Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): Guidelines for medical 3D printing and appropriateness for clinical scenarios

Este número da revista Cadernos de Estudos Sociais estava em organização quando fomos colhidos pela morte do sociólogo Ernesto Laclau. Seu falecimento em 13 de abril de 2014 surpreendeu a todos, e particularmente ao editor Joanildo Burity, que foi seu orientando de doutorado na University of Essex, Inglaterra, e que recentemente o trouxe à Fundação Joaquim Nabuco para uma palestra, permitindo que muitos pudessem dialogar com um dos grandes intelectuais latinoamericanos contemporâneos. Assim, buscamos fazer uma homenagem ao sociólogo argentino publicando uma entrevista inédita concedida durante a sua passagem pelo Recife, em 2013, encerrando essa revista com uma sessão especial sobre a sua trajetória

Global Perspective on Diabetic Foot Ulcerations

Over the last decade, it is becoming increasingly clear that diabetes mellitus is a global epidemic. The influence of diabetes is most readily apparent in its manifestation in foot complications across cultures and continents. In this unique collaboration of global specialists, we examine the explosion of foot disease in locations that must quickly grapple with both mobilizing medical expertise and shaping public policy to best prevent and treat these serious complications. In other areas of the world where diabetic foot complications have unfortunately been all too common, diagnostic testing and advanced treatments have been developed in response. The bulk of this book is devoted to examining the newest developments in basic and clinical research on the diabetic foot. It is hoped that as our understanding of the pathophysiologic process expands, the devastating impact of diabetic foot complications can be minimized on a global scale

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Abstract Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.https://deepblue.lib.umich.edu/bitstream/2027.42/146524/1/41205_2018_Article_30.pd

Infantile external hydrocephalus : Epidemiological, radiological, clinical, cognitive, and social aspects

