Magnetic resonance imaging findings in Reye syndrome have been reported only infrequently. A previously well 8-year-old boy presented with repeated episodes of vomiting and abdominal pain followed by altered sensorium and tonic spasms. This occurred 5 days after upper respiratory tract infection. His laboratory data revealed elevated liver enzymes, prolonged ...

To investigate the morphological features of nonpuerperal mastitis on magnetic resonance imaging (MRI). MRI results of 27 patients diagnosed with nonpuerperal mastitis were retrospectively analyzed according to the Breast Imaging Reporting and Data System (BI-RADS). According to the enhanced MRI results, 22 cases presented as nonmass-like enhancements and five cases ...

We propose the two-dimensional scanning probe operating with a single actuator, which is thought useful as a sample probe for optical coherence tomography (OCT). The probe was designed to use a single-body lensed fiber cantilever loaded with an iron-bead and driven by a single-solenoid actuator. Elliptic spiral trace patterns were ...

OBJECTIVE: The purpose of this study was to compare estimates of calcified plaque volume in the carotid arteries based on contrast-enhanced dual-energy CT angiograms with volume estimates based on native CT scans. CONCLUSION: Detection of hard plaque in the carotid arteries with dual-energy CT angiography was successful in all patients. ...

Purpose: To investigate the effects of 3,4-methylenedioxymethamphetamine (MDMA, commonly known as "ecstasy") on the alterations of brain metabolites and anatomic tissue integrity related to the function of the basal ganglia-thalamocortical circuit by using proton magnetic resonance (MR) spectroscopy and diffusion-tensor MR imaging. Materials and Methods: This study was approved by ...

Glomangiopericytoma (GPC) is a rare vascular neoplasm that arises almost exclusively from the nasal cavity or paranasal sinuses. GPC is also called sinonasal-type hemangiopericytoma, although current nomenclature, as well as classification in a group with myopericytomas, better emphasizes the relatively indolent behavior of this tumor. The authors present the FDG ...

Background  The presence of active brown adipose tissue (BAT) has been associated with a reduced risk of obesity in adult humans. Aim  To examine whether the presence and activity of BAT in patients undergoing PET-CT examinations is related to the presence of fatty liver. Method  We retrospectively analysed 3666 consecutive ...

To describe the spectrum of Magnetic Resonance spectroscopy in focal brain lesions and determine its diagnostic accuracy using histopathology as gold standard in differentiating neoplastic and non-neoplastic focal brain lesions. The study was conducted in Department of Radiology, Aga Khan University Hospital, Karachi from Dec 2006 till Jan 2009. Fifty ...

Purpose: To determine the feasibility of applying functional magnetic resonance (MR) imaging as an objective indicator of language disability in autism by using passive speech stimulation. Materials and Methods: This prospective study was approved by the institutional review board, and informed consent was obtained from the parents or guardians of ...

A synthetic hybrid nanomotor, which combines chemically powered propulsion and magnetically driven locomotion, is described. The new catalytic-magnetic nanomotor consists of a flexible multisegment Pt-Au-Ag(flex) -Ni nanowire, with the Pt-Au and Au-Ag(flex) -Ni portions responsible for the catalytic and magnetic propulsion modes, respectively. The experimental data and theoretical considerations indicate ...

The response of myocardial blood flow to sympathetic stimulation with cold is modulated by endothelium-related factors. As endothelial dysfunction is an early step in patients with coronary artery disease, the aim of this study was to establish a cold pressor test (CPT) setting for quantitative analysis of myocardial perfusion in ...

Microstructural metrics obtained using magnetic resonance imaging (MRI) such as transverse relaxation time and radial diffusivity has been used as in vivo markers of human brain tissue integrity. Considering the sensitivity of these parameters to some common biophysical contributors and their structural and spatial heterogeneity, we hypothesized that strong inter ...

Splenosis is the autotransplantation of splenic tissue resulting from the dissemination of cells from the pulp of the spleen after splenic injury or splenectomy. Implants can be found anywhere in the peritoneal cavity, especially on the serosal surfaces of small and large bowel, in the mesentery and diaphragm, implanted in ...

Recent magnetic resonance imaging studies suggest an increased transverse relaxation rate and reduced diffusion tensor imaging fractional anisotropy values in the substantia nigra in Parkinson's disease. The transverse relaxation rate and fractional anisotropy changes may reflect different aspects of Parkinson's disease-related pathological processes (ie, tissue iron deposition and microstructure disorganization). ...

Huntington's disease (HD) is a neurodegenerative genetic disorder that affects the brain. Atrophy of deep grey matter structures has been reported and it is likely that underlying pathologic processes occur before, or in concurrence with, volumetric changes. Measurement of metabolite concentrations in these brain structures has the potential to provide ...

PURPOSE: To extract the brain region from brain magnetic resonance (MR) images using a fast 3D level set method and a refinement process. MATERIALS AND METHODS: The proposed method introduces a speedup operator to the conventional 3D level set method in order to accelerate the level set evolution. While the ...

PURPOSE: The objective of this paper was to automatically segment the cerebellum from T1-weighted human brain magnetic resonance (MR) images. MATERIALS AND METHODS: The proposed method constructs a cerebellum template using five sets of 3-T MR imaging (MRI) data, which are used to determine the initial position and the shape ...

Quantitative magnetization transfer imaging yields indices describing the interactions between free water protons and immobile, macromolecular protons-including the macromolecular to free pool size ratio (PSR) and the rate of magnetization transfer between pools k(mf) . This study describes the first implementation of the selective inversion recovery quantitative magnetization transfer method ...

A novel architecture for a phased-array high intensity focused ultrasound (HIFU) device was investigated, aiming to increase the capabilities of electronic steering without reducing the size of the elementary emitters. The principal medical application expected to benefit from these developments is the time-effective sonication of large tumours in moving organs. ...

OBJECTIVES: White matter abnormalities are one of the most consistently reported findings in neuroimaging studies of bipolar disorder (BD). We conducted an anatomical likelihood estimation meta-analysis of BD whole-brain diffusion tensor imaging (DTI) studies, with the aim of identifying statistically consistent fractional anisotropy (FA) changes reflecting microstructural modifications to white ...

Amide proton transfer (APT) imaging has shown promise as an indicator of tissue pH and as a marker for brain tumors. Sources of error in APT measurements include direct water saturation, and magnetization transfer (MT) from membranes and macromolecules. These are typically suppressed by postprocessing asymmetry analysis. However, this approach ...

The processes by which new white-matter lesions in multiple sclerosis (MS) develop are only partially understood. Much of this understanding has come through magnetic resonance imaging (MRI) of the human brain. One of the hallmarks of new lesion development in MS is enhancement on T1-weighted MRI scans following the intravenous ...

We present the development of a microfluidically cryo-cooled planar coil for magnetic resonance (MR) microscopy. Cryogenically cooling radiofrequency (RF) coils for magnetic resonance imaging (MRI) can improve the signal to noise ratio (SNR) of the experiment. Conventional cryostats typically use a vacuum gap to keep samples to be imaged, especially ...

PURPOSE: To evaluate the accuracy in distinguishing adrenal adenomas from nonadenomas by means of quadriphasic CT exam, including unenhanced (UE), arterial enhanced (AE), portal enhanced (PE) and 5-min delayed enhanced (DE) CT scans. METHODS: This retrospective study had institutional review board approval; the need for informed consent was waived. From ...

Acute renal failure with severe loin pain induced by anaerobic exercise (ALPE) is a rare condition that is accompanied by wedge-shaped contrast enhancement on computed tomography (CT) without evidence of rhabdomyolysis. In two pediatric cases with ALPE, we tried to determine the relationship between findings from CT and magnetic resonance ...

Background: In order to view the position of the deep brain stimulator (DBS) lead in relation to the stereotactic target on 3-tesla magnetic resonance (3T-MR) images prior to the conclusion of the procedure, intraoperative postimplantation computed tomography (CT) images were fused with preoperative 3T-MR images. The method to do this ...

This work aims at assessing the in vitro potential of paramagnetic pH sensitive liposomes as imaging tools for visualizing drug-delivery and release processes by Magnetic Resonance Imaging (MRI). pH sensitive liposomes (pSLs) were formulated using the fusogenic phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE), the membrane stabilizer D-α-tocopherol-hemisuccinate (THS), and were loaded with several ...

A study on subjective perception has been carried out in order to gain further insight into subjective discomfort and sensations experienced during 7 T magnetic resonance imaging (MRI). This study provides information about subjective acceptance, which is essential if 7 T MRI is to become a clinical diagnostic tool. Of 573 subjects ...

Estimation of magnetization transfer (MT) parameters in vivo can be compromised by an inability to drive the magnetization to a steady state using allowable levels of radiofrequency (RF) irradiation, due to safety concerns (tissue heating and specific absorption rate (SAR)). Rather than increasing the RF duration or amplitude, here we ...

PURPOSE: To assess the value of hepatobiliary phase gadoxetic acid (EOB)-enhanced magnetic resonance imaging (MRI) for the diagnosis of early stage hepatocellular carcinoma (HCC) (<3 cm) compared to triple-phase dynamic multidetector computed tomography (MDCT). MATERIALS AND METHODS: In all, 52 patients with 60 pathologically proven HCCs underwent both EOB-enhanced MRI ...

After obtaining experimental data of CO(2) hydrate formation and dissociation in a porous medium using magnetic resonance imaging (MRI), the purpose of this study was to analyze the different dissociation rate of CO(2) hydrate using two heating rates. Images were obtained by using a fast spin-echo sequence, and the field ...

OBJECTIVES: Nephrogenic systemic fibrosis is a novel clinical entity encountered in subjects undergoing contrast enhanced magnetic resonance imaging (MRI). The aim of the present study is to evaluate the impact of contrast enhanced MRI exposure on lymphocyte DNA damage and serum levels of visfatin. DESIGN AND METHODS: Twenty-eight subjects undergoing ...

BACKGROUND AND PURPOSE: To evaluate the accuracy of (11)C-choline PET scans in defining dominant intraprostatic lesions (DILs) for radiotherapy target volume definition. MATERIAL AND METHODS: Eight men with prostate cancer who had (11)C-choline PET scans prior to radical prostatectomy were studied. Several methods were used to contour the DIL on ...

In the study we assessed the distortion of 7.0 T magnetic resonance (MR) images in reference to 1.5 T MR images in the radiosurgery of metastatic brain tumors. Radiosurgery with Gamma Knife Perfexion® was performed for the treatment of a 54-yr-old female patient with multiple brain metastases by the co-registered ...

INTRODUCTION: A multimodal approach of the human immunodeficiency virus (HIV) encephalopathy using quantitative magnetic resonance (MR) techniques can demonstrate brain changes not detectable only with conventional magnetic resonance imaging (MRI). The aim of this study was to compare conventional MRI and MR quantitative techniques, such as magnetic resonance spectroscopy (MRS) ...

Functional information regarding cardiac performance, pressure gradients, and local flow derangement are available from blood acceleration fields. Thus, this study examines a 2D and 3D phase contrast sequence optimized to efficiently encode three-directional, time-resolved acceleration in vitro and in vivo. Stenosis phantom acceleration measurements were compared to acceleration derived from ...

High-throughput magnetic resonance imaging (MRI) tools are required for the longitudinal investigation of vascular diseases in mouse models. Angiographic data from various anatomic regions may be needed in a single experiment. This study involves a three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) method using sequential acquisitions of four data ...

High resolution diffusion tensor images of the mouse brain were acquired using the pulsed gradient spin echo sequence and the oscillating gradient spin echo sequence. The oscillating gradient spin echo tensor images demonstrated frequency-dependent changes in diffusion measurements, including apparent diffusion coefficient and fractional anisotropy, in major brain structures. Maps ...

Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. A Medtronic Hall tilting disc (MH), and Carbomedics (CM), ...

Transcranial magnetic stimulation (TMS) is a neuropsychiatric tool that can serve as a useful method to better understand the neurobiology of cognitive function, behavior, and emotional processing. The purpose of this article is to examine the utility of TMS as a means to measure neocortical function in neuropsychiatric disorders in ...

This study quantified the impact of the well-known physiologic noise correction algorithm RETROICOR applied to a pain functional magnetic resonance imaging (FMRI) experiment at two field strengths: 1.5 and 3.0 T. In the 1.5-T acquisition, there was an 8.2% decrease in time course variance (σ) and a 227% improvement in ...

We have investigated dual-time-point (18)F-FDG PET for the detection and delineation of high-grade brain tumors using quantitative criteria applied on a voxel basis. METHODS: Twenty-five patients with suspected high-grade brain tumors and inconclusive MRI findings underwent (11)C-methionine PET and dual-time-point (18)F-FDG PET. Images from each subject were registered and spatially ...

ABSTRACT: BACKGROUND: Direct sputum smear microscopy is the mainstay of TB diagnosis in most low and middle income countries, and is highly specific for Mycobacterium tuberculosis in such settings. However it is limited by low sensitivity, particularly in HIV co-infected patients. Concentration by centrifugation has been reported to be more ...

Differential magnetic catch and release (DMCR) has been used as a method for the purification and separation of magnetic nanoparticles. DMCR separates nanoparticles in the mobile phase by magnetic trapping of magnetic nanoparticles against the wall of an open tubular capillary wrapped between two narrowly spaced electromagnetic poles. Using Au ...

Early cortical folding and the emergence of structural brain asymmetries have been previously analyzed by neuropathology as well as qualitative analysis of magnetic resonance imaging (MRI) of fetuses and preterm neonates. In this study, we present a dedicated image analysis framework and its application for the detection of folding patterns ...

BACKGROUND: The cerebellum has never been mechanically characterised, despite its physiological importance in the control of motion and the clinical prevalence of cerebellar pathologies. The aim of this study was to measure the linear viscoelastic properties of the cerebellum in human volunteers using Magnetic Resonance Elastography (MRE). METHODS: Coronal plane ...

PURPOSE: To analyze, in a pilot study, rapidly acquired dynamic contrast-enhanced (DCE)-MRI data with a general two-compartment exchange tracer kinetic model and correlate parameters obtained with measurements of hypoxia and vascular endothelial growth factor (VEGF) expression in patients with squamous cell carcinoma of the head and neck. METHODS AND MATERIALS: ...

We have studied the magnetic properties of aggregates of Mn0.5Zn0.5Gd(x)Fe(2-x)O4 ferrite nanoparticles, with x = 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.18, 0.20. The scanning electron microscopy micrographs show significant aggregation of the nanoparticles in all samples. Zero field cooled ...

To the Editor: Pleural malignant mesothelioma (MM) is an uncommon neoplasm with poor prognosis, strongly related to asbestos exposure, arising from mesothelial cells of the pleura. Pleurodynia is its most usual symptom, whereas the presence of pleural effusion combined with thickened pleura and calcified plaques in both computed tomographic (CT) ...

The pattern of myelination over the cerebral cortex, termed myeloarchitecture, is an established and often-used feature to visualize cortical organization with histology in a variety of primate species. In this paper, we use in vivo magnetic resonance imaging (MRI) and advanced image processing using surface rendering to visualize and characterize ...