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In the past decade, significant progress has been made in understanding both microRNA function and cellular pluripotency. Here we review the intersection of these two exciting fields. While microRNAs are not required for the establishment and maintenance of pluripotency in early development and cell culture, respectively, they are critically important in the regulation of the cell cycle structure of pluripotent stem cells as well as the silencing of the pluripotency program upon differentiation. Pluripotent cells, both in vivo and in vitro, dominantly express a single family of microRNAs, which can promote the reprogramming of a somatic cell back to a pluripotent state. Here, we review the known mechanisms by which these and other microRNAs regulate the different aspects of the pluripotent stem cell program in both mouse and human.
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MicroRNAs/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Animais , Técnicas de Cultura de Células , Diferenciação Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Humanos , CamundongosRESUMO
BACKGROUND: Patients with intracranial meningiomas frequently suffer from tumor-related seizures prior to resection, impacting patients' quality of life. We aimed to elaborate on incidence and predictors for seizures in a patient cohort with meningiomas WHO grade 2 and 3. METHODS: We retrospectively searched for patients with meningioma WHO grade 2 and 3 according to the 2021 WHO classification undergoing tumor resection. Clinical, histopathological and imaging findings were collected and correlated with preoperative seizure development. Tumor and edema volumes were quantified. RESULTS: Ninety-five patients with a mean age of 59.5 ± 16.0 years were included. Most tumors (86/95, 90.5%) were classified as atypical meningioma WHO grade 2. Nine of 95 tumors (9.5%) corresponded to anaplastic meningiomas WHO grade 3, including six patients harboring TERT promoter mutations. Meningiomas were most frequently located at the convexity in 38/95 patients (40.0%). Twenty-eight of 95 patients (29.5%) experienced preoperative seizures. Peritumoral edema was detected in 62/95 patients (65.3%) with a median volume of 9 cm3 (IR: 0-54 cm3). Presence of peritumoral edema but not age, tumor localization, TERT promoter mutation, brain invasion or WHO grading was associated with incidence of preoperative seizures, as confirmed in multivariate analysis (OR: 6.61, 95% CI: 1.18, 58.12, p = *0.049). Postoperative freedom of seizures was achieved in 91/95 patients (95.8%). CONCLUSIONS: Preoperative seizures were frequently encountered in about every third patient with meningioma WHO grade 2 or 3. Patients presenting with peritumoral edema on preoperative imaging are at particular risk for developing tumor-related seizures. Tumor resection was highly effective in achieving seizure freedom.
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Edema Encefálico , Neoplasias Meníngeas , Meningioma , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Meningioma/complicações , Meningioma/cirurgia , Meningioma/patologia , Estudos Retrospectivos , Qualidade de Vida , Convulsões/etiologia , Convulsões/epidemiologia , Fatores de Risco , Edema , Neoplasias Meníngeas/complicações , Neoplasias Meníngeas/cirurgia , Neoplasias Meníngeas/patologia , Organização Mundial da Saúde , Edema Encefálico/etiologia , Edema Encefálico/cirurgiaRESUMO
PURPOSE: In surgery for intramedullary spinal cord tumors (imSCT), distortion of the anatomy challenges the visual identification of dorsal columns (DC) for midline myelotomy. Dorsal column mapping (DCM) and spinal cord stimulation (SCS) can identify DC neurophysiologically. We compare application and feasibility of both methods. METHODS: Patients with surgically treated imSCT were prospectively included between 04/2017 and 06/2019. The anatomical midline (AM) was marked. SSEPs at the DC after stimulation of tibial/median nerve with an 8-channel DCM electrode and cortical SSEP phase reversal at C3/C4 after SCS using a bipolar concentric probe were recorded. Procedural and technical aspects were compared. Standardized neurological examinations were performed preoperatively, 1 week postoperatively and after more than 12 months. RESULTS: The DCM electrode detected the midline in 9/13 patients with handling limitations in the remaining patients. SCS was applicable in all patients with determination of the midline in 9/13. If both recordings could be acquired (6/13), concordance was 100%. If baseline SSEPs were poor, both methods were limited. SCS was less time-consuming (p = 0.001), cheaper, and easier to handle. In 92% of cases, the AM and neurophysiologic midlines were concordant. After myelotomy, 3 patients experienced > 50% reduction in amplitude of SSEPs. Despite early postoperative worsening of DC function, long-term follow-up showed significant recovery and improvement in quality of life. CONCLUSION: DCM and SCS may help confirm and correct the AM for myelotomy in imSCT, leading to a favorable long-term neurological outcome in this cohort. SCS evolved to be superior concerning applicability, cost-effectiveness, and time expenditure.
