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The objective of this pilot study was to assess the reliability of superb microvascular ultrasound (SMI) for the measurement of the cerebrospinal fluid (CSF) flow within VPS systems as an indirect sign for shunt dysfunction. Asymptomatic hydrocephalus patients, with a VPS system implanted between 2017 and 2021, were prospectively enrolled in the study. Using SMI, the CSF flow within the proximal and distal catheters were analysed. Before and after pumping the shunt reservoir, intraabdominal free fluid, optical nerve sheath diameter (ONSD), and papilla diameter (PD) were evaluated and correlated with the amount of valve activation. Nineteen patients were included. A flow was detectable in 100% (N = 19) patients in the proximal and in 89.5% (N = 17) in the distal catheter. The distal catheter tip was detectable in 27.7% (N = 5) patients. Free intraabdominal fluid was initially detected in 21.4% (N = 4) patients and in 57.9% (N = 11) at the end of the examination (P = 0.049). ONSD was significantly lower after pump activation (4.4 ± 0.9 mm versus 4.1 ± 0.8 mm, P = 0.049). Both peak velocity and flow volume per second were higher in proximal compared to distal catheters (32.2 ± 45.2 versus 5.6 ± 3.7 cm/sec, P = 0.015; 16.6 ± 9.5 ml/sec versus 5.1 ± 4.0 ml/sec, P = 0.001, respectively). No correlation was found between the number of pump activations and the changes in ONSD (P = 0.975) or PD (P = 0.820). SMI appears to be a very promising non-invasive diagnostic tool to assess CSF flow within the VPS systems and therefore affirm their function. Furthermore, appearance of free intraperitoneal fluid followed by repeated compression of a shunt reservoir indicates an intact functioning shunt system.
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Estudios de Factibilidad , Hidrocefalia , Ultrasonografía , Derivación Ventriculoperitoneal , Humanos , Masculino , Femenino , Persona de Mediana Edad , Hidrocefalia/cirugía , Hidrocefalia/diagnóstico por imagen , Anciano , Proyectos Piloto , Ultrasonografía/métodos , Adulto , Estudios Prospectivos , Microvasos/diagnóstico por imagen , Anciano de 80 o más Años , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Lateral mass screw fixation is the standard for posterior cervical fusion between C3 and C6. Traditional trajectories stabilize but carry risks, including nerve root and vertebral artery injuries. Minimally invasive spine surgery (MISS) is gaining popularity, but trajectories present anatomical challenges. RESEARCH QUESTION: This study proposes a novel pars interarticularis screw trajectory to address these issues and enhance in-line instrumentation with cervical pedicle screws. MATERIALS AND METHODS: A retrospective analysis of reformatted cervical CT scans included 10 patients. Measurements of the pars interarticularis morphology were performed on 80 segments (C3-C6). Two pars interarticularis screw trajectories were evaluated: Trajectory A (upper outer quadrant entry, horizontal trajectory) and Trajectory B (lower outer quadrant entry, cranially pointed trajectory). These were compared to standard lateral mass and cervical pedicle screw trajectories, assessing screw lengths, angles, and potential risks to the spinal canal and transverse foramen. RESULTS: Trajectory B showed significantly longer pars lengths (15.69 ± 0.65 mm) compared to Trajectory A (12.51 ± 0.24 mm; p < 0.01). Lateral mass screw lengths were comparable to pars interarticularis screw lengths using Trajectory B. Both trajectories provided safe angular ranges, minimizing the risk to delicate structures. DISCUSSION: and Conclusion. Pars interarticularis screws offer a viable alternative to lateral mass screws for posterior cervical fusion, especially in MISS contexts. Trajectory B, in particular, presents a feasible and safe alternative, reducing the risk of vertebral artery and spinal cord injury. Preoperative assessment and intraoperative technologies are essential for successful implementation. Biomechanical validation is needed before clinical application.
