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We previously reported that syndecan-2 expression is increased on the colonic epithelium during chronic inflammation. Here, we report that syndecan-2 exhibits a different pattern of site-specific colonic expression during acute inflammation. Syndecan-2 expression was up-regulated predominantly in the proximal colon of dextran sulfate sodium-induced colitis mice. The colitis-associated up-regulation of syndecan-2 was barely detected in Rag-1-/- (recombination activating gene 1 knockout) mice under colitis-inducing conditions. Increased syndecan-2 expression correlated with increased levels of infiltrated CD4+ IL-17A+ T cells in the proximal colon. Serum levels of IL-17A were increased during the acute inflammatory response in normal mice but not Rag-1-/- mice. IL-17A directly induced IL-17 receptor (IL-17RA) and syndecan-2 expression in ex vivo-cultured proximal colon tissues and adenoma cell lines from proximal colon. IL-17RA knockdown reduced the IL-17A-mediated syndecan-2 expression in SNU1235 cells. No elevation of syndecan-2 or IL-17RA was observed in colonic tissues from IL-17A-/- mice during colitis induction. Finally, increased expression of syndecan-2 and IL-17RA was observed in the proximal colons of cecal ligation and puncture-induced sepsis mice and infectious pan colitis patients. Together, these data suggest that acute inflammation induces syndecan-2 expression predominantly in the proximal colon via IL-17A-IL-17RA signaling during the early stage of the inflammatory response and that proximal colonic syndecan-2 might be a biomarker for acute inflammation.-Hong, H., Song, H.-K., Hwang, E. S., Lee, A. R., Han, D. S., Kim, S.-E., Oh, E.-S. Up-regulation of syndecan-2 in proximal colon correlates with acute inflammation.

Purpose To demonstrate the interchangeable neck shape-specific (NSS) coil concept that supplements standard commercial spine and head/neck coils to provide simultaneous high-resolution (hi-res) head/neck imaging with high signal-to-noise ratio (SNR). Methods Two NSS coils were constructed on formers designed to fit two different neck shapes. A 7-channel (7ch) ladder array was constructed on a medium neck former, and a 9-channel (9ch) ladder array was constructed on large neck former. Both coils were interchangeable with the same preamp housing. Results The 7ch and 9ch coils demonstrate SNR gains of approximately 4 times and 3 times over the Siemens 20-channel head/neck coil in the carotid arteries of our volunteers, respectively. Coupling between the Siemens 32-channel spine coil, Siemens 20-channel head/neck coil, and the NSS coils was negligible, allowing for simultaneous hi-res head/neck imaging with high SNR. Conclusions This study demonstrates that supplementing existing commercial spine and head/neck coils with an NSS coil allows uniform simultaneous hi-res imaging with high SNR in the anterior neck, while maintaining SNR of the commercial coil in the head and posterior neck. Magn Reson Med 78:2460-2468, 2017. © 2017 International Society for Magnetic Resonance in Medicine.

Chronic inflammation is known to be a key causative factor in tumor progression, but we do not yet fully understand the molecular mechanism through which inflammation leads to cancer. Here, we report that the dextran sulfate sodium (DSS)-induced mouse model of chronic colitis is associated with increases in the serum level of IL-1β and the colonic epithelial expression of the cell-surface heparan sulfate proteoglycan, syndecan-2. We further show that IL-1β stimulated the transcription of syndecan-2 via NF-κB-dependent FOXO3a activation in CCD841CoN normal colonic epithelial cells and early-stage HT29 colon cancer cells. Inflammatory hypoxia was observed in the colonic epithelia of mice with chronic colitis, suggesting that hypoxic stress is involved in the regulation of syndecan-2 expression. Consistently, experimental inflammatory hypoxia induced hypoxia inducible factor-1α-dependent FOXO3a expression and the p38 MAPK-mediated nuclear localization of FOXO3a. FOXO3a directly mediated syndecan-2 expression in both cell lines and the colonic epithelia of mice with DSS-induced colitis. Moreover, syndecan-2 expression was detected in azoxymethane/DSS-induced colon tumors. Together, these data demonstrate that inflammatory hypoxia up-regulates syndecan-2 via the IL-1β-NF-κB-FOXO3a pathway. These findings provide new mechanistic insights into inflammatory hypoxia-mediated syndecan-2 expression to connect chronic inflammation and the development of colon cancer.-Choi, S., Chung, H., Hong, H., Kim, S. Y., Kim, S.-E., Seoh, J.-Y., Moon, C. M., Yang, E. G., Oh, E.-S. Inflammatory hypoxia induces syndecan-2 expression through IL-1β-mediated FOXO3a activation in colonic epithelia.

