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1.
Cereb Cortex ; 34(1)2024 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-37950874

RESUMO

Cortical neurons of eutherian mammals project to the contralateral hemisphere, crossing the midline primarily via the corpus callosum and the anterior, posterior, and hippocampal commissures. We recently reported and named the thalamic commissures (TCs) as an additional interhemispheric axonal fiber pathway connecting the cortex to the contralateral thalamus in the rodent brain. Here, we demonstrate that TCs also exist in primates and characterize the connectivity of these pathways with high-resolution diffusion-weighted MRI, viral axonal tracing, and fMRI. We present evidence of TCs in both New World (Callithrix jacchus and Cebus apella) and Old World primates (Macaca mulatta). Further, like rodents, we show that the TCs in primates develop during the embryonic period, forming anatomical and functionally active connections of the cortex with the contralateral thalamus. We also searched for TCs in the human brain, showing their presence in humans with brain malformations, although we could not identify TCs in healthy subjects. These results pose the TCs as a vital fiber pathway in the primate brain, allowing for more robust interhemispheric connectivity and synchrony and serving as an alternative commissural route in developmental brain malformations.


Assuntos
Substância Branca , Animais , Humanos , Substância Branca/diagnóstico por imagem , Encéfalo , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/fisiologia , Tálamo/diagnóstico por imagem , Macaca mulatta , Mamíferos
2.
BMC Musculoskelet Disord ; 25(1): 528, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982362

RESUMO

BACKGROUND: Epidemiological research on fractures in children under the age of two is of great importance to help understand differences between accidental and abusive trauma. OBJECTIVE: This systematic review aimed to evaluate studies reporting on the incidence of fractures in children under two years of age, excluding birth injuries. Secondary outcome measures included fracture location, mechanisms of injury and fracture characteristics. METHODS: A systematic literature review (1946 to February 7th 2024), including prospective and retrospective cohort studies and cross-sectional cohort studies, was performed. Studies including children from other age groups were included if the actual measures for those aged 0-2 years could be extracted. We also included studies restricted to infants. Annual incidence rates of fractures were extracted and reported as the main result. Critical appraisal of was performed using the Appraisal tool for Cross-Sectional Studies. RESULTS: Twelve moderate to good quality studies met eligibility criteria, of which seven were based on data from medical records and five were registry studies. Studies investigated different aspects of fractures, making comprehensive synthesis challenging. There was an overall annual fracture incidence rate of 5.3 to 9.5 per 1,000 children from 0-2 years of age; with commonest sites being the radius/ulna (25.2-40.0%), followed by tibia/fibula (17.3-27.6%) and the clavicle (14.6-14.8%) (location based on 3 studies with a total of 407 patients). In infants, the reported incidence ranged between 0.7 to 4.6 per 1,000 (based on 3 studies), with involvement of the clavicle in 22.2% and the distal humerus in 22.2% of cases (based on 1 study). Only a single metaphyseal lesion was reported (proximal humerus of an 11-month-old infant). Fracture mechanisms were detailed in four studies, with fall from chair, bed, table, own height or fall following indoor activities causing 50-60% of fractures. CONCLUSIONS: There is a paucity of good quality data on fracture incidence in children under the age of two. Larger, prospective and unbiased studies would be helpful in determining normal pattern of injuries, so that differences from abusive trauma may be better understood.


Assuntos
Fraturas Ósseas , Humanos , Incidência , Lactente , Fraturas Ósseas/epidemiologia , Recém-Nascido , Maus-Tratos Infantis/estatística & dados numéricos , Estudos Transversais
3.
Pediatr Radiol ; 54(2): 260-268, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37985493

