290 research outputs found

    Fijación activa y perforación ventricular: ¿una nueva entidad?

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    First, a new active fixation lead was implanted in the interventricular septum; the old lead was then extracted with a Cook stylet. The patient’s clinical course was satisfactory and there were no procedure-related complications. In conclusion, within the battery of diagnostic tests available to investigate suspected cardiac perforation, computed angiotomography of the chest is a highly useful complementary technique for the management of this complication

    Development of a Sentinel-2 burned area algorithm: Generation of a small fire database for sub-Saharan Africa

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    A locally-adapted multitemporal two-phase burned area (BA) algorithm has been developed using as inputs Sentinel-2 MSI reflectance measurements in the short and near infrared wavebands plus the active fires detected by Terra and Aqua MODIS sensors. An initial burned area map is created in the first step, from which tile dependent statistics are extracted for the second step. The whole Sub-Saharan Africa (around 25 M km(2)) was processed with this algorithm at a spatial resolution of 20 m, from January to December 2016. This period covers two half fire seasons on the Northern Hemisphere and an entire fire season in the South. The area was selected as existing BA products account it to include around 70% of global BA. Validation of this product was based on a two-stage stratified random sampling of Landsat multitemporal images. Higher accuracy values than existing global BA products were observed, with Dice coefficient of 77% and omission and commission errors of 26.5% and 19.3% respectively. The standard NASA BA product (MCD64A1 c6) showed a similar commission error (20.4%), but much higher omission errors (59.6%), with a lower Dice coefficient (53.6%). The BA algorithm was processed over > 11,000 Sentinel-2 images to create a database that would also include small fires (< 100 ha). This is the first time a continental BA product is generated from medium resolution sensors (spatial resolution = 20 m), showing their operational potential for improving our current understanding of global fire impacts. Total BA estimated from our product was 4.9 M km(2), around 80% larger area than what the NASA BA product (MCD64A1 c6) detected in the same period (2.7 M km(2)). The main differences between the two products were found in regions where small fires (< 100 ha) account for a significant proportion of total BA, as global products based on coarse pixel sizes (500 m for MCD64A1) unlikely detect them. On the negative side, Sentinel-2 based products have lower temporal resolution and consequently are more affected by cloud/cloud shadows and have less temporal reporting accuracy than global BA products. The product derived from S2 imagery would greatly contribute to better understanding the impacts of small fires in global fire regimes, particularly in tropical regions, where such fires are frequent. This product is named FireCCISFD11 and it is publicly available at: https://www.esa-fire-cci.org/node/262, last accessed on November 2018.This research was carried out within the Fire_cci project (https://www.esa-fire-cci.org/, last accessed on November 2018), contract no. 4000115006/15/I-NB, which has been funded by the European Space Agency (ESA) under the Climate Change Initiative Programme. The FireCCISFD11 product can be downloaded at https://www.esa-fire-cci.org/node/262 (last accessed on November 2018)

    Migrating azygos vein and vanishing azygos lobe: MDCT findings

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    OBJECTIVE: The purpose of this study was to describe six cases of migrating azygos vein and to explain the etiologic factors that contribute to the migration. Six patients with migrating azygos vein were studied by MDCT before and after migration. Five patients had right pneumothorax. All patients had repeated episodes of cough, vomiting, and a short mesoazygos. CONCLUSION: Pneumothorax, increased intrathoracic pressure, and a short mesoazygos, in combination or alone, are the main factors in azygos vein migration

    Valoración global del corazón en el paciente con transplante cardiaco mediante tomografía computarizada de doble fuente

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    In routine clinical practice surveillance of heart transplant recipients is usually performed using echocardiography and conventional coronary angiography. The latter permits diagnosis and follow-up of coronary allograft vasculopathy. However, this procedure is invasive and is not free of complications. Conventional multislice computed tomography (MSCT) has been shown to be a useful non-invasive tool for ruling out coronary artery disease and evaluating cardiac function. However, due to its limited temporal resolution betablocker administration is required, and its usefulness in certain patient populations with restricted response to this medication, such as heart transplant recipients, may therefore be limited. Dual-source CT (DSCT) allows evaluation of the coronary arteries in all individuals independent of their heart rate. In the case presented here, we demonstrate that DSCT may be useful for evaluating cardiac function and ruling out coronary allograft vasculopathy in heart transplant recipients