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Qualidade de Vida , Neoplasias da Medula Espinal , Humanos , Seguimentos , Potenciais Somatossensoriais Evocados/fisiologia , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/cirurgia , Eletrodos , Medula Espinal/cirurgiaRESUMO
OBJECTIVE: The transsphenoidal approach is the standard for most pituitary tumors. Despite low morbidity, postoperative CSF fistulas and meningitis are specific complications. Various surgical closure techniques for intraoperative CSF (iCSF) leak and sellar reconstruction have been described. For many years the authors have applied synthetic materials for iCSF leak repair and sellar closure in a standardized fashion in their department. Here they analyze the surgical outcome as well as risk factors for iCSF leak and meningitis. METHODS: All patients with transsphenoidal resection of a pituitary adenoma performed by the same surgeon between January 2013 and December 2019 were screened retrospectively. A small amount of iCSF flow without a diaphragmatic defect was classified as a minor leak, and obvious CSF flow with or without a diaphragmatic defect was classified as a major leak. In case of iCSF leak, a fibrin- and thrombin-coated sponge was used to cover the diaphragmatic defect and another one was used for the sellar opening. A gelatin sponge was placed in the sphenoid sinus as an abutment. The primary and secondary outcomes were the number of postoperative CSF (pCSF) leaks and meningitis, respectively. Clinical, histological, and perioperative data from medical records were collected to identify risk factors for CSF leak and meningitis. RESULTS: Of 417 transsphenoidal surgeries, 359 procedures in 348 patients with a median age of 54 years were included. There were 96 iCSF leaks (26.7%; 37.5% major, 62.5% minor). In 3 of 359 cases (0.8%) a pCSF fistula occurred, requiring revision surgery in 2 patients and a lumbar drain in 1 patient. Meningitis occurred in 3 of 359 cases (0.8%). All 3 patients recovered without sequelae after antibiotic therapy. According to univariate analysis, risk factors for iCSF leak were macroadenoma (p = 0.006) and recurrent adenoma (p = 0.032). An iCSF leak was found less often in functioning adenomas (p = 0.025). In multivariate analysis recurrent tumors remained as a risk factor (p = 0.021) for iCSF leak. Patients with iCSF leak were at increased risk for a pCSF leak (p = 0.005). A pCSF leak in turn represented the key risk factor for meningitis (p = 0.033). CONCLUSIONS: Patients with macroadenomas and recurrent adenomas are especially at risk for iCSF leak. An iCSF leak in turn increases the risk for a pCSF leak, which carries the risk for meningitis. The authors' surgical technique leads to a very low rate of pCSF leaks and meningitis without using autologous graft materials. Hence, this technique is safe and improves patient comfort by avoiding the disadvantages of autologous graft harvesting.
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Adenoma , Meningite , Neoplasias Hipofisárias , Humanos , Pessoa de Meia-Idade , Neoplasias Hipofisárias/cirurgia , Estudos Retrospectivos , Adenoma/cirurgia , Vazamento de Líquido Cefalorraquidiano/etiologia , Vazamento de Líquido Cefalorraquidiano/cirurgia , Meningite/etiologia , Fatores de Risco , Complicações Pós-Operatórias/etiologiaRESUMO
BACKGROUND: Prognostic markers for meningioma recurrence are needed to guide patient management. Apart from rare hereditary syndromes, the impact of a previous unrelated tumor disease on meningioma recurrence has not been described before. METHODS: We retrospectively searched our database for patients with meningioma WHO grade I and complete resection provided between 2002 and 2016. Demographical, clinical, pathological, and outcome data were recorded. The following covariates were included in the statistical model: age, sex, clinical history of unrelated tumor disease, and localization (skull base vs. convexity). Particular interest was paid to the patients' past medical history. The study endpoint was date of tumor recurrence on imaging. Prognostic factors were obtained from multivariate proportional hazards models. RESULTS: Out of 976 meningioma patients diagnosed with a meningioma WHO grade I, 416 patients fulfilled our inclusion criteria. We encountered 305 women and 111 men with a median age of 57 years (range: 21-89 years). Forty-six patients suffered from a tumor other than meningioma, and no TERT mutation was detected in these patients. There were no differences between patients with and without a positive oncological history in terms of age, tumor localization, or mitotic cell count. Clinical history of prior tumors other than meningioma showed the strongest association with meningioma recurrence (p = 0.004, HR = 3.113, CI = 1.431-6.771) both on uni- and multivariate analysis. CONCLUSION: Past medical history of tumors other than meningioma might be associated with an increased risk of meningioma recurrence. A detailed pre-surgical history might help to identify patients at risk for early recurrence.