PURPOSE Carotid artery imaging is important in the clinical management of patients at risk for stroke. Carotid intraplaque hemorrhage (IPH) presents an important diagnostic challenge. 3D magnetization prepared rapid acquisition gradient echo (MPRAGE) has been shown to accurately image carotid IPH; however, this sequence can be limited due to motion- and flow-related artifact. The purpose of this work was to develop and evaluate an improved 3D carotid MPRAGE sequence for IPH detection. We hypothesized that a radial-based k-space trajectory sequence such as "Stack of Stars" (SOS) incorporated with inversion recovery preparation would offer reduced motion sensitivity and more robust flow suppression by oversampling of central k-space. MATERIALS AND METHODS A total of 31 patients with carotid disease (62 carotid arteries) were imaged at 3T magnetic resonance imaging (MRI) with 3D IR-prep Cartesian and SOS sequences. Image quality was determined between SOS and Cartesian MPRAGE in 62 carotid arteries using t-tests and multivariable linear regression. Kappa analysis was used to determine interrater reliability. RESULTS In all, 25 among 62 carotid plaques had carotid IPH by consensus from the reviewers on SOS compared to 24 on Cartesian sequence. Image quality was significantly higher with SOS compared to Cartesian (mean 3.74 vs. 3.11, P < 0.001). SOS acquisition yielded sharper image features with less motion (19.4% vs. 45.2%, P < 0.002) and flow artifact (27.4% vs. 41.9%, P < 0.089). There was also excellent interrater reliability with SOS (kappa = 0.89), higher than that of Cartesian (kappa = 0.84). CONCLUSION By minimizing flow and motion artifacts and retaining high interrater reliability, the SOS MPRAGE has important advantages over Cartesian MPRAGE in carotid IPH detection. LEVEL OF EVIDENCE 1 J. Magn. Reson. Imaging 2017;45:410-417.

Purpose To compare the clinical outcomes of intravitreal bevacizumab (IVB) injection, with different dosing (0.25 mg/0.01 ml versus 0.625 mg/0.025 ml) in each eye of the same patient with retinopathy of prematurity (ROP). Methods Intravitreal bevacizumab (IVB) was injected into eight patients with stage 3+ in zone I or posterior zone II ROP (16 eyes). Bevacizumab, with different dosing (0.25 mg/0.01 ml and 0.625 mg/0.025 ml), was injected into the vitreous cavity of each eye. Results Among the 16 eyes treated with IVB, six eyes had zone I ROP and 10 eyes had zone II ROP. The mean birthweight was 800 ± 139 g (range, 533–955 g), and the mean gestational age was 25.9 ± 1.2 gestational weeks (range, 24.4–28.7 weeks). The postmenstrual age at initial treatment was 37.2 gestational weeks (range, 33.7–41 weeks). The mean follow-up was 312 ± 50 days (median, 305 days; range, 238–376 days). All eyes showed regression of plus sign after IVB injection within 1 week and revascularization to the ora serrata at the time of final visit. There was no difference in the time of anatomical achievement between the eyes with different doses. None of the patients received any additional IVB injection or laser photocoagulation. After the regression of ROP, tractional retinal detachment and macular ectopia were not observed in any patients during follow-up. Conclusions There was no difference in the short-term clinical outcomes of stage 3+ ROP in zone I or II between the eyes with low dose and conventional dose of IVB.

