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In order to obtain meaningful ultrasonic images, the operator must have an overall understanding and therefore correct use of the controls available on the ultrasound device. In fact, unsuitable regulation of the equipment produces poor images and can lead to false positive or negative diagnosis.
Preoperative high-dose radiation for treatment of patients with advanced rectal cancer has been used to enhance resectability, facilitate sphincter-saving procedures, reduce the local recurrence rate and potentially improve survival. More recently concomitant chemotherapy as a sensitizing agent has been added in attempt to improve these results. One explanation of the greater efficacy and tolerance...
In examinations using external energy sources such as X-rays, ultrasound and injected radioactive substances, the information contained in the images is produced by the interaction between the energy and the organ under examination. This interaction can be visualized in two different ways: an image may be formed by the energy which manages to pass through the organ or its parts, or the energy reflected...
Precise staging of rectal carcinomas is mandatory in order to improve the long-term results and to individualize therapeutic approach. Endorectal ultrasound is important in accurately staging the tumor by identifying both depth of invasion and presumptive nodal status. Conventional local excision (LE) of a properly selected group of patients with low risk rectal cancers can provide long-term survival,...
The anal canal is 2–4 cm long. The dentate line of the mucosa denotes the squamocolumnar junction. The circular smooth muscle of the rectal wall continues downward as the internal anal sphincter (IAS). Anteriorly the muscle fibers from its anterior superior part run into the perineal body. The outer longitudinal component of the muscolaris propria extends as the longitudinal layer of the anal canal...
Staging of rectal cancer has assumed new meaning and importance in recent times. Dukes’ classification (1932) remains the most commonly used staging system today [1]. It was intended to provide a pathologic basis for prognosis in patients with rectal cancer.
Histologically the mucosa of the anal canal can be divided into three zones (Fig. VII.1). The upper part is covered with colorectal type mucosa. The middle part is the anal transitional zone (ATZ), which is covered by a specialized epithelium with varying appearances; it extends from the dentate line and on average 0.5–1.0 cm upwards. The lower part extends from the dentate line and downwards to the...
The intensity of postoperative surveillance for rectal cancer varies greatly between institutions, and recommendations in literature are inconsistent [1]. It is still unclear which method of detection will reveal local recurrence before clinical symptoms or markers of advanced growth appear. Lohnert et al. [2] very well summarized the effectiveness of common follow-up schedules. Anamnesis, tumor markers,...
Hemodialysis sessions are often complicated by the occurrence of intradialytic hypotension (IDH), mainly due to the decrease of central blood volume. Blood oxygen content may play a role in hypotension onset and can reflect changes in cardiac output and tissue perfusion. Currently, there is an increasing interest in intradialytic monitoring, through the development of biofeedback based technologies...
We present a method to recover the dynamic writing order from static images of handwriting. The static handwriting is initially represented by its skeleton, which is then converted into a graph, whose arcs correspond to the skeleton branches, and nodes to either end point or branch point of the skeleton. Criteria derived by handwriting generation are then applied to transform the graph in such a way...
Acute hypotension is a frequent complication of hemodialysis. Blood oxygenation may play a role in hypotension and hypoxemia may be considered as a surrogate marker of hemodynamic instability. Continuous, non-invasive monitoring of oxygen saturation (SO2) during hemodialysis is now possible, by means of sensors measuring SO2 in blood entering the dialyzer. The aim of the present work was to analyze...
Input characterization to describe the flow of incoming traffic in network systems, such as the grid and the WWW, is often performed by using Markov modulated poisson processes (MMPP). Therefore, to enact capacity planning and quality-of-service (QoS) oriented design, the model of the servers that receive the incoming traffic is often described as a MMPP/M/1 queue. In a work we have provided an approximate...
The Markov modulated Poisson process (MMPP) has been shown to well describe the flow of incoming traffic in networked systems, such as the Grid and the WWW. This makes the MMPP/M/1 queue a valuable instrument to evaluate and predict the service level of networked servers. In a recent work we have provided an approximate solution for the response time distribution of the MMPP/M/1 queue, which is based...
The high-level-architecture (HLA) is an IEEE standard for the interoperability and integration of (autonomous) simulation packages and applications (termed federates in the HLA context). It is based on a middleware-level component referred to as run-time-infrastructure (RTI) offering a set of interoperability services to the overlying simulation software. Time-management is the suite of services allowing...
Input characterization to describe the flow of incoming traffic in network systems, such as the GRID and the WWW, is often performed by using Markov modulated Poisson processes (MMPP). Therefore, to enact capacity planning and quality-of-service (QoS) oriented design, the model of the hosts that receive the incoming traffic is often described as a MMPP/M/1 queue. The drawback of this model is that...
The 24-hour changes in the complexity of ventricular repolarization in hemodialysis (HD) patients were quantified by principal component analysis (PCA) of the T wave. The effects of dialysis sessions leading to different plasma potassium levels ('Ktow' and 'Khigh') were analyzed. Forty-six Hotter recordings were collected from twelve patients. PCA was applied to the T waves extracted from each beat...
In this paper we present the design and implementation of a Time Management Converter (TiMaC) for HLA based simulation systems. TiMaC is a layer interposed in between the federate and the underlying RTI in order to map the conservative Time Management interface onto the optimistic one. In this way, TiMaC transparently supports optimistic execution for federates originally designed for the conservative...
A differential, nonlinear model of patients under hemodialytic treatment has been used to analyze the patient's state during the dialysis and to evaluate the optimal temporal course to be assigned to the dialysis variables (ultrafiltration rate and dialysate sodium concentration) in order to obtain prescribed changes in the patient's biological variables. Examples show how the model is able to predict...
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