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Neoplasias Meníngeas , Meningioma , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/cirurgia , Meningioma/genética , Meningioma/cirurgia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/cirurgia , Prognóstico , Estudos Retrospectivos , Organização Mundial da Saúde , Adulto JovemRESUMO
OBJECTIVE: To systematically compare time-of-flight magnetic resonance angiography (TOF-MRA) acquired with Compressed SENSE (TOF-CS) to spiral imaging (TOF-Spiral) for imaging of brain-feeding arteries. METHODS: Seventy-one patients (60.2 ± 19.5 years, 43.7% females, 28.2% with pathology) who underwent TOF-MRA after implementation of a new scanner software program enabling spiral imaging were analyzed retrospectively. TOF-CS (standard sequence; duration ~ 4 min) and the new TOF-Spiral (duration ~ 3 min) were acquired. Image evaluation (vessel image quality and detectability, diagnostic confidence (1 (diagnosis very uncertain) to 5 (diagnosis very certain)), quantitative measurement of aneurysm diameter or degree of stenosis according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria) was performed by two readers. Quantitative assessments of pathology were compared to computed tomography angiography (CTA) or digital subtraction angiography (DSA). RESULTS: TOF-CS showed higher image quality for intraosseous and intradural segments of the internal carotid artery while TOF-Spiral better depicted small intracranial vessels like the anterior choroidal artery. All vessel pathologies were correctly identified by both readers for TOF-CS and TOF-Spiral with high confidence (TOF-CS (4.4 ± 0.6 and 4.3 ± 0.8), TOF-Spiral (4.3 ± 0.7 and 4.3 ± 0.8)) and good inter-reader agreement (Cohen's kappa > 0.8). Quantitative assessments of aneurysm size or stenosis did not significantly differ between TOF-CS or TOF-Spiral and CTA or DSA (p > 0.05). CONCLUSIONS: TOF-Spiral for imaging of brain-feeding arteries enables reductions in scan time without drawbacks in diagnostic confidence. A combination of spiral imaging and CS may help to overcome shortcomings of both sequences alone and could further reduce acquisition times in the future. KEY POINTS: ⢠TOF-MRA with Compressed SENSE is superior in depicting arteries at the skull base while spiral TOF-MRA is able to better depict small intracranial vessels. ⢠Both TOF-MRA with Compressed SENSE and TOF-MRA with spiral imaging provide high diagnostic confidence for detection of pathologies of brain-feeding arteries. ⢠Spiral TOF-MRA is faster (by 25% for the sequence used in this study) than TOF-MRA with Compressed SENSE, thus enabling clear reductions in scan time for the clinical setting.
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Transtornos Cerebrovasculares/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia Digital/métodos , Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Software , Adulto JovemRESUMO
In intraoperative neuromonitoring (IONM), facial nerve motor function (FaNMF) is assessed by facial muscle corticobulbar motor evoked potentials (FMcoMEP). Mostly only amplitude decrease is used as warning criterion. We related a refined criterion for FMcoMEP consisting of a bilateral final-to-baseline motor threshold ratio with standard criteria and postoperative FaNMF. 79 patients (45 females; 48 ± 16 years) undergoing IONM-guided cerebellopontine angle tumor surgery were retrospectively analyzed. An intraoperative final-to-baseline motor threshold increase ≥ 20% ipsi- versus contralaterally (bFBMT20) was correlated to postoperative FaNMF at day 1 (D1), 7 (D7) and 3 months (3 M). An ipsilateral-only final-to-baseline motor threshold increase ≥ 20 mA (iAMT20) and amplitude decrement ≥ 50% (iAR50) served as reference. Tumors included vestibular schwannomas (68%), meningiomas (19%) and others (13%). Mean tumor diameter was 2.7 ± 1.1 cm. Postoperatively, HB-increase ≥ 2 was seen in 27% (D1), 17% (D7), and 6% (3 M) of patients, respectively. FMcoMEP were obtained in 75/79 cases. Pathological bFBMT20, iAMT20 and iAR50 were seen in 17, 17, and 46 cases, respectively. Area under the ROC curve for bFBMT20 (iAMT20) was 0.894 (0.868) at D1; 0.903 (0.822) at D7 and 0.941 (0.959) at 3 M. iAR50 performed worse at all time points. Diagnostic odds ratios were highest for bfBMT20 compared to iAMT20 and iAR50 for D1 (172.5 vs. 8.7 vs. 0.45) and D7 (51.4 vs. 6.1 vs. 0.8). The refined parameter bFBMT20 provides a valuable contribution to the prognostic assessment of FaNMF. Due to its bihemispheric character, it might thus circumvent false-positive events which affect FMcoMEP bilaterally.
