, there were no significant differences among 3 regions. Spleen stiffness measurement success rate in lower pole region, central region, and the region between them was 63.7% (79), 91.1% (113), and 78.2% (97), respectively. The success rate in the central region was significantly higher than that in the other 2 regions (P < 0.05). Reliability in the central region was also highest among the 3 regions. Location of stiffness measurement has a limited effect on SSM. Changing location of measurement will not influence mean stiffness value in spleen.