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Introduction: Launched in 2018 for revision total ankle arthroplasty (rTAA), the INVISION talar component addresses subsidence when poor talar bone stock is present. Due to the recency of the market-availability of the INVISION, studies evaluating its efficacy are lacking. This study presents the first analysis of early-term outcomes of patients undergoing rTAA with the INVISION talar component. Methods: This was a single-center, retrospective review of 28 patients undergoing rTAA with the INVISION talar component and INBONE II tibial component performed between 2018 and 2022. Data on preoperative characteristics, postoperative complications, secondary procedures, and survivorship were collected. The primary outcome measures were rates of major complications, re-operation, and implant failure. Secondary outcomes included post-operative changes in varus and valgus alignment of the tibia and talus. Results: The most common secondary procedures performed with rTAA were medial malleolus fixation (n = 22, 78.6%) and gastrocnemius recession (n = 14, 50%). Overall, 10.7% (n = 3) of patients underwent reoperation and 14.3% (n = 4) suffered major complications. Incidence of implant failure was 10.7% (n = 3). All reoperations were caused by infection. Mean varus alignment of the tibia and talus improved from 4.07 degrees and 4.83 degrees to 1.67 degrees and 1.23 degrees, respectively. Mean valgus alignment of the tibia and talus improved from 3.67 degrees and 4.22 degrees to 2.00 degrees and 2.32 degrees, respectively. Conclusions: In a series of 28 patients undergoing rTAA with the INVISION talar component, we discovered comparatively low rates of reoperation, major complication, and implant failure (10.7%, 14.3%, and 10.7%). The INVISION system appears to have a reasonable safety profile, but further studies evaluating long-term outcomes are required to assess the efficacy of the INVISION system. [ABSTRACT FROM AUTHOR]

Antibiotic-loaded cement spacers (ALCSs) are essential for treating periprosthetic joint infections (PJIs) by providing mechanical support and local antibiotic delivery. The purpose of this review is to comprehensively examine the various types of spacers utilised in the management of periprosthetic joint infections (PJIs), including both static and articulating variants and to analyse the fundamental principles underlying spacer use, their clinical benefits, the selection and administration of antimicrobial agents, appropriate dosages, and potential adverse effects. Articulating spacers, which allow joint mobility, often yield better outcomes than static ones. Spacer pharmacokinetics are vital for maintaining therapeutic antibiotic levels, influenced by cement porosity, mixing techniques, and the contact area. Antibiotic choice depends on heat stability, solubility, and impact on cement's mechanical properties. Mechanical properties are crucial, as spacers must withstand physical stresses, with antibiotics potentially affecting these properties. Complications, such as tissue damage and systemic toxicity, are discussed, along with mitigation strategies. Future advancements include surface modifications and novel carriers to enhance biofilm management and infection control. [ABSTRACT FROM AUTHOR]

Introduction: Extra-articular hip resection may be necessary in cases of malignant tumour of the pelvic bone or of the proximal femur invading the hip joint. When the tumour is in the proximal femur, it is possible to resect the acetabulum en bloc by performing a periacetabular osteotomy, but this creates a discontinuity in the pelvic ring with difficult reconstruction and diminished function. Several techniques described recently seek to be as sparing as possible on the pelvic bone by preserving the posterior column or both columns in order to facilitate reconstruction and improve function. However, these still require complex reconstructions and can necessitate intra-pelvic dissection. Technique: We describe here an extra-articular hip resection technique for tumours of the proximal femur invading the joint, with maintenance of pelvic continuity by preserving both columns and the quadrilateral plate of the acetabulum, without intra-pelvic dissection, that can be performed on patients in whom the medial wall of the acetabulum is thick enough. Our preliminary assessments have included studies on dry bone and imaging analyses. The technique was first tested on a single cadaver pelvis (encompassing 2 hips) and subsequently performed on a patient with a pathological fracture of the femoral neck due to osteosarcoma secondary to Paget's disease. Conclusions: Further clinical applications are essential to evaluate the overall effectiveness, safety and impact on patient functionality of this experimental technique. [ABSTRACT FROM AUTHOR]

The article focuses on comparing the outcomes of acromioclavicular joint (ACJ) reconstruction using the modified Weaver–Dunn operation versus hamstring tendon autograft. Topics include the surgical techniques and their effectiveness in achieving stable joint reconstruction; the clinical and radiological results observed in patients; and the advantages and disadvantages of each method in terms of biomechanical stability and postoperative complications.

Skeleton-based human action recognition (HAR) is being utilized in various fields like action classification and abnormal behavior detection. The accurate coordinates of the human joints are a crucial factor for the high performance in skeleton-based HAR. However, the missing joints caused by occlusion and invisibility result in performance degradation. Hence, in this paper, a missing joint reconstruction model is proposed to improve the performance of skeleton-based HAR. The proposed model, based on a denoising graph autoencoder (DGAE), regards missing joints as noise corrupted information and aims to reconstruct them to be close to their original coordinates. When the encoder of the proposed model compresses the noised input into a latent vector, a masking Laplacian matrix is introduced to reduce the effect of the missing joints’ features. The masking Laplacian matrix adjusts the effect of features between a missing joint and its adjacent joints by altering the weights of an adjacent matrix. In the decoder, a Laplacian matrix, which represents the connections among the joints, is utilized to reconstruct an output from the latent vector. The experiment result shows that the proposed model reconstructs the coordinates of missing joints with a marginal error. In addition, the performance of skeleton-based HAR is enhanced by reconstructing the missing joints.

Introduction: Individuals suffering from facial deformities experience esthetic, functional and social setback in their lives every day. These patients benefit greatly with single-stage temporomandibular joint replacement along with orthognathic surgical procedures to correct functional as well as esthetic components. Methodology: Five individuals with facial deformities due to hemifacial macrosomia, fibrous dysplasia, idiopathic condylar resorption, ankylosis, etc., were treated with total joint replacement along with orthognathic surgical procedures for functional and esthetic correction. The customized temporomandibular joint was digitally custom designed, and the orthognathic procedures were virtually planned on NemoFAB software before performing the surgical procedure. Results: Intraoperatively, the overall time was reduced considerably with minimal unpredictable complications. One-week postoperative computed tomographs were obtained and superimposed on preoperative virtual surgical planning which showed minimal discrepancy. Follow-up period of 18–30 months was maintained for all the patients with stable results, minimal relapse and satisfactory functional abilities. Discussion: Total joint replacement along with orthognathic procedure provides single-stage functional and esthetic corrections for the patients, considerably improving their quality of life. Precise preoperative surgical planning proves to be an indispensable step for achieving desired results with minimal margin of error and avoid any unseen complications during the surgical procedure. [ABSTRACT FROM AUTHOR]