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Monitorização Neurofisiológica Intraoperatória , Neoplasias Meníngeas , Neuroma Acústico , Potencial Evocado Motor , Feminino , Humanos , Neuroma Acústico/cirurgia , Prognóstico , Estudos RetrospectivosRESUMO
In clinical practice, diagnosis of suspected carious lesions is verified by using conventional dental radiography (DR), including panoramic radiography (OPT), bitewing imaging, and dental X-ray. The aim of this study was to evaluate the use of magnetic resonance imaging (MRI) for caries visualization. Fourteen patients with clinically suspected carious lesions, verified by standardized dental examination including DR and OPT, were imaged with 3D isotropic T2-weighted STIR (short tau inversion recovery) and T1 FFE Black bone sequences. Intensities of dental caries, hard tissue and pulp were measured and calculated as aSNR (apparent signal to noise ratio) and aHTMCNR (apparent hard tissue to muscle contrast to noise ratio) in both sequences. Imaging findings were then correlated to clinical examination results. In STIR as well as in T1 FFE black bone images, aSNR and aHTMCNR was significantly higher in carious lesions than in healthy hard tissue (p < 0.001). Using water-sensitive STIR sequence allowed for detecting significantly lower aSNR and aHTMCNR in carious teeth compared to healthy teeth (p = 0.01). The use of MRI for the detection of caries is a promising imaging technique that may complement clinical exams and traditional imaging.
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Cárie Dentária , Humanos , Cárie Dentária/diagnóstico por imagem , Suscetibilidade à Cárie Dentária , Imageamento por Ressonância Magnética , Inversão Cromossômica , Nível de SaúdeRESUMO
Background: In 2016, nationwide cystic fibrosis newborn screening (CFNS) was newly implemented in Germany, using an immunoreactive trypsin/pancreatitis-associated protein/DNA screening algorithm that differs from most other nationwide screening programmes. Methods: We analysed real-life feasibility of the confirmation process with respect to our pre-specified procedural objectives. These included overall accuracy through false-negative and false-positive results, effectiveness of the Bavarian tracking system, and accuracy of Macroduct and Nanoduct sweat conductivity compared with quantitative chloride determination. All consecutive CFNS-positive newborns assigned to our CF centre and born between 1 September 2016 and 31 August 2021 (n=162) were included. Results: The German CFNS was feasible at our CF centre as all procedural objectives were met. The positive predictive value (PPV) of positive CFNS was low (0.23) and two initially negatively screened children were later diagnosed with CF. The tracking system was highly efficient with a 100% tracking rate. The Macroduct and Nanoduct systems had comparable success rates (93.2% versus 95.9%). Importantly, conductivity via Macroduct was more accurate than via Nanoduct (zero and four false-positive newborns, respectively). Conclusions: CF confirmation diagnostics of neonates in a certified regional CF centre was well managed in daily routine. The PPV of the German CFNS needs to be improved, e.g. by extending the DNA analysis within the screening algorithm and by increasing the number of variants tested. The Bavarian tracking system can serve as a successful model for other tracking systems. We preferred the Macroduct system because of its more accurate sweat conductivity readings.
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TSPO is a promising novel tracer target for positron-emission tomography (PET) imaging of brain tumors. However, due to the heterogeneity of cell populations that contribute to the TSPO-PET signal, imaging interpretation may be challenging. We therefore evaluated TSPO enrichment/expression in connection with its underlying histopathological and molecular features in gliomas. We analyzed TSPO expression and its regulatory mechanisms in large in silico datasets and by performing direct bisulfite sequencing of the TSPO promotor. In glioblastoma tissue samples of our TSPO-PET imaging study cohort, we dissected the association of TSPO tracer enrichment and protein labeling with the expression of cell lineage markers by immunohistochemistry and fluorescence multiplex stains. Furthermore, we identified relevant TSPO-associated signaling pathways by RNA sequencing.We found that TSPO expression is associated with prognostically unfavorable glioma phenotypes and that TSPO promotor hypermethylation is linked to IDH mutation. Careful histological analysis revealed that TSPO immunohistochemistry correlates with the TSPO-PET signal and that TSPO is expressed by diverse cell populations. While tumor core areas are the major contributor to the overall TSPO signal, TSPO signals in the tumor rim are mainly driven by CD68-positive microglia/macrophages. Molecularly, high TSPO expression marks prognostically unfavorable glioblastoma cell subpopulations characterized by an enrichment of mesenchymal gene sets and higher amounts of tumor-associated macrophages.In conclusion, our study improves the understanding of TSPO as an imaging marker in gliomas by unveiling IDH-dependent differences in TSPO expression/regulation, regional heterogeneity of the TSPO PET signal and functional implications of TSPO in terms of tumor immune cell interactions.
