OBJECTIVES: To investigate the ability of susceptibility-weighted imaging (SWI) to predict stroke evolution in comparison with perfusion-weighted imaging (PWI). METHODS: In a retrospective analysis of 15 patients with non-lacunar ischaemic stroke studied no later than 24 h after symptom onset, we used the Alberta Stroke Program Early CT Score (ASPECTS) to ...

Magnetic elastomers have been widely pursued for sensing and actuation applications. Silicone-based magnetic elastomers have a number of advantages over other materials such as hydrogels, but aggregation of magnetic nanoparticles within silicones is difficult to prevent. Aggregation inherently limits the minimum size of fabricated structures and leads to non-uniform response ...

A 58-year-old woman with breast carcinoma, after mastectomy, radiotherapy, and chemotherapy, underwent a whole-body F-18 FDG PET/CT for restaging, which revealed multiple skeletal metastasis. Hypometabolism was noted in the right frontal lobe. The patient subsequently underwent a C-11 methionine brain scan, which demonstrated multiple dural-based metastatic foci confirmed on contrast-enhanced ...

The purposes of this study were to assess chronologic changes in normal growth plate after radiofrequency-induced thermal injury and to evaluate the feasibility of MRI for revealing alteration of the growth plate. Radiofrequency ablation was performed on the right proximal tibia of 13 8-week-old New Zealand White rabbits. An 18-gauge ...

PURPOSE: To evaluate the findings of hepatic metastases from malignant pheochromocytoma/paraganglioma on non-contrast-enhanced and contrast-enhanced ultrasonography (US) and compare them with other imaging modalities. SUBJECTS AND METHODS: US was performed on eight patients with 65 hepatic metastases. Non-contrast computed tomography (CT), meta-iodo-benzyl-guanidine scintigraphy ((123)I-MIBG), and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) ...

OBJECTIVE: To assess the correlation between the enlarged vestibular aqueduct (EVA) diameter and (1) the hearing loss level (mild, moderate, severe and profound and (2) the hearing evolution. The secondary objective was to obtain measurement limits on the coronal plane of the temporal bone CT scan for the diagnosis of ...

PURPOSE: To evaluate the use of a novel real-time magnetic resonance imaging (MRI) technique for the assessment of normal swallowing dynamics. MATERIALS AND METHODS: In a cohort of 10 healthy subjects, real-time MRI movies at 24.3 frames per second were obtained in sagittal, coronal, and axial orientation during self-controlled swallows ...

Glutamate, a major neurotransmitter in the brain, shows a pH- and concentration-dependent chemical exchange saturation transfer effect (GluCEST) between its amine group and bulk water, with potential for in vivo imaging by nuclear magnetic resonance. GluCEST asymmetry is observed ∼3 p.p.m. downfield from bulk water. Middle cerebral artery occlusion in ...

Introduction: Apolipoprotein E4 (ApoE ε4) polymorphism is a known genetic risk factor for Alzheimer's disease (AD). Objectives: To evaluate the role of ApoE ε4 on white matter structural integrity in AD. Methods: Subjects were 32 patients with probable AD (ApoE ε4-positive: n = 15) and 18 matched controls (ApoE ε4-positive: ...

PURPOSE: To evaluate hyperintense Gd-DTPA- compared with hyper- and hypointense Gd-EOB-DTPA-enhanced magnet resonance imaging (MRI) in c-myc/TGFα transgenic mice for detecting hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty HCC-bearing transgenic mice with overexpression of the protooncogene c-myc and transforming growth factor-alpha (TGF-α) were analyzed. MRI was performed using a 3-T ...

PURPOSE: Positron emission tomography (PET) imaging of brain amyloid load has been suggested as a core biomarker for Alzheimer's disease (AD). The aim of this study was to test the feasibility of using PET imaging with (18)F-AV-45 (florbetapir) in a routine clinical environment to differentiate between patients with mild to ...

