Search results for "imaging technique"
showing 10 items of 199 documents
Cardiac imaging in congenital heart disease during the coronavirus disease-2019 pandemic: Recommendations from the Working Group on Congenital Heart …
2020
: The recent outbreak of 2019 severe acute respiratory syndrome coronavirus-2 is having major repercussions on healthcare services provision in Italy and worldwide. Data suggest the virus has a strong impact on the cardiovascular system, and cardiac imaging will play an important role in patients affected by coronavirus disease-2019. Although paediatric patients are mildly affected, they represent a clear accelerator in spreading the virus, and healthcare workers are at higher risk of infection. The aim of this position paper is to provide clinical recommendation regarding the execution of imaging investigations for the cardiac diagnostic work-up of paediatric patients with suspected or con…
High rate concentration measurement of molecular gas mixtures using a spatial detection technique
2010
International audience; Concentration measurement in molecular gas mixtures using a snapshot spatial imaging technique is reported. The approach consists of measuring the birefringence of the molecular sample when field-free alignment takes place, each molecular component producing a signal with an amplitude depending on the molecular density. The concentration measurement is obtained on a single-shot basis by probing the time-varying birefringence through femtosecond time-resolved optical polarigraphy (FTOP). The relevance of the method is assessed in air.
Lightfield recording and reconstruction by integral imaging
2011
Integral imaging is a rising 3D imaging technique that can be considered the incoherent version of holography. In integral imaging the multiperspective information of 3D scenes is stored in a 2D picture. Such picture is nothing but a sampling version of the lightfield emitted by the 3D scene. The recorded lightfield can be used for many purposes. One is the display of 3D color scenes to audiences or much more than one person. Other is the 3D display, with full parallax, in personal monitors, like the screen of a Smartphone, a tablet, or the monitor used by a surgeon in an endoscopic operation. Other important types of applications are connected with the topographic reconstruction, slice by …
Comparison of Elastic and Rigid Registration during Magnetic Resonance Imaging/Ultrasound Fusion-Guided Prostate Biopsy: A Multi-Operator Phantom Stu…
2018
The relative value of rigid or elastic registration during magnetic resonance imaging/ultrasound fusion guided prostate biopsy has been poorly studied. We compared registration errors (the distance between a region of interest and fiducial markers) between rigid and elastic registration during fusion guided prostate biopsy using a prostate phantom model.Four gold fiducial markers visible on magnetic resonance imaging and ultrasound were placed throughout 1 phantom prostate model. The phantom underwent magnetic resonance imaging and the fiducial markers were labeled as regions of interest. An experienced user and a novice user of fusion guided prostate biopsy targeted regions of interest and…
eNOS S-nitrosylates β-actin on Cys374 and regulates PKC-θ at the immune synapse by impairing actin binding to profilin-1.
2017
The actin cytoskeleton coordinates the organization of signaling microclusters at the immune synapse (IS); however, the mechanisms involved remain poorly understood. We show here that nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) controls the coalescence of protein kinase C-¿ (PKC-¿) at the central supramolecular activation cluster (c-SMAC) of the IS. eNOS translocated with the Golgi to the IS and partially colocalized with F-actin around the c-SMAC. This resulted in reduced actin polymerization and centripetal retrograde flow of ß-actin and PKC-¿ from the lamellipodium-like distal (d)-SMAC, promoting PKC-¿ activation. Furthermore, eNOS-derived NO S-nitrosylated ß-…
Improved noninvasive prediction of liver fibrosis by liver stiffness measurement in patients with nonalcoholic fatty liver disease accounting for con…
2016
Background and aims: Liver stiffness measurement (LSM) frequently overestimates the severity of liver fibrosis In Nonalcoholic Fatty Liver Disease (NAFLD). Controlled Attenuation Parameter (CAP) is a new parameter provided by the same machine used for LSM, and associated with both steatosis and BMI, the two factors mostly affecting LSM peformance in NAFLD. We aimed to determine wheter prediction of liver fibrosis by LSM in NAFLD patients is affected by CAP values. Methods: Patients (n=324) were assessed by clinical and histological (Kleiner score) features. LSM and CAP were performed using the M probe. CAP values were grouped by tertiles (lower from 132 to 298, middle from 299 to 338, highe…
Liver stiffness measurement by vibration-controlled transient elastography improves outcome prediction in primary biliary cholangitis
2022
BACKGROUND & AIMS: Liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) has been shown to predict outcomes of patients with primary biliary cholangitis (PBC) in small-size studies. We aimed to validate the prognostic value of LSM in a large cohort study. METHODS: We performed an international, multicentre, retrospective follow-up study of 3,985 patients with PBC seen at 23 centres in 12 countries. Eligibility criteria included at least 1 reliable LSM by VCTE and a follow-up ≥ 1 year. Independent derivation (n = 2,740) and validation (n = 568) cohorts were built. The primary endpoint was time to poor clinical outcomes defined as liver-related complications,…
Liver-related and extrahepatic events in patients with non-alcoholic fatty liver disease: a retrospective competing risks analysis.
2022
Background & Aim: Non-alcoholic fatty liver disease (NAFLD), and especially fibrotic non-alcoholic steatohepatitis, is associated with high risks of liver-related events (LRE) and extrahepatic events (EHE). We evaluated the competitive risk occurrence of LRE and EHE in a large cohort of biopsy-proven NAFLD stratified according to baseline severity of fibrosis. Methods: Two thousand one hundred thirty-five patients with biopsy-proven NAFLD were enrolled. Observed cumulative incidence functions (CIFs) were used to evaluate the risk of LRE and EHE; cause-specific Cox model and predicted CIFs were fitted to identify predictors of LRE and EHE. A replication cohort of NAFLD patients with live…
Comparison of screening strategies with two new tests to score and diagnose varices needing treatment.
2022
Background and aims: We aimed to improve non-invasive screening of varices needing treatment (VNT) and compare different screening strategies. Methods: 2,290 patients with chronic liver disease were included in a retrospective study. Etiologies were: virus: 50.0%, NAFLD: 29.5%, alcohol: 20.5%, VNT: 14.9%. Test descriptors were performance (spared endoscopy) and safety (missed VNT). VNT tests were evaluated according to their safety levels either for individual screening (95% negative predictive value (NPV)), population screening (95% sensitivity) or undifferentiated screening (100% sensitivity/NPV) without missed VNT. The tests provided three categories: missed VNT <5%, VNT 100% specific…
Liver Fibrosis and Metabolic Alterations in Adults With alpha-1-antitrypsin Deficiency Caused by the Pi*ZZ Mutation
2019
Background & Aims Alpha-1 antitrypsin deficiency (AATD) is among the most common genetic disorders. Severe AATD is caused by a homozygous mutation in the SERPINA1 gene that encodes the Glu342Lys substitution (called the Pi*Z mutation, Pi*ZZ genotype). Pi*ZZ carriers may develop lung and liver diseases. Mutation-associated lung disorders have been well studied, but less is known about the effects in liver. We assessed the liver disease burden and associated features in adults with this form of AATD. Methods We collected data from 554 Pi*ZZ adults (403 in an exploratory cohort, 151 in a confirmatory cohort), in 9 European countries, with AATD who were homozygous for the Pi*Z mutation, and 234…