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Glioblastoma , Glioma , Células-Tronco Mesenquimais , Humanos , Glioblastoma/diagnóstico por imagem , Glioblastoma/genética , Macrófagos Associados a Tumor , Macrófagos , Receptores de GABA/genéticaRESUMO
BACKGROUND AND IMPORTANCE: Intraoperative neuromonitoring (IONM) is routinely used to monitor cranial nerve function during resection of vestibular schwannomas. Sudden movements in the surgical field can be a disturbing factor for the surgeon. IONM can help determine the cause of unexpected patient movements. CLINICAL PRESENTATION: We report the case of a 54-year-old patient who underwent retromastoid craniotomy and resection of a vestibular schwannoma. Toward the end of dissection of the tumor from the lower cranial nerves and brainstem, the patient showed repetitive shoulder elevation. Electroencephalography showed burst suppression, confirming deep sedation and excluding voluntary movements. Free-running electromyography recorded spontaneous, simultaneous, bilateral vocal cord activity that was synchronous with upper body movement. There was simultaneous but smaller activity in the right genioglossus muscle and levator veli palatini, indicative for far-field activity. These IONM findings allowed us to classify the clinical observations as intraoperative hiccups. CONCLUSION: Hiccups during general anesthesia are rare but should be considered as a differential diagnosis of sudden upper body movement. To the best of our knowledge, this is the first reported case of acute hiccups during resection of a vestibular schwannoma. IONM reliably distinguished it from an increase in intraoperative consciousness or accessory nerve activation resulting in shoulder movements.
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Soluço , Neuroma Acústico , Nervos Cranianos , Eletromiografia , Humanos , Pessoa de Meia-Idade , Neuroma Acústico/complicações , Neuroma Acústico/cirurgia , Procedimentos NeurocirúrgicosRESUMO
Chemical shift encoding-based water−fat MRI (CSE-MRI)-derived proton density fat fraction (PDFF) has been used for non-invasive assessment of regional body fat distributions. More recently, texture analysis (TA) has been proposed to reveal even more detailed information about the vertebral or muscular composition beyond PDFF. The aim of this study was to investigate associations between vertebral bone marrow and paraspinal muscle texture features derived from CSE-MRI-based PDFF maps in a cohort of healthy subjects. In this study, 44 healthy subjects (13 males, 55 ± 30 years; 31 females, 39 ± 17 years) underwent 3T MRI including a six-echo three-dimensional (3D) spoiled gradient echo sequence used for CSE-MRI at the lumbar spine and the paraspinal musculature. The erector spinae muscles (ES), the psoas muscles (PS), and the vertebral bodies L1-4 (LS) were manually segmented. Mean PDFF values and texture features were extracted for each compartment. Features were compared between males and females using logistic regression analysis adjusted for age and body mass index (BMI). All texture features of ES except for Sum Average were significantly (p < 0.05) different between men and women. The three global texture features (Variance, Skewness, Kurtosis) for PS as well as LS showed a significant difference between male and female subjects (p < 0.05). Mean PDFF measured in PS and ES was significantly higher in females, but no difference was found for the vertebral bone marrow's PDFF. Partial correlation analysis between the texture features of the spine and the paraspinal muscles revealed a highly significant correlation for Variance(global) (r = 0.61 for ES, r = 0.62 for PS; p < 0.001 respectively). Texture analysis using PDFF maps based on CSE-MRI revealed differences between healthy male and female subjects. Global texture features in the lumbar vertebral bone marrow allowed for differentiation between men and women, when the overall PDFF was not significantly different, indicating that PDFF maps may contain detailed and subtle textural information beyond fat fraction. The observed significant correlation of Variance(global) suggests a metabolic interrelationship between vertebral bone marrow and the paraspinal muscles.