Antibiotic-loaded cement spacers (ALCSs) are essential for treating periprosthetic joint infections (PJIs) by providing mechanical support and local antibiotic delivery. The purpose of this review is to comprehensively examine the various types of spacers utilised in the management of periprosthetic joint infections (PJIs), including both static and articulating variants and to analyse the fundamental principles underlying spacer use, their clinical benefits, the selection and administration of antimicrobial agents, appropriate dosages, and potential adverse effects. Articulating spacers, which allow joint mobility, often yield better outcomes than static ones. Spacer pharmacokinetics are vital for maintaining therapeutic antibiotic levels, influenced by cement porosity, mixing techniques, and the contact area. Antibiotic choice depends on heat stability, solubility, and impact on cement’s mechanical properties. Mechanical properties are crucial, as spacers must withstand physical stresses, with antibiotics potentially affecting these properties. Complications, such as tissue damage and systemic toxicity, are discussed, along with mitigation strategies. Future advancements include surface modifications and novel carriers to enhance biofilm management and infection control.

This case report describes the surgical management of a patient with a complex hand trauma. This injury included tendon, vascular, and nerve injuries, a partial amputation of the index finger, fractures of the third proximal phalanx, and destruction of the metacarpophalangeal joint of the fifth finger. Firstly, the acute treatment of a complex hand injury is described. Secondly, the planning and execution of a joint reconstruction using a vascularized lateral femoral condylar flap, assisted by an individual 3D model, is illustrated. Precise reconstruction of the affected structures resulted in good revascularization as well as an anatomical bone consolidation. Intensive physical therapy, including autonomous proprioceptive range-of-motion exercises by the patient, resulted in significant functional improvement of the hand in daily life. Overall, we report on the successful reconstruction of a metacarpophalangeal joint by using a vascularized flap from the lateral femoral condyle. Furthermore, this case report highlights the efficacy of integrating individualized 3D printing technology to plan complex reconstructions, opening up promising opportunities for personalized and optimized interventions. [ABSTRACT FROM AUTHOR]

Purpose: To improve calibrationless parallel imaging using pre‐learned subspaces of coil sensitivity functions. Theory and Methods: A subspace‐based joint sensitivity estimation and image reconstruction method was developed for improved parallel imaging with no calibration data. Specifically, we proposed to use a probabilistic subspace model to capture prior information of the coil sensitivity functions from previous scans acquired using the same receiver system. Both the subspace basis and coefficient distributions were learned from a small set of training data. The learned subspace model was then incorporated into the regularized reconstruction formalism that includes a sparsity prior. The nonlinear optimization problem was solved using alternating minimization algorithm. Public fastMRI brain dataset was retrospectively undersampled by different schemes for performance evaluation of the proposed method. Results: With no calibration data, the proposed method consistently produced the most accurate coil sensitivity estimation and highest quality image reconstructions at all acceleration factors tested in comparison with state‐of‐the‐art methods including JSENSE, DeepSENSE, P‐LORAKS, and Sparse BLIP. Our results are comparable to or even better than those from SparseSENSE, which used calibration data for sensitivity estimation. The work also demonstrated that the probabilistic subspace model learned from T2w data can be generalized to aiding the reconstruction of FLAIR data acquired from the same receiver system. Conclusion: A subspace‐based method named JSENSE‐Pro has been proposed for accelerated parallel imaging without the acquisition of companion calibration data. The method is expected to further enhance the practical utility of parallel imaging, especially in applications where calibration data acquisition is not desirable or limited. [ABSTRACT FROM AUTHOR]

A 28-year–old female recreational athlete presented with middle finger proximal interphalangeal joint pain, stiffness, and ulnar deviation deformity 2 years after internal fixation of a middle phalanx base fracture-dislocation. Radiographs revealed posttraumatic changes on both sides of the proximal interphalangeal joint. Having failed nonsurgical measures, she elected to proceed with surgical reconstruction. Intraoperatively, we confirmed substantial articular damage on both sides of the joint. We proceeded with hemi-hamate autograft for 80% of the middle phalanx base. We used a cobalt chrome proximal phalanx component. After healing, the patient returned to all daily-living and athletic activities with resolution of preoperative pain, stiffness, and deformity. Twelve years after surgey, she had no pain or substantial limitations because of the finger. We measured 80° of proximal interphalangeal joint motion. The grip and fingertip-pinch strength were 91% and 73%, respectively, of the contralateral dominant hand. Radiographs showed no progressive changes compared to 3 years after surgery.

Vascularized joint transfer (VJT) from the proximal interphalangeal joint (PIPJ) of the toe is an attractive reconstructive option in cases of nonsalvageable finger PIPJ but is limited by equivocal functional outcomes. This systematic review aims to provide an update on vascularized toe-to-finger PIPJ transfers, examining functional outcomes, complications, and the latest refinements in operative technique. A systematic review of the available literature was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies examining vascularized toe-to-finger PIPJ transfer for post-traumatic indications were included for analysis. Outcomes assessed included postoperative active range of motion, extension lag, and complications. Thirteen studies examining 210 VJTs were analyzed. Five VJTs experienced microsurgical failure giving an overall survival rate of 97.6%. Average postoperative PIPJ active range of motion (ROM) was 40.3° ± 12.9°, with an average extensor lag of 29° ± 10.5° and mean flexion of 68.9° ± 10.9°. For studies reporting complication outcomes, 59/162 complications were seen. No significant differences were seen between studies published prior to 2013 and after 2013 when comparing digital ROM (P =.123), flexion (P =.602), and extensor lag (P =.280). Studies using a reconstructive algorithm based on prior assessment of the donor toe central slip and recipient finger anatomy had significantly improved ROM outcomes (P =.013). Although VJT provides a reliable option for autologous reconstruction in posttraumatic joints, it is limited by impaired postoperative ROM. Careful assessment of the donor toe and recipient finger anatomy followed by systematic and meticulous reconstruction may lead to improved functional outcomes. [ABSTRACT FROM AUTHOR]

