Search results for "COMPUTED TOMOGRAPHY"
showing 10 items of 713 documents
Analysis of discrete and continuous distributions of ventilatory time constants from dynamic computed tomography.
2005
In this study, an algorithm was developed to measure the distribution of pulmonary time constants (TCs) from dynamic computed tomography (CT) data sets during a sudden airway pressure step up. Simulations with synthetic data were performed to test the methodology as well as the influence of experimental noise. Furthermore the algorithm was applied to in vivo data. In five pigs sudden changes in airway pressure were imposed during dynamic CT acquisition in healthy lungs and in a saline lavage ARDS model. The fractional gas content in the imaged slice (FGC) was calculated by density measurements for each CT image. Temporal variations of the FGC were analysed assuming a model with a continuous…
Patient-Specific Analysis of Ascending Thoracic Aortic Aneurysm with the Living Heart Human Model
2021
In ascending thoracic aortic aneurysms (ATAAs), aneurysm kinematics are driven by ventricular traction occurring every heartbeat, increasing the stress level of dilated aortic wall. Aortic elongation due to heart motion and aortic length are emerging as potential indicators of adverse events in ATAAs
Interventistica eco-guidata per l’articolazione d’anca
2013
Lo scopo di questo lavoro è di rivedere le principali applicazioni della interventistica eco-guidata d’anca, descrivendone le indicazioni e la metodologia. L’ecografia è una metodica considerata sicura per i pazienti, in quanto non è stato dimostrato un possibile danno dovuto all’energia trasmessa dagli ultrasuoni ai tessuti del paziente, contrariamente alle metodiche che fanno uso di radiazioni ionizzanti, come la radiografia convenzionale e la tomografia computerizzata. Inoltre, l’ecografia risulta rapida ed efficace nel guidare l’ago verso la sede voluta evitando di intercettare strutture vascolari e/o nervose, consentendo quindi una maggiore sicurezza, rispetto alle tecniche interventis…
Therapy response evaluation of malignant lymphoma in a multicenter study: comparison of manual and semiautomatic measurements in CT.
2014
Purpose: Comparison of manual one-/bi-dimensional measurements versus semi-automatically derived one-/bi-dimensional and volumetric measurements for therapy response evaluation of malignant lymphoma during CT follow-up examinations in a multicenter setting. Materials and Methods: MSCT data sets of patients with malignant lymphoma were evaluated before (baseline) and after two cycles of chemotherapy (follow-up) at radiological centers of five university hospitals. The long axis diameter (LAD), the short axis diameter (SAD) and the bi-dimensional WHO of 307 target lymph nodes were measured manually and semi-automatically using dedicated software. Lymph node volumetry was performed semi-automa…
Findings and Utility of Chest Computed Tomography in Pediatric Tuberculosis
2017
AbstractThe objectives of this study are to describe the radiologic abnormalities detected on chest computed tomography (CT) of children suffering from tuberculosis and identify in which asymptomatic children, with positive tuberculin skin test and normal chest radiography, CT has the highest diagnostic yield using a low radiation dose protocol. The most common finding on CT in cases of tuberculosis is lymphadenopathy with necrotic appearance. In asymptomatic children with positive tuberculin skin test and normal chest radiography, CT had higher diagnostic yield in children younger than 5 years, modifying the therapeutic approach in a high percentage of cases. Reduction kilovoltage (kV) and…
Discovery and validation of small-molecule heat-shock protein 90 inhibitors through multimodality molecular imaging in living subjects.
2012
Up-regulation of the folding machinery of the heat-shock protein 90 (Hsp90) chaperone protein is crucial for cancer progression. The two Hsp90 isoforms (α and β) play different roles in response to chemotherapy. To identify isoform-selective inhibitors of Hsp90(α/β)/cochaperone p23 interactions, we developed a dual-luciferase (Renilla and Firefly) reporter system for high-throughput screening (HTS) and monitoring the efficacy of Hsp90 inhibitors in cell culture and live mice. HTS of a 30,176 small-molecule chemical library in cell culture identified a compound, N -(5-methylisoxazol-3-yl)-2-[4-(thiophen-2-yl)-6-(trifluoromethyl)pyrimidin-2-ylthio]acetamide (CP9), that binds to Hsp90(α/β) an…
Introduction to coronary imaging with 64-slice computed tomography
2005
The aim of this article is to illustrate the main technical improvements in the last generation of 64-row CT scanners and the possible applications in coronary angiography. In particular, we describe the new physical components (X-ray tube-detectors system) and the general scan and reconstruction parameters. We then define the scan protocols for coronary angiography with the new generation of 64-row CT scanners to enable radiologists to perform a CT study on the basis of the diagnostic possibilities.
Three-Dimensional Surface Display in Blood Pool Gated SPECT
1994
In 14 patients (4 in good health and 10 with coronary heart disease) a blood pool gated single photon emission computed tomography (SPECT) was executed. The transaxial slices of the cardiac blood pool were reconstructed. A three-dimensional surface display was employed for the analysis of the tomographic data. A fixed distance, a fixed threshold (50%), and some different planes of view were employed. The test permitted visualiza tion of the ventricular and the atrial movements in all patients. The right ventricle was clearly seen in the right anterior oblique plane of view. The aortic beating was seen. In normal patients the left ventricle, clearly seen in left anterior oblique plane, shra…
Quantitative structural analysis of trabecular alveolar bone in the mandible by multidetector computed tomography: Differences according to tooth pre…
2019
Background and objective: There is a lack of quantitative measures of the quality of alveolar trabecular bone, an important factor in implantology. This study aimed to develop a method of objectively assessing the quality of trabecular bone by means of image processing and structural analysis of multidetector computed tomography images and to establish differences between tooth types and tooth presence/absence. Materials and methods: We analyzed 20 patients who underwent multidetector computed tomography to evaluate mandibular bone and tooth positioning. Image analysis included automatic segmentation of the mandible, obtainment of sections perpendicular to the dental arch, and structural an…
Aortic valve and vascular calcium score in pre-TAVI CT: correlation with early post-procedural complications
2023
Abstract Purpose The aim of our study was to evaluate the prevalence of early complications after Transcatheter Aortic Valve Implantation (TAVI) and their correlation with the Calcium Score (CS) of the aortic valve, aorta and ilio-femoral arteries derived from pre-procedural computed tomography (CT). Materials and methods We retrospectively reviewed 226 patients (100 males, mean age 79.4 ± 6.7 years) undergoing 64-slice CT for pre-TAVI evaluation from January 2018 to April 2021. The population was divided into CS quartiles. Results Overall, 173 patients underwent TAVI procedure, of whom 61% presented paravalvular leak after the procedure, 28% presented bleeding or vascular complications, 25…