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Purpose: Osteoporosis is prevalent and entails alterations of vertebral bone and marrow. Yet, the spine is also a common site of metastatic spread. Parameters that can be non-invasively measured and could capture these alterations are the volumetric bone mineral density (vBMD), proton density fat fraction (PDFF) as an estimate of relative fat content, and failure displacement and load from finite element analysis (FEA) for assessment of bone strength. This study's purpose was to investigate if osteoporotic and osteoblastic metastatic changes in lumbar vertebrae can be differentiated based on the abovementioned parameters (vBMD, PDFF, and measures from FEA), and how these parameters correlate with each other. Materials and Methods: Seven patients (3 females, median age: 77.5 years) who received 3-Tesla magnetic resonance imaging (MRI) and multi-detector computed tomography (CT) of the lumbar spine and were diagnosed with either osteoporosis (4 patients) or diffuse osteoblastic metastases (3 patients) were included. Chemical shift encoding-based water-fat MRI (CSE-MRI) was used to extract the PDFF, while vBMD was extracted after automated vertebral body segmentation using CT. Segmentation masks were used for FEA-based failure displacement and failure load calculations. Failure displacement, failure load, and PDFF were compared between patients with osteoporotic vertebrae versus patients with osteoblastic metastases, considering non-fractured vertebrae (L1-L4). Associations between those parameters were assessed using Spearman correlation. Results: Median vBMD was 59.3 mg/cm3 in osteoporotic patients. Median PDFF was lower in the metastatic compared to the osteoporotic patients (11.9% vs. 43.8%, p=0.032). Median failure displacement and failure load were significantly higher in metastatic compared to osteoporotic patients (0.874 mm vs. 0.348 mm, 29,589 N vs. 3,095 N, p=0.034 each). A strong correlation was noted between PDFF and failure displacement (rho -0.679, p=0.094). A very strong correlation was noted between PDFF and failure load (rho -0.893, p=0.007). Conclusion: PDFF as well as failure displacement and load allowed to distinguish osteoporotic from diffuse osteoblastic vertebrae. Our findings further show strong associations between PDFF and failure displacement and load, thus may indicate complimentary pathophysiological associations derived from two non-invasive techniques (CSE-MRI and CT) that inherently measure different properties of vertebral bone and marrow.
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Osteoporose , Prótons , Idoso , Feminino , Análise de Elementos Finitos , Humanos , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Osteoporose/diagnóstico por imagem , ÁguaRESUMO
OBJECTIVE: The safety and efficacy of surgical microvascular decompression (MVD) in elderly patients with trigeminal neuralgia (TN) is controversially discussed in the literature. A widespread reluctance to expose this cohort to major intracranial surgery persists. Our aim was to compare the efficacy and safety between older and younger patients with TN. METHODS: In this cross-sectional study, 139 MVD procedures (103 patients < 70 and 36 patients ≥ 70) were included. Surgical fitness was assessed by the American Society of Anesthesiology (ASA) grade. The pain-free interval was evaluated using Kaplan-Meier analysis only in patients with a recent follow-up visit. Independent risk factors for recurrence in patients with a minimum 12-month follow-up were determined. RESULTS: Patients ≥ 70 showed a significantly higher number of comorbidities. Pain intensity, affection of trigeminal branches and symptom duration was similar between groups. No significant difference in treatment associated complications and permanent neurological deficits was shown. There was no treatment-related mortality. A tendency towards a lower recurrence rate in patients < 70 did not reach statistical significance (17.6% vs. 28.6%, P = 0.274). Pain-free interval was not different between both cohorts (78.7 vs. 73.5 months, P = 0.391). CONCLUSION: Despite a higher prevalence of comorbidities in elderly patients, complication rates and neurological deficits after MVD were comparable to younger patients. Rates of immediate and long-term pain relief compared favorably to previous studies and were similar between elderly and younger patients. These data endorse MVD as a safe and effective first-line surgical procedure for elderly patients with TN and neurovascular conflict on MRI.
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Cirurgia de Descompressão Microvascular , Neuralgia do Trigêmeo , Idoso , Estudos Transversais , Humanos , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento , Neuralgia do Trigêmeo/cirurgiaRESUMO
BACKGROUND AND PURPOSE: Intracranial vessel imaging by time-of-flight MR angiography (TOF-MRA) is one of the most frequently performed investigations in clinical neuroradiology. Particularly in the acute setting, fast imaging is needed for diagnostics, with a sequence ideally depicting even small vessels. The purpose of this study was to compare image and diagnostic quality of a novel ultrashort TOF-MRA sequence accelerated by spiral imaging (TOF-Spiral-short) to a standard TOF-MRA sequence accelerated by compressed sensing (TOF-CS) and to CT angiography (CTA). METHODS: Forty-one patients (36.6% showing vessel pathologies) who had undergone TOF-CS (acquisition duration: 4 minutes 8 seconds), TOF-Spiral-short (acquisition duration: 51 seconds; spiral imaging [accelerating factor 1.3], decreased field of view [accelerating factor 1.2], and increased voxel size [accelerating factor 3.3]), and CTA were retrospectively evaluated. Assessment of image quality, diagnostic confidence, and quantification of stenosis or aneurysm diameter were performed by two readers. RESULTS: Image quality at the skull base was slightly reduced with TOF-Spiral-short compared to CTA and TOF-CS (P < .05). Delineation of small intracranial vessels was improved by TOF-Spiral-short compared to CTA (P < .0001). In TOF-Spiral-short, diagnostic confidence was not reduced compared to TOF-CS in patients with vessel pathologies. We observed no significant difference in quantitative pathology assessment between TOF-Spiral-short and the other two modalities. TOF-Spiral-short enabled the correct identification of all vessel pathologies. CONCLUSIONS: Accelerating TOF-MRA of brain-feeding arteries by a novel ultrashort spiral imaging sequence shows adequate image quality and sufficient diagnostic performance. Thus, TOF-Spiral-short holds potential for fast and reliable diagnostics of vessel pathologies, particularly in the acute setting.
