Objective evaluation of acute adverse events and image quality of gadolinium-based contrast agents (gadobutrol and gadobenate dimeglumine) by blinded evaluation. Pilot study

Purpose

The purpose was to objectively evaluate a recently FDA-approved gadolinium-based contrast agent (GBCA) in comparison to our standard GBCA for acute adverse events and image quality by blinded evaluation.

Methods

Evaluation was made of a recently FDA-approved GBCA, gadobutrol (Gadavist; Bayer), in comparison to our standard GBCA, gadobenate dimeglumine (MultiHance; Bracco), in an IRB- and HIPAA-compliant study. Both the imaging technologist and patient were not aware of the brand of the GBCA used. A total of 59 magnetic resonance studies were evaluated (59 patients, 31 men, 28 women, age range of 5–85 years, mean age of 52 years). Twenty-nine studies were performed with gadobutrol (22 abdominal and 7 brain studies), and 30 studies were performed with gadobenate dimeglumine (22 abdominal and 8 brain studies). Assessment was made of acute adverse events focusing on objective observations of vomiting, hives, and moderate and severe reactions. Adequacy of enhancement was rated as poor, fair and good by one of two experienced radiologists who were blinded to the type of agent evaluated.

Results

No patient experienced acute adverse events with either agent. The target minor adverse events of vomiting or hives, and moderate and severe reactions were not observed in any patient. Adequacy of enhancement was rated as good for both agents in all patients.

Conclusions

Objective, blinded evaluation is feasible and readily performable for the evaluation of GBCAs. This proof-of-concept study showed that both GBCAs evaluated exhibited consistent good image quality and no noteworthy adverse events.     

Pressure-induced phase transition of ice in aqueous LiOH solution

I have examined the changes in in situ Raman spectra of ice in aqueous LiOH solution as a function of pressure at liquid nitrogen temperature (77 K). Here, I have shown the possibility that ice in aqueous LiOH solution transforms to a high-density amorphous like phase at around 0.9 GPa. I have mentioned that the results show differences strongly depending on the salts dissolved in the aqueous solutions.     

Incident-energy dependence of crystalline structures of ion beam deposited Au thin films

The energy dependence of crystalline structures in Au thin-film deposition processes was investigated with the use of a low-energy mass-selected ion beam system. Au films deposited on Si(100) untreated wafer surfaces by the beam system at different ion energies in the range of 20–200?eV were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD) and in-situ reflection high-energy electron diffraction (RHEED). The XRD results show that the kinetic energy provided by ion bombardment can facilitate crystal growth with specific orientations such as (100) or (110), the surfaces of which have relatively high surface energies. Our observations also suggest that each crystalline orientation appears only in a specific energy range of ion bombardment. These results indicate that Au crystalline orientations may be controlled by the ion irradiation energy during deposition processes.     

Flame Emission Spectrometry Using Atomic Absorption Apparatus (I) Determination of Sr In Sea Water

Flame emission determination of Sr in sea water is studied using an ordinary atomic absorption apparatus. The analytical line 4607 A is used with background correction at 4616 A. The ionization is found to be negligible in air acetylene flame with sea water, and the interference of H₂SO₄ is elimentated using the higher part of the flame.     

Incommensurate cooperative tilting modes of MnF6 octahedra relatedto the structural phasetransitions in BaMnF4

The structural phase transitions of the layer compound BaMnF₄ were studied by high-resolution X-ray diffraction using synchrotron radiation. The intensities and profiles of two kinds of superlattice reflections having incommensurate reduced wave vectors q ₁= (～ ± 1/5,0,0) _p and q ₂ =(～ ± 2/5,1/2,1/2)_p, respectively, were measured as a function of temperature from 25 K to 280 K. These temperature dependencies show that incommensurate structural phase transitions of second order occur at 234 K and 244 K. These structural phase transitions are interpreted as successive condensations of a folding-screen-like incommensurate plane-distortion mode and a commensurate anti-ferro-distortive tilting mode of the MnF₆ octahedra around the primitive a₀ - and b₀ -axes, when cooled down. It is also found that there is another structural phase transition at about 45 K related to a precursor structural distortion for the antiferromagnetic transition occurring at about 26 K.     