Background: Open articular fractures often include contaminated, devascularized osteoarticular fragments that are critical for joint reconstruction. Definitive treatment is often delayed such that decontamination and preservation of critical fragments for joint reconstruction is highly desirable. To validate decontamination and preservation protocols for safe and effective preservation of osteoarticular fragments for re-implantation, a preclinical animal model for inducing type 3 open articular fractures with contaminated, devascularized osteoarticular fragments was developed and validated., Materials and Methods: With IACUC approval, purpose-bred hounds (n = 5) were humanely euthanized. Immediately following euthanasia, a penetrating captive bolt pistol with 1.25 grain cartridge centered on the cranial aspect of each distal humerus was discharged to create open fractures in 3 dogs (6 elbows). In 2 dogs, matched osteoarticular tissues from non-injured elbows (controls) were retrieved for comparison. Distal humerus, proximal radius, and proximal ulna osteoarticular fragments (n = 27) were immediately placed in Missouri Osteochondral Preservation System (MOPS) solution and stored at room temperature. Radiographic, chondrocyte viability, and quantitative microbial culture assessments were performed immediately (time-0) and at 7 and 14 days of storage., Results: This preclinical canine model reliably produced type 3 open distal humeral fractures characterized by devascularized and contaminated osteoarticular fracture fragments. All fragments produced extensive microbial growth through 14 days of storage. Without decontamination, viable chondrocyte density in the fragments decreased significantly within 7 days, likely attributable to the profound contamination., Conclusion: These data highlight the importance of developing a reliable method for point-of-care decontamination and preservation of osteoarticular fracture fragments for safe and effective reimplantation of articular fracture fragments for joint reconstruction., Competing Interests: Co-authors James L. Cook and Aaron Stoker are patent holders in the MOPS system used in this research. They also receive IP royalties and research support from the Musculoskeletal Transplant Network (MTF Biologics), which has exclusive distribution rights to this preservation technology. Corresponding author Julia A.V. Nuelle receives research support from MTF. No other authors have disclosures in this study., (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

The temporomandibular joint (TMJ) is the critical functional unit in the human stomatognathic system. Damage of the TMJ causes orofacial dysfunction and secondary jaw deformities, leading to seriously decreased quality of life in patients. The TMJ prosthetic replacement is an important treatment method for severe joint destruction because of its remarkable advantages compared with other methods. In recent years, this technique has gradually attracted wide attention in China, but it has not been popularized on a large scale in our country because of several limitations. Thus, in this study, the clinical experience of patients with TMJ prosthetic replacement in clinical units was summarized, and the treatment principles, treatment processes, and technical advantages were systematically discussed, aiming to promote the popularization and application of TMJ prosthetic replacement in China.

Aims: Hydroxyapatite (HA)-coated collars have been shown to reduce aseptic loosening of massive endoprostheses following primary surgery. Limited information exists about their effectiveness in revision surgery. The aim of this study was to radiologically assess osteointegration to HA-coated collars of cemented massive endoprostheses following revision surgery. Methods: Retrospective review of osseointegration frequency, pattern, and timing to a specific HA-coated collar on massive endoprostheses used in revision surgery at our tertiary referral centre between 2010 to 2017 was undertaken. Osseointegration was radiologically classified on cases with a minimum follow-up of six months. Results: In all, 39 patients underwent radiological review at mean 43.5 months; 22/39 (56.4%) showed no osseointegration to the collar. Revision endoprostheses for aseptic loosening were less likely to show osseointegration compared with other indications for revision. Oncological cases with previous or current infection were more likely to show osseointegration to ≥ 1 collar side than those without evidence of prior infection. Conclusion: This seven-year review identified osseointegration of HA-coated collars after revision surgery is less likely (43.6%, 17/39) than after primary surgery. Young patients who undergo revision surgery following initial oncological indication may benefit the most from this collar design. Use in revision oncological cases with a history of infection may be beneficial. HA-coated collars showed limited benefit for patients undergoing revision for failed arthroplasty with history of infection.

This study evaluated knee collateral ligaments for use as allografts in small joint reconstruction in the hand, specifically the thumb metacarpophalangeal (MCP) joint ulnar collateral ligament (UCL) and the index finger proximal interphalangeal (PIP) joint radial collateral ligament (RCL), and compared them to the current gold standard, tendon autograft. Uniaxial tensile testing was performed on native thumb MCP UCLs and index finger PIP RCLs and 2.5-mm–diameter grafts prepared from hemi-flexor carpi radialis (hemi-FCR) tendons and knee medial collateral ligaments (MCLs) cadaveric allografts. In situ angular testing was performed in thumb MCP and index finger PIP joints. Each MCP/PIP joint was secured to a mechanical testing system and cyclically loaded. The UCL/RCL was resected and reconstructed with either an MCL or hemi-FCR. Cyclic loading was repeated, followed by angular load to failure. Uniaxial testing of MCL allografts demonstrated greater ultimate stress, ultimate load, and elastic modulus than hemi-FCR grafts and native UCLs/RCLs. The maximum angular deviation of the reconstructed MCP and PIP joints was not significantly different compared with the intact joint with either an MCL or hemi-FCR graft. In situ load to failure demonstrated no differences in failure torque or angular stiffness between MCPs reconstructed with a hemi-FCR and MCL allograft, whereas reconstructed PIP joints demonstrated improved angular stiffness with an MCL allograft compared with a hemi-FCR. Medial collateral ligament allografts demonstrated improved mechanical properties compared with hemi-FCR tendon grafts during uniaxial testing, and grafts performed equivalently in in situ testing of reconstructed thumb/finger joints. Prepared knee ligament allografts may provide a viable graft material for use in reconstruction of small hand ligaments. This new allograft material avoids the need to harvest a tendon autograft and has a biologic structure similar to native hand ligaments. [ABSTRACT FROM AUTHOR]

Purpose: To propose a new method for the recovery of combined in‐plane‐ and multi‐band (MB)‐accelerated diffusion MRI data. Methods: Combining MB acceleration with in‐plane acceleration is crucial to improve the time efficiency of high (angular and spatial) resolution diffusion scans. However, as the MB factor and in‐plane acceleration increase, the reconstruction becomes challenging due to the heavy aliasing. The new reconstruction utilizes an additional q‐space prior to constrain the recovery, which is derived from the previously proposed qModeL framework. Specifically, the qModeL prior provides a pre‐learned representation of the diffusion signal space to which the measured data belongs. We show that the pre‐learned q‐space prior along with a model‐based iterative reconstruction that accommodate multi‐band unaliasing, can efficiently reconstruct the in‐plane‐ and MB‐accelerated data. The power of joint reconstruction is maximally utilized by using an incoherent under‐sampling pattern in the k‐q domain. We tested the proposed method on single‐ and multi‐shell data, with high/low angular resolution, high/low spatial resolution, healthy/abnormal tissues, and 3T/7T field strengths. Furthermore, the learning is extended to the spherical harmonic basis, to provide a rotational invariant learning framework. Results: The qModeL joint reconstruction is shown to simultaneously unalias and jointly recover DWIs with reasonable accuracy in all the cases studied. The reconstruction error from 18‐fold accelerated multi‐shell datasets was <3%. The microstructural maps derived from the accelerated acquisitions also exhibit reasonable accuracy for both healthy and abnormal tissues. The deep learning (DL)‐enabled reconstructions are comparable to those derived using traditional methods. Conclusion: qModeL enables the joint recovery of combined in‐plane‐ and MB‐accelerated dMRI utilizing DL. [ABSTRACT FROM AUTHOR]