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Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Angiografia por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
PURPOSE: After coil embolization of intracranial aneurysms, it is currently not well understood whether the initial coil packing density or the type of aneurysm residual perfusion, depicted by the modified Raymond-Roy occlusion classification, primarily effects the rate of aneurysm recurrence. We hypothesized that these factors interact and only one remains an independent risk factor. METHODS: In this single center retrospective study, 440 patients with intracranial ruptured and unruptured aneurysms between 2010 and 2017 were screened. A total of 267 patients treated with stand-alone coiling, with or without stent or balloon assistance were included (age 54.1⯱ 12.2 years, sex 70.4% female). Flow diverter or Woven EndoBridge (WEB) device implantation were exclusion criteria. RESULTS: Using a binary logistic regression model, independent risk factors for aneurysm recurrence were postinterventional modified Raymond-Roy occlusion classification class (Odds ratio [OR] 1.747, 95% confidence interval [CI] 1.231-2.480) and aneurysm diameter (OR 1.145, CI 1.032-1.271). A trend towards a higher recurrence in ruptured aneurysms did not reach significance (OR 1.656, CI 0.863-3.179). Aneurysm localization, packing density, and neck width were not independently associated with aneurysm recurrence. CONCLUSION: Independent risk factors for aneurysm recurrence after coil embolization with and without stent or balloon assistance were aneurysm diameter and postinterventional grading within the modified Raymond-Roy occlusion classification. Packing density interacted with the latter and was not independently associated to recurrence.
Assuntos
Aneurisma Intracraniano , Adulto , Idoso , Aneurisma Roto/diagnóstico por imagem , Aneurisma Roto/terapia , Embolização Terapêutica , Procedimentos Endovasculares , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Stents , Resultado do TratamentoRESUMO
Facial muscle corticobulbar motor evoked potentials (FMcoMEPs) are used to monitor facial nerve integrity during vestibular schwannoma resections to increase maximal safe tumor resection. Established warning criteria, based on ipsilateral amplitude reduction, have the limitation that the rate of false positive alarms is high, in part because FMcoMEP changes occur on both sides, e.g., due to brain shift or pneumocephalus. We retrospectively compared the predictive value of ipsilateral-only warning criteria and actual intraoperative warnings with a novel candidate warning criterion, based on "ipsilateral versus contralateral difference in relative stimulation threshold increase, from baseline to end of resection" (BilatMT ≥ 20%), combined with an optimistic approach in which a warning would be triggered only if all facial muscles on the affected side deteriorated. We included 60 patients who underwent resection of vestibular schwannoma. The outcome variable was postoperative facial muscle function. Retrospectively applying BilatMT, with the optimistic approach, was found to have a significantly better false positive rate, which was much lower (9% at day 90) than the traditionally used ipsilateral warning criteria (>20%) and was also lower than actual intraoperative warnings. This is the first report combining the threshold method with an optimistic approach in a bilateral multi-facial muscle setup. This method could substantially reduce the rate of false positive alarms in FMcoMEP monitoring.
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In this case-control study the value of bone mineral density (BMD) at different vertebral levels, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) to identify patients with incident osteoporotic vertebral fractures in routine multi-detector computed tomography (MDCT) exams was assessed. MATERIAL AND METHODS: Seventeen patients who underwent baseline and follow-up routine contrast-enhanced MDCT and had an incident osteoporotic vertebral fracture at follow-up were included. Seventeen age-, sex- and follow-up duration-matched controls were identified. Trabecular BMD (from Th5 to L5) as well as cross-sectional area of SAT and VAT were extracted. RESULTS: BMD performed best to differentiate patients with an incident fracture from controls at the levels of Th5 (area under the curve [AUC] = 0.781, p = 0.014), Th7 (AUC = 0.877, p = 0.001), and Th9 (AUC = 0.818, p = 0.005). Applying multivariate logistic regression BMD at Th7 level remained the only significant predictor of incident vertebral fractures (Th5-L5) with an odds ratio of 1.07 per BMD SD decrease. VAT and SAT did not show significant differences between the fracture and control group (p > 0.05). CONCLUSION: The local BMD measurement appears to be more suitable than standard mean BMD from L1-L3 for fracture risk assessment.