Objectives The aim of the present study was to measure brain phosphorus-31 magnetic resonance spectroscopy (31P MRS) metabolite levels and the creatine kinase reaction forward rate constant (kf) in subjects with bipolar disorder (BD). Methods Subjects with bipolar euthymia (n = 14) or depression (n = 11) were recruited. Healthy comparison subjects (HC) (n = 23) were recruited and matched to subjects with BD on age, gender, and educational level. All studies were performed on a 3-Tesla clinical magnetic resonance imaging system using a 31P/1H double-tuned volume head coil. 31P spectra were acquired without 1H-decoupling using magnetization-transfer image-selected in vivo spectroscopy. Metabolite ratios from a brain region that includes the frontal lobe, corpus callosum, thalamus, and occipital lobe are expressed as a percentage of the total phosphorus (TP) signal. Brain pH was also investigated. Results Beta-nucleoside-triphosphate (β-NTP/TP) in subjects with bipolar depression was positively correlated with kf (p = 0.039, r2 = 0.39); similar correlations were not observed in bipolar euthymia or HC. In addition, no differences in kf and brain pH were observed among the three diagnostic groups. A decrease in the ratio of phosphomonoesters to phosphodiesters (PME/PDE) was observed in subjects with bipolar depression relative to HC (p = 0.032). We also observed a trend toward an inverse correlation in bipolar depression characterized by decreased phosphocreatine and increased depression severity. Conclusions In our sample, kf was not altered in the euthymic or depressed mood state in BD. However, decreased PME/PDE in subjects with bipolar depression was consistent with differences in membrane turnover. These data provide preliminary support for alterations in phospholipid metabolism and mitochondrial function in bipolar depression.

Purpose The purpose of this work was to develop and evaluate a system consisting of an insertable gradient, RF coils, and animal positioning hardware to enable imaging of the internal structure of the cochlea and other inner ear structures of a guinea pig model at 3T. Methods Transmit and receive RF coils, and an animal positioning system, were developed and integrated with an insertable gradient and animal monitoring system for improved guinea pig cochlea imaging when compared to a standard clinical 3T MRI system. A resolution phantom with 120 μm line separations was used to assess the contrast improvements with the insertable gradient. A homogeneous phantom was used to assess the SNR and homogeneity of the RF coils. FLASH imaging was used to observe the temporal passage of gadolinium contrast through the guinea pig cochlea. Results The insertable gradient enabled increased resolution imaging with nearly twice the contrast-to-noise ratio. The small animal array had better SNR for imaging the guinea pig cochlea (about 14 mm deep) than the commercial Siemens wrist coil (2.2×) and the small birdcage coil (1.6×). The positioning device kept the animal secure and stationary. Injected gadolinium contrast allowed visualization of the internal cochlear structures with FLASH image acquisition, which achieved 100 μm isotropic resolution images in 33 min. Conclusion The specialized RF coils and animal holding equipment designed to operate within the composite gradient enabled higher resolution images than could be obtained from the available RF coils operating in the conventional gradients on the clinical MRI system. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 44B: 89–101, 2015

Purpose: This work compared peripheral nerve stimulation (PNS) thresholds for the MRI scanner body gradients (BODY), a head/neck insert gradient (INSERT), and the combination of both gradient sets used simultaneously (COMPOSITE). Methods: For BODY, INSERT and COMPOSITE gradients, PNS thresholds were determined by exposing subject volunteers to stepped increases in gradient strength. For COMPOSITE mode, the INSERT was applied at equal (experiment 1) or double (experiment 2) the BODY gradient strength. Results: The locations and thresholds of peripheral nerve stimulation depended on the gradient system configuration, gradient axis, and gradient strength. Stimulation in the body occurred when using the BODY Y-gradient axis either singly (110 T/m/s) or in COMPOSITE mode (315 T/m/s experiment 2) and adding the insert gradient had negligible effect on stimulation. Stimulation in the head/sinus area generally occurred when using the INSERT X-gradient either singly (213 T/m/s) or in COMPOSITE mode (320 T/m/s) and adding the body gradient had negligible effect on stimulation. In the COMPOSITE mode, both the location of stimulation and the limiting gradient strength matched location and strength of the limiting component gradient. Conclusion: Stimulation, to a first-order approximation, is independent for the two gradient systems. In COMPOSITE mode, PNS can be dominated by either of the individual gradient components, indicating that the contribution of each component can be increased until the threshold limit of each component gradient is reached. COMPOSITE gradients provide increased gradient performance with PNS thresholds higher than either component gradient system operating alone. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 44B: 66–74, 2015