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Vértebras Cervicales , Fusión Vertebral , Tomografía Computarizada por Rayos X , Humanos , Fusión Vertebral/métodos , Fusión Vertebral/instrumentación , Vértebras Cervicales/cirugía , Vértebras Cervicales/diagnóstico por imagen , Estudios Retrospectivos , Femenino , Persona de Mediana Edad , Masculino , Tomografía Computarizada por Rayos X/métodos , Tornillos Pediculares , Anciano , Adulto , Tornillos Óseos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentaciónRESUMEN
BACKGROUND: One of the key features of orthognathic surgery is altering temporomandibular joint (TMJ) condylar positions. PURPOSE: This multivariate study aimed to identify surgical interventions and patient factors significantly associated with changes in TMJ spatial dimensions after the surgical correction of skeletal Class II deformities. STUDY DESIGN, SETTING, SAMPLE: This is a retrospective cohort study including patients who had undergone an isolated bilateral sagittal split ramus osteotomy (BSSO) or a bimaxillary osteotomy (BMO) for mandibular advancement and a control sample of patients treated with the removal of odontogenic cysts in the mandibular posterior region. Excluded were those who presented with specific radiographic signs of TMJ osteoarthrosis, severe facial asymmetry, or deformity secondary to trauma. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The primary predictors were condylar position at baseline (anterior, concentric, and posterior), time points (T0, preoperatively; T1, immediately after surgery; and T2, 1-year follow-up), and surgical intervention type (BSSO, BMO, and control group). MAIN OUTCOME VARIABLES: The primary outcomes were changes in posterior spatial dimension (PSD), superior spatial dimension, and medial spatial dimension assessed by cone-beam computed tomography preoperatively, immediately after surgery, and at 1-year follow-up. COVARIATES: Covariates included sex, age, and amount of mandibular advancement. ANALYSES: Estimations of independent effects of primary predictors on outcome variables were made by applying generalized estimation equation models. The value of statistical significance was P < .05. RESULTS: The study sample included 88 participants. The BSSO samples included 39 patients, and the BMO group included 22 patients; the control group comprised 27 subjects. The average age was 31.2 years; the majority were female (61.4%). Adjusted generalized estimation equation models yielded a significant time interaction between BSSO and spatial dimensions over time (PSD, P < .001). Key predictors of spatial dimension changes were the baseline posterior (PSD, P < .001) and the central condylar position (PSD, P < .001). CONCLUSION AND RELEVANCE: This controlled study, for the first time, provides scientific evidence on the effects of surgical intervention type and baseline condylar position on spatial dimension changes in the TMJ. It shows a more favorable outcome in long-term spatial dimension changes for patients treated by a BMO procedure.
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Maloclusión Clase II de Angle , Cóndilo Mandibular , Osteotomía Sagital de Rama Mandibular , Humanos , Femenino , Masculino , Estudios Retrospectivos , Cóndilo Mandibular/diagnóstico por imagen , Cóndilo Mandibular/cirugía , Adulto , Maloclusión Clase II de Angle/cirugía , Maloclusión Clase II de Angle/diagnóstico por imagen , Osteotomía Sagital de Rama Mandibular/métodos , Articulación Temporomandibular/diagnóstico por imagen , Articulación Temporomandibular/cirugía , Avance Mandibular/métodos , Adulto Joven , Adolescente , Tomografía Computarizada de Haz CónicoRESUMEN
Rhinoresistometry (RRM) is implemented along with active anterior rhinomanometry (AAR) and can evaluate nasal dimensions [hydraulic diameter (HD)]. As acoustic rhinometry (AR) is time-consuming, the authors investigated if RRM can be an efficient alternative to AR in nasal dimension assessment in orthognathic surgery. In patients undergoing maxillary advancement and impaction (cases) and removal of maxillary cysts (controls), the authors evaluated RRM and AR, before and 1 year after surgery. Furthermore, the authors investigated the correlation of HD with Nasal Obstruction Symptom Evaluation score and volume by computed tomography and AAR. Lastly, the authors measured RMM reproducibility by the Bland-Altman agreement method in controls. In 14 cases, AR and RMM revealed a significant increase on both sides (all P < 0.011) and the right side, respectively (P = 0.028). The authors noted no changes in 14 controls. Hydraulic diameter correlated only with AAR (most P < 0.004). Acoustic rhinometry lasted ~4 minutes before or after decongestion. In controls, HD after surgery was as large (1.05 times larger) as before surgery (up to 39% error rates). Rhinoresistometry can reproducibly assess nasal dimension changes in orthognathic surgery in a way that is different from AR and correlates with nasal function. Rhinoresistometry can help clinicians avoid AR and save significant time, as well as financial and human resources.
