Search results for "computed tomography"

The Foreign Body Response to an Implantable Therapeutic Reservoir in a Diabetic Rodent Model

2021

Advancements in type 1 diabetes mellitus treatments have vastly improved in recent years. The move toward a bioartificial pancreas and other fully implantable systems could help restore patient's glycemic control. However, the long-term success of implantable medical devices is often hindered by the foreign body response. Fibrous encapsulation "walls off" the implant to the surrounding tissue, impairing its functionality. In this study we aim to examine how streptozotocin-induced diabetes affects fibrous capsule formation and composition surrounding implantable drug delivery devices following subcutaneous implantation in a rodent model. After 2 weeks of implantation, the fibrous capsule sur…

MASSE RENALI INCIDENTALI: DIAGNOSI DIFFERENZIALE IN ECOGRAFIA, TC E RM

2018

Uncommon evolutions and complications of common benign liver lesions

2018

International audience; Frequently encountered on abdominal imaging studies, the majority of common benign liver lesions are asymptomatic, confidently diagnosed by imaging, and do not require further workup, follow-up, or treatment. The increasing use of multimodality liver imaging, has allowed the recognition of uncommon evolutions of common benign liver lesions such as size changes, fibrotic regression, and content and vascularization changes, and their complications such as rupture, hemorrhage, thrombosis, extrinsic compression, and malignancy. The purpose of this pictorial review is to describe and illustrate the incidence and diagnostic features of these uncommon evolutions and complic…

Use of Dual-Energy Computed Tomography for Evaluation of Genitourinary Diseases

2018

Since its clinical inception a decade ago, dual-energy computed tomography has expanded the array of computed tomography imaging tools available to the practicing abdominal radiologist. Of note, diagnostic solutions for imaging-based evaluation of genitourinary diseases, foremost kidney calculi and renal tumors characterization, represent the apogee applications of dual-energy computed tomography in abdominal imaging. This article reviews clinical applications of dual-energy computed tomography for the assessment of genitourinary diseases.

Comparison of MRI and VQ-SPECT as a Screening Test for Patients With Suspected CTEPH: CHANGE-MRI Study Design and Rationale

2020

The diagnostic strategy for chronic thromboembolic pulmonary hypertension (CTEPH) is composed of two components required for a diagnosis of CTEPH: the presence of chronic pulmonary embolism and an elevated pulmonary artery pressure. The current guidelines require that ventilation–perfusion single-photon emission computed tomography (VQ-SPECT) is used for the first step diagnosis of chronic pulmonary embolism. However, VQ-SPECT exposes patients to ionizing radiation in a radiation sensitive population. The prospective, multicenter, comparative phase III diagnostic trial CTEPH diagnosis Europe - MRI (CHANGE-MRI, ClinicalTrials.gov identifier NCT02791282) aims to demonstrate whether functional…

Automatische Klassifikation der Lebersegmente nach Couinaud: Entwicklung eines neuen Algorithmus und Evaluierung an Spiral-CT-Datensätzen

2003

Purpose: To develop a software tool that analyzes the anatomy of the portal vein branches and assigns segmental and subsegmental branches according to Couinaud's classification system and to evaluate its accuracy. Materials and Methods: The algorithm was developed in C++ on a PC. The algorithm recognizes the three major branching patterns of the portal vein. Segmental and subsegmental branches are assigned to 8 segments following Couinaud and encoded by 8 colors. The software was evaluated using CT data sets of 39 patients. After the individual segmental anatomy of each patient was determined by an experienced radiologist, automatic classification was performed and the results were compared…

Reclaimed asphalt test specimen preparation assisted by image analysis

2015

This paper presents a laboratory investigation aimed at establishing a protocol for the production of homogeneous asphalt mixtures test specimens, incorporating reclaimed asphalt by using a gyratory compactor with coring and trimming works. Stone mastic asphalt specimens were compacted at the previously identified target densities with the final aim of obtaining specimens with a fixed and homogeneous air void distribution. A microstructural study was conducted to characterize the homogeneity in the air void distribution using X-ray computed tomography (CT) combined with image analysis techniques. The study concluded that the gyratory compactor is suitable for producing homogeneous test spec…

A 10-Year Cone Beam Computerized Tomography Observation of the Buccal Bony Wall of an Immediately Placed Implant at the Anterior Maxilla: A Case Repo…

2017

Since the introduction of immediate implant placements, the buccal bony wall has been a major consideration for success due to its correlation with soft tissue contour and color. This report presents the stability of the buccal wall thickness of an immediately placed implant at the anterior maxilla over 10 years. Although the width of the buccal wall decreased at the 2-year post-op follow-up, it remained stable afterward according to cone beam computerized tomography (CBCT) scans. Hence, this report suggests that ensuring adequate bony wall thickness with bone augmentation and fixture position may promise the longevity of the buccal bony wall and surrounding soft tissue in an immediate impl…

Integrating user preference to similarity queries over medical images datasets

2010

International audience; Large amounts of images from medical exams are being stored in databases, so developing retrieval techniques is an important research problem. Retrieval based on the image visual content is usually better than using textual descriptions, as they seldom gives every nuances that the user may be interested in. Content-based image retrieval employs the similarity among images for retrieval. However, similarity is evaluated using numeric methods, and they often orders the images by similarity in a way rather distinct from the user's intention. In this paper, we propose a technique to allow expressing the user's preference over attributes associated to the images, so simil…

Left-Ventricle Segmentation of SPECT Images of Rats

2015

Single-photon emission computed tomography (SPECT) imaging of the heart is helpful to quantify the left-ventricular ejection fraction and study myocardial perfusion scans. However, these evaluations require a 3-D segmentation of the left-ventricular wall on each phase of the cardiac cycle. This paper presents a fast and interactive graph cut method for 3-D segmentation of the left ventricle (LV) of rats in SPECT images. The method is carried out in three steps. First, 3-D sampling of the LV cavity is made in a spherical-cylindrical coordinate system. Then, a graph-cut-based energy minimization procedure provides delineation of the myocardium centerline surface. From there, it is possible to…