The value of 18F-FDG PET/contrast-enhanced CT in detection of tumor thrombus

PURPOSE: The differentiation between tumor and bland thromboses is important as the management differs. Retrospectively, we aim to evaluate the utility of FDG PET in detecting and differentiating tumor from bland thromboses and if FDG PET provides additional value to contrast-enhanced CT for tumor thrombus detection. PATIENTS AND METHODS: Twenty-four sites of venous thromboembolism, detected on PET/CT, were retrospectively reviewed. Classification of type of thrombosis was based on histology and radiological follow-up. We evaluated the presence of contrast-enhanced CT findings that were suggestive of tumor thrombosis; sign of invasion, neovascularity, and enhancement. Metabolic activity by means of SUV(max) was measured by drawing ROI at the site of thrombosis. Mann-Whitney U test was used to compare the mean SUV(max) between thromboses and internal references. We used ROC analysis to identify the optimal cutoff value of SUV(max) for detection of tumor thrombosis. RESULTS: Twenty-four sites of venous thromboembolism were identified in 15 patients. All tumor thromboses demonstrated at least 1 positive sign on contrast-enhanced CT, whereas 33% of bland thromboses had the same finding. The difference between tumor and bland thrombus SUV(max) was statistically significant (P < 0.005). On ROC analysis, a cutoff of SUV(max) 2.25 (sensitivity, 78%; specificity, 100%) was suggested to differentiate tumor from bland thrombosis. CONCLUSION: PET/CT is able to differentiate tumor from bland thrombosis, with an optimal cutoff value of SUV(max) 2.25. The metabolic information increases the diagnostic accuracy of tumor thrombus and is a useful adjunct to the described features on contrast-enhanced CT.postprin

Conditions on input disturbance suppression for multivariable nonlinear systems on the basis of feedforward passivity

In this paper, we consider the problem of input disturbance suppression for nonlinear systems based on feedforward passivity. First, we show that integral control can sufficiently suppress a class of slowly variant (including constant) input disturbance and track constant references provided certain closed-loop stability is achieved. Then, sufficient conditions of integral controllability for nonlinear processes are presented. These conditions are further relaxed by using an input and output transformation

Control of multivariable Hammerstein systems by using feedforward passivation

This paper presents a new control method for processes which can be described by Hammerstein models. The control design is based on the concept of passive systems. The proposed method is based on feedforward passivation and thus can be applied to nonminimum phase processes and/or processes of high relative degree. A synthesis technique for marginally stable positive real systems has been developed to achieve offset free control. The new control design can be easily implemented by solving a set of linear matrix inequalities. The proposed approach is illustrated using the example of an acid-base pH control problem

Analysis of decentralized integral controllability for nonlinear systems

This paper extends the concept of decentralized integral controllability to nonlinear process, and presents a steady state sufficient condition by using the singular perturbation theory. A numerical method is provided to facilitate the analysis of the proposed condition and is illustrated using an example of a dual tank level control system. © 2004 Elsevier Ltd. All rights reserved

Peritoneal dissemination: comparison of 18F-FDG PET/CT and DWI with conventional MRI

Scientific Formal (Paper) Presentation - SSK13: Nuclear Medicine (Oncology)PURPOSE: The purpose of this study was to evaluate the diagnostic performance of 18F-FDG PET/CT in peritoneal dissemination detection, in comparison to MRI with and without diffusion-weighted imaging (DWI). METHOD AND MATERIALS: Prospective subjects with peritoneal metastases were recruited for 18F-FDG PET/CT and MRI, performed within 4-week of each other, without intervening therapeutic interventions. Images were evaluated in separate sessions as following: DWI alone, conventional MRI alone, DWI with conventional MRI, and 18F-FDG PET/CT for peritoneal dissemination in 16 anatomical ...postprin

Metabolic Phenotype of Stage IV Lung Adenocarcinoma: relationship with epidermal growth factor receptor mutation

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Bone marrow uptake of indolent non-Hodgkin lymphoma on PET/CT with histopathological correlation

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Digit-only sauropod pes trackways from China - evidence of swimming or a preservational phenomenon?

For more than 70 years unusual sauropod trackways have played a pivotal role in debates about the swimming ability of sauropods. Most claims that sauropods could swim have been based on manus-only or manus-dominated trackways. However none of these incomplete trackways has been entirely convincing, and most have proved to be taphonomic artifacts, either undertracks or the result of differential depth of penetration of manus and pes tracks, but otherwise showed the typical pattern of normal walking trackways. Here we report an assemblage of unusual sauropod tracks from the Lower Cretaceous Hekou Group of Gansu Province, northern China, characterized by the preservation of only the pes claw traces, that we interpret as having been left by walking, not buoyant or swimming, individuals. They are interpreted as the result of animals moving on a soft mud-silt substrate, projecting their claws deeply to register their traces on an underlying sand layer where they gained more grip during progression. Other sauropod walking trackways on the same surface with both pes and manus traces preserved, were probably left earlier on relatively firm substrates that predated the deposition of soft mud and silt . Presently, there is no convincing evidence of swimming sauropods from their trackways, which is not to say that sauropods did not swim at all

Multi-functional fluorescent carbon dots with antibacterial and gene delivery properties

Glucose is abundant in nature and can be found in various sources. In this study, we developed multifunctional carbon dots (CDs) with glucose, and poly(ethyleneimine) (PEI) which were further quaternized using a facile approach. The CDs are designed to possess both antibacteria and gene delivery capabilities. The inherent property was characterized with TEM, NMR, FTIR and fluorescent spectroscopy. Antibacterial activity was evaluated with Broth minimum inhibitory concentration (MIC) assay on both gram-positive and gram-negative bacteria. The CDs showed excellent inhibitation to both bacteria. The expression of CDs condensed plasmid DNA in HEK 293T cells was investigated with Luciferase expression assay. Gene transfection capability of the quaternized CDs was found to be up to 104 times efficient than naked DNA delivery

Intravoxel incoherent motion MR imaging in nasopharyngeal carcinoma: Comparison and correlation with dynamic contrast enhanced MR imaging

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