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BACKGROUND: The number of fluoroscopically guided interventions (FGI) has increased significantly over time. However, little attention has been paid to possible stochastic radiation effects. The aim of this retrospective study was to investigate the number of patients who received cumulative effective doses over 100 mSv during FGI procedures. MATERIAL AND METHODS: Five thousand five hundred and fifty four classified FGI procedures were included. Radiation dose data, retrieved from an in-house-dose-management system, was analysed. Effective doses and cumulative effective doses (CED) were calculated. Patients who received a CED > 100 mSv were identified. Radiology reports, patient age, imaging and clinical data of these patients were used to identify reasons for CED ≥ 100 mSv. RESULTS: One Hundred and thirty two (41.1% female) of 3981 patients received a CED > 100 mSy, with a mean CED of 173.5 ± 84.5 mSv. Mean age at first intervention was 66.1 ± 11.7 years. 81 (61.4%) of 132 were older than 64 years, one patient was < 30 years. 110 patients received ≥ 100 mSv within one year (83.4%), through FGIs: EVAR, pelvic/mesenteric interventions (stent or embolization), hepatic interventions (chemoembolization, TIPSS), embolization of cerebral aneurysms or arterio-venous-malformations. CONCLUSIONS: Substantial CED may occur in a small but not ignorable fraction of patients (~ 3%) undergoing FGIs. Approximately 2/3rd of patients may most likely not encounter radiation-related stochastic effects due to life-threatening diseases and age at first treatment > 65 years but 1/3rd may. Patients undergoing more than one FGI (77%) carry a higher risk of accumulating effective doses > 100 mSv. Remarkably, 23% received a mean CED 162.2 ± 72.3 mSv in a single procedure.
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Embolización Terapéutica , Traumatismos por Radiación , Humanos , Femenino , Persona de Mediana Edad , Anciano , Masculino , Dosis de Radiación , Estudios Retrospectivos , Diagnóstico por ImagenRESUMEN
The aim of this study was to investigate the change of nasal patency after maxillary advancement and impaction (MAXADV + IMP) in subjects with skeletal class III malocclusion (cases) and after removal of maxillary cysts in close proximity to the nasal floor in subjects that served as controls. NOSE score, volume derived by computed tomography (VOL), and acoustic rhinometry and rhinomanometry were retrospectively evaluated, before and one year after surgery. The movement of specific landmarks was also measured. NOSE score did not change after surgery, neither in 17 cases (p = 0.10) nor in 17 controls (p = 0.14). In cases, VOLpostop (10088 ± 4200 mm3) was significantly higher than VOLpreop (7807 ± 3721 mm3; p = 0.036). Maxillary advancement and inferior displacement of the ventral maxilla were noted by the movement of incisive foramen in the coronal (3.9 ± 5.4; p = 0.011) and Frankfurt Horizontal plane (2.2 ± 2.0; p = 0.001), respectively. In controls, VOLpostop (9749 ± 3654 mm3) was also significantly higher than VOLpreop (8473 ± 2624 mm3; p = 0.050). Cross-sectional areas, nasal flow and nasal resistance changed significantly after surgery in cases (6/30 pairs; p < 0.018), but not in controls (all p > 0.066). MAXADV + IMP increased nasal patency, but did not change the feeling of nasal breathing. Physicians should proceed with caution when informing patients about improvement of nasal breathing after MAXADV + IMP.
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Maxilar , Diente Impactado , Humanos , Maxilar/cirugía , Estudios Retrospectivos , Estudios de Casos y Controles , Osteotomía Le Fort/métodos , Nariz/cirugíaRESUMEN
BACKGROUND: To model the effect of isolated bilateral sagittal split osteotomy (BSSO) on changes in posterior (PSD), superior (SSD), and medial space dimensions (MSD) of the temporomandibular joint. METHODS: Using a retrospective cohort study design, pre- and postoperative (immediately after surgery; 1 year follow-up) cone-beam computed tomography measurements of 36 patients who had undergone BSSO for mandibular advancement were compared with a control group of 25 subjects from whom a mandibular odontogenic cyst was removed under general anesthesia. Generalized estimation equation (GEE) models were used to examine the independent effects of study group, preoperative condylar position, and time points on PSD, SSD, and MSD adjusting for covariates (age, sex, and mandibular advancement). RESULTS: No significant differences were found regarding changes in PSD (p = 0.144), SSD (p = 0.607), or MSD (p = 0.565) between the BSSO and control groups. However, the preoperative posterior condylar position showed significant effects on PSD (p < 0.001) and MSD (p = 0.043), while the preoperative central condylar position demonstrated a significant effect on PSD (p < 0.001). CONCLUSION: The data suggest that preoperative posterior condylar position is a significant effect modifier of PSD and MSD over time in this cohort.
