Phase Difference Enhanced Imaging

The phase image of MRI has a much high diagnosis potential. Susceptibility or another properties of tissue directly or indirectly affect on phase differences in the phase image. Therefore, it is possible to enhance a tissue\u27s physical properties via phase differences. These enhanced images are great of use for discriminating the different tissues and further clinical applications. In this paper, we report on new imaging technique "PhAse DiffeRence Enhanced imaging (PADRE)" as an application of using the phase information in which we use a phase difference between tissues. This new technique can enhance the phase difference on the magnitude image, which corresponds to the local magnetic field difference caused by susceptibility difference, physical dynamics and so on. For comprehensive understanding of PADRE, a simple model is to be examined. The enhanced tissue makes a higher contrast between different tissues, which is going to support the diagnosis of problems. We examine an improvement of contrast by using the PADRE thorough a comparison between a CNR of experimental data and theory which we introduced. Discussions and results of this paper determine the best imaging parameters. We can see wonderful appearance of small vessels in the brain by using these parameters

Association of HK2 and NCK2 with normal tension glaucoma in the Japanese population.

Although family studies and genome-wide association studies have shown that genetic factors play a role in glaucoma, it has been difficult to identify the specific genetic variants involved. We tested 669 single nucleotide polymorphisms (SNPs) from the region of chromosome 2 that includes the GLC1B glaucoma locus for association with primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) in the Japanese population. We performed a two-stage case-control study. The first cohort consisted of 123 POAG cases, 121 NTG cases and 120 controls: the second cohort consisted of 187 POAG cases, 286 NTG cases, and 271 controls. Out of six SNPs showing significant association with POAG in the first round screening, seven SNPs were tested in the second round. Rs678350 in the HK2 gene coding sequence showed significant allelic (p=0.0027 in Stage Two, 2.7XE-4 in meta-analysis) association with POAG, and significant allelic (p=4.7XE-4 in Stage Two, 1.0XE-5 in meta-analysis) association with NTG. Although alleles in the TMEM182 gene did not show significant association with glaucoma in the second round, subjects with the A/A allele in TMEM182 rs869833 showed worse visual field mean deviation (p=0.01). Even though rs2033008 in the NCK2 gene coding sequence did not show significant association in the first round, it had previously shown association with NTG so it was tested for association with NTG in round 2 (p=0.0053 in Stage Two). Immunohistochemistry showed that both HK2 and NCK2 are expressed in the retinal ganglion cell layer. Once multi-testing was taken into account, only HK2 showed significant association with POAG and NTG in Stage Two. Our data also support previous reports of NCK2 association with NTG, and raise questions about what role TMEM182 might play in phenotypic variability. Our data suggest that HK2 may play an important role in NTG in the Japanese population

Stage Two <i>HK2</i> SNPs Allele Frequencies in Japanese POAG, NTG and Control Subjects.

*<p>Fisher's exact test; dominant model.</p><p>G/G or T/T is mutant homozygote, A/G or A/T is heterozygote, and A/A is wild homozygote.</p

Stage One and Stage Two Association Test Results.

<p>MAF; Minor allele frequency, CNTL; Control.</p>*<p>Fisher's exact test.</p

Stage one Test of SNPs in GLC1B-Region Genes for Association with POAG or NTG.

*<p>chi-square test.</p>**<p>minor allele frequency in stage 2 control was 0.494.</p>***<p>minor allele in control was major allele in POAG and NTG subjects.</p><p>MAF; minor allele frequency, CI; confidence interval.</p

Correlation between the POAG or NTG Endophenotypes and <i>HK2</i> SNPs Screened in Stage Two.

*<p>IOP; intraocular pressure (under medication).</p>**<p>Dunnett's test.</p><p>G/G or T/T is mutant homozygote, A/G or A/T is heterozygote, and A/A is wild homozygote.</p

<i>Hk2</i> and <i>Nck2</i> Immunohistochemistory.

<p>Representative IHC photographs showing Hk2, Nck2, astrocyte maker (GFAP) and RGC marker (C38) in the retinas of untreated mice. Arrows indicated the co-localization area.</p

Clinical Characteristics of Subjects studied in Stage One and Two Screening.

*<p>IOP; intra ocular pressure (under medication).</p>**<p>The Visual Field Score was evaluated by Humphrey MD value or Goldmann perimetry (Stage One) and Humphrey MD value (Stage Two).</p><p>In Stage One, the severity of the visual field defects was scored from 1 to 5 according to previously reported criteria. The data obtained by two types of perimetry were combined using a five-point scale: 1, no alterations; 2, early defects; 3, moderate defects; 4, severe defects; and 5, light perception only or no light perception. The first four groups on this severity scale followed Kozaki's classification based on Goldmann perimetry or the classification was based on results of visual field perimetry (Humphrey Field Analyzer; Carl Zeiss Meditec, Dublin, CA). Kozaki's classification is widely used in Japan.</p