BACKGROUND AND PURPOSE Carotid intraplaque hemorrhage leads to plaque progression and ischemic events. Detection can be accomplished with 3T T1w sequences, but may be limited by false-positive lipid/necrosis. The purpose of this study was threefold: (1) to determine if magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) detects intraplaque hemorrhage versus lipid/necrosis; (2) if 3T MPRAGE image quality is retained at 1.5T; and (3) to determine observer agreement. METHODS MPRAGE positive areas were compared to hemorrhage and lipid/necrosis areas from 100 carotid endarterectomy slides in 12 subjects using multivariable linear regression. Image quality was determined between 3T and 1.5T in 716 carotid arteries using t-tests and multivariable linear regression. Kappa analysis was used to determine agreement. RESULTS Intraplaque hemorrhage, not lipid/necrosis, was a significant predictor of MPRAGE positive area before and after adjusting for confounders (slope = .52 vs. .51, P < .001). Image quality at 3T was slightly lower than 1.5T (mean 3.87 vs. 4.34, P < .0001). 3T image quality remained slightly decreased before and after adjusting for confounders (slope = –.46 vs. –.41, P < .001). Kappa values for inter-/intraobserver agreement were .807/.919 at 3T and .803/.871 at 1.5T. CONCLUSIONS Carotid MPRAGE detects intraplaque hemorrhage, not lipid/necrosis. 3T image quality was retained at 1.5T with very good observer agreement.

Purpose To evaluate the feasibility of diffusion tensor imaging (DTI) for the medial and lateral rectus extraocular muscle (EOM) evaluation, to investigate the normal DTI parameters of the medial and lateral rectus EOM, and to compare with other skeletal muscle. Materials and Methods Seven multiple sclerosis patients and five normal subjects (M:F = 5:7, mean age = 31.6 ± 9.2) without EOM disorder were included. The orbital DTIs using 2D-ss-IMVI-DWEPI were scanned with b = 500 s/mm2 and 12 directions. The mean diffusivity (MD) and fractional anisotrophy (FA) of medial and lateral rectus EOMs in both orbits, and temporalis muscles were measured in regions of interest on two consecutive axial slices. Student t-test was performed to compare the mean apparent diffusion coefficient and FA values between medial and lateral rectus EOMs, and between EOMs and temporalis muscles. Results The MDs in medial (0.58 ± 0.18 × 10−3mm2/s) and lateral rectus EOMs (0.71 ± 0.18 × 10−3mm2/s) were significantly lower than temporalis muscle (0.84 ± 0.14 × 10−3 mm2/s) (P 0.05). Conclusion The MDs of EOMs were lower and the FAs were higher than those of skeletal muscle. These are well correlated to the unique characteristics of EOMs. J. Magn. Reson. Imaging 2013;38:1162–1168. © 2013 Wiley Periodicals, Inc.

Magnetization Prepared Rapid Acquisition Gradient Echo (3D MPRAGE) has been shown to be a sensitive method to image carotid intraplaque hemorrhage (IPH). Since the MPRAGE sequence used to identify potential IPH does not utilize cardiac gating, it is difficult to optimize the inversion times due to the dynamic nature of flowing blood. As a result, a best fit inversion time is often determined experimentally and then used for in vivo clinical examination. This results in compromised blood suppression and occasional hemorrhage mimicking flow artifacts. We demonstrate that a retrospective cardiac correlated reconstruction can be applied to the conventional MPRAGE sequence (CineMPRAGE) to more accurately identify blood signal. This CineMPRAGE reconstruction uses the data from a standard non-gated MPRAGE sequence to generate a full sequence of cardiac correlated images throughout the cardiac cycle and therefore provides a dynamic view of the carotid artery and a better ability to discern blood signal from potential intraplaque hemorrhage. In our preliminary study of 35 patients, signal from potential hemorrhage was constant over the cardiac cycle while any signal from blood flow artifact was observed as an oscillating signal over the cardiac cycle.