Bakgrunn: Ekstern hydrocefalus («utvendig vannhode») er en tilstand som kan sees hos noen spedbarn med raskt økende hodeomkrets. Radiologisk utredning viser utvidete, væskefylte hulrom på hjernens overflate, spesielt frontalt. Tilstanden har blitt kalt benign (godartet), da de fleste barna tilsynelatende har utviklet seg normalt. Mange barn har dermed heller ikke blitt behandlet. Det foreligger imidlertid begrenset kunnskap om ekstern hydrocephalus, både hyppigheten, utviklingen på lang sikt, og sammenhengen med den liknende tilstanden subduralt hematom (blodansamling på hjernens overflate). Mål: Å finne epidemiologiske data om ekstern hydrocefalus hos spedbarn. Å studere langtidsfølgene av tilstanden, og eventuell effekt av behandling. Å studere patofysiologien bak ekstern hydrocefalus og kronisk subduralt hematom, samt sammenhengen med mistenkt påført hodeskade. Metode: Artikkel 1-4 er en populasjonsbasert studie av alle spedbarn med idiopatisk ekstern hydrocefalus i Helse Vest og Helse Sør-Øst i 10-årsperioden 1994-2003. I artikkel 1 og 3 presenteres epidemiologi, kliniske karakteristika og radiologiske funn. I artikkel 2 og 4 presenteres resultatene av nevropsykologiske tester og livskvalitet hos 8 til 18 år gamle barn/ungdommer som hadde ekstern hydrocefalus som spedbarn. Artikkel 5 er en litteraturstudie av patofysiologien bak ekstern hydrocefalus og kronisk subduralt hematom. Artikkel 6 er en litteraturstudie om tromboserte brovener og sammenhengen med påført hodeskade. Artikkel 7 er en registerstudie av spedbarn med subduralt hematom og mistanke om påført hodeskade, med søkelys på kliniske og radiologiske funn. Resultater: Hyppigheten av idiopatisk ekstern hydrocefalus var 0,4 per 1000 fødte per år. Det var flest gutter (86,4 %). Hovedsymptomet som førte til henvisning var økende hodeomkrets, som oppsto mellom 0 og 7 måneder (snitt 3,4 måneder). Radiologisk utredning viste utvidete sideventrikler hos de fleste barna, og de radiologiske funnene lot til å bestå etter ett års alder. Resultatene av de nevropsykologiske testene ble sammenlignet med normaldata. Utførings-IQ og verbal produksjon var signifikant bedre hos barn med tidligere ekstern hydrocefalus sammenlignet med normaldata, mens oppmerksomhetsspenn, psykomotorisk tempo, eksekutive funksjoner og finmotorikk var dårligere. Barna anga god livskvalitet, mens foreldrene skåret barna til dårligere enn normal livskvalitet på underkategorien ‘skolefunksjon’. Kirurgisk behandlede barn (ventriculoperitoneal shunt) skåret dårligere enn ikke-opererte på to tester for psykomotorisk tempo. Hos noen av pasientene ble det også rapportert ulike kognitive og sosiale problemer. Likheter mellom ekstern hydrocefalus og kronisk subduralt hematom ble studert og diskutert, så som nevroradiologi og væskeegenskaper, og kjønns- og aldersfordeling. En hypotese om perinatalt subduralt hematom som felles utgangspunkt ble presentert. En gjennomgang av relevant litteratur om tromboserte brovener kunne ikke støtte påstanden om at dette radiologiske funnet beviser påført hodeskade hos spedbarn (en påstand som nylig er fremmet i internasjonale studier). Spedbarn med kronisk subduralt hematom og mistanke om påført hodeskade var i hovedsak gutter, var premature, hadde lav dødelighet og var assosiert med mulig forutgående ekstern hydrocefalus. Spedbarn med akutt subduralt hematom, subaraknoidalblødning, eller hypoksisk-iskemisk skade, så ut til å utgjøre andre grupper av barn, muligens med annen etiologi. Konklusjoner: Ekstern hydrocefalus hos spedbarn forekommer hos 0,4 per 1000 fødte per år, om lag halvparten av alle med primær hydrocefalus, og er mest vanlig hos gutter. Selv om det ser ut til å gå bra med de fleste av barna på lang sikt, sliter noen av barna med ulike utviklingsforstyrrelser, og spesielt i forhold til skolefunksjon. Behandling ser ikke ut til å endre utfallet. Mindre blødninger på hjernens overflate er ikke uvanlig i forbindelse med fødselen, og kan muligens være en årsak til både ekstern hydrocefalus og kronisk subduralt hematom noen måneder senere. Disse to tilstandene har påfallende like epidemiologiske trekk, og deres assosiasjon med hverandre må være sentral i tolkningen av subdurale hematomer hos barn der en mistenker påført hodeskade.Background: External hydrocephalus is a condition sometimes seen in infants. It is characterized by an enlarged head or rapidly increasing head circumference. Neuroimaging shows wide subarachnoid spaces, especially overlying the frontal lobes. The condition has traditionally been termed ‘benign’, as most children seem to do well, and symptoms and neuroimaging findings normalize over time. Hence, few infants have been treated for this condition. However, limited knowledge exists on long-term consequences of external hydrocephalus, the possible benefit of treatment, epidemiology, and its connection with the very similar conditions chronic subdural hematoma (SDH) and hygroma (SDHy). Aim: To gain thorough epidemiological data about external hydrocephalus in infants. To explore the long-term consequences of external hydrocephalus, both with and without treatment. To examine the pathophysiology of external hydrocephalus and chronic SDH/SDHy, and their relation to and importance in the investigation of infants with suspected abusive head trauma (AHT). Methods: Papers 1-4 are based on a cohort of infants diagnosed with idiopathic external hydrocephalus in a relatively well-defined population in Southern Norway during the period 1994-2003. Papers 1 and 3 explored the epidemiology, clinical features, and radiology of external hydrocephalus in this cohort. In papers 2 and 4, long-term neurocognitive and psychosocial functioning were evaluated using neuropsychological tests and questionnaires. Paper 5 is a literature survey exploring the pathophysiology behind external hydrocephalus and chronic SDH. Paper 6 is also a review, focusing on the existing knowledge about bridging veins, thrombosis, and its role in AHT diagnostics. Paper 7 is based on a cohort of infants with SDH and alleged AHT. Clinical and neuroimaging findings are explored. Results: The incidence of idiopathic external hydrocephalus was 0.4 per 1000 live births, with a large male preponderance (86.4 %) (paper 1). The main symptom was a large and/or rapidly increasing head circumference, with a mean age at debut of 3.4, range 0-7 months. Neuroimaging showed lateral ventricle enlargement in most cases, with neuroimaging characteristics persisting beyond one year of age (paper 3). The results on neuropsychological tests were compared with the normative mean (paper 2). Performance IQ and verbal fluency in children with prior external hydrocephalus were better than the normative mean, while attention span, psychomotor speed, executive functions, and fine motor functions were poorer. On quality of life, the children scored themselves better than the normative mean, while the parents scored the children poorer on the school subscore. Operated children performed poorer than non-operated ones on two tests of psychomotor speed. For some of the patients, various cognitive and social problems were reported (paper 4). Reviewing the literature, the similarities between external hydrocephalus and chronic SDH were discussed, such as neuroimaging and fluid characteristics, and sex and age distribution. A birth-related perinatal SDH was suggested as a common etiological condition (paper 5). A thorough literature review covering radiological studies, autopsy studies and biomechanical studies could not support the suggestion that neuroimaging signs of thrombosis are markers of bridging vein rupture, and thus AHT (paper 6). Infants with chronic SDH and alleged AHT had a male preponderance and low mortality, and were associated with external hydrocephalus and stretched bridging veins. Infants with acute SDH, subarachnoid hemorrhage, or hypoxic-ischemic injury, seemed to comprise distinct groups (paper 7). Conclusions: Infantile external hydrocephalus occurs in 0.4 of 1000 live births, which is around half of all infants with primary hydrocephalus, and has a marked male preponderance. Although most children with external hydrocephalus seem to do well when growing up, a non-negligible number of patients struggle in various areas, especially related to school functioning. Treatment with a shunting procedure does not seem to improve outcome. As the epidemiological and neuroimaging features of external hydrocephalus and chronic SDH are similar, a common etiology seems plausible. A small SDH during birth could be one possible common cause. External hydrocephalus should also be kept in mind when investigating infants with chronic SDH and alleged AHT. Our results both question the neuroimaging “evidence” of bridging vein rupture, and show that an underlying external hydrocephalus can mimic symptoms and findings of suspected AHT.Doktorgradsavhandlin

