400 research outputs found

    Use of 3-D navigation to target the site of autologous blood installation for lung volume reduction in bullous emphysema

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    Bronchoscopic lung volume reduction (BLVR) using intrabullous autologous blood instillation has been reported in single cases where other techniques are not possible. We present the use of three-dimensional navigation to instill autologous blood into emphysematous bullae for BLVR. A 62-year-old man presented with increasing dyspnea, due to emphysema with a conglomerate of giant bullae with two particularly large bullae. Surgical treatment was refused, so bronchoscopic autologous blood instillation into the bronchial segment leading to the large bullae was attempted, but was unsuccessful; blood failed to penetrate into the bullous cavity. Dyspnea worsened over the following year. We therefore performed another bronchoscopy and punctured a large bulla with a needle and created a tunnel from the central airways. Puncture position and direction were determined using a prototype of an electromagnetic navigation system. Under fluoroscopic guidance, a catheter was placed via the tunnel into the bulla and blood was instilled. This resulted in an almost complete shrinkage of the bullae, reduction of residual volume, and marked improvement in dyspnea within 4 months. To our knowledge, this is the first reported case of successful BLVR by navigated bronchoscopy with transbronchial puncture, dilatation, and autologous blood instillation into a giant bulla

    A New Functional Method to Choose the Target Lobe for Lung Volume Reduction in Emphysema - Comparison with the Conventional Densitometric Method

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    Lung volume reduction (LVR) improves breathing mechanics by reducing hyperinflation. Lobar selection usually focuses on choosing the most destroyed emphysematous lobes as seen on an inspiratory CT scan. However, it has never been shown to what extent these densitometric CT parameters predict the least deflation of an individual lobe during expiration. The addition of expiratory CT analysis allows measurement of the extent of lobar air trapping and could therefore provide additional functional information for choice of potential treatment targets.To determine lobar vital capacity/lobar total capacity (LVC/LTC) as a functional parameter for lobar air trapping using on an inspiratory and expiratory CT scan. To compare lobar selection by LVC/LTC with the established morphological CT density parameters.36 patients referred for endoscopic LVR were studied. LVC/LTC, defined as delta volume over maximum volume of a lobe, was calculated using inspiratory and expiratory CT scans. The CT morphological parameters of mean lung density (MLD), low attenuation volume (LAV), and 15th percentile of Hounsfield units (15%P) were determined on an inspiratory CT scan for each lobe. We compared and correlated LVC/LTC with MLD, LAV, and 15%P.There was a weak correlation between the functional parameter LVC/LTC and all inspiratory densitometric parameters. Target lobe selection using lowest lobar deflation (lowest LVC/LTC) correlated with target lobe selection based on lowest MLD in 18 patients (50.0%), with the highest LAV in 13 patients (36.1%), and with the lowest 15%P in 12 patients (33.3%).CT-based measurement of deflation (LVC/LTC) as a functional parameter correlates weakly with all densitometric CT parameters on a lobar level. Therefore, morphological criteria based on inspiratory CT densitometry partially reflect the deflation of particular lung lobes, and may be of limited value as a sole predictor for target lobe selection in LVR

    Cryobiopsy increases the EGFR detection rate in non-small cell lung cancer

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    Objectives: Detection of activating epidermal growth factor receptor (EGFR) mutation is crucial for individualized treatment of advanced non-small-cell lung cancer (NSCLC). However little is known about how biopsy technique affects the detection rate of EGFR mutations. This retrospective, single center study evaluated the detection rate of EGFR mutations in tissue obtained by bronchoscopic cryobiopsy and compared this to other standard tissue sampling techniques. Materials and methods: We retrospectively analyzed 414 patients with histologically confirmed NSCLC and known EGFR mutation status between 3/2008-7/2014. Tumor specimens obtained by tissue preserving bronchoscopic cryobiopsy were compared to those obtained by other techniques. Results and conclusion: Analysis of bronchoscopic cryobiopsy tissue detected 29 activating EGFR mutations in 27 (21.6 ) out of 125 patients, while analysis of tissue obtained by non-cryobiopsy techniques (bronchoscopic forceps biopsies, fine needle aspiration, imaging guided transthoracical and surgical procedures) detected 42 EGFR mutations in 40 (13.8 ) out of 298 patients (p < 0.05). Cryobiopsy increased detection rate of EGFR mutations in central tumors compared with forceps biopsy (19.6 versus 6.5 , p < 0.05), while an insignificant trend was detected also for peripheral tumors (33.3 versus 26.9 ). Bronchosopic cryobiopsy increases the detection rate of activating EGFR mutations in NSCLC in comparison to other tissue sampling techniques. This will help to optimize individualized treatment of patients with advanced tumors. Because of the retrospective nature of this analysis, a prospective trial is mandatory for final assessment. © 2020 The Author(s