OBJECTIVE:To evaluate cognitive changes in a cohort of radiologically isolated syndromes (RIS) suggestive of multiple sclerosis (MS) and to assess their relationship with quantitative magnetic resonance (MR) measures such as white matter (WM), lesion loads, and cerebral atrophy. METHODS:We assessed the cognitive performance in a group of 29 subjects with ...

OBJECTIVE: (a) To relate MRI patterns of brain injury to somatosensory evoked potentials (SEPs), and (b) to determine the prognostic value of SEPs in addition to continuous EEG monitoring (cEEG) and cerebral imaging, in term asphyxiated newborns. METHODS: Fifty one consecutive neonates were studied. Survivors were followed for at least ...

BACKGROUND: In addition to classic midbrain pathology, Parkinson's disease (PD) is accompanied by changes in pontine and medullary brainstem structures. These additional abnormalities may underlie non-motor features as well as play a role in motor disability. Methods: Using novel magnetic resonance imaging (MRI) methods based on rotating frame adiabatic R(1ρ) ...

PURPOSE: To investigate the within and between subject variability of quantitative cerebral blood flow (CBF) measurements in normal subjects using various MRI techniques and positron emission tomography (PET). MATERIALS AND METHODS: Repeated CBF measurements were performed in 17 healthy, young subjects using three different MRI techniques: arterial spin labeling (ASL), ...

MR acoustic radiation force imaging (ARFI) is an elegant adjunct to MR-guided high intensity focused ultrasound for treatment planning and optimization, permitting in situ assessment of the focusing and targeting quality. The thermal effect of high intensity focused ultrasound pulses associated with ARFI measurements is recommended to be monitored on ...

Organophosphates are highly toxic substances, which cause severe brain damage. The hallmark of the brain injury is major convulsions. The goal of this study was to assess the spatial and temporal MR changes in the brain of paraoxon intoxicated rats. T2-weighted MRI and (1) H-MR-spectroscopy were conducted before intoxication, 3 ...

PURPOSE: To systematically evaluate and compare the performance of water-saturated and nonwater-saturated T1-weighted 3.0 T magnetic resonance imaging (MRI) in the application of visceral adipose tissue (VAT) quantification. MATERIALS AND METHODS: Forty-five patients underwent abdomen MRI using two different sequences at 3.0 T: 1) a traditional T1-weighted gradient echo sequence, ...

Object Immunotherapy targeting the Wilms tumor 1 (WT1) gene product is a promising treatment modality for patients with malignant gliomas, and there have been reports of encouraging results. It has become clear, however, that Gd-enhanced MR imaging does not reflect prognosis, thereby necessitating a more robust imaging evaluation system for ...

A toroidal magnetic moment in the absence of a conventional total magnetic moment was first observed in a novel tetranuclear dysprosium cluster with nonmagnetic ground state. The toroidal state is quite robust with respect to variations of the exchange parameters.

BACKGROUND AND PURPOSE:MTI has the potential to detect abnormalities in normal-appearing white and gray matter on conventional MR imaging. Early detection methods and disease progression markers are needed in HD research. Therefore, we investigated MTI parameters and their clinical correlates in premanifest and manifest HD.MATERIALS AND METHODS:From the Leiden TRACK-HD ...

We model a very large, tunable magnetoresistance (MR) in a graphene nanoribbon field-effect transistor, without artificial engineering of ferromagnetic contacts. A high MR of nearly 100% (about 50%) is obtained at low temperature (room temperature). We show that the MR ratio can be further tuned by using conventional electric field, ...

We report Lorentz force-induced actuation of a silicon microcantilever having an integrated resistive heater. Oscillating current through the cantilever interacts with the magnetic field around a NdFeB permanent magnet and induces a Lorentz force that deflects the cantilever. The same current induces cantilever heating. With AC currents as low as ...

Noncontrast computed tomography (NCCT) has been considered the standard test for determining eligibility for thrombolysis from the beginning of the thrombolytic era. CT angiography (CTA) reveals the cranio-cervical vessel and the occlusion site. Furthermore, the source image (SI) of the CTA (CTA-SI) reflects cerebral blood volume and can detect the ...