During the development of microvascular surgery in 1980-95 many new methods to overcome different traumatic disorders were studied. Previously unsolved problems could be treated using free tissue transfer. Typical problems in wrist surgery were the painful complications from ulna head resection. No sound or acceptable artificial protheses for ulna head were available. Author did study the possibilities of reversal of resected ulna head using an autogenous microvascular joint transfer. First it was done using cadaver models and evaluating the possibilities of a toe MTP-II joint in replacing the distal radio-ulnar joint. Then same principle was used in three clinical cases. All patients had suffered a poor result after ulna head resection or Darrach procedure. First two cases had complications but third case from year 1994 resulted in a good outcome. This paper introduces the development of a surgical technique for the replacement of the resected ulna head. Also, it will describe the excellent long-term result achieved in the last case with 26-year follow-up. Although today many sophisticated prosthetic replacement techniques have become developed for this purpose, this kind of autogenous reconstruction might have a place in treating similar problems in young posttraumatic patients. Also it demonstrates the potential benefit of microsurgery in a difficult wrist problem. [ABSTRACT FROM AUTHOR]

Independent processing of each polarization channel and three-dimensional multistage imaging ignore the correlation between data, resulting in the mismatch between scattering centers and the inaccurate acquisition of polarization scattering matrices. To address these issues, a full-polarization Synthetic Aperture Radar (SAR) joint multidimensional reconstruction method based on sparse reconstruction is proposed in this study. In this method, all polarization channels and dimensions are integrated by setting the joint sparse constraints, and the full-polarization SAR joint multidimensional reconstruction is modeled as a multichannel joint sparse reconstruction problem. After the model is simplified by data interpolation, an efficient model-solving method is proposed by combining the three-dimensional fast Fourier transform, conjugate gradient method, and Newton iteration method, where the polarization scattering matrix and three-dimensional information of the target can be obtained at the same time. The proposed method ensures that the sparse support sets of different polarization channels and dimensions are consistent and utilizes the additional information generated by the correlation between data. On the basis of the simulation and electromagnetic calculation data, the experimental results indicate that the proposed method is tolerant of noise and immune to the types of targets. Moreover, the proposed method can effectively obtain the multidimensional reconstruction results of the target, where both the resolution of the imaging results and the estimation accuracy of the polarization scattering matrix are high.

A 300 kg, 11-month-old quarter horse filly was presented with a joint dislocation in the right anterior limb. The animal was attended at the Federal University of Pará (UFPA) Veterinary Hospital in September 2016, where it was reported that the horse was injured on a fence. On clinical examination, the dislocation of the metacarpophalangeal joint with a rupture of the joint capsule and exposure of bone surfaces was observed, however, with no rupture of the extensor and flexor tendons. Surgery was recommended and the patient was anaesthetised with detomidine (Dormiun V; Agener União, São Paulo, Brazil; 0.04 mg/kg), ketamine (Cetamin; Syntec, São Paulo, Brazil; 0.03 mg/kg/h) and guaiacol glyceryl ether (JA Saúde Animal, São Paulo, Brasil, 0.5 ml/kg/h) i.v. The reconstitution of the joint capsule, lateral collateral ligament (LCL) and the other soft tissues around the injury was performed. A chemical arthrodesis was performed, then the tissue approximation and finally the skin suture. Bandages were applied on the wound with hydrophobic cotton and a Robert-Jones dressing. Systemic treatment was performed with enrofloxacin (Zelotril 10%; Agener União, São Paulo, Brazil; 5 mg/kg) i.m., meloxicam (Maxicam 2%; São Paulo, Brasil; 0.6 mg/kg) i.v. during 10 and 20 days, respectively, then replacing the antibiotic with ceftiofur (Cef 50; Agener União, São Paulo, Brasil; 2.2 mg/kg) i.m. for another 22 days. An iodine solution was applied to the joint optimising arthrodesis. After three and a half months, the lesion was entirely healed and with good movement, so the patient was discharged. This case demonstrates that, with adequate treatment and attention, it is possible to recover the patient's quality of life.

Abstract Background Gratifying long-term results are difficult to achieve when reconstructing osteoarthritic finger joints. Implant surgery is the most commonly used method to restore function and dexterity. However, all types of implant have disadvantages and may be a less favorable option in some cases, especially in young patients with a long expected lifetime and high demands on manual load. Implant related complications as loosening, instability, subsidence and stiffness are the main concerns. In this context, joint reconstruction using rib perichondrium might be a reasonable alternative in selected cases. The aim of the study was to evaluate the long-term results of finger joint reconstruction using rib perichondrial transplantation. Methods The study group (n = 11) consisted of eight individuals reconstructed in the proximal interphalangeal (PIP) joints and three reconstructed in the metacarpophalangeal (MCP) joints during 1974–1981. All patients were evaluated at clinical visits (median: 37 years after perichondrial transplantation, range: 34–41 years) using radiographs, disability in arm-shoulder-hand (DASH) score, Visual Analog Scale (VAS), range-of-motion (ROM) and manual strength (JAMAR). Results None of the 11 patients had undergone additional surgery. All of the PIP-joints (n = 8) were almost pain-free at activity (VAS 0,6) (range 0–4), had an average range-of-motion of 41 degrees (range 5–80) and a mean DASH-score of 8,3 (range 1–51). The mean strength was 41 kg compared to 44 kg in the contralateral hand (93%). The three MCP joints were almost pain-free at activity (VAS 0,7), (range 0–1). The ROM was on average 80 degrees (range 70–90) and the mean DASH-score was 2 (range 1–3). The mean strength was 43 kg compared to 53 kg in the contralateral hand (81%). Conclusions Perichondrium transplants restored injured PIP and MCP joints that remained essentially pain-free and mostly well-functioning without need for additional surgeries up to 41 years after the procedure. Additional studies are needed to evaluate long-term results in comparison to modern implants and to better describe the factors that determine the outcome of these procedures. Level of evidence Level IV, Therapeutic Study.