Intraocular Pressure and Ocular Hypertension

Primary open-angle glaucoma (POAG) is a multi-factorial progressive optic neuropathy characterized by retinal ganglion cell degeneration and progressive visual field loss which, if left untreated, may lead to blindness. Increased intraocular pressure (IOP) is considered to be the main risk factor for developing POAG, and its reduction has been shown to correlate with a decrease in glaucoma incidence and progression. Considering that fewer than 10% of the subjects with ocular hypertension (OHT) will develop morphological and/or functional glaucomatous damage within 5 years if not treated, glaucoma causes and molecular changes leading to ocular tissue damage in glaucoma are still largely unknown. The contemporary treatment of POAG is mainly oriented towards reducing IOP; the importance of the IOP reduction in other types of glaucoma, such as the “normal pressure glaucoma”, is still discussed. The IOP value is maintained by balancing the amount of fluid contained within the anterior and posterior chambers of the eye; our comprehension of the mechanisms underlying the secretion and active and passive outflow of the aqueous humor is extremely important for improving the treatment of glaucoma. Innovative pharmacological approaches, and laser and surgical procedures aiming to reduce IOP, have been developed in recent years. This book provides a compendium of topics regarding IOP, aqueous humor dynamics, tonometry, and medical and surgical techniques developed to reduce the IOP in subjects with ocular hypertension or glaucoma

Tactile sensing of shape : biomechanics of contact investigated using imaging and modeling

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (leaves 123-131).The overall goal of this research effort is to improve the understanding of the biomechanics of skin as it pertains to human tactile sense. During touch, mechanoreceptors beneath the skin surface are mechanically loaded due to physical contact of the skin with an object and respond with a series of neural impulses. This neural population response is decoded by the central nervous system to result in tactile perception of properties such as the shape, surface texture and softness of the object. The particular approach taken in this research is to develop a realistic model of the human fingertip based on empirical measurements of in vivo geometric and material properties of skin layers, so that the mechanical response of the fingertip skin to different shapes of objects in contact can be investigated, to help identify the relevant mechanism that triggers the mechanoreceptors in tactile encoding of object shape. To obtain geometric data on the ridged skin surface and the layers underneath together with their deformation patterns, optical coherence tomography (OCT) was used to image human fingertips in vivo, free of load as well as when loaded with rigid indenters of different shapes.(cont.) The images of undeformed and deformed finger pads were obtained, processed, and used for biomechanically validating the fingertip model. To obtain material properties of skin layers, axial strain imaging using high frequency ultrasound backscatter microscopy (UBM) was utilized in experiments on human fingertips in vivo to estimate the ratio of stiffnesses of the epidermis and dermis. By utilizing the data from OCT and UBM experiments, a multilayered three dimensional finite element model of the human fingertip composed of the ridged fingerpad skin surface as well as the papillary interface between the epidermis and dermis was developed. The model was used to simulate static indentation of the fingertip by rigid objects of different shapes and to compute stress and strain measures, such as strain energy density (SED), and maximum compressive or tensile strain (MCS, MTS), which have been previously proposed as the relevant stimuli that trigger mechanoreceptor response.(cont.) The results showed that the intricate geometry of skin layers and inhomogeneous material properties around the locations of the SA-I and RA mechanoreceptors caused significant differences in the spatial distribution of candidate relevant stimuli, compared with other locations at the same depths or the predictions from previous homogeneous models of the fingertip. The distribution of the SED at the locations of SA-I mechanoreceptors and the distribution of MCS/MTS at the locations of RA mechanoreceptors under indentation of different object shapes were obtained to serve as predictions to be tested in future biomechanical and neurophysiological experiments.by Wan-Chen Wu.Ph.D

PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery