Search Results
Results 1 - 50 of 1126
1 2 3 4 5 6 7 8 9 10 >
Alterio Daniela D Advanced Radiotherapy Center, European Institute of Oncology, Milan, Italy. Electronic address: - - 2014
Irradiation of the Pharyngeal Superior Constrictor Muscle (PSCM) seems to play a crucial role in radiation-related swallowing dysfunctions. Purpose of our study was to quantify operator-related variability in the contouring of PSCM on Computed Tomography (CT) scans and adherence with contours derived from MR images. Three sets of treatment planning ...
Wiener Erik C EC Hillman Cancer Center, University of Pittsburgh Medical Center , 5117 Centre Avenue, Pittsburgh, Pennsylvania 15213, United - - 2014
Important requirements for exogenous dyes or contrast agents in magnetic resonance imaging (MRI) include an effective concentration of paramagnetic or superparamagnetic ions at the target to be imaged. We report the concise synthesis and characterization of several new enantiopure bifunctional derivatives of (α(1)R,α(4)R,α(7)R,α(10)R)-α(1),α(4),α(7),α(10)-tetramethyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTMA) (and their 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) ...
Lehner Sebastian S Department of Nuclear Medicine, University of Munich, Munich, - - 2014
To evaluate the influence of SPECT attenuation correction on the quantification of hibernating myocardium derived from perfusion SPECT and (18)F-FDG PET. 20 patients underwent rest (99m)Tc-tetrofosmin perfusion SPECT/CT and (18)F-FDG PET/CT. Perfusion images were reconstructed without attenuation correction (NC), with attenuation correction based on the CT from the SPECT/CT (AC_SPECT), ...
Schneider Thomas T Policlinic for Oral Surgery, Clinic for Cranio-Maxillofacial Surgery, Centre of Dental Medicine, University of Zurich, Zurich, - - 2014
Stafne bone cavities are usually found in men 50-70 years old. Typically they appear as lingual, open, ovoid lesions of the molar region of the lower jaw, and most contain parts of the submandibular gland. We have retrospectively examined panoramic radiographs acquired over a 5-year period. All lesions suspected of ...
Zhang Jianyuan - - 2014
Water-soluble derivatives of gadolinium-containing metallofullerenes have been considered to be excellent candidates for new magnetic resonance imaging (MRI) contrast agents because of their high relaxivity and characteristic encapsulation of the lanthanide ions (Gd3+), preventing their release into the bioenvironment. The trimetallic nitride template endohedral metallofullerenes (TNT EMFs) have further advantages ...
Kamata Ken - - 2013
Background and study aims: Pancreatic ductal adenocarcinomas (PDAC) sometimes arise in patients with intraductal papillary mucinous neoplasms (IPMNs). This study examined the incidence of PDACs concomitant to or derived from branch duct IPMNs. The usefulness of endoscopic ultrasonography (EUS) relative to other imaging methods for detecting these tumors was also ...
Aubrey-Bassler F Kris - - 2013
ABSTRACTObjective:Because a majority of urinary tract stones (UTSs) pass spontaneously and clinically significant alternative pathology is rare, we hypothesize that many computed tomographic (CT) scans to diagnose them are likely unnecessary. We sought to measure the impact of renal CT scans on resource use and to justify a prospective study ...
Ungi Tamas - - 2013
Computerized navigation improves the accuracy of minimally invasive pedicle screw placement during spine surgery. Such navigation, however, exposes both the patient and the staff to radiation during surgery. To avoid intraoperative exposure to radiation, tracked ultrasound snapshots-ultrasound image frames coupled with corresponding spatial positions-could be used to map preoperatively defined ...
Mylonas Ilias - - 2013
We sought to quantify coronary artery calcium (CAC) using a single contrast-enhanced cardiac computed tomography angiography (CCTA) study. CCTA has been successfully used for the assessment of coronary artery stenoses, whereas non-contrast ECG-gated computed tomography (Standard-CAC) is commonly performed to quantify CAC. Thus each scan individually contributes to the total ...
Arimura Hidetaka - - 2013
We have proposed an automated method for three-dimensional (3D) measurement of cerebral cortical thicknesses based on fuzzy membership maps derived from magnetic resonance (MR) images for evaluation of Alzheimer's disease (AD). The cerebral cortical thickness was three-dimensionally measured on each cortical surface voxel by using a localized gradient vector trajectory ...
Black David E - - 2013
Background: The gold standard for determining the left ventricular ejection fraction is cardiac magnetic resonance imaging. Other parameters for determining the ejection fraction such as M-mode echocardiography are operator-dependant and often inaccurate. Assessment of the displacement of the mitral valve annulus using two-dimensional speckle tracking echocardiography may provide an accurate ...