RESUMO

BACKGROUND: Liver transplantation is the state-of-the-art curative treatment in end-stage liver disease. Imaging is a key element for successful organ-transplantation to assist surgical planning. So far, only limited data regarding the best radiological approach to prepare children for liver transplantation is available. OBJECTIVES: In an attempt to harmonize imaging surrounding pediatric liver transplantation, the European Society of Pediatric Radiology (ESPR) Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phase. This paper reports the responses on preoperative imaging. MATERIAL AND METHODS: An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted and 22 institutions from 11 countries returned the survey. From 2018 to 2020, the participating centers collectively conducted 1,524 transplantations, with a median of 20 transplantations per center per annum (range, 8-60). RESULTS: Most sites (64%) consider ultrasound their preferred modality to define anatomy and to plan surgery in children before liver transplantation, and additional cross-sectional imaging is only used to answer specific questions (computed tomography [CT], 90.9%; magnetic resonance imaging [MRI], 54.5%). One-third of centers (31.8%) rely primarily on CT for pre-transplant evaluation. Imaging protocols differed substantially regarding applied CT scan ranges, number of contrast phases (range 1-4 phases), and applied MRI techniques. CONCLUSION: Diagnostic imaging is generally used in the work-up of children before liver transplantation. Substantial differences were noted regarding choice of modalities and protocols. We have identified starting points for future optimization and harmonization of the imaging approach to multicenter studies.


Assuntos
Transplante de Fígado , Radiologia , Criança , Humanos , Ultrassonografia , Tomografia Computadorizada por Raios X , Imageamento por Ressonância Magnética/métodos
4.
Pediatr Radiol ; 54(2): 269-275, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38216682

RESUMO

BACKGROUND: Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of intraoperative and postoperative complications. So far, only limited data regarding the best radiological approach to monitor children during liver transplantation is available. OBJECTIVE: To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra- and postoperative phase. This paper reports the responses related to intraoperative imaging. MATERIALS AND METHODS: An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey. RESULTS: Intraoperative ultrasound (US) is used by all sites to assess the quality of the vascular anastomosis in order to ensure optimal perfusion of the liver transplant. Vessel depiction is commonly achieved using color Doppler (95.3%). Additional US-based techniques are employed by fewer centers (power angio mode, 28.6%; B-flow, 19%; contrast-enhanced US, 14.3%). Most centers prefer a collaborative approach, with surgeons responsible for probe handling, while radiologists operate the US machine (47.6%). Less commonly, the intraoperative US is performed by the surgeon alone (28.6%) or by the radiologist alone (23.8%). Timing of US, imaging frequency, and documentation practices vary among centers. CONCLUSION: Intraoperative US is consistently utilized across all sites during pediatric liver transplantation. However, considerable variations were observed in terms of the US setup, technique preferences, timing of controls, and documentation practices. These differences provide valuable insights for future optimization and harmonization studies.


Assuntos
Transplante de Fígado , Radiologia , Criança , Humanos , Ultrassonografia , Radiografia , Complicações Pós-Operatórias/diagnóstico por imagem
5.
Pediatr Radiol ; 54(2): 276-284, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38285190

RESUMO

BACKGROUND: Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of postoperative complications. So far, limited data is available regarding the best radiologic approach to monitor children after liver transplantation. OBJECTIVE: To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phases. This paper reports the responses related to postoperative imaging. MATERIALS AND METHODS: An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey. RESULTS: All sites commence ultrasound (US) monitoring within 24 h after liver transplantation. Monitoring frequency varies across sites, ranging from every 8 h to 72 h in early, and from daily to sporadic use in late postoperative phases. Predefined US protocols are used by 73% of sites. This commonly includes gray scale, color Doppler, and quantitative flow assessment. Alternative flow imaging techniques, contrast-enhanced US, and elastography are applied at 31.8%, 18.2%, and 63.6% of sites, respectively. Computed tomography is performed at 86.4% of sites when clarification is needed. Magnetic resonance imaging is used for selected cases at 36.4% of sites, mainly for assessment of biliary abnormalities or when blood tests are abnormal. CONCLUSION: Diagnostic imaging is extensively used for postoperative surveillance of children after liver transplantation. While US is generally prioritized, substantial differences were noted in US protocol, timing, and monitoring frequency. The study highlights potential areas for future optimization and standardization of imaging, essential for conducting multicenter studies.