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Cóndilo Mandibular , Osteotomía Sagital de Rama Mandibular , Humanos , Cóndilo Mandibular/diagnóstico por imagen , Cóndilo Mandibular/cirugía , Estudios Retrospectivos , Estudios de Cohortes , Osteotomía Sagital de Rama Mandibular/métodos , Articulación Temporomandibular/diagnóstico por imagen , Articulación Temporomandibular/cirugía , Mandíbula/cirugíaRESUMEN
Rationale and objectives: Patients receiving high cumulative effective doses (CED) from recurrent computed tomography (CT) in a real-life setting are not well identified. Evaluation of causes and patient characteristics may help to define individuals potentially at risk of radiation-induced secondary malignancies. Materials and methods: Patients who received a CED > 100 mSv from CT scans during October 2012 and April 2020 at a tertiary university center were identified with the help of a radiological radiation dose monitoring system. The primary disease and referral diagnosis, number of CT exams, time period, age, BMI and gender distribution of the 1000 patients with the highest CED were analysed. Results: 3431 patients had a CED of more than 100 mSv, which corresponded to 2.75% of all patients who received a CT exam. From the 1000 patients with the highest CED, mean number of CT exams per patient was 14.6, mean CED was 257 mSv (SD 98, range 177-1339). Mean age of patients was 63.9 years (SD 10.6), male to female ratio 3:2, and mean BMI 28.7 kg/m2 (SD 5.5). 728 (72.9%) patients had cancer. The leading primary diagnosis was liver cirrhosis in 197 patients and 103 patients had a liver transplantation. In patients with liver cirrhosis, 750 exams were indicated for the follow-up of the disease, 662 for the clarification of an acute clinical condition, and 202 for CT-guided stereotactic radiofrequency ablation. Conclusion: Recurrent CT scans of patients with cancer, liver cirrhosis and liver transplantation may lead to critically high CED.
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BACKGROUND: Premature fusion of cranial sutures affects skull development and leads to head deformity. Intracranial pressure increase and brain growth restriction can occur in untreated craniosynostosis. Operative treatment aims to achieve an immediate and long-lasting correction of skull shape that is close to the average and to prevent or release possible increased intracranial pressure by increasing the intracranial volume (ICV) or normalizing the ICV if it is already below the standards. This study was designed to evaluate the effect of a total calvarial reconstruction on skull development in patients with nonsyndromic sagittal synostosis. MATERIAL AND METHODS: The study population included 19 male and 5 female patients with isolated nonsyndromic sagittal suture synostosis. During the operation, temporarily fixed prebent metal plates provided an intraoperative reference for the desired cranial expansion gain of height and shortening. Preoperative and postoperative ICVs and cephalic indices were measured on computed tomography datasets using the software program ImageJ and were compared with one another and with normative data. RESULTS: The male population presented with a preoperative mean ICV of 863.3 cm³. A postoperative mean ICV increase of 243.5 cm³ (p < 0.001) and a further ICV enlargement (p < 0.001) was measured. The mean CI changed from 71.0% preoperatively to 75.4% postoperatively (p = 0.002) and decreased insignificantly in the follow-up (p = 0.546). The female population had a preoperative mean ICV of 804.9 cm³. Postoperatively, the mean ICV increased by 211.1 cm³ (p = 0.043) and also increased in the follow-up (p = 0.043). Their mean CI values increased from 66.5% preoperatively to 72.8% (p = 0.043) postoperatively and decreased insignificantly in the follow-up (p = 0.345). CONCLUSION: This method of total vault remodeling provides reliable ICV increase and improvement in length and width of skull proportions beyond the immediate postoperative period together with an ICV increase.
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Craneosinostosis , Hipertensión Intracraneal , Suturas Craneales/diagnóstico por imagen , Suturas Craneales/cirugía , Craneosinostosis/diagnóstico por imagen , Craneosinostosis/cirugía , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Cráneo/diagnóstico por imagen , Cráneo/cirugíaRESUMEN
Voxel-based morphometry (VBM) is a widely used tool for studying structural patterns of brain plasticity, brain development and disease. The source of the T1-signal changes is not understood. Most of these changes are discussed to represent loss or possibly gain of brain gray matter and recent publications speculate also about non-structural changes affecting T1-signal. We investigated the potential of pain stimulation to ultra-short-term alter gray matter signal changes in pain relevant brain regions in healthy volunteers using a longitudinal design. Immediately following regional nociceptive input, we detected significant gray matter volume (GMV) changes in central pain processing areas, i.e. anterior cingulate and insula cortex. However, similar results were observed in a control group using the identical time intervals but without nociceptive painful input. These GMV changes could be reproduced in almost 100 scanning sessions enrolling 72 healthy individuals comprising repetitive magnetization-prepared rapid gradient-echo (MPRAGE) sequences. These data suggest that short-term longitudinal repetitive MPRAGE may produce significant GMV changes without any intervention. Future studies investigating brain plasticity should focus and specifically report a consistent timing at which time-point during the experiment the T1-weighted scan is conducted. There is a necessity of a control group for longitudinal imaging studies.
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BACKGROUND: Chronic pelvic pain, in particular dysmenorrhoea, is a significant yet unresolved healthcare problem in gynaecology. As interoceptive sensitivity and underlying neural mechanisms remain incompletely understood, this functional magnetic resonance imaging (fMRI) study assessed behavioural and neural responses to visceral stimuli in primary dysmenorrhoea (PMD). METHODS: Women with PMD (N = 19) without psychological comorbidity and healthy women (N = 20) were compared with respect to visceral sensory and pain thresholds, and to neural responses to individually calibrated mildly painful and painful rectal distensions implemented during scanning. Trial-by-trial ratings of perceived intensity were accomplished with visual analogue scales (VAS). RESULTS: Although women with dysmenorrhoea reported significantly higher chronic pain intensity and pain interference with daily life activities (p < 0.01, assessed with the West Haven-Yale Multidimensional Pain Inventory), there were no differences between groups in visceral sensitivity and mean trial-by-trial VAS ratings were virtually identical. Analysis of neural responses revealed activation in brain regions previously shown to be involved in the processing of visceral stimuli with differences between painful and mildly painful stimulation, but no group differences were found even when using a liberal statistical threshold. CONCLUSIONS: Dysmenorrhoea patients show unaltered perceptual and neural responses to experimental interoceptive stimuli. Despite limited sample size, these negative results argue against a generalized sensitization towards interoceptive stimuli in patients without psychological comorbidities. Future studies should clarify the role of psychosocial factors in central sensitization using more pain region-specific models in larger and clinically more heterogeneous samples. SIGNIFICANCE: Despite higher chronic pain and pain interference with daily life activities, women with primary dysmenorrhoea do not differ from healthy women with respect to visceral sensitivity or neural processing of aversive interoceptive stimuli induced by rectal distensions. Generalized sensitization may be present only in subgroups with pronounced psychosocial or psychiatric disturbances.
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Dismenorrea/fisiopatología , Dismenorrea/psicología , Dolor Visceral/fisiopatología , Dolor Visceral/psicología , Adulto , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Estudios de Casos y Controles , Sensibilización del Sistema Nervioso Central , Dismenorrea/diagnóstico por imagen , Femenino , Humanos , Imagen por Resonancia Magnética , Dimensión del Dolor , Percepción del Dolor , Umbral del Dolor , Dolor Visceral/diagnóstico por imagen , Adulto JovenRESUMEN
To demonstrate the importance of calibration measurements in 3 Tesla proton magnetic resonance (MR) spectroscopy (1H-MRS) thermometry for human brain temperature estimation for routine clinical applications. In vitro proton MR spectroscopy to obtain calibration constants of the water-chemical shift was conducted at 3 Tesla with a temperature-controlled phantom, containing a pH-buffered aqueous solution of N-acetyl aspartate (NAA), creatine (Cr), methylene protons of Cr (Cr2), dimethyl silapentane sulfonic acid (DSS), and sodium formate (NaFor). Estimations of absolute human brain temperature were performed utilizing the correlation of temperature to the water-chemical shift for the resonances of NAA, Cr, and Cr2. Data for calibration of the metabolites' chemical shift differences and in vivo temperature estimations were acquired with single-voxel point-resolved spectroscopy (PRESS) sequences (repetition time/echo time = 2000/30 ms; voxel size 2 × 2 × 2 cm3). Spectroscopy data were quantified in the time-domain, and a Pearson correlation analysis was performed to estimate the correlation between the chemical shift of metabolites and measured temperatures. The correlation coefficients (r) of our calibration measurements were NAA 0.9975 (±0.0609), Cr -0.9979 (±0.0621), Cr2 - 0.9973 (±0.0577), DSS -0.9976 (±0.0615), and NaFor -0.8132 (±2.348). The mean calculated brain temperature was 37.78 ± 1.447°C, and the mean tympanic temperature was 36.83 ± 0.2456°C. Calculated temperatures derived from Cr and Cr2 provided significant (p = 0.0241 and p = 0.0210, respectively) correlations with measured temperatures (r = 0.4108 and r = -0.4194, respectively). Calibration measurements are vital for 1H-MRS thermometry. Small numeric differences in measured signal and data preprocessing without any calibration measurements reduce accuracy of temperature calculations, which indicates that calculated temperatures should be interpreted with caution. Application of this method for clinical purposes warrants further investigation and a more practical approach.