Win Thida T Lister Hospital, Coreys Mills Lane, Stevenage, Hertfordshire, United - - 2013
We prospectively examined the role of tumor textural heterogeneity on positron emission tomography/computed tomography (PET/CT) in predicting survival compared with other clinical and imaging parameters in patients with non-small cell lung cancer (NSCLC). The feasibility study consisted of 56 assessed consecutive patients with NSCLC (32 males, 24 females; mean age ...
Phan C M CM Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, - - 2013
Bone histomorphometry measurements require high spatial resolution that may not be feasible using multidetector CT (MDCT). This study evaluated the trabecular microarchitecture of lumbar spine using MDCT and C-arm CT in a series of young adult patients with anorexia nervosa (AN). 11 young females with AN underwent MDCT (anisotropic resolution ...
Roy Bhaswati - - 2013
INTRODUCTION: The study was performed to compare dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) with 3-dimensional (3D) pseudocontinuous arterial spin labeling (PCASL) MRI in gliomas with an aim to see whether arterial spin labeling (ASL)-derived cerebral blood flow (CBF) values can be used as an alternative to DCE-MRI for its ...
Torii Masaaki M Department of Neurobiology and Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06510, USA. - - 2013
Corticothalamic (CT) feedback outnumbers thalamocortical projections and regulates sensory information processing at the level of the thalamus. It is well established that EphA7, a member of EphA receptor family, is involved in the topographic mapping of CT projections. The aim of the present study was to dissect the precise impact ...
Aubrey-Bassler F Kris - - 2013
ABSTRACTObjective:Because a majority of urinary tract stones (UTSs) pass spontaneously and clinically significant alternative pathology is rare, we hypothesize that many computed tomographic (CT) scans to diagnose them are likely unnecessary. We sought to measure the impact of renal CT scans on resource use and to justify a prospective study ...
Okumura Yasuo - - 2012
Anatomic Distortion of 3D Mapping. Background: Although catheter tip-tissue contact is known as a reliable basis for mapping and ablation of atrial fibrillation (AF), the effects of different mapping methods on 3-dimensional (3D) map configuration remain unknown. Methods and Results: Twenty AF patients underwent Carto-based 3D ultrasound (US) evaluation. Left atrium ...
Bourier Felix - - 2012
MRI-Derived 3D-Augmented Biplane Fluoroscopy. Background: Despite the advancement of technology in electroanatomic mapping systems (EAMS), fluoroscopy remains a necessary, basic imaging modality for electrophysiology procedures. We present a feasibility study of new software that enables 3D-augmented fluoroscopy in biplane catheterization laboratories for planning and guidance of pulmonary vein isolation (PVI). The ...
Pellegrino Pier Luigi - - 2012
BACKGROUND: Radiofrequency catheter ablation (RFCA) of atrial fibrillation is an effective and definitive treatment. The methods used to guide RFCA have evolved over the years from a purely electrophysiological approach, in which anatomical lesions were guided solely by fluoroscopy and angiographic imaging of the pulmonary veins, to an approach guided ...
Deipolyi Amy R AR Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114, - - 2012
To assess the reliability of cerebral blood volume (CBV) maps as a substitute for diffusion-weighted MRI (DWI) in acute ischemic stroke. In acute stroke, DWI is often used to identify irreversibly injured "core" tissue. Some propose using perfusion imaging, specifically CBV maps, in place of DWI. We examined whether CBV ...
Schweser Ferdinand - - 2012
Quantitative susceptibility mapping (QSM) is a novel magnetic resonance-based technique that determines tissue magnetic susceptibility from measurements of the magnetic field perturbation. Due to the ill-posed nature of this problem, regularization strategies are generally required to reduce streaking artifacts on the computed maps. The present study introduces a new algorithm ...
Ullmann Jeremy F P - - 2012
The C57BL mouse is the centrepiece of efforts to use gene-targeting technology to understand cerebellar pathology, thus creating a need for a detailed magnetic resonance imaging (MRI) atlas of the cerebellum of this strain. In this study we present a methodology for systematic delineation of the vermal and hemispheric lobules ...
Yasuda R R Department of Neurosurgery, Mie University Graduate School of Medicine, Tsu, Mie, - - 2012
Measurement of perfusion parameters is typically done using an intravenous injection of contrast medium. This purpose of this study was to evaluate the feasibility of measuring regional and global CBV using C-arm CT with IA injections of contrast medium. Twelve canines were studied. CBV measurement was performed using standard PCT, ...
Voyvodic James T - - 2012
To evaluate the reproducibility of presurgical functional MRI (fMRI) language mapping based on test-retest scans, comparing traditional activation t-maps to relative activation maps normalized by activation mapping as percentage of local excitation (AMPLE). Language fMRI scans were performed by 12 healthy volunteer subjects undergoing a standard clinical presurgical mapping protocol ...