Assuntos
Transplante de Fígado , Radiologia , Criança , Humanos , Ultrassonografia , Imageamento por Ressonância Magnética/métodos , Ultrassonografia Doppler , Complicações Pós-Operatórias/diagnóstico por imagem
6.
Eur J Pediatr ; 182(7): 3083-3091, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37074459

RESUMO

The purpose of this prospective ultrasound-based pilot study was to identify the most suitable tibial puncture site for intraosseous (IO) access in term and preterm neonates, describe tibial dimensions at this site, and provide anatomical landmarks for rapid localization. We measured the tibial dimensions and distances to anatomical landmarks at puncture sites A (proximal: 10 mm distal to the tibial tuberosity; distal: 10 mm proximal to the malleolus medialis) and B (chosen by palpation of the pediatrician), in 40 newborns in four weight groups (< 1000 g; 1000-2000 g, 2000-3000 g, and 3000-4000 g). Sites were rejected if they fell short of the assumed safety distance to the tibial growth plate of 10 mm. If both A and B were rejected, puncture site C was determined sonographically at the maximum tibial diameter while maintaining the safety distance. Puncture site A violated the safety distance in 53% and 85% (proximally and distally, respectively) and puncture site B in 38% and 33%. In newborns weighing 3000-4000 g, at median (IQR), the most suitable puncture site at the proximal tibia was 13.0 mm (12.0-15.8) distal to the tuberosity and 6.0 mm (4.0-8.0) medial to the anterior rim of the tibia. The median (IQR) diameters at this site were 8.3 mm (7.9-9.1) (transverse) and 9.2 mm (8.9-9.8) (anterior-posterior). The diameters increased significantly with increasing weight.  Conclusion: This study adds concise, practical information on the implementation of IO access in neonatal patients: the tibial dimensions in newborns in four different weight groups and initial data on anatomical landmarks to easily locate the IO puncture site. The results may help implement IO access in newborns more safely. What is Known: • Intraosseous access is a feasible option for emergency administration of vital drugs and fluids in newborns undergoing resuscitation when an umbilical venous catheter is impossible to place. • Severe complications of IO access due to malpositioned IO needles have been reported in neonates. What is New: • This study reports the most suitable tibial puncture sites for IO access and the tibial dimensions, in newborns of four weight groups. • The results can help to implement safe IO access in newborns.


Assuntos
Ressuscitação , Tíbia , Humanos , Recém-Nascido , Projetos Piloto , Estudos Prospectivos , Tíbia/diagnóstico por imagem , Ressuscitação/métodos , Infusões Intraósseas
8.
BMC Musculoskelet Disord ; 23(1): 901, 2022 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-36209080

RESUMO

BACKGROUND: Injectable biphasic ceramic bone substitutes (BCBSs) represent a modern alternative to conventional options for bone defect filling, as they further open the possibilities for percutaneous cavity reconstruction. Although recent studies have shown good surgical outcomes after treatment with BCBSs, mid-term follow-up data are still missing. PATIENTS AND METHODS: Between 2013 and 2017, 18 patients were [1] treated with BCBS [2] for benign bone lesions and [3] had a complete set of retrospective information, including surgical protocols, imaging, patient dismission letters and outpatient clinic protocols, [4] with a minimum follow-up time of one year. Eleven patients received percutaneous surgery, while 7 patients had open curettage and BCBS filling. The median follow-up time was 36.5 (range 12-80) months. RESULTS: Local recurrence was reported in four patients. A distinctive bone remodelling pattern was noted on follow-up X-ray and magnetic resonance imaging showing a double-line phenomenon and continuously increasing cortical thickness one year after treatment in nine of thirteen patients. Regarding surgical complications, one patient suffered from a septic complication that required BCBS removal and lavage. One patient experienced superficial surgical site inflammation with redness and swelling, while two other patients had prolonged wound secretion. CONCLUSION: In a limited case series, the studied BCBS demonstrated acceptable surgical outcomes. Initial wound leakage and recurrence seemed to be associated with percutaneous injection. Further studies are needed to compare recurrence and bone graft resorption after open and percutaneous bone cyst surgeries and to further evaluate postoperative surgical site inflammation, which appears self-limiting in most cases.