    Reduced basis isogeometric mortar approximations for eigenvalue problems in vibroacoustics

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    We simulate the vibration of a violin bridge in a multi-query context using reduced basis techniques. The mathematical model is based on an eigenvalue problem for the orthotropic linear elasticity equation. In addition to the nine material parameters, a geometrical thickness parameter is considered. This parameter enters as a 10th material parameter into the system by a mapping onto a parameter independent reference domain. The detailed simulation is carried out by isogeometric mortar methods. Weakly coupled patch-wise tensorial structured isogeometric elements are of special interest for complex geometries with piecewise smooth but curvilinear boundaries. To obtain locality in the detailed system, we use the saddle point approach and do not apply static condensation techniques. However within the reduced basis context, it is natural to eliminate the Lagrange multiplier and formulate a reduced eigenvalue problem for a symmetric positive definite matrix. The selection of the snapshots is controlled by a multi-query greedy strategy taking into account an error indicator allowing for multiple eigenvalues

    NUT Carcinoma—An Underdiagnosed Malignancy

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    NUT carcinoma (NC) is a rare and highly aggressive malignancy with a dismal prognosis and a median survival of 6–9 months only. Although very few cases of NC are reported each year, the true prevalence is estimated to be much higher, with NC potentially widely underdiagnosed due to the lack of awareness. NC primarily occurs in midline structures including thorax, head, and neck; however, other sites such as pancreas and kidney are also affected, albeit at lower frequencies. NC is characterized by a single translocation involving the NUTM1 (NUT midline carcinoma family member 1) gene and different partner genes. The resulting fusion proteins initiate tumorigenesis through a mechanism involving BET (bromo-domain and extra-terminal motif) proteins such as Bromodomain-containing protein 4 (BRD4) and inordinate acetylation of chromatin, leading to the dysregulation of growth and differentiation genes. While no clinical characteristics are specific for NC, some histologic features can be indicative; therefore, patients with these tumor characteristics should be routinely tested for NUTM1. The diagnosis of NC using immunohistochemistry with a highly specific antibody is straightforward. There are currently no standard-of-care treatment options for patients with NC. However, novel therapies specifically addressing the unique tumorigenic mechanism are under investigation, including BET inhibitors. This review aims to raise awareness of this underdiagnosed cancer entity and provide all patients the opportunity to be properly diagnosed and referred to a clinical study

    Scintigraphic assessment of bone status at one year following hip resurfacing : comparison of two surgical approaches using SPECT-CT scan

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    Objectives: To study the vascularity and bone metabolism of the femoral head/neck following hip resurfacing arthroplasty, and to use these results to compare the posterior and the trochanteric-flip approaches. Methods: In our previous work, we reported changes to intra-operative blood flow during hip resurfacing arthroplasty comparing two surgical approaches. In this study, we report the vascularity and the metabolic bone function in the proximal femur in these same patients at one year after the surgery. Vascularity and bone function was assessed using scintigraphic techniques. Of the 13 patients who agreed to take part, eight had their arthroplasty through a posterior approach and five through a trochanteric-flip approach. Results: One year after surgery, we found no difference in the vascularity (vascular phase) and metabolic bone function (delayed phase) at the junction of the femoral head/neck between the two groups of patients. Higher radiopharmaceutical uptake was found in the region of the greater trochanter in the trochanteric-flip group, related to the healing osteotomy. Conclusions: Our findings using scintigraphic techniques suggest that the greater intra-operative reduction in blood flow to the junction of the femoral head/neck, which is seen with the posterior approach compared with trochanteric flip, does not result in any difference in vascularity or metabolic bone function one year after surgery