The median is a commonly used parameter to characterize biomarker data. In particular, with two vastly different underlying distributions, comparing medians provides different information than comparing means; however, very few tests for medians are available. We propose a series of two-sample median-specific tests using empirical likelihood methodology and investigate their properties. We present the technical details of incorporating the relevant constraints into the empirical likelihood function for in-depth median testing. An extensive Monte Carlo study shows that the proposed tests have excellent operating characteristics even under unfavourable occasions such as non-exchangeability under the null hypothesis. We apply the proposed methods to analyze biomarker data from Western blot analysis to compare normal cells with bronchial epithelial cells from a case–control study. The Canadian Journal of Statistics 39: 671–689; 2011. © 2011 Statistical Society of Canada La mediane est le parametre habituellement utilise pour caracteriser les douuees de biomarqueurs. Eu particulier, si les deux distributions sous-jacentes sont tres differentes, la comparaison des medianes fournit de l'information differente que celle obtenue par la comparaison de moyennes. Cependant, il y a tres peu de tests pour comparer les medianes. Nous proposons une serie de tests pour deux echantillons specifiques aux medianes utilisant les methodes de vraisemblance empirique et nous etudions leurs proprietes. Nous presentons les details techniques pour incorporer les contraintes appropriees dans la fonction de vraisemblance empirique pour comparer en detail les medianes. Une etude de Monte-Carlo exhaustive montre que les tests proposes ont d'excellentes proprietes statistiques meme sous des conditions defavorables telle que la non-echangeabilite sous l'hypothese nulle. Nous appliquons les methodes proposees a l'analyse de donnees de biomarqueurs provenant d'une etude cas-controle utilisant le transfert de proteines afin de comparer les cellules normales avec celles epitheliales bronchiques. La revue canadienne de statistique 39: 671–689; 2011. © 2011 Societe statistique du Canada

High-resolution turbo spin echo (TSE) images have demonstrated important details of carotid artery morphology; however, it is evident that pulsatile blood and wall motion related to the cardiac cycle are still significant sources of image degradation. Although ECG gating can reduce artifacts due to cardiac-induced pulsations, gating is rarely used because it lengthens the acquisition time and can cause image degradation due to nonconstant repetition time. This work introduces a relatively simple method of converting a conventional TSE acquisition into a retrospectively ECG-correlated cineTSE sequence. The cineTSE sequence generates a full sequence of ECG-correlated images at each slice location throughout the cardiac cycle in the same scan time that is conventionally used by standard TSE sequences to produce a single image at each slice location. The cineTSE images exhibit reduced pulsatile artifacts associated with a gated sequence but without the increased scan time or associated nonconstant repetition time effects.

Optic neuritis is characterized by inflammation of the optic nerve, which causes a loss of vision due to swelling and destruction of the myelin sheath covering the optic nerve (1). The most common etiology is Multiple Sclerosis (MS). Nearly 50% of patients with MS will develop optic neuritis and 20-30% of the time optic neuritis is the presenting sign of MS (2). Early diagnosis can decrease the risk of developing negative symptoms from optic neuritis (3, 4). In MRI the presence of lesions, which indicate demyelization of the white matter, is the strongest predictor for clinically definite MS. Other methods of determining optic neuritis include a funduscopic exam, which in some cases does not give an adequate diagnosis. MRI of the optic nerve, which is usually performed with a standard head coil such as the clinical 12-channel coil available on the Siemens TIM Trio 3T MRI scanner, is subject to several limitations such as artifacts from eye movement (5). Many limitations could be overcome using a coil built specifically to image the optic nerves (6-8). For example, increased SNR obtained using a dedicated optic nerve coil would enable reduced field-of-view (FOV) DTI images as well as faster scans through parallel imaging techniques to minimize patient movement artifacts. Phased array receiver coil designs have been increasingly applied in MRI (9-13). Phased arrays are advantageous since multiple channels can provide an increase in signal sensitivity and imaging acceleration (14). A single surface coil typically has sufficient signal to noise ratio (rSNR) at the surface of a sample; however, at greater depths the SNR can suffer greatly compared to a traditional volume coil. Use of a phased array coil can compensate at the greater imaging depths and, if utilized correctly, can provide similar or greater SNR values compared to a volume coil (15). It has also been discovered that one of the factors that improves accelerated imaging is increasing the number of coils surrounding a volume of interest. This is due to the increased number of different coil sensitivity profiles. The increased parallel imaging performance can aid in the use of multiple parallel imaging techniques (16, 17). Furthermore, in addition to providing increased resolution and/or decreasing imaging time, the increase in SNR can enable diffusion tensor imaging (DTI) (18, 19), enhance temperature measurements (20), and fundamentally improve clinical diagnosis and patient treatment planning. In this study, an RF phased array coil was built to image the optic nerve from the orbits to the optic chiasm for the purposes of visualizing optic neuritis that typically manifests in Multiple Sclerosis patients. As opposed to previous designs, which are limited by the number of coils or generalized to imaging all of the head (9-11) we present a dedicated 20-channel coil for imaging of the optic nerve. This coil achieves improved SNR for higher resolution, faster imaging times and useful DTI performance.