We have measured the magnetization-induced second harmonic generation (MSHG) of a nanocomposite consisting of iron oxide nanoparticles in a polymer film. The existing theoretical framework is extended to include DC magnetic fields in order to characterize the MSHG signal and analyze the measurements. Additionally, magnetic hysteresis loops are measured for ...

We report the implementation of nuclear magnetic resonance (NMR) shielding tensors within the four-component relativistic Kohn-Sham density functional theory including non-collinear spin magnetization and employing London atomic orbitals to ensure gauge origin independent results, together with a new and efficient scheme for assuring correct balance between the large and small ...

Recent magnetic resonance imaging (MRI) studies suggest that abnormalities in Huntington's disease (HD) extend to white matter (WM) tracts in early HD and even in presymptomatic stages. Thus, changes of the corpus callosum (CC) may reflect various aspects of HD pathogenesis. We recruited 17 HD patients, 17 pre-HD subjects, and ...

We evaluated the efficacy of fusion imaging that fuses conventional sonography images with hepatobiliary phase contrast-enhanced MR images obtained with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) as the reference image for the detection of hepatocellular carcinomas (HCCs). Eighty-seven HCCs with a maximum diameter of between 1 and 3 cm at the time ...

The objective of our study was to determine the clinical display thresholds of an ultrasound tomography prototype relative to MRI for comparable visualization of breast anatomy and tumor rendering. Thirty-six women were imaged with MRI and our ultrasound tomography prototype. The ultrasound tomography scan generated reflection, sound-speed, and attenuation images. ...

Exposure of patients with active implants (e.g. cardiac pacemakers and neurostimulators) to magnetic gradient fields (kHz range) during magnetic resonance imaging presents safety issues, such as unintended stimulation. Magnetically induced electric fields generate currents along the implant's lead, especially high at the distal tip. Experimental evaluation of the induced electric ...

Patients with Crohn's disease are at increased risk for small bowel adenocarcinoma. We report herein two cases of Crohn's disease-related ileal adenocarcinoma, which were investigated by means of magnetic resonance (MR)-enterography. Two different patterns were observed. In one case, the tumor presented as long circumferential, asymmetric and heterogeneous thickening of ...

Purpose: Partial volume effect in positron emission tomography (PET) can cause incorrect quantification of radiopharmaceutical uptake in functional imaging. A PET partial volume correction method is presented to attenuate partial volume blurring and to yield voxel-based corrected PET images.Methods: By modeling partial volume effect as a convolution of point spread ...

Purpose: Partial scan reconstruction (PSR) artifacts are present in myocardial perfusion imaging using dynamic multidetector computed tomography (MDCT). PSR artifacts appear as temporal CT number variations due to inconsistencies in the angular data range used to reconstruct images and compromise the quantitative value of myocardial perfusion when using MDCT. The ...

We have used liquid state ("Overhauser") Dynamic Nuclear Polarization (DNP) to significantly enhance the signal to noise ratio (SNR) of Magnetic Resonance Imaging (MRI). For the first time this was achieved by hyperpolarizing directly in the MRI-scanner field of 1.5T in continuous flow mode and immediately delivering the hyperpolarized substance ...

Magnetic resonance (MR) provides a non-invasive way to investigate changes in the brain resulting from aging or neurodegenerative disorders such as Alzheimer's disease (AD). Performing accurate analysis for population studies is challenging because of the interindividual anatomical variability. A large set of tools is found to perform studies of brain ...

The high molecular weight and low concentration of brain glycogen render its noninvasive quantification challenging. Therefore, the precision increase of the quantification by localized (13) C MR at 9.4 to 14.1 T was investigated. Signal-to-noise ratio increased by 66%, slightly offset by a T(1) increase of 332 ± 15 to ...

A major function of the human brain is to mediate interactions with other people. Until recently, studying social interactions as they occur within the brain was not possible due to the lack of measurable methods to observe two interacting minds simultaneously. We have developed a novel MRI dual-head volume coil ...