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BACKGROUND: Wasting disease entities like cachexia or sarcopenia are associated with a decreasing muscle mass and changing muscle composition. For valid and reliable disease detection and monitoring diagnostic techniques offering quantitative musculature assessment are needed. Multi-detector computed tomography (MDCT) is a broadly available imaging modality allowing for muscle composition analysis. A major disadvantage of using MDCT for muscle composition assessment is the radiation exposure. In this study we evaluated the performance of different methods of radiation dose reduction for paravertebral muscle composition assessment. METHODS: MDCT scans of eighteen subjects (6 males, age: 71.5±15.9 years, and 12 females, age: 71.0±8.9 years) were retrospectively simulated as if they were acquired at 50%, 10%, 5%, and 3% of the original X-ray tube current or number of projections (i.e., sparse sampling). Images were reconstructed with a statistical iterative reconstruction (SIR) algorithm. Paraspinal muscles (psoas and erector spinae muscles) at the level of L4 were segmented in the original-dose images. Segmentations were superimposed on all low-dose scans and muscle density (MD) extracted. RESULTS: Sparse sampling derived mean MD showed no significant changes (P=0.57 and P=0.22) down to 5% of the original projections in the erector spinae and psoas muscles, respectively. All virtually reduced tube current series showed significantly different (P>0.05) mean MD in the psoas and erector spinae muscles as compared to the original dose except for the images of 5% of the original tube current in the erector spinae muscle. CONCLUSIONS: Our findings demonstrated the possibility of considerable radiation dose reduction using MDCT scans for assessing the composition of the paravertebral musculature. The sparse sampling approach seems to be promising and a potentially superior technique for dose reduction as compared to tube current reduction.
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(1) Background and Purpose: The skeletal muscles of patients suffering from neuromuscular diseases (NMD) are affected by atrophy, hypertrophy, fatty infiltration, and edematous changes. Magnetic resonance imaging (MRI) is an important tool for diagnosis and monitoring. Concerning fatty infiltration, T1-weighted or T2-weighted DIXON turbo spin echo (TSE) sequences enable a qualitative assessment of muscle involvement. To achieve higher comparability, semi-quantitative grading scales, such as the four-point Mercuri scale, are commonly applied. However, the evaluation remains investigator-dependent. Therefore, effort is being invested to develop quantitative MRI techniques for determination of imaging markers such as the proton density fat fraction (PDFF). The present work aims to assess the diagnostic value of PDFF in correlation to Mercuri grading and clinically determined muscle strength in patients with myotonic dystrophy type 2 (DM2), limb girdle muscular dystrophy type 2A (LGMD2A), and adult Pompe disease. (2) Methods: T2-weighted two-dimensional (2D) DIXON TSE and chemical shift encoding-based water-fat MRI were acquired in 13 patients (DM2: n = 5; LGMD2A: n = 5; Pompe disease: n = 3). Nine different thigh muscles were rated in all patients according to the Mercuri grading and segmented to extract PDFF values. Muscle strength was assessed according to the British Medical Research Council (BMRC) scale. For correlation analyses between Mercuri grading, muscle strength, and PDFF, the Spearman correlation coefficient (rs) was computed. (3) Results: Mean PDFF values ranged from 7% to 37% in adults with Pompe disease and DM2 and up to 79% in LGMD2A patients. In all three groups, a strong correlation of the Mercuri grading and PDFF values was observed for almost all muscles (rs > 0.70, p < 0.05). PDFF values correlated significantly to muscle strength for muscle groups responsible for knee flexion (rs = -0.80, p < 0.01). (4) Conclusion: In the small, investigated patient cohort, PDFF offers similar diagnostic precision as the clinically established Mercuri grading. Based on these preliminary data, PDFF could be further considered as an MRI-based biomarker in the assessment of fatty infiltration of muscle tissue in NMD. Further studies with larger patient cohorts are needed to advance PDFF as an MRI-based biomarker in NMD, with advantages such as its greater dynamic range, enabling the assessment of subtler changes, the amplified objectivity, and the potential of direct correlation to muscle function for selected muscles.