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Temperatura Corporal , Encéfalo/metabolismo , Espectroscopía de Protones por Resonancia Magnética/normas , Termometría/normas , Adolescente , Adulto , Ácidos Alcanesulfónicos/metabolismo , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Biomarcadores/metabolismo , Encéfalo/diagnóstico por imagen , Calibración , Creatina/metabolismo , Estudios de Factibilidad , Femenino , Formiatos/metabolismo , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estándares de Referencia , Reproducibilidad de los Resultados , Termometría/métodos , Compuestos de Trimetilsililo/metabolismo , Adulto JovenRESUMEN
PURPOSE: to explore whether the NK1 and Y2 receptors are involved in the pathogenesis of laser-induced CNV (choroidal neovascularization) in C57Bl/6N mice. METHODS: CNV was induced by laser damage of Bruch's membrane and the CNV volume was determined by OCT and/or flatmount preparation. First, the development of the CNV volume over time was evaluated. Second, the CNV development in NK1- and Y2 KO mice was analyzed. Third, the effect on the development as well as the regression of CNV by intravitreal injections of the NK1 antagonist SR140333 and the Y2 antagonist BIIEO246 separately and each in combination with Eylea®, was investigated. Furthermore, flatmount CNV volume measurements were correlated to volumes obtained by the in vivo OCT technique. RESULTS: CNV volume peak was observed at day 4 after laser treatment. Compared to wild type mice, NK1 and Y2 KO mice showed significantly smaller CNV volumes. Eylea® and the Y2 antagonist significantly reduced the volume of the developing CNV. In contrast to Eylea® there was no effect of either antagonist on the regression of CNV, additionally no additive effect upon combined Eylea®/antagonist treatment was observed. There was a strong positive correlation between CNV volumes obtained by OCT and flatmount. CONCLUSION: NK1 and Y2 receptors mediate the development of laser-induced CNVs in mice. They seem to play an important role at the developmental stage of CNVs, whereas VEGF via VEGF receptor may be an important mediator throughout the CNV existence. In vivo OCT correlates with flatmount CNV volume, representing a useful tool for in vivo evaluations of CNV over time.
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Neovascularización Coroidal , Receptores de Neuroquinina-1/fisiología , Receptores de Neuropéptido Y/fisiología , Inhibidores de la Angiogénesis/farmacología , Animales , Células Cultivadas , Coroides/patología , Neovascularización Coroidal/tratamiento farmacológico , Neovascularización Coroidal/patología , Neovascularización Coroidal/fisiopatología , Modelos Animales de Enfermedad , Células Endoteliales/efectos de los fármacos , Angiografía con Fluoresceína , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Antagonistas del Receptor de Neuroquinina-1/farmacología , Receptores de Neuroquinina-1/deficiencia , Receptores de Neuropéptido Y/antagonistas & inhibidores , Receptores de Neuropéptido Y/deficiencia , Receptores de Factores de Crecimiento Endotelial Vascular , Proteínas Recombinantes de Fusión/farmacologíaRESUMEN
BACKGROUND: Reconstruction of large cranial defects after craniectomy can be accomplished by free-hand poly-methyl-methacrylate (PMMA) or industrially manufactured implants. The free-hand technique often does not achieve satisfactory cosmetic results but is inexpensive. In an attempt to combine the accuracy of specifically manufactured implants with low cost of PMMA. METHODS: Forty-six consecutive patients with large skull defects after trauma or infection were retrospectively analyzed. The defects were reconstructed using computer-aided design/computer-aided manufacturing (CAD/CAM) techniques. The computer file was imported into a rapid prototyping (RP) machine to produce an acrylonitrile-butadiene-styrene model (ABS) of the patient's bony head. The gas-sterilized model was used as a template for the intraoperative modeling of the PMMA cranioplasty. Thus, not the PMMA implant was generated by CAD/CAM technique but the model of the patients head to easily form a well-fitting implant. Cosmetic outcome was rated on a six-tiered scale by the patients after a minimum follow-up of three months. RESULTS: The mean size of the defect was 74.36cm2. The implants fitted well in all patients. Seven patients had a postoperative complication and underwent reoperation. Mean follow-up period was 41 months (range 2-91 months). Results were excellent in 42, good in three and not satisfactory in one patient. Costs per implant were approximately 550 Euros. CONCLUSION: PMMA implants fabricated in-house by direct molding using a bio-model of the patients bony head are easily produced, fit properly and are inexpensive compared to cranial implants fabricated with other RP or milling techniques.