    Coronariografía por tomografía computarizada de doble fuente

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    La tomografía computarizada multicorte (TCMC) permite estudiar las arterias coronarias de forma no invasiva. A pesar de la elevada resolución espacial y temporal de los equipos de sesenta y cuatro cortes (TCMC- 64) esta técnica no se encuentra exenta de limitaciones. La tomografía computarizada de doble fuente (TCDF) permite estudiar las arterias coronarias con gran calidad diagnóstica en todos los sujetos independien- temente de su frecuencia cardiaca sin necesidad, por tanto, de emplear betabloqueantes. En este trabajo se describen los estudios por TCDF de tres pacientes con elevada frecuencia cardiaca y gran variabilidad del ritmo. Se demuestra la utilidad de esta técnica para obtener estudios de excelente calidad diagnóstica en casos en que la coronariografía por TCMC-64 convencional presenta limitaciones. INGLÉS: Multidetector computed tomography (MDCT) has been demonstrated to be a very useful technique to non-invasively study coronary arteries. Despite the high spatial and temporal resolution of 64-slice MDCT scanners, this technique has several limitations. Dual-source computed tomography (DSCT) allows to study coronary arteries with excellent diagnostic quality in all subjects independent of the heart rate, thus avoiding the use of beta-blockers. In this article DSCT studies from three subjects with elevated heart rate and irregular heart rhythm are described. Usefulness of this technique to obtain studies of excellent quality in cases in which conventional 64-row-MDCT might present limitations is emphasized

    Dual-source CT for visualization of the coronary arteries in heart transplant patients with high heart rates

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    OBJECTIVE. The purpose of this study was to evaluate the quality of dual-source CT images of the coronary arteries in heart transplant recipients with high heart rates. SUBJECTS AND METHODS. Contrast-enhanced dual-source CT coronary angiography was performed on 23 heart transplant recipients (20 men, three women; mean age, 61.1 ± 12.8 years). Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent readers using a 5-point scale (0, not evaluative; 4, excellent quality) assessed the quality of images of coronary segments. RESULTS. The mean heart rate during scanning was 89.2 ± 10.4 beats/min. Interobserver agreement on the quality of images of the whole coronary tree was a kappa value of 0.78 and for selection of the optimal reconstruction interval was a kappa value of 0.82. The optimal reconstruction interval was systole in 17 (74%) of the 23 of heart transplant recipients. At the best reconstruction interval, diagnostic image quality (score ≥ 2) was obtained in 92.1% (303 of 329) of the coronary artery segments. The mean image quality score for the whole coronary tree was 3.1 ± 1.01. No significant correlation between mean heart rate (ρ = 0.31) or heart rate variability (ρ = 0.23) and overall image quality score was observed (p = not significant). CONCLUSION. Dual-source CT acquisition yields coronary angiograms of diagnostic quality in heart transplant recipients. Mean heart rate and heart rate variability during scanning do not have a negative effect on the overall quality of images of the coronary arteries

    Filariasis of the Axilla in a Patient Returning from Travel Abroad: A Case Report

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    Background: The term filariasis comprises a group of parasitic infections caused by helminths belonging to different genera in the superfamily Filaroidea. The human parasites occur mainly in tropical and subtropical regions, but filariae are also found in temperate climates, where they can infect wild and domestic animals. Humans are rarely infected by these zoonotic parasites. Patients and Methods: A 55-year-old patient presented with a new-onset, subcutaneous, non-tender palpable mass in the right axilla. Ultrasonography showed a 1.3-cm, solid, singular encapsulated node. Sonography of the breast on both sides, axilla and lymphatic drainage on the left side, lymphatic drainage on the right side, and mammography on both sides were without pathological findings. The node was excised under local anesthesia as the patient refused minimal invasive biopsy. Results: On histopathological examination, the tail of a parasite of the group of filariae was found. The patient revealed that she had stayed in Africa and Malaysia for professional reasons. 6 months before the time of diagnosis, she had also suffered from a fever and poor general condition after a trip abroad. The patient was referred for further treatment to the Institute for Tropical Medicine at the University of Dusseldorf, where a treatment with ivermectin was conducted on the basis of positive staining with antibodies against filariae. Conclusion: Our case demonstrates the importance of interdisciplinary collaboration between breast center, pathology, and other specialties such as microbiology and tropical medicine

    Safety, feasibility, and hemodynamic response of regadenoson for stress perfusion CMR

