N-{4-[4-( l0-Trimethylammoniodecyloxy)phenylazo]benzoyl~-~-alanine alkyl ester bromides with n-C, to -CI3 alkyl chains have been newly synthesized. The bilayer aggregates absorbed at 355 nm when the number of carbons was even and at 320 nm when odd. Regardless of whether the number was even or odd, X-ray diffraction patterns suggested a chain penetration structure, where the tail chains in one molecular layer penetrated into the opposite molecular layer, and hence every other azobenzene group was distributed into the opposite layers. However, a remarkable splitting of the CH, scissoring band into 1473 and 1463 cm-' indicated perpendicular alignments of the trans-zigzag planes of the chains containing an even number of carbons, whereas the singlet CH, scissoring band at 1465 cm-' indicated parallel alignments of the planes of the chains containing an odd number of carbons. In accord with the chain packing, when the amphiphiles possess an even number of carbons, the adjacent neighbouring azobenzenes in each layer were arranged perpendicular to each other. The perpendicular location causes a loss of interchromophore interaction, giving a, , , at 355 nm. In contrast, the azobenzenes in the bilayers of the amphiphiles containing an odd number of carbons were all parallel to each other. Because the molecules were tilted above about 60°, a H aggregate should be predominantly formed, which absorbed at 320 nm. In addition, the amphiphiles containing an even number of carbons formed stronger H bonding than those containing an odd number of carbons.

Background: Quantitative susceptibility mapping (QSM) is used to differentiate between calcification and iron deposits. Few studies have examined the relationship between CT attenuation values and magnetic susceptibility in such materials. Purpose:To assess the relationship among metal concentration, CT attenuation values, and magnetic susceptibility in paramagnetic and diamagnetic phantoms, and the relationship between CT attenuation values and susceptibility in brain structures that have paramagnetic or diamagnetic properties. Materials and Methods:In this retrospective study, CT and MRI with QSM were performed in gadolinium and calcium phantoms, patients, and healthy volunteers between June 2016 and September 2017. In the phantom study, we evaluated correlations among metal concentration, CT attenuation values, and susceptibility. In the human study, Pearson and Spearman correlations were performed to assess the relationship between CT attenuation values and susceptibility in regions of interest placed in the globus pallidus (GP), putamen, caudate nucleus, substantia nigra, red nucleus, dentate nucleus, choroid plexus, and hemorrhagic and calcified lesions.Results: Eighty-four patients (mean age, 64.8 years 6 19.6; 49 women) and 20 healthy volunteers (mean age, 72.0 years 6 7.6; 11 men) were evaluated. In the phantoms, strong linear correlations were identified between gadolinium concentration and CT and MRI QSM values (R 2 = 0.95 and 0.99, respectively; P , .001 for both) and between calcium concentration and CT and MRI QSM values (R 2 = 0.89 [P = .005] and R 2 = 0.98 [P , .001], respectively). In human studies, positive correlations between CT attenuation values and susceptibility were observed in the GP (R 2 = 0.52, P , .001) and in hemorrhagic lesions (R 2 = 0.38, P , .001), and negative correlations were found in the choroid plexus (R 2 = 0.53, P , .001) and in calcified lesions (R 2 = 0.38, P = .009). Conclusion:CT attenuation values showed a positive correlation with susceptibility in the globus pallidus and hemorrhagic lesions and negative correlation in the choroid plexus and calcified lesions.

Background Neuromelanin‐sensitive magnetic resonance imaging techniques have been developed but currently require relatively long scan times. The aim of this study was to assess the ability of black‐blood delay alternating with nutation for tailored excitation‐prepared T1‐weighted variable flip angle turbo spin echo (DANTE T1‐SPACE), which provides relatively high resolution with a short scan time, to visualize neuromelanin in the substantia nigra pars compacta (SNpc). Methods Participants comprised 49 healthy controls and 25 patients with Parkinson's disease (PD). Contrast ratios of SNpc and hyperintense SNpc areas, which show pixels brighter than thresholds, were assessed between DANTE T1‐SPACE and T1‐SPACE in healthy controls. To evaluate the diagnostic ability of DANTE T1‐SPACE, the contrast ratios and hyperintense areas were compared between healthy and PD groups, and receiver operating characteristic analyses were performed. We also compared areas under the curve (AUCs) between DANTE T1‐SPACE and the previously reported gradient echo neuromelanin (GRE‐NM) imaging. Each analysis was performed using original images in native space and images transformed into Montreal Neurological Institute space. Values of P < 0.05 were considered significant. Results DANTE T1‐SPACE showed significantly higher contrast ratios and larger hyperintense areas than T1‐SPACE. On DANTE T1‐SPACE, healthy controls showed significantly higher contrast ratios and larger hyperintense areas than patients with PD. Hyperintense areas in native space analysis achieved the best AUC (0.94). DANTE T1‐SPACE showed AUCs as high as those of GRE‐NM. Conclusions DANTE T1‐SPACE successfully visualized neuromelanin of the SNpc and showed potential for evaluating PD. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

An eight-nation cooperative epidemiological study revealed the Asian and African features of sarcoidosis. Almost every country reported from several to less than 30 cases, except for Japan which had already collected over 3,000 cases. Not a single case was found in the mass x-ray surveys conducted by several countries on a large scale (Tables 1 and 2). Although the number of the cases included in this study were small, this information is the first of this kind for Asia and Africa.

Objectives The aim of this study was to assess the accuracy, reliability, and cerebral microbleed (CMB) detection performance of 2-minute quantitative susceptibility mapping (QSM) from 3-dimensional echo-planar imaging (3D-EPI). Materials and Methods Gadolinium phantom study was conducted using 3D-EPI, single–echo time (TE), and multi-TE gradient-recalled echo (GRE) sequences on two 3-T magnetic resonance (MR) scanners to assess the accuracy between measured and theoretical susceptibility values. The institutional review board approved this prospective study, and 40 healthy volunteers were enrolled with written consent between April 2018 and October 2019. Each underwent 3D-EPI, single-TE, and multi-TE GRE sequences consecutively on one 3-T MR scanner, and QSMs were calculated to assess the reliability of 3D-EPI QSM. Intraclass correlation coefficient (ICC), linear regression, and Bland-Altman plots were calculated. Patients with CMB who underwent both 3D-EPI and GRE QSM scans were retrospectively enrolled. Two radiologists evaluated images independently, and Cohen κ coefficients were calculated to compare CMB detection performance. Results Phantom study showed excellent validity of 3D-EPI QSM on both MR scanners: Skyra, R 2 = 0.996, P < 0.001, ICC = 0.997, mean difference, −2 ppb (95% confidence interval [CI], −45 to 40 ppb); Prisma, R 2 = 0.992, P < 0.001, ICC = 0.988, mean difference, 15 ppb (95% CI, −67 to 97 ppb). A human study of 40 healthy volunteers (59 ± 13 years, 25 women) showed excellent reliability with 3D-EPI QSM for both single-TE and multi-TE GRE (R 2 = 0.981, P < 0.001, ICC = 0.988; R 2 = 0.983, P < 0.001, ICC = 0.990, respectively), supported by a Bland-Altman mean difference of 4 ppb (95% CI, −15 to 23 ppb) for single-TE GRE and 3 ppb (95% CI, −15 to 20 ppb) for multi-TE GRE. The CMB detection performance evaluation from 38 patients (51 ± 20 years, 20 women) showed almost perfect agreement between 3D-EPI and GRE QSM for both raters (κ = 0.923 and 0.942, P < 0.001). Conclusions Faster QSM from 3D-EPI demonstrated excellent accuracy, reliability, and CMB detection performance.