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Diseño Asistido por Computadora , Craneotomía/métodos , Procedimientos de Cirugía Plástica/métodos , Polimetil Metacrilato , Prótesis e Implantes , Adolescente , Adulto , Anciano , Niño , Femenino , Estudios de Seguimiento , Humanos , Periodo Intraoperatorio , Masculino , Persona de Mediana Edad , Modelos Anatómicos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Diseño de Prótesis , Reoperación , Adulto JovenRESUMEN
The human attachment system is activated in situations of danger such as potential separation, threats of loss of a significant other and potential insecurity on the availability of the attachment figure. To date, however, a precise characterization of the neural correlates of the attachment system in healthy individuals is lacking. This functional magnetic resonance imaging (fMRI) study aims at characterizing the distinctive neural substrates activated by the exposure to attachment vs. non-attachment scenes. Healthy participants (N = 25) were presented scenes from the Adult Attachment Projective Picture System (AAP), a validated set of standardized attachment-related pictures extended by a control picture stimulus set consisting of scenes without attachment-related content. When compared to the control neutral pictures, attachment scenes activated the inferior parietal lobes (IPLs), the middle temporal gyrus (MTG), and the anterior medial prefrontal cortex (mPFC). These areas are associated with reasoning about mental representations, semantic memory of social knowledge, and social cognition. This neural activation pattern confirms the distinctive quality of this stimulus set, and suggests its use as a potential neuroimaging probe to assess social cognition/mentalizing related to attachment in healthy and clinical populations.
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This study provides first data about the spatial variability of fMRI sensorimotor localizations when investigating the same subjects at different fMRI sites. Results are comparable to a previous patient study. We found a median between-site variability of about 6 mm independent of task (motor or sensory) and experimental standardization (high or low). An intraclass correlation coefficient analysis using data quality measures indicated a major influence of the fMRI site on variability. In accordance with this, within-site localization variability was considerably lower (about 3 mm). We conclude that the fMRI site is a considerable confound for localization of brain activity. However, when performed by experienced clinical fMRI experts, brain pathology does not seem to have a relevant impact on the reliability of fMRI localizations. Hum Brain Mapp 37:2151-2160, 2016. © 2016 Wiley Periodicals, Inc.
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Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Imagen por Resonancia Magnética , Adulto , Análisis de Varianza , Mapeo Encefálico/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora/fisiología , Pruebas Neuropsicológicas , Reproducibilidad de los Resultados , Percepción del Tacto/fisiología , Adulto JovenRESUMEN
PURPOSE: To investigate intersite variability of clinical functional magnetic resonance (MR) imaging, including influence of task standardization on variability and use of various parameters to inform the clinician whether the reliability of a given functional localization is high or low. MATERIALS AND METHODS: Local ethics committees approved the study; all participants gave written informed consent. Eight women and seven men (mean age, 40 years) were prospectively investigated at three experienced functional MR sites with 1.5- (two sites) or 3-T (one site) MR. Nonstandardized motor and highly standardized somatosensory versions of a frequently requested clinical task (localization of the primary sensorimotor cortex) were used. Perirolandic functional MR variability was assessed (peak activation variability, center of mass [COM] variability, intraclass correlation values, overlap ratio [OR], activation size ratio). Data quality measures for functional MR images included percentage signal change (PSC), contrast-to-noise ratio (CNR), and head motion parameters. Data were analyzed with analysis of variance and a correlation analysis. RESULTS: Localization of perirolandic functional MR activity differed by 8 mm (peak activity) and 6 mm (COM activity) among sites. Peak activation varied up to 16.5 mm (COM range, 0.4-16.5 mm) and 45.5 mm (peak activity range, 1.8-45.5 mm). Signal strength (PSC, CNR) was significantly lower for the somatosensory task (mean PSC, 1.0% ± 0.5 [standard deviation]; mean CNR, 1.2 ± 0.4) than for the motor task (mean PSC, 2.4% ± 0.8; mean CNR, 2.9 ± 0.9) (P < .001, both). Intersite variability was larger with low signal strength (negative correlations between signal strength and peak activation variability) even if the task was highly standardized (mean OR, 22.0% ± 18.9 [somatosensory task] and 50.1% ± 18.8 [motor task]). CONCLUSION: Clinical practice and clinical functional MR biomarker studies should consider that the center of task-specific brain activation may vary up to 16.5 mm, with the investigating site, and should maximize functional MR signal strength and evaluate reliability of local results with PSC and CNR.