Assuntos
Doenças Ósseas , Neoplasias Ósseas , Substitutos Ósseos , Doenças Ósseas/cirurgia , Neoplasias Ósseas/cirurgia , Substitutos Ósseos/uso terapêutico , Curetagem , Humanos , Inflamação , Estudos Retrospectivos
9.
Clin Orthop Relat Res ; 479(11): 2493-2501, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34077400

RESUMO

BACKGROUND: Neoadjuvant chemotherapy in patients with primary osteosarcoma improves survival rates, but it also causes side effects in various organs including bone. Low bone mineral density (BMD) can occur owing partly to chemotherapy or limited mobility. This can cause a higher risk of fractures compared with those who do not receive such treatment. Changes in BMD alone cannot explain the propensity of fractures. Studying microarchitectural changes of bone might help to understand the effect. QUESTIONS/PURPOSES: (1) Do patients who were treated for osteosarcoma (more than 20 years previously) have low BMD? (2) Do these patients experience more fractures than controls who do not have osteosarcoma? (3) What differences in bone microarchitecture are present between patients treated for high-grade osteosarcoma and individuals who have never had osteosarcoma? METHODS: We contacted 48 patients who were treated for osteosarcoma and who participated in an earlier study. These patients underwent multimodal treatment including chemotherapy more than 20 years ago. Of the original patient group, 60% (29 of 48) were missing, leaving 40% (19 of 48) available for inclusion in this study; all 19 agreed to participate. There were nine men and 10 women with a mean age of 46 ± 4 years and a mean time from surgery to examination of 28 ± 3 years. BMD was measured by dual-energy x-ray absorptiometry, and any fracture history was assessed using a questionnaire. Additionally, high-resolution peripheral quantitative CT was performed to compare the groups in terms of microarchitectural changes, such as cortical and trabecular area, cortical and trabecular thickness, cortical porosity, and endocortical perimeter. Participants in the control group were selected from a cohort consisting of a population-based random sample of 499 healthy adult women and men. Osteoporosis or low BMD was not an exclusion criterion for entering this study; however, the patients in the control group were selected based on a normal BMD (that is, T score > -1.0 at both the spine and hip). Also, the participants were matched based on age and sex. Differences between patients and controls were assessed using the Wilcoxon rank sum test for continuous variables and a chi-square test for categorical variables. A multiple regression analysis was performed. Model assumptions were checked using histograms and quantile-quantile plots of residuals. RESULTS: Twelve of 19 patients who were treated for osteosarcoma had either osteopenia (eight patients) or osteoporosis (four patients). More patients with osteosarcoma reported sustaining fractures (11 of 19 patients) than did control patients (2 of 19 controls; p < 0.001). Among all microarchitectural parameters, only the endocortical perimeter was increased in patients compared with the control group (75 ± 15 mm versus 62 ± 18 mm; p = 0.04); we found no differences between the groups in terms of cortical and trabecular area, cortical and trabecular thickness, or cortical porosity. CONCLUSION: Although patients who were treated for osteosarcoma had osteopenic or osteoporotic BMD and a higher proportion of patients experienced fractures than did patients in the control group, we could not confirm differences in microarchitectural parameters using high-resolution peripheral quantitative CT. Therefore, it seems that bone geometry and microstructural parameters are not likely the cause of the increased proportion of fractures observed in our patients who were treated for osteosarcoma. Until we learn more about the bone changes associated with chemotherapy in patients with osteosarcoma, we recommend that patients undergo regular BMD testing, and we recommend that physicians consider osteoporosis treatment in patients with low BMD. These data might provide the impetus for future multicenter prospective studies examining the association between chemotherapy and bone microarchitecture. LEVEL OF EVIDENCE: Level III, therapeutic study.


Assuntos
Doenças Ósseas Metabólicas/induzido quimicamente , Fraturas Ósseas/induzido quimicamente , Terapia Neoadjuvante/efeitos adversos , Osteoporose/induzido quimicamente , Osteossarcoma/terapia , Absorciometria de Fóton , Adulto , Densidade Óssea , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/fisiopatologia , Osso Esponjoso/ultraestrutura , Terapia Combinada , Osso Cortical/diagnóstico por imagem , Osso Cortical/fisiopatologia , Osso Cortical/ultraestrutura , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteossarcoma/fisiopatologia , Tomografia Computadorizada por Raios X
10.
Wien Med Wochenschr ; 171(5-6): 102-110, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33570693

RESUMO

Children and adolescents with bone and growth disorders require interdisciplinary care from various specialists including pediatric radiologists with a focus on musculoskeletal disorders. This article covers routine topics, differential diagnoses, and selected research imaging in children with osteogenesis imperfecta (OI), X­linked hypophosphatemic rickets (XLH), achondroplasia, and other bone and growth disorders from the standpoint of a tertiary referral center.