Samarin Andrei - - 2012
PURPOSE: Accurate attenuation correction (AC) is essential for quantitative analysis of PET tracer distribution. In MR, the lack of cortical bone signal makes bone segmentation difficult and may require implementation of special sequences. The purpose of this study was to evaluate the need for accurate bone segmentation in MR-based AC ...
Berker Yannick - - 2012
Accurate γ-photon attenuation correction (AC) is essential for quantitative PET/MRI as there is no simple relation between MR image intensity and attenuation coefficients. Attenuation maps (μ-maps) can be derived by segmenting MR images and assigning attenuation coefficients to the compartments. Ultrashort-echo-time (UTE) sequences have been used to separate cortical bone ...
Teimourian B - - 2012
Purpose: Dual-energy CT (DECT) is arguably the most accurate energy mapping technique in CT-based attenuation correction (CTAC) implemented on hybrid PET/CT systems. However, this approach is not attractive for clinical use owing to increased patient dose. The authors propose a novel energy mapping approach referred to as virtual DECT (VDECT) ...
Bittersohl Bernd - - 2012
OBJECTIVE: To evaluate T2* values in various histological severities of Osteoarthritis (OA). METHOD: Magnetic resonance imaging (MRI) and T2* mapping including a 3D double-echo steady-state (DESS) sequence for morphological cartilage assessment and a 3D multiecho data image combination (MEDIC) sequence for T2* mapping were conducted in 21 human femoral head ...
Chen Cheng-Kuang - - 2012
We present metamaterial-induced transparency (MIT) phenomena with enhanced magnetic fields in hybrid dielectric metamaterials. Using two hybrid structures of identical-dielectric-constant resonators (IDRs) and distinct-dielectric-constant resonators (DDRs), we demonstrate a larger group index (ng~354), better bandwidth-delay product (BDP~0.9) than metallic-type metamaterials. The keys to enable these properties are to excite either ...
Wang Z I - - 2012
We aim to report on the usefulness of a voxel-based morphometric MRI post-processing technique in detecting subtle epileptogenic structural lesions. The MRI post-processing technique was implemented in a morphometric analysis program (MAP), in a 30-year-old male with pharmacoresistant focal epilepsy and negative MRI. MAP gray-white matter junction file facilitated the ...
Chen Zikuan - - 2012
This article reports a computed inverse magnetic resonance imaging (CIMRI) model for reconstructing the magnetic susceptibility source from MRI data using a 2-step computational approach. The forward T2*-weighted MRI (T2*MRI) process is broken down into 2 steps: (1) from magnetic susceptibility source to field map establishment via magnetization in the ...
Cano M E - - 2012
A scanning system developed for planar magnetic surfaces composed of a moving line of three magnetoresistive ultrasensitive transducers, complemented by a signal conditioning circuit is presented. After the calibration of the sensors, it was used to determine magnetized surface images with different shapes to evaluate the sensitivity of the device, ...
Nguyen Vien X - - 2012
Unilateral hypermetabolic lesion of parotid gland demonstrated on PET/CT imaging may originate from a large spectrum of benign or malignant processes, such as adenoma, Warthin's tumor, oncocytic neoplasm, lymphoma, and primary or secondary malignancy of the gland. Bilateral and multifocal parotid gland disease is less common but possible because of ...
Ellingson Benjamin M - - 2012
PURPOSE: To compare "standardization," "Gaussian normalization," and "Z-score normalization" intensity transformation techniques in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) estimates of cerebral blood volume (CBV) in human gliomas. DSC-MRI is a well-established biomarker for CBV in brain tumors; however, DSC-MRI estimates of CBV are semiquantitative. The use of image ...
Williams A - - 2012
OBJECTIVE: Meniscus tear is a known risk factor for osteoarthritis (OA). Quantitative assessment of meniscus degeneration, prior to surface break-down, is important to identification of early disease potentially amenable to therapeutic interventions. This work examines the diagnostic potential of ultrashort echo time-enhanced T2∗ (UTE-T2∗) mapping to detect human meniscus degeneration ...
Li Jianqi - - 2012
This study demonstrates the dependence of non-local susceptibility effects on object orientation in gradient echo MRI and the reduction of non-local effects by deconvolution using quantitative susceptibility mapping. Imaging experiments were performed on a 3T MRI system using a spoiled 3D multi-echo GRE sequence on phantoms of known susceptibilities, and ...
Koshino Kazuhiro - - 2012
Attenuation correction of a single photon emission computed tomography (SPECT) image is possible using computed tomography (CT)-based attenuation maps with hybrid SPECT/CT. CT attenuation maps acquired during breath holding can be misaligned with SPECT, generating artifacts in the reconstructed images. The purpose of this study was to investigate the effects ...