In this experiment, we evaluated the effects of strong static magnetic fields (SMF) on the orientation of myotubes formed from a mouse-derived myoblast cell line, C2C12. Myogenic differentiation of C2C12 cells was conducted under exposure to SMF at a magnetic flux density of 0-10 T and a magnetic gradient of 0-41.7 T/m. ...

BACKGROUND: We evaluated the sensitivity and specificity of post-vascular phase (Kupffer imaging) by contrast-enhanced ultrasonography (CEUS) using perflubutane microbubbles (Sonazoid) in comparison with conventional B-mode ultrasonography (US) for the detection of hepatocellular carcinoma (HCC) nodules. METHODS: A total of 100 treatment-naïve HCC patients admitted at our hospital between December 2007 ...

Abstract Conclusions: An abrupt change in the venous caliber, producing turbulent flow, may be a cause of pulsatile tinnitus (PT). The largest area/smallest area (L/S) ratio >4.75 may be a criterion indicating abrupt caliber change and causing PT. Objectives: Contrast-enhanced CT is recommended as an initial work-up modality in PT. ...

To date, growth of the human fetal cerebellum has been estimated primarily from linear measurements from ultrasound and 2D magnetic resonance imaging (MRI). In this study, we use 3D analytical methods to develop normative growth trajectories for the cerebellum in utero. We measured cerebellar volume, linear dimensions, and local surface ...

We present a lab on a chip (LOC) compatible modular platform for magnetic resonance (MR)-based investigation of sub-millimetre samples. The platform combines the advantages offered respectively by microcoils (high resolution at the microscale) and macroscopic surface coils (large field of view) as MR-detectors and consists of a phased array of ...

BACKGROUND AND PURPOSE:Various CTP parameters have been used to identify ischemic penumbra. The purpose of this study was to determine the optimal CTP parameter and threshold to distinguish true "at-risk" penumbra from benign oligemia in acute stroke patients without reperfusion.MATERIALS AND METHODS:Consecutive stroke patients were screened and 23 met the ...

According to the seventh edition of the American Joint Committee on Cancer guidelines, the TNM staging category in thin cutaneous melanomas depends on the mitotic rate (MR). In this study, we analyze the interobserver agreement of the MR in a series of 92 thin cutaneous melanomas. Serial sections of the ...

Introduction:Appeal for the domestic pig as a preclinical model for neurodevelopmental research is increasing. One limitation, however, is lack of magnetic resonance imaging (MRI) methods for brain volume quantification in the neonatal piglet. The purpose of this study was to develop and validate MRI methods for estimating brain volume in ...

BackgroundIn the early phase of viral encephalitis, conventional MRI may appear normal. Diffusion-weighted imaging (DWI) is a sensitive tool for detecting early changes in cellular function in the central nervous system.PurposeTo investigate the usefulness of DWI in the diagnosis of enterovirus 71 (EV71) encephalitis, and to determine whether DWI is ...

Background: Several authors have used advanced magnetic resonance imaging (MRI) techniques to investigate whether patients with neuromyelitis optica (NMO) have occult damage in normal-appearing brain tissue, similarly to multiple sclerosis (MS). To date, the literature contains no data derived from the combined use of several advanced MRI techniques in the ...

Apolipoprotein E (ApoE) ε4 is known as a genetic risk factor for Alzheimer's disease (AD). This study investigated the prevalence of imaging abnormalities suggestive of AD in cognitively normal ApoE ε4 carriers using (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and voxel-based morphometry (VBM). Forty-five cognitive normal ApoE ε4 allele carriers ...

The magnetic structures of ferromagnetic-film-coated carbon nanotube (CNT) probes and conventional pyramidal probes for a magnetic force microscope (MFM) were simulated using three-dimensional micromagnetic simulation. The CNT-MFM probes with a total probe diameter less than 60 nm are almost uniformly magnetized along the longitudinal direction of the CNT, which is the ...

Osteoarthritis is a degenerative disease of articular cartilage that may be associated with a loss of glycosaminoglycans. Quantitative sodium magnetic resonance imaging is highly specific to glycosaminoglycan content and could be used to assess the biochemical degradation of cartilage in early osteoarthritis. However, the reproducibility and repeatability of this technique ...