Assuntos
Raquitismo Hipofosfatêmico Familiar , Osteogênese Imperfeita , Adolescente , Osso e Ossos , Criança , Diagnóstico por Imagem , Transtornos do Crescimento , Humanos , Osteogênese Imperfeita/diagnóstico
11.
Carcinogenesis ; 41(4): 483-489, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31840161

RESUMO

Intestinal microbiota are considered a sensor for molecular pathways, which orchestrate energy balance, immune responses, and cell regeneration. We previously reported that microbiota restriction promoted higher levels of systemic radiation-induced genotoxicity, proliferative lymphocyte activation, and apoptotic polarization of metabolic pathways. Restricted intestinal microbiota (RM) that harbors increased abundance of Lactobacillus johnsonii (LBJ) has been investigated for bacterial communities that correlated radiation-induced genotoxicity. Indicator phylotypes were more abundant in RM mice and increased in prevalence after whole body irradiation in conventional microbiota (CM) mice, while none of the same ten most abundant phylotypes were different in abundance between CM mice before and after heavy ion irradiation. Muribaculum intestinale was detected highest in female small intestines in RM mice, which were lacking Ureaplasma felinum compared with males, and thus these bacteria could be contributing to the differential amounts of radiation-induced systemic genotoxicity between the CM and RM groups. Helicobacter rodentium and M.intestinale were found in colons in the radiation-resistant CM phenotype. While the expression of interferon-γ was elevated in the small intestine, and lower in blood in CM mice, high-linear energy transfer radiation reduced transforming growth factor-ß with peripheral interleukin (IL)-17 in RM mice, particularly in females. We found that female RM mice showed improved micro-architectural bone structure and anti-inflammatory radiation response compared with CM mice at a delayed phase 6 weeks postexposure to particle radiation. However, microbiota restriction reduced inflammatory markers of tumor necrosis factor in marrow, when IL-17 was reduced by intraperitoneal injection of IL-17 neutralizing antibody.


Assuntos
Biomarcadores/metabolismo , Osso e Ossos/anatomia & histologia , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Microbioma Gastrointestinal/fisiologia , Animais , Osso e Ossos/microbiologia , Osso e Ossos/efeitos da radiação , Feminino , Microbioma Gastrointestinal/efeitos da radiação , Interleucina-17/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Filogenia
12.
Calcif Tissue Int ; 105(1): 15-25, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30850857

RESUMO

Although Paget's disease of bone (PDB) is the second most common metabolic bone disease, there is only limited information about the microarchitecture of affected bones. Therefore, the aim of this study was to determine cortical and trabecular bone properties in clinically relevant locations by microcomputed tomography (µCT). Ten femora and ten tibiae affected by Paget's disease taken from the Natural History Museum Vienna were compared to 13 femora and 10 tibiae of non-affected body donors. Digitization of the cortical and trabecular bone microarchitecture was performed with an X-ray-based µCT scanner. Additionally, semi-quantitative gradings of trabecular and cortical architectural parameters of the femora and the tibiae were generated. Microcomputed tomography images showed changes in the thickness of cortices, cortical porosity, and trabecularization of cortical structures. Moreover, severe disorganization of trabecular structures, trabecular defects, and thickening of (remaining) trabeculae were detected. Numerical cortical analyses showed lower total bone volume (BV) and lower BV in the outer region (66-100%) (- 36%, p = 0.004, and - 50%, p < 0.001, respectively), lower total volume (TV) in the outer region (66-100%) (- 42%, p < 0.001), lower total bone volume fraction (BV/TV) and BV/TV in the outer region (66-100%) (- 23%, and - 12%, p < 0.001, respectively), higher BV and TV in the middle region (33-66%) and higher BV/TV in the inner region (0-33%) (123%, p = 0.011, 147%, p = 0.010, and 33%, p = 0.025, respectively) in Pagetic compared to non-affected bones. Trabecular analyses showed higher BV/TV (96%, p = 0.008) and Tb.Th (43%, p = 0.004) in Pagetic compared to non-affected bones. There is a major and consistent structural alteration of PDB at cortical and trabecular sites in weight-bearing long bones. Our findings are relevant for the differential diagnosis of PDB and for the pathogenesis of associated complications, since the disorder produces abnormalities in the structure that might lead to bone fragility.