Abstract Background Simultaneous reconstruction of emission and attenuation images in time-of-flight (TOF) positron emission tomography (PET) does not provide a unique solution. In this study, we propose to solve this limitation by including additional information given by a reference object with known attenuation placed outside the patient. Different configurations of the reference object were studied including geometry, material composition, and activity, and an optimal configuration was defined. In addition, this configuration was tested for different timing resolutions and noise levels. Results The proposed strategy was tested in 2D simulations obtained by forward projection of available PET/CT data and noise was included using Monte Carlo techniques. Obtained results suggest that the optimal configuration corresponds to a water cylinder inserted in the patient table and filled with activity. In that case, mean differences between reconstructed and true images were below 10%. However, better results can be obtained by increasing the activity of the reference object. Conclusion This study shows promising results that might allow to obtain an accurate attenuation map from pure TOF-PET data without prior knowledge obtained from CT, MRI, or transmission scans.

Objective . Positron Emission Tomography and Magnetic Resonance Imaging (PET-MRI) systems can obtain functional and anatomical scans. But PET suffers from a low signal-to-noise ratio, while MRI are time-consuming. To address time-consuming, an effective strategy involves reducing k-space data collection, albeit at the cost of lowering image quality. This study aims to leverage the inherent complementarity within PET-MRI data to enhance the image quality of PET-MRI. Approach . A novel PET-MRI joint reconstruction model, termed MC-Diffusion, is proposed in the Bayesian framework. The joint reconstruction problem is transformed into a joint regularization problem, where data fidelity terms of PET and MRI are expressed independently. The regular term, the derivative of the logarithm of the joint probability distribution of PET and MRI, employs a joint score-based diffusion model for learning. The diffusion model involves the forward diffusion process and the reverse diffusion process. The forward diffusion process adds noise to transform a complex joint data distribution into a known joint prior distribution for PET and MRI simultaneously, resembling a denoiser. The reverse diffusion process removes noise using a denoiser to revert the joint prior distribution to the original joint data distribution, effectively utilizing joint probability distribution to describe the correlations of PET and MRI for improved quality of joint reconstruction. Main results . Qualitative and quantitative improvements are observed with the MC-Diffusion model. Comparative analysis against LPLS and Joint ISAT-net on the ADNI dataset demonstrates superior performance by exploiting complementary information between PET and MRI. The MC-Diffusion model effectively enhances the quality of PET and MRI images. Significance . This study employs the MC-Diffusion model to enhance the quality of PET-MRI images by integrating the fundamental principles of PET and MRI modalities and leveraging their inherent complementarity. Furthermore, utilizing the diffusion model to learn the joint probability distribution of PET and MRI, thereby elucidating their latent correlation, facilitates a more profound comprehension of the priors obtained through deep learning, contrasting with black-box prior or artificially constructed structural similarities., (© 2024 Institute of Physics and Engineering in Medicine.)

Introduction: Traumatic osteoarthritis of the ankle joint caused after malleolar fractures of the ankle and tibial plafond fractures are frequently observed in comparatively young and highly active patients. Since the ankle movement in these patients is in general, comparatively favorable, orthopedists may sometimes have difficulty in deciding on a treatment policy. In our department, when treating traumatic osteoarthritis patients having a movable range within their ankle joints, we proactively applied distal tibial oblique osteotomy (DTOO) developed by Dr. Teramoto in 1994 or intra-articular osteotomy developed based on DTOO concepts such as distal tibial intra-articular osteotomy (DTIO) and distal fibular oblique osteotomy (DFOO).The objectives of the current study are to radiologically assess the ankle joint after intra-articular osteotomy for traumatic ankle osteoarthritis and evaluate the change in configuration of the ankle joint. This study summarizes the clinical results of intra-articular osteotomy obtained through the above-mentioned study.Patients and Methods: The subjects of this study were 20 patients diagnosed with traumatic osteoarthritis who were surgically treated for a total of 20 ankles. All patients underwent treatment with intra-articular osteotomy and were evaluated retrospectively for the following parameters: surgical procedure, fixation devices, clinical results based on the Japanese Society for Surgery of the Foot ankle/hindfoot scale (hereafter, JSSF scale) and post-operative adverse events. They were also assessed radiologically with pre- and post-operative anterior-posterior (AP) and lateral weight-bearing ankle radiographs.Results: The 20 patients consisted of 12 males and 8 females. The median age at surgery was 49 years old (range 14 - 87 years old) and the average follow-up period was 42 months (range 19 to 121 months). DTOO was applied to 10 cases, DFOO to 2 cases, DTOO and DFOO to 2 cases, medial-distal tibial intra-articular osteotomy (M-DTIO) and DFOO to 1 case, lateral-distal tibial intra-articular osteotomy (L-DTIO) and DFOO to 3 cases, M-DTIO followed by DTOO and DFOO to 1 case, and DTOO followed by low tibial osteotomy (LTO) to 1 case. Fixation devices utilized included circular external fixator for 15 cases, locking compression plate (LCP) to 3 cases, LCP and Kirschner-wire (K-wire) to 1 case, and screw and K-wire to 1 case. Radiological assessment revealed significant changes in the following parameters after surgery: tibial ankle surface angle (TAS, P= 0.0203), tibiotalar surface angle (TTS, P= 0.0021), medial malleolar angle (MMA, P= 0.0217), empirical axis (EA, P= 0.0019), fibular angle (FA, P= 0.0002), talar tilt angle (TTA, P= 0.0374), and tibial lateral surface angle (TLS, P= 0.0279). The JSSF scale also improved significantly after surgery (pre-operative JSSF scale: 51.1±11.0, post-operative JSSF scale: 89.2±8.2), p=0.0001.Conclusion: Intra-articular osteotomy may change the radiological configuration of the ankle in a weight-bearing state. The present study showed very good short-term clinical results. Intra-articular osteotomy can prove a viable surgical option applicable for treatment of patients with traumatic ankle osteoarthritis having a reasonable range of motion within their ankle joints. [ABSTRACT FROM AUTHOR]