High-energy phosphate metabolism, which allows the synthesis and regeneration of adenosine triphosphate (ATP), is a vital process for neuronal survival and activity. In particular, creatine kinase (CK) serves as an energy reservoir for the rapid buffering of ATP levels. Altered CK enzyme activity, reflecting compromised high-energy phosphate metabolism or mitochondrial dysfunction in the brain, can be assessed using magnetization transfer (MT) MRS. MT 31P MRS has been used to measure the forward CK reaction rate in animal and human brain, employing a surface radiofrequency coil. However, long acquisition times and excessive radiofrequency irradiation prevent these methods from being used routinely for clinical evaluations. In this article, a new MT 31P MRS method is presented, which can be practically used to measure the CK forward reaction rate constant in a clinical MRI system employing a volume head 31P coil for spatial localization, without contamination from the scalp muscle, and an acquisition time of 30 min. Other advantages associated with the method include radiofrequency homogeneity within the regions of interest of the brain using a volume coil with image-selected in vivo spectroscopy localization, and reduction of the specific absorption rate using nonadiabatic radiofrequency pulses for MT saturation. The mean value of kf was measured as 0.320 ± 0.075 s−1 from 10 healthy volunteers with an age range of 18–40 years. These values are consistent with those obtained using earlier methods, and the technique may be used routinely to evaluate energetic processes in the brain on a clinical MRI system. Copyright © 2010 John Wiley & Sons, Ltd.

Purpose: This article systematically examines arterial spin labeling (ASL) as a flow quantification technique through theoretical simulation,in vitro, and in vivo experiment. The authors present a novel imaging pulse sequence design consisting of a single ASL magnetization preparation followed by Look-Locker-like image readouts. Bloch-equation-based modeling has been developed and validated using a hemodialyzer as a tissue-mimicking flow phantom. Methods: After the single in-plane slice-selective double inversion magnetization preparation, multiple TFL readouts are acquired with linear k-space ordering, causing a signal variation that depends on through-slice flow velocity. Computer simulations were performed to assess the behavior of the flow-dependent ASL signal as a function of varying imaging parameters. The signal was optimized by choosing imaging parameters that maximize the simulated flow-sensitive signal. Furthermore, a hemodialyzer which mimics blood flow in human tissues was tested with a wide range of flow rates. An exponential curve fitting of the flow-sensitive dynamics to the model derived from Bloch equations provides a method to estimate through-slice velocity for varying flow rates on the hemodialyzer andin vivo human brain. Results: The flow dependency of the ASL signal and the sensitivity of the ASL signal to imaging parameters were demonstrated. Experimental results from a hemodialyzer when fitted with a Bloch-equation-based model provide flow measurements that are consistent with ground truth velocities. Human brain velocity mapping was obtained as well. Conclusions: The results provide evidence that the proposed pulse sequence design is an effective technique to measure total fluid flow through image voxels. The unique combination of the two main features, multiple-image readout after a single ASL preparation and linear acquisition ordering in the phase encoding direction in TFL imaging, make this technique an appealing flowimaging method to quantify through-plane flow in a time-efficient manner.