Assuntos
Densidade Óssea/fisiologia , Fêmur/diagnóstico por imagem , Osteíte Deformante/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Osteíte Deformante/patologia , Porosidade , Microtomografia por Raio-X/métodos
13.
Eur Radiol ; 29(4): 2127-2136, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30315420

RESUMO

OBJECTIVES: To evaluate the feasibility and reproducibility of superb microvascular imaging (SMI) of the neonatal brain and to describe normal imaging features. METHODS: We performed transcranial ultrasound with SMI in 19 healthy term-born neonates. SMI was done according to a structured examination protocol, using two linear 18 MHz and 14 MHz transducers. Superficial and deep scans were acquired in the coronal and sagittal planes, using the left and right superior frontal gyri as anatomical landmarks. All SMI views were imaged by monochrome and colour SMI and evaluated with respect to visibility of extrastriatal (i.e. cortical and medullary) and striatal microvessels. RESULTS: We have described normal morphologic features of intraparenchymal brain microvasculature as "short parallel" cortical vessels, "smoothly curved" medullary vessels, and deep striatal vessels. In general, SMI performance was better on coronal views than on sagittal views. On superficial coronal scans, cortical microvessels were identifiable in 90-100%, medullary microvessels in 95-100%. On deep scans, cortical and medullary microvessels were visible in all cases, while striatal microvessels were identifiable in 71% of cases. CONCLUSIONS: Cerebral SMI ultrasound is feasible and well-reproducible and provides a novel non-invasive imaging tool for the assessment of intraparenchymal brain microvasculature (extrastriatal and striatal microvessels) in neonates without the use of contrast. KEY POINTS: • Superb microvascular imaging (SMI) of the neonatal brain is feasible and reproducible. • SMI depicts extrastriatal and striatal microvessels. • SMI detects two types of extrastriatal microvessels: cortical and medullary.


Assuntos
Artérias Cerebrais/diagnóstico por imagem , Microvasos/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodos , Feminino , Humanos , Recém-Nascido , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes
14.
Acta Radiol ; 60(4): 501-508, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29979104

RESUMO

BACKGROUND: Non-traumatic avascular osteonecrosis of the femoral head (ONFH) is a severe disease causing destruction of the hip joint, often necessitating total hip arthroplasty (THA) even in young patients. Magnetic resonance imaging (MRI) is commonly used for diagnosis of ONFH, but provides limited insight into the subchondral bone microstructure. PURPOSE: To analyze routine MRI findings in comparison to high-resolution quantitative computed tomography (HR-QCT) with a special focus on the subchondral layer and to estimate the importance of differences determining the indication for THA. MATERIAL AND METHODS: Twelve patients with ONFH were included before THA. Preoperative MRI and HR-QCT of the retrieved femoral heads were aligned using a registration algorithm. Pathological findings and trabecular bone parameters in matched areas were analyzed by two readers. McNemar, marginal homogeneity test, and Pearson's correlation coefficient were used for comparison. RESULTS: Subchondral delamination was found in nine cases on HR-QCT, but missed or underestimated in all but one case on MRI ( P = 0.016). Chondral discontinuity was found in all cases on HR-QCT and in two cases on MRI ( P = 0.016). Areas of complete bone resorption on HR-QCT were linked to high signal intensity on 3D gradient-echo MRI sequences with water-selective excitation, while there was no correlation between trabecular bone parameters and MRI signal intensities in other areas ( P = 0.304). CONCLUSION: Subchondral delamination, subchondral resorption, and chondral discontinuity are found frequently in advanced stages of ONFH. These lesions tend to be underestimated on conventional MRI. Our results support the importance of CT imaging in the evaluation of ONFH.