Electrical and elasticity imaging are promising modalities for a suite of different applications, including medical tomography, non-destructive testing and structural health monitoring. These emerging modalities are capable of providing remote, non-invasive and low-cost opportunities. Unfortunately, both modalities are severely ill-posed nonlinear inverse problems, susceptive to noise and modelling errors. Nevertheless, the ability to incorporate complimentary datasets obtained simultaneously offers mutually beneficial information. By fusing electrical and elastic modalities as a joint problem, we are afforded the possibility to stabilize the inversion process via the utilization of auxiliary information from both modalities as well as joint structural operators. In this study, we will discuss a possible approach to combine electrical and elasticity imaging in a joint reconstruction problem giving rise to novel multi-modality applications for use in both medical and structural engineering. This article is part of the theme issue 'Synergistic tomographic image reconstruction: part 1'. [ABSTRACT FROM AUTHOR]

BACKGROUND: For patients with Crowe II and III developmental dysplasia of hip combined with severe hip osteoarthritis, total hip arthroplasty is still controversial whether to choose acetabular anatomical reconstruction or high hip rotation center reconstruction. OBJECTIVE: To compare the differences in gait characteristics between the reconstruction technique of the high hip center and the anatomical hip center during total hip arthroplasty. METHODS: Forty patients with Crowe II-III developmental dysplasia of hip with unilateral hip disease from January 2014 to July 2017 were selected. All patients received total hip arthroplasty, of which 20 cases underwent acetabular anatomical reconstruction, and another 20 patients underwent high hip center reconstruction. The patients were followed up for more than 2 years after arthroplasty for gait analysis. The study was approved by Ethics Committee of Affiliated Hospital of Xuzhou Medical University. RESULTS AND CONCLUSION: (1) Spatiotemporal parameters: The pace, stride frequency, step length, single leg support time, single leg swing time, and double leg support time of the two groups of surgical side and non-surgical side were similar. There was no significant difference in pace, stride frequency, step length, one-leg support time, one-leg swing time, and two-leg support time between the two groups (P > 0.05). (2) Kinematic parameters: The maximum extension of the hip joint on the surgical side of the high reconstruction group was lower than that on the non-surgical side (P < 0.01). The maximum hip flexion and hip flexion and extension range of the two groups on the surgical side were lower than those on the non-surgical side (P=0.01). The maximum extension of the hip joint and hip flexion and extension range in the high reconstruction group were lower than those in the anatomical reconstruction group (P < 0.05). The maximum flexion of the hip joint, maximum knee flexion, knee flexion and extension range, and maximum dorsiflexion of the ankle, the maximum plantar flexion of the ankle, and the range of ankle dorsiflexion were not significantly different between the two groups (P > 0.05). (3) Kinetic parameters: The longitudinal peak of the plantar reaction force on the surgical side of the high reconstruction group was higher than that of the anatomical reconstruction group (P < 0.05). There was no significant difference between the internal and external peaks of the plantar reaction force and the front and back peaks of the two groups on the surgical side (P > 0.05). (4) The results show that in patients with developmental dysplasia of hip, total hip arthroplasty using high hip center reconstruction can obtain gait parameters similar to anatomical hip center reconstruction. However, compared with patients undergoing anatomical hip rotation center reconstruction, patients with high hip center reconstruction had limited hip flexion and extension range movement and greater longitudinal force on the hip. [ABSTRACT FROM AUTHOR]

Preserving the ability to maintain an active lifestyle is a major concern in the reconstruction of the knee in young patients. for the healthy individual who desires to maintain a relatively active lifestyle, fresh osteochondral allografts may serve as an alternative to total joint reconstruction. The use of fresh allografts is primarily indicated in the patient suffering from a traumatic loss of articular seg- ments, who is too young or active for arthroplasty. In addition, fresh osteochon- dral allografts have a number of advantages over arthroplasty such as providing surgeons with a source of large grafts that can be ftted to replace osteochondral defects and cover the majority or entirety of articular surfaces without any donor site morbidity. In this case, a young, active patient lost a 7 x 8 cm portion of their distal femur, including a large portion of the articulating surface. Using a fresh os- teochondral allograft, harvested within 24 hours of donor death, a segment was ftted to match bony apposition, articular congruity, and congruity with the femoral notch and affxed with four partially threaded cancellous screws. Joint function was restored with the allograft in place, allowing the patient to delay the need for a total joint replacement.

Background: Accessible, adequate online information is important to fellowship applicants. Program web sites can affect which programs applicants apply to, subsequently altering interview costs incurred by both parties and ultimately impacting rank lists. Web site analyses have been performed for all orthopaedic subspecialties other than those involved in the combined adult reconstruction and musculoskeletal (MSK) oncology fellowship match. Methods: A complete list of active programs was obtained from the official adult reconstruction and MSK oncology society web sites. Web site accessibility was assessed using a structured Google search. Accessible web sites were evaluated based on 21 previously reported content criteria. Results: Seventy-four adult reconstruction programs and 11 MSK oncology programs were listed on the official society web sites. Web sites were identified and accessible for 58 (78%) adult reconstruction and 9 (82%) MSK oncology fellowship programs. No web site contained all content criteria and more than half of both adult reconstruction and MSK oncology web sites failed to include 12 of the 21 criteria. Conclusions: Several programs participating in the combined Adult Reconstructive Hip and Knee/Musculoskeletal Oncology Fellowship Match did not have accessible web sites. Of the web sites that were accessible, none contained comprehensive information and the majority lacked information that has been previously identified as being important to perspective applicants.

Several real-time visual monitoring applications such as surveillance, mental state monitoring, driver drowsiness and patient care, require equipping high-quality cameras with wireless sensors to form visual sensors and this creates an enormous amount of data that has to be managed and transmitted at the sensor node. Moreover, as the sensor nodes are battery-operated, power utilization is one of the key concerns that must be considered. One solution to this issue is to reduce the amount of data that has to be transmitted using specific compression techniques. The conventional compression standards are based on complex encoders (which require high processing power) and simple decoders and thus are not pertinent for battery-operated applications, i.e., VSN (primitive hardware). In contrast, compressive sensing (CS) a distributive source coding mechanism, has transformed the standard coding mechanism and is based on the idea of a simple encoder (i.e., transmitting fewer data-low processing requirements) and a complex decoder and is considered a better option for VSN applications. In this paper, a CS-based joint decoding (JD) framework using frame prediction (using keyframes) and residual reconstruction for single-view video is proposed. The idea is to exploit the redundancies present in the key and non-key frames to produce side information to refine the non-key frames' quality. The proposed method consists of two main steps: frame prediction and residual reconstruction. The final reconstruction is performed by adding a residual frame with the predicted frame. The proposed scheme was validated on various arrangements. The association among correlated frames and compression performance is also analyzed. Various arrangements of the frames have been studied to select the one that produces better results. The comprehensive experimental analysis proves that the proposed JD method performs notably better than the independent block compressive sensing scheme at different subrates for various video sequences with low, moderate and high motion contents. Also, the proposed scheme outperforms the conventional CS video reconstruction schemes at lower subrates. Further, the proposed scheme was quantized and compared with conventional video codecs (DISCOVER, H-263, H264) at various bitrates to evaluate its efficiency (rate-distortion, encoding, decoding). [ABSTRACT FROM AUTHOR]