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Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Adolescente , Adulto , Análisis de Varianza , Biomarcadores , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reproducibilidad de los ResultadosRESUMEN
Functional MRI was used to investigate brain activation in healthy volunteers during encoding of unfamiliar faces as well as during correct recognition of newly learned faces (CR) compared to correct identification of distractor faces (CF), missed alarms (not recognizing previously presented faces, MA), and false alarms (incorrectly recognizing newly presented faces, FA). Encoding was associated with frontal, occipital/fusiform, thalamic, and cerebellar activation. CR produced activation in frontal and cerebellar regions, whereas CF activated frontal and occipitotemporal regions as well as the thalamus. In contrast, MA was associated with frontal and thalamic activation, and FA with frontal activation. The CR minus CF comparison showed left lateral prefrontal and parietal activation, while no suprathreshold positive signal changes were detected when subtracting the other conditions (CR minus MA, CR minus FA, and vice versa). These results support the view that the successful episodic retrieval of newly learned faces is based on a dorsal visual stream mechanism.
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Mapeo Encefálico , Discriminación en Psicología/fisiología , Cara , Reconocimiento Visual de Modelos/fisiología , Reconocimiento en Psicología/fisiología , Adulto , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Valores de ReferenciaRESUMEN
In this functional MRI experiment, encoding of objects was associated with activation in left ventrolateral prefrontal/insular and right dorsolateral prefrontal and fusiform regions as well as in the left putamen. By contrast, correct recognition of previously learned objects (R judgments) produced activation in left superior frontal, bilateral inferior frontal, and right cerebellar regions, whereas correct rejection of distractor objects (N judgments) was associated with activation in bilateral prefrontal and anterior cingulate cortices, in right parietal and cerebellar regions, in the left putamen, and in the right caudate nucleus. The R minus N comparison showed activation in the left lateral prefrontal cortex and in bilateral cingulate cortices and precunei, while the N minus R comparison did not reveal any positive signal change. These results support the view that similar regions of the frontal lobe are involved in episodic encoding and retrieval processes, and that the successful episodic retrieval of newly learned objects is mainly based on a frontoparietal network.
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Mapeo Encefálico , Encéfalo/fisiología , Aprendizaje Discriminativo/fisiología , Lateralidad Funcional/fisiología , Reconocimiento en Psicología/fisiología , Adulto , Cerebelo/fisiología , Corteza Cerebral/fisiología , Potenciales Evocados/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiología , Putamen/fisiología , Valores de ReferenciaRESUMEN
BACKGROUND: Previous studies have suggested that men and women process emotional stimuli differently. In this study, we used event-related functional magnetic resonance imaging (fMRI) to investigate gender differences in regional cerebral activity during the perception of positive or negative emotions. METHOD: The experiment comprised two emotional conditions (positively/negatively valenced words) during which fMRI data were acquired. RESULTS: Thirty-eight healthy volunteers (19 males, 19 females) were investigated. A direct comparison of brain activation between men and women revealed differential activation in the right putamen, the right superior temporal gyrus, and the left supramarginal gyrus during processing of positively valenced words versus non-words for women versus men. By contrast, during processing of negatively valenced words versus non-words, relatively greater activation was seen in the left perirhinal cortex and hippocampus for women versus men, and in the right supramarginal gyrus for men versus women. CONCLUSIONS: Our findings suggest gender-related neural responses to emotional stimuli and could contribute to the understanding of mechanisms underlying the gender disparity of neuropsychiatric diseases such as mood disorders.