Assuntos
Necrose da Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto Jovem
17.
Pediatr Radiol ; 48(4): 486-498, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29550863

RESUMO

Prenatal detection of abnormal white matter tracts might serve as a structural marker for altered neurodevelopment. As a result of many technical and patient-related challenges, the accuracy of prenatal tractography remains unknown. We hypothesized that characteristics of prenatal tractography of the corpus callosum and corticospinal tracts derived from fetal diffusion tensor imaging (DTI) data are accurate and predictive of the integrity of these tracts postnatally. We compared callosal and corticospinal tracts of 12 subjects with paired prenatal (age: 23-35 gestational weeks) and postnatal (age: 1 day to 2 years) DTI examinations (b values of 0 s/mm2 and 700 s/mm2, 16 gradient encoding directions) using deterministic tractography. Evaluation for the presence of callosal segments and corticospinal tracts showed moderate degrees of accuracy (67-75%) for the four segments of the corpus callosum and moderate to high degrees of accuracy (75-92%) for the corticospinal tracts. Positive predictive values for segments of the corpus callosum ranged from 50% to 100% and for the corticospinal tracts, 89% to 100%. Negative predictive values for segments of the corpus callosum ranged from 25% to 80% and for the corticospinal tracts, 33% to 50%. The results suggest that when the tracts are not well characterized on the fetal MR, predictions about the postnatal tracts are difficult to make. However, accounting for brain maturation, prenatal visualization of the main projection and commissural tracts can be clinically used as an important predictive tool in the context of image interpretation for the assessment of fetal brain malformations.


Assuntos
Agenesia do Corpo Caloso/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Tratos Piramidais/anormalidades , Substância Branca/anormalidades , Feminino , Seguimentos , Idade Gestacional , Humanos , Lactente , Masculino , Valor Preditivo dos Testes , Gravidez , Estudos Retrospectivos , Sensibilidade e Especificidade
18.
Semin Musculoskelet Radiol ; 20(3): 300-304, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27741545

RESUMO

Skeletal fragility has been recognized as an important feature of diabetes mellitus type 1 (T1D) and type 2 (T2D). While patients with DM1 typically display low bone mineral density (BMD) and concomitant increases in fracture risk, T2D bone disease is more complex and less understood. Although BMD is often normal or even slightly elevated, the risk of fragility fractures is disproportionally high. Alterations in bone quality (i.e., bone microstructure and matrix properties) have been reported by independent groups of researchers. Cortical porosity and the deposition of advanced glycation end-products appear to play key roles. Paired with low bone turnover, another distinct feature of T2D bone disease, secondary complications (including nephropathy, neuropathy, and angiopathy) are adding up to form a complex entity distinct from postmenopausal and age-related osteoporosis. This article offers an overview of current concepts in pathophysiology, clinical features, and imaging features of diabetic bone disease.


Assuntos
Doenças Ósseas/diagnóstico por imagem , Doenças Ósseas/terapia , Complicações do Diabetes/diagnóstico por imagem , Complicações do Diabetes/terapia , Fraturas Ósseas/complicações , Densidade Óssea , Doenças Ósseas/complicações , Osso e Ossos/diagnóstico por imagem , Fraturas Ósseas/diagnóstico por imagem , Humanos
19.
Clin Orthop Relat Res ; 474(6): 1508-15, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26883654

