We present a deep learning framework for volumetric speckle reduction in optical coherence tomography (OCT) based on a conditional generative adversarial network (cGAN) that leverages the volumetric nature of OCT data. In order to utilize the volumetric nature of OCT data, our network takes partial OCT volumes as input, resulting in artifact-free despeckled volumes that exhibit excellent speckle reduction and resolution preservation in all three dimensions. Furthermore, we address the ongoing challenge of generating ground truth data for supervised speckle suppression deep learning frameworks by using volumetric non-local means despeckling-TNode- to generate training data.
View Article and Find Full Text PDFBacterial osteomyelitis, an inflammatory response in the bone caused by microorganisms, typically affects the metaphysis in the skeletally immature. Bacterial osteomyelitis possesses a significant diagnostic challenge in pediatric patients due to its nonspecific clinical presentation. Because the metaphysis is the primary focus of infection in skeletally immature patients, understanding the normal physiologic, maturation process of bones throughout childhood allows to understand the pathophysiology of osteomyelitis.
View Article and Find Full Text PDFJ Pediatr Gastroenterol Nutr
February 2024
Vulvar involvement as an extraintestinal manifestation of Crohn's disease (CD) is a challenging diagnosis considering that vaginal findings may precede gastrointestinal symptoms. The aim of this study is to describe the clinical presentation, radiological findings, and treatment of vulvar Crohn's disease (VCD). We reviewed the time from initial presentation to diagnosis, presenting symptoms, radiological findings, gastrointestinal Crohn's disease Paris classification, and treatment response of five female pediatric patients.
View Article and Find Full Text PDFWe present a deep learning framework for volumetric speckle reduction in optical coherence tomography (OCT) based on a conditional generative adversarial network (cGAN) that leverages the volumetric nature of OCT data. In order to utilize the volumetric nature of OCT data, our network takes partial OCT volumes as input, resulting in artifact-free despeckled volumes that exhibit excellent speckle reduction and resolution preservation in all three dimensions. Furthermore, we address the ongoing challenge of generating ground truth data for supervised speckle suppression deep learning frameworks by using volumetric non-local means despeckling-TNode to generate training data.
View Article and Find Full Text PDFBackground: Secondary bacterial infection (SBI) occurs in a proportion of individuals with dengue and results in longer hospitalization, higher mortality, and increased health-related costs. However, the frequency, risk factors and predictive biomarkers of this comorbidity in pediatric dengue is partially known.
Methods: We conducted a retrospective multicenter study in a dengue hyperendemic region of Colombia, analyzing 1597 children from two pediatric cohorts.
Infantile hemangioma (IH) is the most common neoplasm in children, but it may mimic other types of vascular anomalies or nonvascular benign and malignant tumors. In most cases, the clinical appearance, time of onset, and pattern of involution facilitate its diagnosis. Imaging evaluation is not always needed since the IH features at clinical presentation are usually characteristic, but when needed, US and frequently MRI are the imaging modalities of choice.
View Article and Find Full Text PDFWe present computational refocusing in polarization-sensitive optical coherence tomography (PS-OCT) to improve spatial resolution in the calculated polarimetric parameters and extend the depth-of-field in phase-unstable, fiber-based PS-OCT systems. To achieve this, we successfully adapted short A-line range phase-stability adaptive optics (SHARP), a computational aberration correction technique compatible with phase-unstable systems, into a Stokes-based PS-OCT system with inter-A-line polarization modulation. Together with the spectral binning technique to mitigate system-induced chromatic polarization effects, we show that computational refocusing improves image quality in tissue polarimetry of swine eye anterior segment ex vivo with PS-OCT.
View Article and Find Full Text PDFAnkle and foot deformity is one of the most common musculoskeletal disorders in children and a leading cause of functional impairment and diminished quality of life when not treated. A spectrum of conditions may produce foot and ankle deformities, with congenital disorders the most frequent cause, followed by acquired conditions. Congenital disorders include congenital talipes equinovarus or congenital clubfoot, metatarsus adductus, skewfoot, congenital vertical talus, and tarsal coalition.
View Article and Find Full Text PDFWithin the framework of effective mass theory, we investigate the effects of spin-orbit interaction (SOI) and Zeeman splitting on the electronic properties of an electron confined in GaAs single quantum rings. Energies and envelope wavefunctions in the system are determined by solving the Schrödinger equation via the finite element method. First, we consider an inversely quadratic model potential to describe electron confining profiles in a single quantum ring.