Zinn Pascal O - - 2012
[This corrects the article on p. e25451 in vol. 6.].
Sancaktutar Ahmet Ali - - 2011
Objective: The goal of our prospective study was to measure the effect of a new standard model male gonad shield on the testicular radiation exposure during routine abdomino-pelvic CT. Subject and Methods: 200 male patients who underwent upper abdominal and pelvic Computerized Tomographys (CT) examinations were included in our study. ...
Ng Inn Wo - - 2011
OBJECTIVE: To evaluate the spatio-temporal relationships between articulators in the anterior oral cavity, during the production of Japanese fricative and plosive articulation using our proposed method for tooth visualization in MR image sequences. DESIGN: Ten healthy adults without malocclusion participated in the study. Customized maxillary and mandibular plates with space ...
Gupta Rajan T - - 2011
PURPOSE: To compare intraindividual differences in enhancement pattern of hepatic hemangiomas between gadobenate dimeglumine (Gd-BOPTA) and gadoxetate disodium (Gd-EOB-DTPA)-enhanced 3T MR imaging. MATERIALS AND METHODS: This is a HIPAA-compliant, IRB-approved retrospective study with waiver for informed consent granted. From 10/07 to 5/09, 10 patients (2 males, 8 females; mean age, ...
Sabat D - - 2011
We report a rare injury of distal humeral epiphyseal separation in a newborn during a Caesarean section. The diagnosis was made using magnetic resonance imaging. Emergency Caesarean deliveries with considerable traction applied to extract the baby can be the risk factor of such an injury.
Higashihara Hiroki - - 2011
PURPOSE: This study was aimed to compare the accuracy, sensitivity, and positive predictive value of C-arm CT (CACT) during selective transcatheter angiography with those of multidetector CT (MDCT) in the detection of hepatocellular carcinoma (HCC). MATERIAL AND METHODS: In this prospective study, 30 patients (mean age, 73 years) with unresectable HCC ...
Leng Lewis Z - - 2011
OBJECTIVE: We introduce a technique that uses intraoperative flat-panel detector computed tomography (FD-CT) and three-dimensional rotational angiography (3D-RA) acquired in the hybrid operative suite to provide full neuronavigation capabilities during cerebrovascular surgery without the use of preoperative imaging studies. METHODS: An Artis Zeego FD system (Siemens AG, Forchheim, Germany), mounted ...
Nakamura Yuko - - 2011
To investigate the clinical significance of the "transitional phase" at gadoxetate disodium (Gd-EOB)-enhanced magnetic resonance imaging for diagnosing hepatocellular carcinoma (HCC). We studied 54 patients with 70 histologically diagnosed HCC. Transitional- and hepatobiliary-phase (TP, HBP) images were acquired 3 and 20 minutes after Gd-EOB injection, respectively. Radiologists measured the size ...
Gilsanz Vicente - - 2012
To characterize the changes in brown adipose tissue (BAT) occurring during puberty in boys and girls. We examined the prevalence and the volume of BAT at different stages of sexual development in 73 pediatric patients who underwent positron emission tomography (PET)/computed tomography (CT) studies. Of the 73 patients studied, 43 ...
Liu Glenn G University of Wisconsin Carbone Cancer Center, Wisconsin Institutes for Medical Research, Room 7051, 1111 Highland Avenue, Madison, WI 53705, USA. - - 2011
To characterize proliferative changes in tumors during the sunitinib malate exposure/withdrawal using 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) positron emission tomography (PET)/computed tomography (CT) imaging. Patients with advanced solid malignancies and no prior anti-VEGF exposure were enrolled. All patients had metastatic lesions amenable to FLT PET/CT imaging. Sunitinib was initiated at the standard dose ...
Wintermark P - - 2011
Induced hypothermia is thought to work partly by mitigating reperfusion injury in asphyxiated term neonates. The purpose of this study was to assess brain perfusion in the first week of life in these neonates. In this prospective cohort study, MR imaging and ASL-PI were used to assess brain perfusion in ...
Biller S - - 2011
Magnetic marker monitoring (MMM) is a technique to determine the motility of the gastrointestinal tract and to observe the dissolution of pharmaceutical compounds. Todays magnetic markers usually consist of magnetized magnetite. Because of their weak magnetic fields, highly sensitive sensor systems are required. For a wider class of applications, stronger ...
Fotopoulos Vassilis - - 2011
One of the new challenges of Information Technology in the medical world is the protection and authentication of a variety of digital medical files, datasets, and images. In this work, the ability of magnetic resonance imaging (MRI) slice sequences to hide digital data is investigated and more specifically the case ...
1 2 3 4 5 6 7 8 9 10 >