With operator experience and careful technique, uterine arterial embolization can be performed at radiation exposures comparable to those used in routine diagnostic studies. However, operators must be familiar with the technical parameters of their angiographic equipment.
Radiation exposure in pediatric fluoroscopy can be reduced to values well below the exposure settings that are typically found on unoptimized fluoroscopes. Pulsed fluoroscopy is considered a requisite for optimal pediatric fluoroscopy.
Abstract:The vertex-deleted subgraph G−v, obtained from the graph G by deleting the vertex v and all edges incident to v, is called a card of G. The deck of G is the multiset of its unlabelled vertex-deleted subgraphs. The number of common cards of G and H (or between G and H) is the cardinality of the multiset intersection of the decks of G and H. In this article, we present infinite families of pairs of graphs of order n ≥ 4 that have at least 2 1 3 (n−1) common cards; we conjecture that these, along with a small number of other families constructed from them, are the only pairs of graphs having this many common cards, for sufficiently large n. This leads us to propose a new stronger version of the Reconstruction Conjecture. In addition, we present an infinite family of pairs of graphs with the same degree sequence that have (n−5) common cards, respectively. We then present new families that have the maximum number of common cards when one graph is connected and the other disconnected. Finally, we present a family with a large number of common cards, where one graph is a tree and the other unicyclic, and discuss how many cards are required to determine whether a graph is a tree.
Cardiac MDCT is here to stay. And, it is more than just imaging coronary arteries. Understanding the differences in and the benefits of one CT scanner from another will help you to optimize the capabilities of the scanner, but requires a basic understanding of the MDCT imaging physics.This review provides key information needed to understand the differences in the types of MDCT scanners, from 64 – 320 detectors, flat panels, single and dual source configurations, step and shoot prospective and retrospective gating, and how each factor influences radiation dose, spatial and temporal resolution, and image noise.
Several studies have reported that short-term thyroid replacement to the euthyroid state in hypothyroid patients produces loss of both cortical and trabecular bone. However, long-term follow-up studies on this subject have not been reported. We conducted a 3 year follow-up study on 35 white male patients, including 24 patients (group 1 and 2) with hypothyroidism receiving thyroid hormone replacement to the euthyroid state and 11 patients (groups 3 and 4) with Graves' disease. The bone mineral content of the distal radius was determined by single-photon absorption techniques with an iodine 125 source. It was found that there was no statistically significant difference in bone mineral content by year for any group, indicating no evidence of significant loss of cortical bone mineral by thyroid hormone replacement to the euthyroid state in hypothyroid patients.
The variability in the number of detected objects was considerably smaller than the variability in radiation exposure. Pulsed fluoroscopy provides improved resolution for moving objects. Optimization of one hospital's fluoroscope especially for pediatric imaging produced the best ratio of image quality to radiation exposure.
Let G be a graph of order n. The vertex-deleted subgraph G −v, obtained from G by deleting the vertex v and all edges incident to v, is called a card of G. Let H be another graph of order n, disjoint from G. Then the number of common cards of G and H is the maximum number of disjoint pairs (v, w), where v and w are vertices of G and H, respectively, such that G −v ∼ = H −w. We prove that if G is connected and H is disconnected, Journal of Graph Theory ᭧ 2010 Wiley Periodicals, Inc.
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JOURNAL OF GRAPH THEORYthen the number of common cards of G and H is at most n / 2 +1. Thus, we can recognize the connectedness of a graph from any n / 2 +2 of its cards. Moreover, we completely characterize those pairs of graphs that attain the upper bound and show that, with the exception of six pairs of graphs of order at most 7, any pair of graphs that attains the maximum is in one of four infinite families. ᭧
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