A 300 kg, 11-month-old quarter horse filly was presented with a joint dislocation in the right anterior limb. The animal was attended at the Federal University of Pará (UFPA) Veterinary Hospital in September 2016, where it was reported that the horse was injured on a fence. On clinical examination, the dislocation of the metacarpophalangeal joint with a rupture of the joint capsule and exposure of bone surfaces was observed, however, with no rupture of the extensor and flexor tendons. Surgery was recommended and the patient was anaesthetised with detomidine (Dormiun V; Agener União, São Paulo, Brazil; 0.04 mg/kg), ketamine (Cetamin; Syntec, São Paulo, Brazil; 0.03 mg/kg/h) and guaiacol glyceryl ether (JA Saúde Animal, São Paulo, Brasil, 0.5 ml/kg/h) i.v. The reconstitution of the joint capsule, lateral collateral ligament (LCL) and the other soft tissues around the injury was performed. A chemical arthrodesis was performed, then the tissue approximation and finally the skin suture. Bandages were applied on the wound with hydrophobic cotton and a Robert-Jones dressing. Systemic treatment was performed with enrofloxacin (Zelotril 10%; Agener União, São Paulo, Brazil; 5 mg/kg) i.m., meloxicam (Maxicam 2%; São Paulo, Brasil; 0.6 mg/kg) i.v. during 10 and 20 days, respectively, then replacing the antibiotic with ceftiofur (Cef 50; Agener União, São Paulo, Brasil; 2.2 mg/kg) i.m. for another 22 days. An iodine solution was applied to the joint optimising arthrodesis. After three and a half months, the lesion was entirely healed and with good movement, so the patient was discharged. This case demonstrates that, with adequate treatment and attention, it is possible to recover the patient's quality of life. [ABSTRACT FROM AUTHOR]

Single-particle cryo-electron microscopy (cryo-EM) reconstructs the three-dimensional (3D) structure of bio-molecules from a large set of 2D projection images with random and unknown orientations. A crucial step in the single-particle cryo-EM pipeline is 3D refinement, which resolves a high-resolution 3D structure from an initial approximate volume by refining the estimation of the orientation of each projection. In this work, we propose a new approach that refines the projection angles on the continuum. We formulate the optimization problem over the density map and the orientations jointly. The density map is updated using the efficient alternating-direction method of multipliers, while the orientations are updated through a semi-coordinate-wise gradient descent for which we provide an explicit derivation of the gradient. Our method eliminates the requirement for a fine discretization of the orientation space and does away with the classical but computationally expensive template-matching step. Numerical results demonstrate the feasibility and performance of our approach compared to several baselines. [ABSTRACT FROM AUTHOR]

Background: Gratifying long-term results are difficult to achieve when reconstructing osteoarthritic finger joints. Implant surgery is the most commonly used method to restore function and dexterity. However, all types of implant have disadvantages and may be a less favorable option in some cases, especially in young patients with a long expected lifetime and high demands on manual load. Implant related complications as loosening, instability, subsidence and stiffness are the main concerns. In this context, joint reconstruction using rib perichondrium might be a reasonable alternative in selected cases. The aim of the study was to evaluate the long-term results of finger joint reconstruction using rib perichondrial transplantation.Methods: The study group (n = 11) consisted of eight individuals reconstructed in the proximal interphalangeal (PIP) joints and three reconstructed in the metacarpophalangeal (MCP) joints during 1974-1981. All patients were evaluated at clinical visits (median: 37 years after perichondrial transplantation, range: 34-41 years) using radiographs, disability in arm-shoulder-hand (DASH) score, Visual Analog Scale (VAS), range-of-motion (ROM) and manual strength (JAMAR).Results: None of the 11 patients had undergone additional surgery. All of the PIP-joints (n = 8) were almost pain-free at activity (VAS 0,6) (range 0-4), had an average range-of-motion of 41 degrees (range 5-80) and a mean DASH-score of 8,3 (range 1-51). The mean strength was 41 kg compared to 44 kg in the contralateral hand (93%). The three MCP joints were almost pain-free at activity (VAS 0,7), (range 0-1). The ROM was on average 80 degrees (range 70-90) and the mean DASH-score was 2 (range 1-3). The mean strength was 43 kg compared to 53 kg in the contralateral hand (81%).Conclusions: Perichondrium transplants restored injured PIP and MCP joints that remained essentially pain-free and mostly well-functioning without need for additional surgeries up to 41 years after the procedure. Additional studies are needed to evaluate long-term results in comparison to modern implants and to better describe the factors that determine the outcome of these procedures.Level Of Evidence: Level IV, Therapeutic Study. [ABSTRACT FROM AUTHOR]

With increasing improvements in the time of flight (TOF) resolution of positron emission tomography (PET) scanners, an accurate model of the TOF measurements is becoming increasingly important. This work considers two parameters of the TOF kernel; the relative positioning of the timing data-bins and the timing resolution along each line of response (LOR). Similar to an existing data-driven method, we assume that any shifts of data-bins along lines of response can be modelled as differences between crystal timing offsets. Inspired by this, timing resolutions of all LORs are modelled as the hypotenuse of timing resolutions of the crystal-pairs in coincidence. Furthermore, in order to mitigate the influence of potential inaccuracies of detector-pair sensitivities on crystal timing resolutions, relative LOR sensitivities are modelled as the product of efficiency factors for the two crystals in coincidence. We validate estimating maps of crystal timing offsets, timing resolutions and efficiencies from the emission data using noisy simulations of a brain phantom. Results are shown for phantom and patient data scanned on clinically available TOF-PET scanners. We find that the estimation of crystal timing resolutions is more sensitive to the data statistics than the estimation of crystal timing offsets. As a result, estimation of crystal timing properties could either be limited to high count emission data, or be obtained utilizing additional regularizations on the estimates. Using a more accurate model of the TOF acquisition, improvements are observed in standard activity reconstructions as well as joint reconstructions of activity and attenuation. [ABSTRACT FROM AUTHOR]

