Search results for " radiography"
showing 10 items of 70 documents
A fully automatic 2D segmentation method for uterine fibroid in MRgFUS treatment evaluation
2015
PurposeMagnetic Resonance guided Focused UltraSound (MRgFUS) represents a non-invasive surgical approach that uses thermal ablation to treat uterine fibroids. After the MRgFUS treatment, an operator must manually segment the treated fibroid areas to evaluate the NonPerfused Volume (NPV). This manual approach is operator-dependent, introducing issues of result reproducibility, which could lead to errors in the subsequent follow-up phase. Moreover, manual segmentation is time-consuming, and can have a negative impact on the optimization of both machine-time and operator-time. MethodTo address these issues, in this paper a novel fully automatic method based on the unsupervised Fuzzy C-Means cl…
Imaging Assessment of Gastroduodenal Perforations.
2016
Gastroduodenal perforation is an emergency situation that usually requires early recognition and well-timed surgical treatment. It can arise from different natural, iatrogenic, or traumatic causes, and it can present with various symptoms especially in the early phase. This article reviews the role of the different imaging techniques in the diagnosis of gastroduodenal perforation, focusing on the direct and indirect signs that are encountered in conventional radiography and computed tomography; our personal experience is also provided.
A CAD system for nodule detection in low-dose lung CTs based on region growing and a new active contour model
2007
A computer-aided detection (CAD) system for the selection of lung nodules in computer tomography (CT) images is presented. The system is based on region growing (RG) algorithms and a new active contour model (ACM), implementing a local convex hull, able to draw the correct contour of the lung parenchyma and to include the pleural nodules. The CAD consists of three steps: (1) the lung parenchymal volume is segmented by means of a RG algorithm; the pleural nodules are included through the new ACM technique; (2) a RG algorithm is iteratively applied to the previously segmented volume in order to detect the candidate nodules; (3) a double-threshold cut and a neural network are applied to reduce…
National guidelines for dental diagnostic imaging in the developmental age
2019
This document aims to support the dental professional in choosing the adequate diagnostic technique, minimising the radiation dose in observance of the As Low As Reasonably Achievable (ALARA) principle (7). This principle states that the biological cost can only be justifed when the beneft, that is, the diagnosis, outweighs the risk related to radiation exposure. In this guideline paper, we report recommendations for radiologists, medical physicists, paediatrician, dentists and maxillofacial surgeons, with reference to the specifc felds.
Die Röntgendigitalanlage als Instrument zur kinematischen Untersuchung der Schulter — Eine Untersuchung zur Strahlenbelastung - Digital Radiography a…
1991
The radiation exposure during biomechanical investigation of the shoulder joint done with a digital radiography system (Polytron 1000 VR - Siemens) was measured experimentally. Total radiation dose and surface dose were determined by phantom measurements. The radiation exposure per image is about 1/6 to 1/7 of that of a conventional study. The digital radiography system used is thus suitable for kinesiologic studies of large joints in healthy volunteers.
Osteomyelitis - Bildgebende Verfahren und ihre Wertigkeit
1998
Various imaging modalities are used in diagnosis of acute and chronic infectious endogenous osteomyelitis and exogenous ostitis. The pathophysiological changes of osteomyelitis/ostitis in the bone and surrounding soft tissue are known. Findings in plain film radiography show these changes only in relatively advanced stages of disease. Hence, plain film radiographs are useful as a basic imaging modality by excluding other differentials and as a follow-up modality under therapy. Ultrasound-using advanced technology--offers diagnostic help in acute osteomyelitis, especially in infants. The various techniques of nuclear medicine show much higher sensitivity for detecting osteomyelitis than plai…
Nachsorge des Mammakarzinoms
1994
7865 follow-up examinations were performed on 420 patients who had had surgery for carcinoma of the breast; there were 2755 radiographs of the chest, 2660 sonographic examinations of the upper abdomen and 2450 contralateral mammograms. The most common findings were metastases seen on the chest radiographs during the 13-24 and 25-60 months intervals in 4.7% of cases. The incidence increased with initially higher tumour stages and in ductal carcinomas. Sonography of the upper abdomen showed 4.3% of liver involvement, mostly between the second and fifth year; this was independent of tumour stage or the histology of the primary tumour. Positive mammography of the contralateral breast was found …
The migration of femoral components after total hip replacement surgery: accuracy and precision of software-aided measurements.
2003
To assess the accuracy and precision of a software-aided system to measure migration of femoral components after total hip replacement (THR) on digitised radiographs.Subsidence and varus-valgus tilt of THR stems within the femur were measured on digitised anteroposterior pelvic radiographs. The measuring software (UMA, GEMED, Germany) relies on bony landmarks and comparability parameters of two consecutive radiographs. Its accuracy and precision were calculated by comparing it with the gold standard in migration measurements, radiostereometric analysis (RSA). Radiographs and corresponding RSA measurements were performed in 60 patients (38-69 years) following cementless THR surgery.The UMA s…
Neutron Radiography Visualization of Solid Particles in Stirring Liquid Metal
2015
Abstract This paper presents the analysis of the first dynamic neutron radiography experiment that visualized motion of solid particles in liquid metal, which was stirred by a system of four counter-rotating magnets. The paper also contains the quantitative results derived from neutron images: the distribution of particle concentration, number of admixed particles and velocities as functions of the magnet rotation speed.
Tonsillolith : a report of three clinical cases
2007
Tonsillolith is a rare dystrophic calcification as a result of chronic inflammation of the tonsils. Three asymptomatic cases of tonsillolith are reported, incidentally discovered through panoramic radiographs, which showed different sizes of radiopaque images, varying from 2 to 5mm; cases I and III images did not overlap the mandible ramus, which led to a probable diagnosis of soft tissue calcification. Case II had radiopaque unilateral images, with osseous tissue density, overlapping the mandibular ramus, leading to a benign intra-osseous lesion, which was considered as differential diagnosis. No symptoms were reported in any case. Only case I had clinical characteristics, showing highly c…