PURPOSE: A three dimensional nanostructure using protein nanoparticles is provided to detect a target material. CONSTITUTION: A method for preparing a protein-DNA multilayer nanostructure comprises: a step of fixing a control protein of which net charge changes at a substrate according to pH concentration except for a metal nano dot; a step of changing pH concentration to adjust the net charge of the control protein; and a step of laminating a DNA layer and a protein layer on the metal nano dot. The protein layer contains allogenic or xenogenic protein particles. The substrate is formed of metal, nickel. [Reference numerals] (AA) Gold; (BB) Nickel layer; (CC) Si wafer; (DD) Adding (his)6-tagged proteasome alpha particles(pH 7.4, 8); (EE) Adding ssDNA(polyA, 20bp), conversion to pH 5; (FF) Adding DPS particles[first layer formation], conversion to pH 8; (GG) Adding dsDNA(519bp), conversion to pH 5; (HH) Adding DPS particles[second layer formation], moving to pH 8; (II) Adding dsDNA(519bp), conversion into pH 5; (JJ) Adding DPS particles[third layer formation], conversion to pH 8; (KK) Type 1 DPS particle layers; (LL) Type 2 DPS particle layers; (MM) N layer formation on fourth layer; (NN) Type 1 DPS particles for capturing antibody marker 1; (OO) Antigen peptide fixed on the surface, which specifically binds to antibody marker 1; (PP) Type 2 DPS particles for capturing antibody marker 2; (QQ) Antigen peptide fixed on the surface, which specifically binds to antibody marker 2; (RR) Simultaneous detection and diagnosis system(example)

Diffusion-weighted and diffusion tensor MR imaging (DWI, DTI) techniques are generally performed with signal averaging of multiple measurements to improve the signal-to-noise ratio (SNR) and the accuracy of the diffusion measurement. Any discrepancy in the images between different averages causes errors which reduce the accuracy of the diffusion MRI measurements. In this report, a motion artifact reduction scheme with a real-time self-gated (RTSG) data acquisition for diffusion MRI using two-dimensional echo planar imaging (2D EPI) is described. A subject's translational and rotational motions during application of the diffusion gradients induce an additional phase term and a shift of the echo-peak position in the k-space, respectively. These motions also reduce the magnitude of the echo-peak. Based on these properties, we present a new scheme which monitors the position and the magnitude of the largest echo-peak in the k-space. The position and the magnitude of each average is compared to those of early averaging shot to determine if the differences are within or beyond the given threshold values. Motion corrupted data are reacquired in real time. Our preliminary results using RTSG indicate an improvement of both SNR and the accuracy of diffusion MRI measurements. Copyright © 2009 John Wiley & Sons, Ltd.

Problems associated with techniques currently used to measure the T1 of flowing blood are evaluated and a method to improve the consistency and repeatability of measurements is presented. Similar to some currently used techniques, the pulse sequence employs a nonselective adiabatic inversion pulse followed by a series of ECG-gated gradient echo EPI (echo planar imaging) images to obtain images where the blood (fluid) signal exhibits a T1-dependent inversion recovery signal from which the spin lattice relaxation constant (T1) of the flowing fluid can be measured. The new method combines curve fitting with a measure of the curve null point to acquire more accurate and consistent T1 values. Simulation and experimental results show that this combined fitting-nulling method is more stable and consistent in measuring the T1 of flowing fluid. The feasibility of temperature measurement of a flowing fluid based on the temperature dependence of the T1 of water protons is shown in this paper. ECG gating is used to reduce the effects of cyclic intensity changes for measurement of T1 in pulsatile flowing blood.