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    Owing to its pharmacodynamics and posology, the use of regadenoson for stress cardiac magnetic resonance (CMR) has potential advantages over other vasodilators. We sought to evaluate the safety, hemodynamic response and diagnostic performance of regadenoson stress-CMR in routine clinical practice. All regadenoson stress-CMR examinations performed between May 2017 and July 2020 at our institution were retrospectively reviewed. A total of 698 studies were included for the final analysis. A conventional stress/rest protocol was performed using a 1.5T MRI scanner (Magnetom Aera, Siemens Healthineers, Erlangen, Germany). Adverse events, clinical symptoms, and hemodynamic response were assessed. Diagnostic accuracy of the test was evaluated in patients who underwent invasive coronary angiography. Nearly half of patients (48.5%) remained asymptomatic. Most common clinical symptoms included dyspnea (137, 19.6%), chest pain (116, 16.6%) and flushing (44, 6.3%). Two patients (0.28%) could not complete the examination due to severe hypotension or unbearable chest pain. Overall, an increase in heart rate (HR) response (36.2% [IQR: 22.5–50.9]) and a decrease in systolic and diastolic blood pressure (BP) (median systolic BP response of -5% [IQR: -11.5-0.6]; median diastolic BP response of -6.3 mmHg [IQR: -13.4-0]) was observed. Patients with symptoms induced by regadenoson showed higher HR response (40.3%, IQR: 26.4–56.1 vs. 32.4%, IQR: 19-45.6, p<0.001), whereas a blunted HR response was observed in diabetic (29.6%, IQR: 18.4–42 p<0.001), obese (31.7%, IQR: 20.7–46.2 p=0.005) and patients aged 70 years or older (32.9%, IQR: 22.6–43.1 p<0.001). Overall, regadenoson stress-CMR showed 95.65% (IQ 91.49–99.81) sensitivity, 54.84% (IQ 35.71–73.97) specificity, 86.99% (IQ 82.74–94.68) positive predictive value, and 77.27% (IQ 57.49–97.06) negative predictive value for detecting significant coronary stenosis as compared with invasive coronary angiography. Regadenoson is a well-tolerated vasodilator that can be safely employed for stress perfusion CMR, with high diagnostic performanc

    Diagnostic yield of electromagnetic navigation bronchoscopy is highly dependent on the presence of a Bronchus sign on CT imaging: results from a prospective study

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    Electromagnetic navigation bronchoscopy (ENB) has been developed as a novel ancillary tool for the bronchoscopic diagnosis of pulmonary nodules. Despite successful navigation in 90% of patients, ENB diagnostic yield does not generally exceed 70%. We sought to determine whether the presence of a bronchus sign on CT imaging conditions diagnostic yield of ENB and might account for the discrepancy between successful navigation and diagnostic yield. METHODS: We conducted a prospective, single-center study of ENB in 51 consecutive patients with pulmonary nodules. ENB was chosen as the least invasive diagnostic technique in patients with a high surgical risk, suspected metastatic disease, or advanced-stage disease, or in those who demanded a preoperative diagnosis prior to undergoing curative resection. We studied patient and technical variables that might condition diagnostic yield, including size, cause, location, distance to the pleural surface, and fluorodeoxyglucose uptake of a given nodule; the presence of a bronchus sign on CT imaging; registration point divergence; and the minimum distance from the tip of the locatable guide to the nodule measured during the procedure. RESULTS: The diagnostic yield of ENB was 67% (34/51). The sensitivity and specificity of ENB for malignancy in this study were 71% and 100%, respectively. ENB was diagnostic in 79% (30/38) patients with a bronchus sign on CT imaging but only in 4/13 (31%) with no discernible bronchus sign. Univariate analysis identified the bronchus sign (P = .005) and nodule size (P = .04) as statistically significant variables conditioning yield, but on multivariate analysis, only the bronchus sign remained significant (OR, 7.6; 95% CI, 1.8-31.7). No procedure-related complications were observed. CONCLUSIONS: ENB diagnostic yield is highly dependent on the presence of a bronchus sign on CT imaging

    Reduction of motion effects in myocardial arterial spin labeling

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    Purpose To evaluate the accuracy and reproducibility of myocardial blood flow measurements obtained under different breathing strategies and motion correction techniques with arterial spin labeling. Methods A prospective cardiac arterial spin labeling study was performed in 12 volunteers at 3 Tesla. Perfusion images were acquired twice under breath-hold, synchronized-breathing, and free-breathing. Motion detection based on the temporal intensity variation of a myocardial voxel, as well as image registration based on pairwise and groupwise approaches, were applied and evaluated in synthetic and in vivo data. A region of interest was drawn over the mean perfusion-weighted image for quantification. Original breath-hold datasets, analyzed with individual regions of interest for each perfusion-weighted image, were considered as reference values. Results Perfusion measurements in the reference breath-hold datasets were in line with those reported in literature. In original datasets, prior to motion correction, myocardial blood flow quantification was significantly overestimated due to contamination of the myocardial perfusion with the high intensity signal of blood pool. These effects were minimized with motion detection or registration. Synthetic data showed that accuracy of the perfusion measurements was higher with the use of registration, in particular after the pairwise approach, which probed to be more robust to motion. Conclusion Satisfactory results were obtained for the free-breathing strategy after pairwise registration, with higher accuracy and robustness (in synthetic datasets) and higher intrasession reproducibility together with lower myocardial blood flow variability across subjects (in in vivo datasets). Breath-hold and synchronized-breathing after motion correction provided similar results, but these breathing strategies can be difficult to perform by patients
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