1,721,006 research outputs found

    Can polar renal artery arising from AAA cause type 2 endoleak?

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    Case 8370 www.eurorad.org, Radiological Case Database. European Society of Radiology, Luglio 201

    Virtual stenting of iliac arteries: a new technique for choosing stents and stent-grafts by means of 3D rotational angiography. Preliminary data

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    PURPOSE: Virtual stenting (VS) is a new tool in the 3D processing work station of rotational angiography (RA) systems. This tool enables the 3D visualization of a stent or stent-graft in the site of a stenotic, obstructive or aneurysmatic lesion to be treated. We report the preliminary results obtained with this software in the treatment of segmental stenotic, obstructive or aneurysmal lesions of the iliac artery. MATERIALS AND METHODS: Seventeen patients under-went rotational angiography and 3D reformations for one or more stenoses (19 cases), obstructive lesions (2 cases) or aneurysms (2 cases) of the common and/or external iliac artery and were treated with stents in 22/23 of cases. In all cases, the VS tool was applied to the stenotic-obstructive lesion on the identified on the 3D angiogram obtained before the stenting procedure. RESULTS: The measurements of the stents/stents-grafts (length, proximal and distal diameter) provided by the tool were compared to those of the stent deployed. In 22/23 procedures, the measurements of virtual stenting and those of the deployed stent showed a good level of concordance. The system failed to provide correct measurements in only one long and tortuous iliac aneurysm. CONCLUSIONS: The ''virtual stenting'' tool proved to be reliable and fast, and enabled a more objective selection of the stent to be deployed on a stenotic-obstructive lesion in almost all cases. In cases of aneurysms of marked tortuosity, the system tends to suggest an inappropriate stent. The possibility of manually defining the optimal stent path within the aneurysmal sac might be useful

    Analysis of different contrast enhancement patterns after microbubble-based contrast agent injection in liver hemangiomas with atypical appearance on baseline scan

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    BACKGROUND: We describe different possible enhancement patterns in liver hemangiomas with atypical appearance on baseline ultrasound after microbubble-based contrast agent injection. METHODS: From a series of 253 consecutive lesions that were indeterminate on baseline ultrasound and then scanned after injection of air-filled microbubble contrast agent, 65 focal liver lesions were retrospectively selected on the basis of a diagnosis of liver hemangioma on multiphase contrast-enhanced computed tomography (n = 23), magnetic resonance imaging (n = 27), or histology (n = 15). Each lesion was scanned during arterial phase (30 s after microbubble injection) and late phase (5 min after injection). On-site sonologists performed retrospective assessment of contrast-enhancement patterns by consensus. RESULTS: Centripetal fill-in preceded (n = 50) or not preceded (n = 3) by peripheral nodular/rim-like enhancement was the prevalently observed contrast-enhancement pattern, equivalent to the typical enhancement pattern of liver hemangiomas on contrast-enhanced computed tomography or magnetic resonance imaging. In the remaining lesions, additional enhancement patterns (diffuse contrast enhancement with rapid fill-in and a late hyper-isoechoic appearance, n = 6; peripheral nodular enhancement with a late hypoechoic appearance, n = 3; or persistent heterogeneous and hyperechoic appearance, n = 3) were observed. CONCLUSION: Different contrast-enhancement patterns are possible in atypical liver hemangiomas after microbubble injection. Typical centripetal fill-in is the prevalent pattern and its evidence allows diagnosis

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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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