Search results for "STED"
showing 10 items of 2256 documents
Imaging processing for CT angiography of the cervicocranial arteries: evaluation of reformatting technique.
2007
Purpose. The aim of this study was to compare computed tomography angiography (CTA) sliding-thin-slab (STS) multiplanar reformatting (MPR), STS maximum intensity projection (MIP) and three-dimensional (3D) volume rendering (VR) reformatting techniques in the evaluation of cervicocranial arteries. Materials and methods. Twenty patients examined with multislice CT were included in this study. CTA images were reformatted as STS-MIP, STS-MPR and 3DVR in orthogonal planes and in the oblique-coronal plane. Images were evaluated in consensus by two radiologists, with a third radiologist to resolve discordances in grading image quality parameters. The Spearman correlation analysis was performed to …
Value and limits of computer-assisted tomography.
1980
Three years ago, at the VIIth International Congress of Radiology in Otorhinolaryngology, held in Copenhagen, the early impressive results of computer-assisted tomography (CAT) in otorhinolaryngology were presented. Since considerable technologic and diagnostic progress of CAT has taken place in the meantime, questions about the increase in CAT's value and the expansion of its limits are appropriate now. Computed and, in some cases, conventional tomograms of facial lesions are used in the discussion of these questions. There is no doubt of CAT's advance within the last few years; there are, however, limits of CAT to be emphasized: (a) coronal CAT might be uncomfortable (especially if the ga…
Reproducible coronary plaque quantification by multislice computed tomography
2007
BACKGROUND: The aim of this study was to investigate reproducibility and accuracy of computer-assisted coronary plaque measurements by multislice computed tomography coronary angiography (QMSCT-CA). METHODS AND RESULTS: Forty-eight patients undergoing MSCT-CA and coronary arteriography for symptomatic coronary artery disease and quantitative intravascular ultrasound (IVUS, QCU) were examined. Two investigators performed the QMSCT-CA twice and a third investigator performed the QCU, all blinded for each other's results. There was no difference found for the matched region of interest (ROI) lengths (QCU 29.4 +/- 13 mm vs. QMSCT-CA 29.6 +/- 13 mm, P = 0.6; total length = 1,400 mm). The compari…
Influence of convolution filtering on coronary plaque attenuation values: observations in an ex vivo model of multislice computed tomography coronary…
2007
Attenuation variability ( measured in Hounsfield Units, HU) of human coronary plaques using multislice computed tomography (MSCT) was evaluated in an ex vivo model with increasing convolution kernels. MSCT was performed in seven ex vivo left coronary arteries sunk into oil followingthe instillation of saline (1/infinity) and a 1/50 solution of contrast material ( 400 mgI/ml iomeprol). Scan parameters were: slices/ collimation, 16/0.75 mm; rotation time, 375 ms. Four convolution kernels were used: b30f-smooth, b36f-medium smooth, b46f-medium and b60f-sharp. An experienced radiologist scored for the presence of plaques and measured the attenuation in lumen, calcified and noncalcified plaques …
Video-thoracoscopic surgical pleurodesis in the management of malignant pleural effusion: the importance of an early intervention.
2005
Thoracentesis plays an important role in cancer patients with symptomatic effusions, although its effect is short-lived and symptoms recur in almost all patients. Early video-thoracoscopic surgical pleurodesis may provide added benefit to a group of patients with advanced cancer presenting with symptomatic malignant pleural effusion. Seventy-six patients with advanced cancer and pleural effusion due to pulmonary-pleural metastases were recruited. In 51 cases (67.1%), at least one thoracentesis was performed before admission for surgery. Preoperative staging consisted of chest radiograph, CT scan, and blood gas analysis. The mean Karnofsky performance status was about 50. Pleurodesis with ta…
Focal cortical damage parallels cognitive impairment in minimal hepatic encephalopathy
2012
Little attention has been paid to cortical integrity in patients with minimal hepatic encephalopathy (MHE), although cognitive functions affected in early stages of liver disease are mainly allocated in different neocortical structures. Here we used cortical surface-based analysis techniques to investigate if patterns of cortical thinning accompany the mildest form of HE. To aim this goal, cortical thickness obtained from high-resolution 31 magnetic resonance imaging (MRI) was measured in patients with no MHE (NMHE), MHE, and healthy controls. Further correlation analyses were performed to examine whether scores in the critical flicker frequency (CFF) test, and blood ammonia levels accounte…
Reducing Patient Radiation Dose With Image Noise Reduction Technology in Transcatheter Aortic Valve Procedures
2015
X-ray radiation exposure is of great concern for patients undergoing structural heart interventions. In addition, a larger group of medical staff is required and exposed to radiation compared with percutaneous coronary interventions. This study aimed at quantifying radiation dose reduction with implementation of specific image noise reduction technology (NRT) in transcatheter aortic valve implantation (TAVI) procedures. We retrospectively analyzed 104 consecutive patients with TAVI procedures, 52 patients before and 52 after optimization of x-ray radiation chain, and implementation of NRT. Patients with 1-step TAVI and complex coronary intervention, or complex TAVI procedures, were excluded…
Value of magnetic-resonance cholangio-pancreatography (MRCP) after unsuccessful endoscopic-retrograde cholangio-pancreatography (ERCP).
1997
Background and Study Aims: The present study tries to evaluate the success rate of MRCP when two attempts by experts to perform ERCP in a center failed. Patients and Methods: From March 1996 to December 1996 thirteen patients fulfilled the inclusion criteria. The MR cholangiopancreatograms were acquired using commercially available software in a clinical MR scanner (Magnetom Expert 1T-Scanner, Siemens, Erlangen, Germany). MRCP utilized heavily T2-weighted turbo-spin echo sequences with fat supression (HASTE). Maximum intensity projection (MIP) of the pancreatic duct and biliary tree was then carried out. Additionally, T1-weighted sequences were obtained using the breath-hold technique. Resu…
Diagnostic performance of whole brain volume perfusion CT in intra-axial brain tumors: preoperative classification accuracy and histopathologic corre…
2012
Abstract Background To evaluate the preoperative diagnostic power and classification accuracy of perfusion parameters derived from whole brain volume perfusion CT (VPCT) in patients with cerebral tumors. Methods Sixty-three patients (31 male, 32 female; mean age 55.6 ± 13.9 years), with MRI findings suspected of cerebral lesions, underwent VPCT. Two readers independently evaluated VPCT data. Volumes of interest (VOIs) were marked circumscript around the tumor according to maximum intensity projection volumes, and then mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability Ktrans perfusion datasets. A second VOI was placed in the contra lateral cortex, as cont…
Acoustics of snoring and automatic snore sound detection in children
2017
Objective Acoustic analyses of snoring sounds have been used to objectively assess snoring and applied in various clinical problems for adult patients. Such studies require highly automatized tools to analyze the sound recordings of the whole night's sleep, in order to extract clinically relevant snore- related statistics. The existing techniques and software used for adults are not efficiently applicable to snoring sounds in children, basically because of different acoustic signal properties. In this paper, we present a broad range of acoustic characteristics of snoring sounds in children (N = 38) in comparison to adult (N = 30) patients. Approach Acoustic characteristics of the signals we…