1,720,960 research outputs found
Sinusoidal phase during contrast enhanced US for the characterization of hypoechoic focal hepatic lesions
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Endovascular management of splanchnic arteries bleeding in pancreato-biliary disease
No full textBackground. Splanchnic artery bleeding is a life-threatening condition, especially in high-risk patients. The purpose of this study is to evaluate the efficacy of endovascular treatment of splanchnic artery bleeding in pancreato-biliary disease, considered as survival at the 3-month follow-up. Patients and methods. From 1992 to 2001 39 patients with upper splanchnic arterial lesion due to acute and chronic pancreatitis after surgery or percutaneous procedures, or as a complication of aneurysms or trauma, were treated using endovascular techniques. The patients underwent CT control immediately after the procedure, after seven days and then at the 3, 6 and 12-month-follow-up. Results. In some patients, more than one angiography was necessary to identify the source of bleeding. Bleeding was stopped in all treated patients. Fatal re-bleeding occurred in 6 patients and, in the first part of the study, 2 patients died of hepatic failure after hepatic artery embolization. Conclusions. Splanchnic artery bleeding is a life-threatening condition. Endovascular treatment can reach a clinical success rate of up to 75% at three months
Angiosonography in suspicious breast lesions with non-diagnostic FNAC: comparison with power Doppler US.
No full textPURPOSE: The purpose of this study was to evaluate the accuracy of angiosonography in comparison with colour Doppler ultrasound (US) in the discrimination of suspicious breast lesions with nondiagnostic fine-needle aspiration cytology (FNAC).
MATERIALS AND METHODS: Pre-operative Power Doppler US and angiosonography were prospectively performed in 20 suspicious breast lesions with non-diagnostic FNAC. A second-generation US contrast agent was utilised with a high-frequency transducer and a contrast-specific algorithm (low acoustic pressure CnTI). The enhancement characteristics of all lesions were analysed using qualitative and quantitative parameters obtained from time-intensity curves with the different imaging modalities. The final diagnosis was confirmed at pathology in all cases. Microvessel density (MVD) was assessed in the surgical specimen using CD34.
RESULTS: The correct assessment of biological behaviour was achieved in all cases by angiosonography (sensitivity of 100%; specificity of 91%) and colour Doppler US (45% sensitivity; 78% specificity). MVD correlated with the biological behaviour.
CONCLUSIONS: Angiosonography is more accurate than colour Doppler US in the correct assessment of biological behaviour of suspicious breast lesion
Contrast-enhanced ultrasonography better identifies pancreatic tumor vascularization than helical CT
No full textBACKGROUND: Contrast-enhanced ultrasonography (CEUS) is a recently introduced field of ultrasonography (US). To assess the ability of CEUS to identify the vascularization of solid pancreatic tumors in comparison to helical CT. METHODS: Forty-two resected pancreatic tumors, found at US, were studied with CEUS and helical CT. The tumor enhancement at CEUS was scored in comparison to the baseline aspect of the lesion and/or the extralesional pancreatic parenchyma together with the adjacent vessels during the dynamic study. All the lesions underwent pathological examination using H&E stains and CD34 markers with an evaluation of the microvessel density (MVD). The correlation of CEUS and helical CT with the MVD of the lesions was established with Spearman's test. RESULTS: The correlation of CEUS with the MVD of the lesions was significantly superior (Rs = 0.914; p < 0.0001) to that of helical CT (Rs = 0.635; p < 0.0001). CONCLUSIONS: CEUS is better than helical CT in the identification of the vascularization of solid pancreatic tumors. CEUS, when the pancreatic gland is optimally visualized, should be therefore considered a complementary imaging modality in the characterization of pancreatic tumors. CEUS can be a valid onco-imaging modality for quantifying tumoral vascularization in a noninvasive and accurate way
Contrast-enhanced ultrasonographic detection of small pancreatic insulinoma.
No full textEndocrine tumors of the pancreas originate from multipotential stem cells that have retained the capacity to proliferate and differentiate themselves in the various cellular lines that make up this group of neoplasms. Insulinomas represent the most frequently found functioning endocrine tumors of the pancreas and are benign in most cases (85%-99%), are single (93%-98%), and have diameters of less than 2.5 cm. When malignant, their diameters are generally greater than 3 cm, and about one third of these have metastases at the moment of diagnosis. They appear early with signs and symptoms linked to hypoglycemia due to the hypersecretion of insulin; they are almost exclusively located at the pancreatic level with no preferential sites. Preoperative ultrasonographic detection of insulinomas is generally difficult but possible in 25% to 60% of cases.3 The main difficulty in detecting a pancreatic insulinoma lies in the organ's anatomic structure and the tumor's small dimensions at clinical appearance. The use of second-generation contrast-enhanced imaging can increase the capacity to detect pancreatic insulinomas in preoperative ultrasonography, as the following case confirms
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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