RESUMO

BACKGROUND: In long-term survivors of osteosarcoma and Ewing sarcoma treated with the addition of radio- and chemotherapy, low bone mineral density (BMD) and fractures have been observed, presumably resulting from these adjuvants. Because patients with chondrosarcoma usually are not treated with conventional adjuvant treatment, observation of low BMD in patients with chondrosarcoma presumably would be the result of other mechanisms. However, BMD in patients with a history of chondrosarcoma has not been well characterized. QUESTIONS/PURPOSES: The aim of our study was to address the following questions: (1) Do long-term survivors of chondrosarcoma have normal BMD and, if not, which factors contribute to low BMD? (2) Is there a greater risk of fracture and does the Fracture Risk Assessment Tool (FRAX(®)) score reflect fracture likelihood? METHODS: All known patients with a history of chondrosarcoma treated at our institution before 2006 were identified. Of 127 patients believed to be alive at the time of this study, 30 agreed to participate in this study (11 females, 19 males; mean age at surgery, 39 ± 12 years; mean followup, 12 ± 5 years). With the data available, the 30 participants were not different from the 97 nonparticipants in terms of age, sex, BMI, tumor grade, tumor location (axial versus appendicular, lower extremity versus elsewhere), and use of any treatment known to influence osteopenia (chemotherapy, lower extremity surgery). BMD was measured and history of fractures was assessed using a questionnaire. The patients´ BMD measurements in this study were sex- and age-matched with a normative sex- and age-categorized reference population reported by Kudlacek et al. Associations were tested by univariate regressions and ANOVAs of all measures of BMD and eligible oncologic and demographic factors. RESULTS: Eighteen of 30 (60%) patients had a pathologic BMD according to the WHO dual-energy x-ray absorptiometry definition, 15 (50%) had osteopenia, and three (10%) had osteoporosis. T-scores in the study cohort were lower than reference values for the femur neck (mean difference, 0.64; 95% CI, 0.27-1.01; p < 0.0015), but not for the spine (mean difference, 0.39; 95% CI, -0.06 to 0.84; p = 0.09). Thirteen patients (45%) reported a history of fractures not distinguishing between low and high impact. The incidence of fractures was 2.8 greater than expected from a comparison with a published microcensus survey of the Austrian population. No effect of the FRAX(®) score on fracture risk could be identified (p = 0.057). CONCLUSIONS: Long-term survivors of chondrosarcoma appear to be at greater risk for having low BMD develop than the healthy population. Although these results are preliminary and based on a very small sampling of patients, if they can be confirmed in larger studies, BMD assessment by dual-energy x-ray absorptiometry might be considered as these patients are followed posttreatment by sarcoma care units. The reasons for low BMD still must be elucidated. LEVEL OF EVIDENCE: Level IV, prognostic study.


Assuntos
Densidade Óssea , Doenças Ósseas Metabólicas/fisiopatologia , Neoplasias Ósseas/cirurgia , Condrossarcoma/cirurgia , Osteoporose/fisiopatologia , Fraturas por Osteoporose/fisiopatologia , Sobreviventes , Absorciometria de Fóton , Adolescente , Adulto , Fatores Etários , Idoso , Áustria/epidemiologia , Doenças Ósseas Metabólicas/epidemiologia , Neoplasias Ósseas/epidemiologia , Neoplasias Ósseas/fisiopatologia , Estudos de Casos e Controles , Condrossarcoma/epidemiologia , Condrossarcoma/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Fraturas por Osteoporose/epidemiologia , Valor Preditivo dos Testes , Prevalência , Sistema de Registros , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
20.
Wien Med Wochenschr ; 166(1-2): 9-14, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26819215

RESUMO

The aim is to review the modalities in musculoskeletal imaging with view on the prognostic impact for the patient's and for social outcome and with view on three major fields of preventive medicine: nutrition and metabolism, sports, and patient education. The added value provided by preventive imaging is (1) to monitor bone health and body composition with a broad spectrum of biomarkers, (2) to detect and quantify variants or abnormalities of nerves, muscles, tendons, bones, and joints with a risk of overuse, rupture, or fracture, and (3) to develop radiology reports from the widely used narrative format to structured text and multimedia datasets. The awareness problem is a term for describing the underreporting and the underdiagnosis of fragility fractures in osteoporosis.


Assuntos
Doenças Musculoesqueléticas/diagnóstico por imagem , Doenças Musculoesqueléticas/prevenção & controle , Dor Musculoesquelética/diagnóstico por imagem , Dor Musculoesquelética/prevenção & controle , Humanos , Medição da Dor/métodos , Exame Físico/métodos , Medicina de Precisão/métodos
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