    MRI in multiple myeloma : a pictorial review of diagnostic and post-treatment findings

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    Magnetic resonance imaging (MRI) is increasingly being used in the diagnostic work-up of patients with multiple myeloma. Since 2014, MRI findings are included in the new diagnostic criteria proposed by the International Myeloma Working Group. Patients with smouldering myeloma presenting with more than one unequivocal focal lesion in the bone marrow on MRI are considered having symptomatic myeloma requiring treatment, regardless of the presence of lytic bone lesions. However, bone marrow evaluation with MRI offers more than only morphological information regarding the detection of focal lesions in patients with MM. The overall performance of MRI is enhanced by applying dynamic contrast-enhanced MRI and diffusion weighted imaging sequences, providing additional functional information on bone marrow vascularization and cellularity. This pictorial review provides an overview of the most important imaging findings in patients with monoclonal gammopathy of undetermined significance, smouldering myeloma and multiple myeloma, by performing a 'total' MRI investigation with implications for the diagnosis, staging and response assessment. Main message aEuro cent Conventional MRI diagnoses multiple myeloma by assessing the infiltration pattern. aEuro cent Dynamic contrast-enhanced MRI diagnoses multiple myeloma by assessing vascularization and perfusion. aEuro cent Diffusion weighted imaging evaluates bone marrow composition and cellularity in multiple myeloma. aEuro cent Combined morphological and functional MRI provides optimal bone marrow assessment for staging. aEuro cent Combined morphological and functional MRI is of considerable value in treatment follow-up

    Early MRI response monitoring of patients with advanced hepatocellular carcinoma under treatment with the multikinase inhibitor sorafenib

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    <p>Abstract</p> <p>Background</p> <p>New therapeutic principles in clinical oncology require the adjustment of response criteria to govern therapy decisions. For advanced hepatocellular carcinoma (HCC) a new era has recently begun by the approval of the multikinase inhibitor sorafenib. As a unique feature, HCC usually develops in a diseased liver and current imaging technologies employing classical response criteria have not been prospectively evaluated for this new treatment.</p> <p>Methods</p> <p>MRI signal patterns were assessed in 21 advanced HCC patients receiving sorafenib. MRI was performed at baseline and in short-term intervals thereafter. Signal changes under therapy on T1WI, T2WI and post-gadolinium images including necrosis volume and its ratio to the entire tumor volume were compared to baseline imaging. To assess the association between the categorical variables, Fisher's exact tests were applied for a statistical analysis. Survey time ranged from 2–65 weeks, and a total of 39 target lesions were evaluated.</p> <p>Results</p> <p>Signal abnormalities during sorafenib therapy were disclosed by T1WI and T2WI in 15/21 patients. The predominant tumor signal change was hyperintensity on both T1WI and T2WI. Interestingly, most patients developed MRI signal changes within 4 weeks of therapy; in contrast, two non-responders did not show any signal alteration at follow-up. Under therapy, 16/21 patients presented with new or progressive necrosis, whereas 7 patients achieved temporarily >75% tumor necrosis under sorafenib. Significantly associated MRI variables were increase in T1WI signal and tumor necrosis (p = 0.017) as well as increase of tumor necrosis with an elevated ratio of necrotic to vital tumor areas (p = 0.002). Remarkably, some (3/13) of the patients developing necrotic tumor areas showed a relevant (>20%) increase in tumor volume, which should be considered in the assessment of imaging studies.</p> <p>Conclusion</p> <p>As sorafenib induces early intralesional necrosis with profound changes in T1WI/T2WI MRI signal intensities and measurable necrotic tumor areas in most HCC patients, early MRI-based evaluation could pave the way for its rationale and cost-effective application.</p
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