Thickness optimization of a multilayered structure on the coupling surface between a structure and an acoustic cavity

This paper describes a new design method to optimize thickness distribution of a multilayered structure which is located on the coupling surface between a structure and an acoustic cavity. The design method is based on the concept of the density approach in topology optimization incorporating a transfer matrix for a multilayered structure that includes a poroelastic media layer. The one-dimensional transfer matrix adopted here is an approximate representation addressing vibro-acoustic effects inherent in a multilayered structure, and balances calculation resources and desired accuracy. Applying the transfer matrix representation as boundary conditions on the coupling surface between a structure and an acoustic cavity, the modified equilibrium equation of the vibro-acoustic system is derived which is approximately but efficiently solved by the modal approach. In this study, the problem of minimizing the acoustic pressure within the cavity over the prescribed frequency range is formulated under the volume constraint of the poroelastic media layer. The continuous approximation of thickness distribution is assumed, and the thickness of the poroelastic media layer at each nodal point is chosen as design variables. Numerical results show that an acoustic response is significantly reduced by the optimal thickness distribution having a total weight equal to or less than that in the initial uniform thickness. These demonstrate that the proposed method is effective to design the optimal thickness distribution of a multilayered structure.     

Simulation of micro/nanometer-scale self-organized lightwave network (SOLNET) using the finite difference time domain method

A simulator for self-organized lightwave network (SOLNET) is developed. The simulator is based on the finite difference time domain method. SOLNET enables us to construct self-aligned coupling waveguides between misaligned micro/nanometer-scale optical devices by self-focusing, which arises from an increase in refractive index induced by write beams in photo-refractive materials. The SOLNET simulator reveals that an L-shaped nanometer-scale optical waveguide of SOLNET is grown from a 0.5-μm-wide optical waveguide when write beams are introduced from the optical waveguide into photo-refractive materials, where a wavelength filter is embedded. The SOLNET simulator also reproduces coupling path construction between a 2-μm-wide optical waveguide and a 0.5-μm-wide optical waveguide having a wavelength filter on the core edge. The optical waveguides are placed with misalignment of 0.5-μm offset. By introducing write beams from the 2-μm-wide optical waveguide, the incident write beams and reflected write beams from the wavelength filter merge into one optical waveguide in the photo-refractive materials, constructing a self-aligned coupling waveguide.     

Geometric analysis of spatial distortion in projection-type integral imaging

In projection-type integral imaging, positional errors in elemental images and elemental lenses affect three-dimensional (3D) image quality. We analyzed the relationships between the geometric distortion in elemental images caused by a projection lens and the spatial distortion in the reconstructed 3D image. As a result, we clarified that 3D images that were reconstructed far from the lens array were largely affected, and that the reconstructed images were significantly distorted in the depth direction at the corners of the displayed images.     

Fourier domain optical coherence tomography using optical demultiplexers imaging at 60,000,000 lines/s

We describe high-speed Fourier domain optical coherence tomography (OCT) using optical demultiplexers (ODs) for spectral dispersion. The OD enables separation of a narrow spectral band of 14 GHz (0.11 nm) from a broadband incident light at 256 different frequencies in 25.0 GHz intervals centered at 192.2 THz (1559.8 nm). OCT imaging of 60,000,000 axial scans per second was achieved through parallel signal acquisition using 256 balanced photoreceivers to simultaneously detect all the output signals from the ODs in a Fourier domain OCT system. OCT imaging at a 16 kHz frame rate, 1100 A-lines per frame, 3 mm depth range, and 23 microm resolution was demonstrated using a resonant scanner for lateral scanning.     

Dielectric properties of ferroelectric/DMS heterointerface using YMnO3 and Ce doped Si

Bottom gate type Al/Si:8.2 at%Ce/YMnO₃/Pt capacitor was fabricated. Although it was polycrystalline, we successfully obtained Si:8.2 at%Ce film on ferroelectric YMnO₃. The dielectric properties of the capacitor were carefully investigated. Although the capacitance shows frequency dispersion, the capacitor exhibits a ferroelectric type C-V hysteresis loop. From the PUND and P-V measurements, ferroelectric polarization was distinguished from the another polarization, Based on these dielectric measurements, effect of polarization induced by the ferroelectric YMnO₃ on the carrier modulation in the diluted magnetic semiconductor, Ce doped Si film was discussed.