Search results for "tomography"
showing 10 items of 2332 documents
The Neoplastic Side of the Abdominal Wall: A Comprehensive Pictorial Essay of Benign and Malignant Neoplasms
2023
Abdominal wall neoplasms are usually benign and, in the majority of these cases, no further work-up or treatment is indicated. The percentage of malignant abdominal neoplasms, however, is not negligible. Radiologists play a pivotal role in identifying imaging features that should favor malignancy, including larger lesion size, edema, neurovascular involvement, and peripheral or inhomogeneous dynamic enhancement, thus indicating to the clinician the need for further work-up. Histopathology is the reference standard for the characterization of abdominal wall neoplasms. In patients undergoing surgery, radiological assessment is needed to guide the surgeon by providing a comprehensive anatomic …
Estudio volumétrico de la cresta ósea infracigomática mediante tomografía computarizada de haz cónico
2023
Introducción. El estudio anatómico en tres dimensiones de la cresta infracigomática bajo un protocolo de estudio común, previo a la colocación de dispositivos de anclaje temporal, proporciona al clínico una herramienta de pronóstico clave en la seguridad y estabilidad del tratamiento. Objetivos. El propósito de la presente tesis doctoral fue evaluar de forma transversal la cresta ósea infracigomática (IZC) mediante Tomografías Computarizadas de Haz Cónico (TCHC) en primeros y segundos molares superiores, para el estudio sistematizado y enfocado a la colocación de dispositivos de anclaje temporal en ortodoncia. Los objetivos fueron: determinar la altura total de la cresta infracigomática en …
Synthesis and preliminary in vivo evaluation of well-dispersed biomimetic nanocrystalline apatites labeled with positron emission tomographic imaging…
2015
In recent years, biomimetic synthetic apatite nanoparticles (AP-NPs), having chemical similarity with the mineral phase of bone, have attracted a great interest in nanomedicine as potential drug carriers. To evaluate the therapeutic perspectives of AP-NPs through the mechanisms of action and organs they interact with, the noninvasive monitoring of their in vivo behavior is of paramount importance. To this aim, here the feasibility to radiolabel AP-NPs ("naked" and surface-modified with citrate to reduce their aggregation) with two positron emission tomographic (PET) imaging agents ([F-18]NaF and Ga-68-NO(2)AP(BP)) was investigated. [F-18]NaF was used for the direct incorporation of the radi…
Unique continuation results for certain generalized ray transforms of symmetric tensor fields
2022
Let $I_{m}$ denote the Euclidean ray transform acting on compactly supported symmetric $m$-tensor field distributions $f$, and $I_{m}^{*}$ be its formal $L^2$ adjoint. We study a unique continuation result for the normal operator $N_{m}=I_{m}^{*}I_{m}$. More precisely, we show that if $N_{m}$ vanishes to infinite order at a point $x_0$ and if the Saint-Venant operator $W$ acting on $f$ vanishes on an open set containing $x_0$, then $f$ is a potential tensor field. This generalizes two recent works of Ilmavirta and M\"onkk\"onen who proved such unique continuation results for the ray transform of functions and vector fields/1-forms. One of the main contributions of this work is identifying t…
The effect of steric hindrance on the packing of elongated objects
2016
Fibres of various materials can be deposited to form planar mats of fibres. These kinds of structures have gained substantial attention owing to their direct relation to both large industrial fields, such as paper and nonwovens, and biological structures, such as natural networks of fibrin, actin and collagen. In addition, similar structures are important in new emerging fields such as flexible electronics and tissue engineering. The physical properties of these structures are directly related to the connectivity of the network, thus a thorough understanding of the contact formation of the system is of great importance from both a scientific viewpoint as well as for its application in the e…
Geophysical study of an landslide in northern Sicily
2002
The San Fratello area in the Nebrodi Mountains (northern Sicily) is a region of high instability. It has suffered many devastating occurrences, which have hit and destroyed the village of San Fratello. At present the area is still subject to a high landslide risk. A series of geophysical surveys have been carried out with the aim of determining the thickness and dimensions of the landslide body as well as some tectonic features, in order to gain insight into the evolution of the landslide. The following geophysical techniques have been used: borehole seismic tomography, i.e. down-hole tomographic seismic soundings (DH TSS), time-domain electromagnetic (TDEM) soundings and georadar profiling…
Recognition of earthquake-induced damage in the Abakainon necropolis (NE Sicily): results from geo-morphological, geophysical and numerical analyses
2017
Seismotectonic activity and slope instability are a permanent threat in the archaeological site of Abakainon and in the nearby village of Tripi in NE Sicily. In recent times, signs of an ancient earthquake have been identified in the necropolis of Abakainon which dating was ascertained to the first century AD earthquake. The site is located on a slope of Peloritani Mts. along the Tindari Fault Line and contains evidence for earthquake-induced landslide, including fallen columns and blocks, horizontal shift and counter slope tilting of the tomb basements. In this paper, we used an integrated geomorphological and geophysical analysis to constrain the landslide. The research was directed to th…
Integration of constrained electrical and seismic tomographies to study the landslide affecting the cathedral of Agrigento
2014
The Cathedral of Saint Gerland, located on the top of the hill of Agrigento, is an important historical church, which dates back to the Arab–Norman period (XI century). Unfortunately throughout its history the Cathedral and the adjacent famous Archaeological Park of the 'Valley of the Temples' have been affected by landslides. In this area the interleaving of calcarenites, silt, sand and clay is complicated by the presence of dislocated rock blocks and cavities and by a system of fractures partly filled with clay or water. Integrated geophysical surveys were carried out on the north side of the hill, on which the Cathedral of Agrigento is founded, to define lithological structures involved …
Geomorphological and geophysical investigations to study the landslide affecting the archaeological site of abakainon
2016
In recent years, a detailed archeoseismological investigation has been carried out in the necropolis of Abakainon in order to identify traces of an ancient earthquake. Although the identification of seismic damage was undoubtedly attributed to the 1st century AD earthquake, it was hypothesised that the level of damaging observed in the necropolis, as well as the counter slope tilting of the tomb basements may have also caused by a seismo-induced landslide, which produced locally an amplification of the seismic shaking. In order to identify the landslide, on which the Greek site lies, detailed geomorphological and geophysical surveys have been carried out. The research was directed to the ac…
Delayed, diffuse acute peritonitis secondary to misplacement of a cystogastrostomic "pigtail" drain in an outpatient after discharge.
2017
Background and aim of the work: Pancreatic pseudocyst endoscopic drainage by pancreatogastrostomy “pigtail” drain placement is spreading worldwide, with high success-rate and low morbidity, and is increasingly performed as outpatient procedure. The paper reports an unusual very early complication of this procedure and discusses the peculiar aspects of this event in an outpatient setting. Methods: The first case of a 56-year-old outpatient developing a postoperative diffused acute peritonitis by gastric juice spilling caused by the misplacement of the distal end of two transgastric drains not reaching the pseudocyst is reported. As the case was programmed as outpatient and acute peritonitis …