Search results for "Sound"
showing 10 items of 1845 documents
Computer-aided diagnosis in digital mammography: comparison of two commercial systems
2014
Aim: Within this work, a comparative analysis of two commercial computer-aided detection or diagnosis (CAD) systems, CyclopusCAD® mammo (v. 6.0) produced by CyclopusCAD Ltd (Palermo, Italy) and SecondLook® (v. 6.1C) produced by iCAD Inc. (OH, USA) is performed by evaluating the results of both systems application on an unique set of mammographic digital images routinely acquired in a hospital structure. Materials & methods: The two CAD systems have been separately applied on a sample set of 126 mammographic digital cases, having been independently diagnosed by two senior radiologists. According to the human diagnosis, the cases in the sample reference set are divided into 61 negatives and 6…
Guidelines for the diagnosis and management of intrahepatic cholangiocarcinoma
2014
Ultrasound Imaging Evaluation of Textural Features in Athletes with Soleus Pathology—A Novel Case-Control Study
2021
Background: the aim of this study was to compare the echotexture of patients with soleus muscle injury and age matched controls. Methods: a sample of 62 athletes was recruited at the private clinic and was divided in two group: a healthy group (n=31) and a soleus pathology group whose athletes had soleus muscle injury, located in the central tendon (n=31). The muscle thickness (MTh), echointensity (EI) and echovariation (EV) were analyzed. An intra-rater reliability test (Intraclass Correlation Coefficient-ICC) was performed in order to analyze the reliability of the values of the measurements. Results: Sociodemographic variables did not show statistically significant differences (p >
Assessment of the fundamental flexural guided wave in cortical bone by an ultrasonic axial-transmission array transducer
2013
Abstract The fundamental flexural guided wave (FFGW), as modeled, for example, by the A0 Lamb mode, is a clinically useful indicator of cortical bone thickness. In the work described in this article, we tested so-called multiridge-based analysis, based on the crazy climber algorithm and short-time Fourier transform, for assessment of the FFGW component recorded by a clinical array transducer featuring a limited number of elements. Methods included numerical finite-element simulations and experiments in bone phantoms and human radius specimens ( n = 41). The proposed approach enabled extraction of the FFGW component and determination of its group velocity. This group velocity was in good ag…
Comparative imaging of structure and metabolites in tumours.
1991
A novel technique for metabolic imaging using quantitative bioluminescence and single photon imaging was used to measure the distribution of ATP and lactate in two types of human melanoma xenografts with different radiobiologically hypoxic cell fractions (MF: 45 +/- 17% and EE: 6 +/- 3%; mean +/- SD). The tumours were s.c. grown in nude mice and were used for measurement at volumes of 153-3072 mm3. For metabolic imaging the rapidly frozen tumours were serially sectioned, and each cryosection was brought into contact with a frozen bioluminescent enzyme cocktail using a specially designed glass sandwich system. After thawing section and cocktail the luminescence was started, and light was emi…
Sonoporation, a redefined ultrasound modality as therapeutic aid: a review.
2011
Traditionally a diagnostic modality, ultrasound is emerging as a promising tool for non-invasive therapy, drug delivery, and gene therapy. The ultrasound is a mechanical wave energy generated in a medium as oscillating pressure in space and time at frequencies above 20 kHz, beyond the audible range. The ultrasound exposure generates bioeffects resulting in tissue heating, shear stress, and cavitation, which have been exploited for therapeutic applications. Ultrasound cavitation, enhanced by injected micro bubbles, perturbs cell membrane structures to cause sonoporation and increases the permeability to bioactive materials. Ultrasound-mediated gene delivery has been applied to heart, blood v…
2017
Background Catheter-based lysis with recombinant tissue plasminogen activator (rtPA) is a well-established therapy for spontaneous intracerebral hemorrhage (ICH). The effectiveness of this therapy can be increased with ultrasound, but the optimal conditions are not yet clearly established. Using a novel in vitro system of blood clots previously developed by our group, we investigated various parameters of intralesional sonothrombolysis using an endosonography catheter in combination with rtPA. Methods Standardized human blood clots were equipped with a drainage catheter and weighed before and after 4 treatments: control (drainage only), rtPA only, ultrasound only and the combination of rtPA…
Ultrasound-based testing of tendon mechanical properties: a critical evaluation.
2015
In the past 20 years, the use of ultrasound-based methods has become a standard approach to measure tendon mechanical properties in vivo. Yet the multitude of methodological approaches adopted by various research groups probably contribute to the large variability of reported values. The technique of obtaining and relating tendon deformation to tensile force in vivo has been applied differently, depending on practical constraints or scientific points of view. Divergence can be seen in 1) methodological considerations, such as the choice of anatomical features to scan and to track, force measurements, or signal synchronization; and 2) in physiological considerations related to the viscoelas…
Bioeffects of ultrasound: an experimental study on human embryos.
1991
Abstract The foetuses of 10 women at 9–12 weeks gestation were irradiated with ultrasound under typical diagnostic exposure conditions immediately prior to abortion. Electron microscopy of liver fragments revealed neither morphological nor structural changes.
Ultrasonic demonstration of small pancreatic islet cell tumors.
1982
In three patients real-time sonography successfully localized small pancreatic islet cell tumors measuring 7, 8, and 17 mm in size. Ultrasound is suggested as the initial radiologic examination for localization of endocrine pancreatic tumors. If ultrasound is negative or equivocal, computerized tomography, arteriography, and pancreatic venous sampling are indicated.