In this work we report on the development of a novel technique for high-resolution diffusion-weighted (DW) MRI based upon 3D steady-state free precession (3D-SSFP). First the 3D-SSFP acquisition was segmented (each segment consisting of a series of RF pulses and gradient-recalled echoes), and then DW-driven equilibrium (DE) was inserted between each segment. The in-plane imaging matrix was typically 256 x 192 or 256 x 160, which resulted in high-resolution DW images. The DW-DE segmented SSFP signal was contaminated by the non-DW magnetization, which recovered and contributed signal during the readout train (T(1) contamination). Center-out slice encoding was used to place the greatest diffusion weighting at the center of k-space. A numerical simulation and supporting experiments were performed to evaluate the relationship of the transverse magnetization to imaging parameters, such as the b-value, echo-train length (ETL), echo-train (group) repetition time (TR(g)), and RF excitation TR (Delta t). Both the numerical simulation and the experiments suggested that the effect of T(1) contamination would be reduced with a longer TR(g), smaller b-value, shorter ETL, and center-out slice phase encoding. Phase errors caused by microscopic motions during the diffusion gradients were converted into amplitude errors by the tip-up pulse at the end of the diffusion-weighting segment. As a result, small bulk motions, such as CSF pulsation, did not cause motion-related ghosting artifacts, which would be typical in images from other multishot DWI techniques. This technique can be used for high-resolution DWI of nonbrain anatomies.

Purpose To demonstrate that the time delay between phase and frequency encoding and the presence of pulsatile blood flow in high-resolution time-of-flight (TOF) imaging of the intracranial arteries (especially near the circle of Willis) can distort the appearance of blood vessels and result in a cross-hatch—appearing artifact in surrounding tissue. Materials and Methods Two techniques to reduce the artifact, tri-directional flow compensation (3DFC) and elliptical-centric (EC) phase-encoding order, are investigated in five volunteer studies. Results 3DFC eliminates the pulsation-related artifacts and the vessel distortion. A residual amplitude variation artifact is observed. EC phase encoding nearly eliminates the pulsatile motion-related artifact, but it does not eliminate vessel distortion. Conclusion The combination of 3DFC and EC phase encoding appears to provide the greatest artifact reduction in the five volunteer studies performed. J. Magn. Reson. Imaging 2003;18:121–127. © 2003 Wiley-Liss, Inc.

dimming of backlights achieves high contrast ratio and low power consumption for LCDs. However, it induces flicker artifacts. The moving average filtering method effectively reduces the flicker artifacts, but causes another problem known as backlight-response-time delaying. This paper presents an adaptive moving average filtering method to deal with above problems. Experimental results show that the proposed method successfully reduces flickers without backlight-response-time-delaying. 1. Introduction Liquid Crystal Displays (LCDs) have adopted backlight local dimming methods. The methods firstly divide the LCD backlight into smaller blocks. Then the dimming duty of each backlight block is separately determined in proportion to the average picture level (APL) of the block as shown in Figure 1 (1)(2)(3). In this way, LCDs achieve high contrast ratio and low power consumption. This method, however, causes another problem. When a glowing light or noise exists in a specific block, the APL of the block is changed continuously as shown in Figure 2(a). This phenomenon makes an unnatural trembling in the block, which is called a flicker artifact (4). The flicker can be solved by the moving average (MA) filtering method (5). The output images can be robust to the flicker by taking the average APL value through several consecutive frames as the backlight dimming duty as shown in Figure 2(b). Since this method is simply implemented, it has been generally applied to local dimming LCDs. However, the MA filtering method causes a delaying problem when a scene change occurs as shown in Figure 2(c). This causes an afterimage of the previous frame in the present frame. This is called backlight-response-time delaying.

— In conventional LCDs, the backlight is set to maximum luminance regardless of the image. For dark scenes, this approach causes light leakage and power waste. Especially, light leakage in dark scenes degrades the contrast ratio of LCDs; to circumvent this problem, local-dimming systems have been proposed. In these systems, the LED backlight is divided into several local blocks and the backlight luminance of each local block is controlled individually, and pixel values are adjusted simultaneously according to the luminance profile of the dimmed backlight. In this paper, a method of determining the LED backlight luminance of each local block depending on the image is proposed; this method significantly improves the image quality of LCDs. First, we introduce methods of quantifying light-leakage at dark gray levels and clipping at bright gray levels. Then, the proposed method to determine the dimming duty, which controls the LED backlight luminance by compromising between these two measures, was derived. The proposed algorithm preserves the original image with little clipping distortion and effectively reduces light leakage.