View Article and Find Full Text PDFMycotic aneurysms are exceedingly rare in the pediatric population. The optimal surgical treatment for children with this disease is unclear as aneurysm resection and vascular reconstruction are uncommonly performed in young children. We present a unique case of a 21-month-old child with a complex cardiac history who presented with limb ischemia and was discovered to have thrombosis of the common femoral and superficial femoral artery.
View Article and Find Full Text PDFA theoretical analysis of optical properties in a ZnS/CdS/ZnS core/shell/shell spherical quantum dot was carried out within the effective mass approximation. The corresponding Schrödinger equation was solved using the finite element method via the 2D axis-symmetric module of COMSOL-Multiphysics software. Calculations included variations of internal dot radius, the application of electric and magnetic fields (both oriented along -direction), as well as the presence of on-center donor impurity.
View Article and Find Full Text PDFAdjustable spatial coherence systems allow the possibility to make different intensity distributions using one source. Most common adjustable sources are based on the Collet-Wolf system. However, it is also possible to adjust the spatial coherence of the illumination field from white light sources by spatially filtering the source mutual intensity spectrum.
View Article and Find Full Text PDFAneurysmal bone cyst (ABC) is a benign but locally aggressive lesion that predominantly affects children and young adults. ABC, which accounts for approximately 70% of the cases, is now recognized to be a true neoplasm, whereas ABC-like changes associated to other bone neoplasms (also referred in the literature as secondary ABC) accounts for the remaining 30%. The solid variant of ABC is also considered a true neoplasm but is rare.
View Article and Find Full Text PDFIatrogenic allogenosis is a disease caused by the injection of biopolymers with esthetic purposes. Clinical manifestations can occur between six hours and 30 years after the procedure with local and/or systemic symptoms. The pathological findings are characterized by the presence of foreign body granulomas with a sarcoid-like reaction.
View Article and Find Full Text PDFIntroduction: Comorbidity trends after median sternectomy were studied at our institution by Vasconze et al (Comorbidity trends in patients requiring sternectomy and reconstruction. Ann Plast Surg. 2005;54:5).
View Article and Find Full Text PDFCase Reports Plast Surg Hand Surg
January 2022
Merkel-cell-carcinoma of the hand is rare. The Pathological and Immunohistochemical diagnosis helps us to focus the treatment. Immunotherapy has shown beneficial effects in unresectable/advanced/metastatic stages.
View Article and Find Full Text PDFRadiol Clin North Am
January 2022
Vascular malformations are commonly encountered in the pediatric population. This article reviews the imaging appearances of simple and syndromic vascular malformations in infants and children that radiologists should know and provides imaging guidelines based on an evidence-based approach. Malformations are discussed within the framework of the International Society for the Study of Vascular Anomalies classification system.
View Article and Find Full Text PDFUsing the effective mass approximation in a parabolic two-band model, we studied the effects of the geometrical parameters, on the electron and hole states, in two truncated conical quantum dots: (i) GaAs-(Ga,Al)As in the presence of a shallow donor impurity and under an applied magnetic field and (ii) CdSe-CdTe core-shell type-II quantum dot. For the first system, the impurity position and the applied magnetic field direction were chosen to preserve the system's azimuthal symmetry. The finite element method obtains the solution of the Schrödinger equations for electron or hole with or without impurity with an adaptive discretization of a triangular mesh.
View Article and Find Full Text PDFIntroduction: Although the literature contains reports of the risks and complications of calvarial vault reconstruction for acquired defects, there are few publications addressing the specific patient population who require such reconstructions in cases preceded by prior infection, radiation, massive associated soft tissue trauma, and so on. We define such clinical presentations as a hostile environment for large surface area reconstruction. Our objective is to compare the safety and efficacy of autologous bone and alloplastic reconstruction in hostile cranial defects.
View Article and Find Full Text PDFBreast tissue undergoes a series of changes from birth to puberty. The majority of the changes are transient, related to physiological hormonal changes. Although the breast is identical in both sexes at birth, its histology and development will eventually differ.
View Article and Find Full Text PDFExogenous pigmentation by silver nitrate is a rare disease whose clinical manifestations appear even years after the contact, making its diagnosis difficult on occasions. It is characterized by the presence of blue-gray macules or plaques on the skin or mucosa in the contact area, sometimes very similar to melanocytic lesions and melanoma, which constitute the main differential diagnosis. We report the case of a male patient from Medellín, Colombia, with a family history of melanoma and the presence of these lesions throughout his body.
View Article and Find Full Text PDFQuantum wires continue to be a subject of novel applications in the fields of electronics and optoelectronics. In this work, we revisit the problem of determining the electron states in semiconductor quantum wires in a self-consistent way. For that purpose, we numerically solve the 2D system of coupled Schrödinger and Poisson equations within the envelope function and effective mass approximations.
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