Objective: The purpose of this study was to delineate the hemodynamic features of VX2 tumor and perineoplastic liver parenchyma and to evaluate the potential usefulness of single-level dynamic ultrasonography in the diagnosis of tumors by the analysis of time-intensity curves.
Methods: An in vivo animal model was studied using a low mechanical index in conjunction with single-level dynamic contrast-enhanced ultrasonography. A sulfur hexafluoride contrast agent (SonoVue; Bracco SpA, Milan, Italy) was applied in 8 rabbits by intravenous bolus injection. Data were acquired before and after VX2 tumor induction. Corresponding parameters of the time-intensity curve were measured using wash-in/wash-out curve software.
Results: No significant difference was found in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between liver parenchyma before and after VX2 tumor induction (P > .05). The typical enhancement pattern of VX2 tumors was hyperechoic relative to liver parenchyma during the early phase and hypoechoic during the later phase. The curves obtained in carcinomas revealed an early arrival time and time to peak intensity with an irregular and sharp decrease of the intensity signal and a very early return to baseline, presenting a much more rapid wash-in and wash-out of ultrasonographic contrast agents. There was a significant difference in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between the VX2 tumors and perineoplastic liver parenchyma (P < .001).
Conclusions: Single-level dynamic contrast-enhanced ultrasonography with a low mechanical index level could provide real-time and continuous enhanced images and fully delineate the typical enhancement pattern of liver tumors. The analysis of time-intensity curves may provide useful, complementary, and quantitative information. This technique may be useful for the diagnosis of liver tumors, especially those showing an atypical enhancement pattern on biphasic helical computed tomographic scanning.
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http://dx.doi.org/10.7863/jum.2005.24.7.975 | DOI Listing |
Ulus Travma Acil Cerrahi Derg
January 2024
Department of Orthopaedic and Traumatology, Medipol University Hospital, İstanbul-Türkiye.
Background: Syndesmosis injuries in ankle fractures can significantly impact patient mobility and recovery, making the choice of fixation method crucial for optimal outcomes. This study aimed to compare the quality of reduction and functional results between screw fixation and dynamic fixation in treating syndesmosis injuries in ankle fractures.
Methods: This cohort study included 48 patients (28 males, 20 females) with an ankle fracture accompanied by syndesmosis injury.
Commun Biol
November 2024
Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA, 92093-0206, USA.
While it is commonly accepted that ecosystem dynamics are nonlinear, what is often not acknowledged is that nonlinearity implies scale-dependence. With the increasing availability of high-resolution ecological time series, there is a growing need to understand how scale and resolution in the data affect the construction and interpretation of causal networks-specifically, networks mapping how changes in one variable drive changes in others as part of a shared dynamic system ("dynamic causation"). We use Convergent Cross Mapping (CCM), a method specifically designed to measure dynamic causation, to study the effects of varying temporal and taxonomic/functional resolution in data when constructing ecological causal networks.
View Article and Find Full Text PDFTurk Neurosurg
November 2024
University of São Paulo, University Hospital of Ribeirão Preto Medical School, Division of Neurosurgery, Brazil.
Aim: To compare lumbar X-ray and magnetic resonance imaging (MRI) findings, and to identify the factors associated with joint instability in cases with lumbar spondylolisthesis.
Material And Methods: We performed a retrospective and observational study of patients with a confirmed diagnosis of lumbar or lumbosacral low-grade spondylolisthesis at a single level. Preoperative X-ray and MRI examinations were evaluated.
Clin Spine Surg
October 2024
Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School.
Study Design/setting: Single center retrospective cohort study.
Objective: We performed a retrospective study evaluating the incidence and degree of L4-5 anterior spondylolisthesis in patients with standard supine MRI, standing flexion-extension radiographs, and prone CT. We hypothesize that prone CT imaging will provide greater sensitivity for instability compared with conventional flexion extension or supine positions.
ACS Nano
October 2024
ICFO─Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain.
Viral capture and entry to target cells are the first crucial steps that ultimately lead to viral infection. Understanding these events is essential toward the design and development of suitable antiviral drugs and/or vaccines. Viral capture involves dynamic interactions of the virus with specific receptors in the plasma membrane of the target cells.
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