Search results for "imaging techniques"
showing 10 items of 178 documents
Combined use of sonographic and elastosonographic parameters can improve the diagnostic accuracy in thyroid nodules at risk of malignancy at cytologi…
2019
BACKGROUND Thyroid nodules diagnosed as Thy3B at fine-needle aspiration biopsy have a relevant risk of malignancy (15-30%) and are usually addressed to surgery. However surgery will result unnecessary in most cases. The present study aims at evaluating the possible increase of diagnostic accuracy for predicting malignancy using novel sonographic and elastographic parameters. METHODS In fifty patients undergoing thyroidectomy because of a Thy3B thyroid nodule, sonographic and elastosonographic evaluation was carried out by single operator before surgery. Five sonographic parameters (echogenicity, irregular margins, microcalcifications, intra-nodule blood flow and its irregularity) and two el…
Rapid nucleus-scale reorganization of chromatin in neurons enables transcriptional adaptation for memory consolidation
2020
AbstractThe interphase nucleus is functionally organized in active and repressed territories defining the transcriptional status of the cell. However, it remains poorly understood how the nuclear architecture of neurons adapts in response to behaviorally relevant stimuli that trigger fast alterations in gene expression patterns. Imaging of fluorescently tagged nucleosomes revealed that pharmacological manipulation of neuronal activity in vitro and auditory cued fear conditioning in vivo induce nucleus-scale restructuring of chromatin within minutes. Furthermore, the acquisition of auditory fear memory is impaired after infusion of a drug into auditory cortex which blocks chromatin reorganiz…
A free plate model can predict guided modes propagating in tubular bone-mimicking phantoms
2014
The goal of this work was to show that a non-absorbing free plate model can predict with a reasonable accuracy guided modes measured in bone-mimicking phantoms that have circular cross-section. Experiments were carried out on uncoated and coated phantoms using a clinical axial transmission setup. Adjustment of the plate model to the experimental data yielded estimates for the waveguide characteristics (thickness, bulk wave velocities). Fair agreement was achieved over a frequency range of 0.4 to 1.6 MHz. A lower accuracy observed for the thinnest bone-mimicking phantoms was caused by limitations in the wave number measurements rather than by the model itself.
Changes in visual function and retinal structure in the progression of Alzheimer's disease
2019
Background Alzheimer's Disease (AD) can cause degeneration in the retina and optic nerve either directly, as a result of amyloid beta deposits, or secondarily, as a result of the degradation of the visual cortex. These effects raise the possibility that tracking ophthalmologic changes in the retina can be used to assess neurodegeneration in AD. This study aimed to detect retinal changes and associated functional changes in three groups of patients consisting of AD patients with mild disease, AD patients with moderate disease and healthy controls by using non-invasive psychophysical ophthalmological tests and optical coherence tomography (OCT). Methods We included 39 patients with mild AD, 2…
Accuracy of Transient Elastography in Assessing Fibrosis at Diagnosis in Naïve Patients With Primary Biliary Cholangitis: A Dual Cut-Off Approach
2021
Background & aims Liver fibrosis holds a relevant prognostic meaning in primary biliary cholangitis (PBC). Non-invasive fibrosis evaluation using vibration-controlled transient elastography (VCTE) is routinely performed. However, there is limited evidence on its accuracy at diagnosis in PBC. We aimed to estimate the diagnostic accuracy of VCTE in assessing advanced fibrosis at disease presentation in PBC. Approach & results We collected data from 167 consecutive treatment-naive PBC patients who underwent liver biopsy(LB) at diagnosis at six Italian centers. VCTE examinations were completed within 12 weeks of LB. Biopsies were scored by two blinded expert pathologists, according to Ludwig sy…
Neuropsychological underpinnings of the dynamics of bipolar disorder
2015
Although we have gained enormous insights into neurobiological and psychological underpinnings of bipolar disorder (BD) symptoms, our knowledge concerning pathogenic mechanisms initiating recurrent affective episodes is still fragmentary. Previous research has highlighted the role of significant life events and social rhythm in recurrent episodes of mania and depression. However, most studies share the drawback of retrospective self-report data, which are prone to recall biases and limited introspective abilities. Therefore, more objective data, such as neuropsychological and neurobiological measures are needed to further unravel the pathogenic mechanisms of the dynamics of bipolar disorder…
Noninvasive cardiovascular imaging for evaluating subclinical target organ damage in hypertensive patients: a consensus article from the European Ass…
2017
International audience; : Arterial hypertension accounts for the largest amount of attributable cardiovascular mortality worldwide, and risk stratification in hypertensive patients is of crucial importance to manage treatment and prevent adverse events. Asymptomatic involvement of different organs in patients affected by hypertension represents an independent determinant of cardiovascular risk, and the identification of target organ damage is recommended to further reclassify patients' risk. Noninvasive cardiovascular imaging is progressively being used and continues to provide new technological opportunities to target organ damage evaluation at early stage. The aim of this article is to pr…
SIRM–SIC appropriateness criteria for the use of Cardiac Computed Tomography. Part 1: Congenital heart diseases, primary prevention, risk assessment …
2021
AbstractIn the past 20 years, Cardiac Computed Tomography (CCT) has become a pivotal technique for the noninvasive diagnostic work-up of coronary and cardiac diseases. Continuous technical and methodological improvements, combined with fast growing scientific evidence, have progressively expanded the clinical role of CCT. Recent large multicenter randomized clinical trials documented the high prognostic value of CCT and its capability to increase the cost-effectiveness of the management of patients with suspected CAD. In the meantime, CCT, initially perceived as a simple non-invasive technique for studying coronary anatomy, has transformed into a multiparametric “one-stop-shop” approach abl…
X-Ray Nanotomography of Individual Pulp Fibre Bonds Reveals the Effect of Wall Thickness on Contact Area
2019
Fibre bonds play an essential role in various properties of paper. Much research has focused on their strength, but the determination of the actual contact area also provides a challenge. Many of the research methods rely on optical tools, which are restricted by the wavelength of light that is utilised. Novel X-ray computed tomography devices utilise X-rays in studying the inner structure of materials, and surpass the optical methods in terms of resolution, allowing detection of even smaller details and variations in distance between the fibres in the bond intersection area. X-ray nanotomography was used to image 26 individual cellulose fibre bonds made of springwood and summerwood fibres …
The Value of Median Nerve Sonography as a Predictor for Short- and Long-Term Clinical Outcomes in Patients with Carpal Tunnel Syndrome: A Prospective…
2016
Objectives To investigate the prognostic value of B-mode and Power Doppler (PD) ultrasound of the median nerve for the short- and long-term clinical outcomes of patients with carpal tunnel syndrome (CTS). Methods Prospective study of 135 patients with suspected CTS seen 3 times: at baseline, then at short-term (3 months) and long-term (15–36 months) follow-up. At baseline, the cross-sectional area (CSA) of the median nerve was measured with ultrasound at 4 levels on the forearm and wrist. PD signals were graded semi-quantitatively (0–3). Clinical outcomes were evaluated at each visit with the Boston Questionnaire (BQ) and the DASH Questionnaire, as well as visual analogue scales for the pat…