Multi‐contrast images are commonly acquired together to maximize complementary diagnostic information, albeit at the expense of longer scan times. A time‐efficient strategy to acquire high‐quality multi‐contrast images is to accelerate individual sequences and then reconstruct undersampled data with joint regularization terms that leverage common information across contrasts. However, these terms can cause features that are unique to a subset of contrasts to leak into the other contrasts. Such leakage‐of‐features may appear as artificial tissues, thereby misleading diagnosis. The goal of this study is to develop a compressive sensing method for multi‐channel multi‐contrast magnetic resonance imaging (MRI) that optimally utilizes shared information while preventing feature leakage. Joint regularization terms group sparsity and colour total variation are used to exploit common features across images while individual sparsity and total variation are also used to prevent leakage of distinct features across contrasts. The multi‐channel multi‐contrast reconstruction problem is solved via a fast algorithm based on Alternating Direction Method of Multipliers. The proposed method is compared against using only individual and only joint regularization terms in reconstruction. Comparisons were performed on single‐channel simulated and multi‐channel in‐vivo datasets in terms of reconstruction quality and neuroradiologist reader scores. The proposed method demonstrates rapid convergence and improved image quality for both simulated and in‐vivo datasets. Furthermore, while reconstructions that solely use joint regularization terms are prone to leakage‐of‐features, the proposed method reliably avoids leakage via simultaneous use of joint and individual terms, thereby holding great promise for clinical use. [ABSTRACT FROM AUTHOR]

Objective: Balanced steady‐state free precession (bSSFP) imaging suffers from banding artifacts in the presence of magnetic field inhomogeneity. The purpose of this study is to identify an efficient strategy to reconstruct banding‐free bSSFP images from multi‐coil multi‐acquisition datasets. Method: Previous techniques either assume that a naïve coil‐combination is performed a priori resulting in suboptimal artifact suppression, or that artifact suppression is performed for each coil separately at the expense of significant computational burden. Here we propose a tailored method that factorizes the estimation of coil and bSSFP sensitivity profiles for improved accuracy and/or speed. Results: In vivo experiments show that the proposed method outperforms naïve coil‐combination and coil‐by‐coil processing in terms of both reconstruction quality and time. Conclusion: The proposed method enables computationally efficient artifact suppression for phase‐cycled bSSFP imaging with modern coil arrays. Rapid imaging applications can efficiently benefit from the improved robustness of bSSFP imaging against field inhomogeneity. [ABSTRACT FROM AUTHOR]

Magnetic resonance (MR) imaging tasks often involve multiple contrasts, such as T1-weighted, T2-weighted and fluid-attenuated inversion recovery (FLAIR) data. These contrasts capture information associated with the same underlying anatomy and thus exhibit similarities in either structure level or gray level. In this paper, we propose a coupled dictionary learning based multi-contrast MRI reconstruction (CDLMRI) approach to leverage the dependency correlation between different contrasts for guided or joint reconstruction from their under-sampled $k$ -space data. Our approach iterates between three stages: coupled dictionary learning, coupled sparse denoising, and enforcing $k$ -space consistency. The first stage learns a set of dictionaries that not only are adaptive to the contrasts, but also capture correlations among multiple contrasts in a sparse transform domain. By capitalizing on the learned dictionaries, the second stage performs coupled sparse coding to remove the aliasing and noise in the corrupted contrasts. The third stage enforces consistency between the denoised contrasts and the measurements in the $k$ -space domain. Numerical experiments, consisting of retrospective under-sampling of various MRI contrasts with a variety of sampling schemes, demonstrate that CDLMRI is capable of capturing structural dependencies between different contrasts. The learned priors indicate notable advantages in multi-contrast MR imaging and promising applications in quantitative MR imaging such as MR fingerprinting. [ABSTRACT FROM AUTHOR]

Background: Simultaneous reconstruction of emission and attenuation images in time-of-flight (TOF) positron emission tomography (PET) does not provide a unique solution. In this study, we propose to solve this limitation by including additional information given by a reference object with known attenuation placed outside the patient. Different configurations of the reference object were studied including geometry, material composition, and activity, and an optimal configuration was defined. In addition, this configuration was tested for different timing resolutions and noise levels. Results: The proposed strategy was tested in 2D simulations obtained by forward projection of available PET/CT data and noise was included using Monte Carlo techniques. Obtained results suggest that the optimal configuration corresponds to a water cylinder inserted in the patient table and filled with activity. In that case, mean differences between reconstructed and true images were below 10%. However, better results can be obtained by increasing the activity of the reference object. Conclusion: This study shows promising results that might allow to obtain an accurate attenuation map from pure TOF-PET data without prior knowledge obtained from CT, MRI, or transmission scans. [ABSTRACT FROM AUTHOR]

We consider the problem of 3D shape reconstruction from multimodal data, given uncertain calibration parameters. Typically, 3D data modalities can come in diverse forms such as sparse point sets, volumetric slices, and 2D photos. To jointly process these data modalities, we exploit a parametric level set method that utilizes ellipsoidal radial basis functions. This method not only allows us to analytically and compactly represent the object; it also confers on us the ability to overcome calibration-related noise that originates from inaccurate acquisition parameters. This essentially implicit regularization leads to a highly robust and scalable reconstruction, surpassing other traditional methods. In our results we first demonstrate the ability of the method to compactly represent complex objects. We then show that our reconstruction method is robust both to a small number of measurements and to noise in the acquisition parameters. Finally, we demonstrate our reconstruction abilities from diverse modalities such as volume slices obtained from liquid displacement (similar to CT scans and X-rays) and visual measurements obtained from shape silhouettes as well as point clouds. [ABSTRACT FROM AUTHOR]

Imaging radar is widely applied in both military and civil fields, including remote sensing. In recent years, polarization information has attracted more and more attention in the imaging radar. The orthogonality between different channels is always the core problem for the full-polarization imaging radar. To solve this problem, an image reconstruction method using orthogonal coding apertures technique is proposed for full-polarization imaging radar in this paper. Firstly, the signal model of the orthogonal coding apertures is proposed. This model realizes the ideal time-domain orthogonality between switching two channels by the apertures with two trains of orthogonal codes. Then, a multichannel joint reconstruction method based on compressed sensing is proposed for the imaging processing, which is named the coded aperture simultaneous orthogonal matching pursuit (CAS-OMP) algorithm. The proposed algorithm combines the information of all polarization channels so as to ensure the consistency of the scattering point position obtained by each polarization channel and also improves the reconstruction accuracy. Finally, the simulation experiments using both the simple scaled model of the satellite and measured data of an unmanned aerial vehicle (UAV) are conducted, and the effectiveness of the proposed method is verified.