Diffusional kurtosis imaging in differentiating nonarteritic anterior ischemic optic neuropathy from acute optic neuritis.

PURPOSE: We aimed to determine the feasibility of using DKI to characterize pathological changes in nonarteritic anterior ischemic optic neuropathy (NAION) and to differentiate it from acute optic neuritis (ON). METHODS: Orbital DKI was performed with a 3.0 T scanner on 75 patients (51 with NAION and 24 with acute ON) and 15 healthy controls. NAION patients were further divided into early and late groups. The mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) were calculated to perform quantitative analyses among groups; and receiver operating characteristic curve analyses were also performed to determine their effectiveness of differential diagnosis. In addition, correlation coefficients were calculated to explore the correlations of the DKI-derived data with duration of disease. RESULTS: The MK, RK, and AK in the affected nerves with NAION were significantly higher than those in the controls, while the trend of FA, RD, and AD was a decline; in acute ON patients, except for RD, which increased, all DKI-derived kurtosis and diffusion parameters were significantly lower than controls (all P < 0.008). Only AK and MD had statistical differences between the early and late groups. Except for MD (early group) and FA, all other DKI-derived parameters were higher in NAION than in acute ON; and parameters in the early group showed better diagnostic efficacy in differentiating NAION from acute ON. Correlation analysis showed that time was negatively correlated with MK, RK, AK, and FA and positively correlated with MD, RD, and AD (all P < 0.05). CONCLUSION: DKI is helpful for assessing the specific pathologic abnormalities resulting from ischemia in NAION by comparison with acute ON. Early DKI should be performed to aid in the diagnosis and evaluation of NAION.

Role of Diffusional Kurtosis Imaging in Differentiating Neuromyelitis Optica-Related and Multiple Sclerosis-Related Acute Optic Neuritis: Comparison With Diffusion-Weighted Imaging.

PURPOSE: The discrimination between neuromyelitis optica (NMO)- and multiple sclerosis (MS)-related acute optic neuritis (ON) after the first presentation is difficult in clinical practice. Through a comparison with diffusion-weighted imaging using readout-segmented echo-planar imaging (RESOLVE-DWI), our aim was to determine the feasibility of diffusional kurtosis imaging (DKI) for differential diagnosis. MATERIALS AND METHODS: Orbital DKI and RESOLVE-DWI in a 3.0-T scanner were performed on 37 patients with acute ON (15 NMO-related and 22 MS-related). The mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), and apparent diffusion coefficient (ADC) were calculated for quantitative analyses, and receiver operating characteristic curve analyses were also performed to determine their abilities to differentiate the 2 conditions. RESULTS: The intraclass correlation coefficients among observers were 0.842, 0.885, 0.828, 0.871, and 0.942 for MK, RK, AK, MD, and ADC, respectively, in the affected nerve group and 0.890, 0.840, 0.832, 0.934, and 0.941 in the unaffected nerve group. Regarding the comparisons of the DKI and RESOLVE-DWI parameters among the groups, the mean MK, RK, AK, MD, and ADC values were significantly lower in the affected groups (all, P < 0.001). Furthermore, the MK, RK, MD, and ADC values were significantly lower in the NMO-ON group than in the MS-ON group (P = 0.001, 0.002, 0.013, and <0.001, respectively), and no significant differences were found in the AK values (P = 0.064). In addition, establishing MK ≤ 0.843 as the diagnostic criterion for NMO-related acute ON provided the highest sensitivity (90.5%), whereas the highest specificity (91.3%) was obtained using RK ≤ 0.784 as the diagnostic criterion. CONCLUSIONS: Diffusional kurtosis imaging is helpful for differentiating NMO-related acute ON from MS-related acute ON, and it can achieve more agreeable sensitivity and specificity than RESOLVE-DWI in differential diagnosis.

Comprehensive comparison of MR image quality between intratympanic and intravenous gadolinium injection using 3D real IR sequences.

Background: Intratympanic and intravenous gadolinium administration is used to visualise endolymphatic hydrops. Aims/objectives: The goal of this study was to compare the image quality between intratympanic (IT-method) and intravenous (IV-method) gadolinium administration using three-dimensional inversion recovery with real reconstruction (3D real IR) sequences. Materials and methods: A number of 152 patients with Meniere's disease were included. The 3D real IR sequence was performed 24 h after IT administration or 4 h after IV administration. The detection rate of endolymphatic hydrops, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the two methods were compared. Specifically, the average image scores of the two methods were evaluated by two radiologists. Results: The SNRROI and CNRs of the IT-method were higher than those of the IV-method, whereas no significant difference between the IT-method and IV-method with regard to the SNRB was found. The average image scores were 3.49 ± 0.12 and 3.30 ± 0.12 for the IT-method and IV-method, respectively (p = .229). No statistically significant difference was found between two methods in terms of the detection rate of endolymphatic hydrops. Conclusions and significance: IT-method images can display endolymphatic hydrops more precisely than IV-method images. The IV-method can be used as an alternative to the IT-method in clinical applications to some extent.

Differentiating Neuromyelitis Optica-Related and Multiple Sclerosis-Related Acute Optic Neuritis Using Conventional Magnetic Resonance Imaging Combined With Readout-Segmented Echo-Planar Diffusion-Weighted Imaging.

PURPOSE: In clinical practice, acute optic neuritis (ON) associated with the development of neuromyelitis optica (NMO) after the first attack is often indistinguishable from that associated with multiple sclerosis (MS). We aimed to determine the optimal combination of features derived from conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging using readout-segmented echo-planar imaging (RESOLVE-DWI) for the differentiation of these conditions. MATERIALS AND METHODS: Orbital conventional MRI and RESOLVE-DWI were performed using a 3.0-T scanner on 54 patients with acute ON (26 NMO-related and 28 MS-related). The features detected by conventional MRI (including laterality, the enhancement pattern, and the extent and position of involvement) and the apparent diffusion coefficient (ADC) measurements were retrospectively compared between the NMO-related and MS-related groups. A multivariate logistic regression analysis was used to identify the most significant variables, and receiver operating characteristic curve analyses were performed to determine the ability of a combined diagnostic model based on the qualitative and quantitative characteristics identified in this study to differentiate the 2 conditions. RESULTS: The multivariate logistic regression analyses indicated that the presence of chiasm involvement and lower ADC values were significantly associated with NMO-related acute ON compared with MS-related acute ON (P = 0.037 and 0.008, respectively). The diagnostic criterion of chiasm involvement or "ADC < 791 × 10 mm/s and chiasm involvement" had the highest specificity (96.9%), and "ADC < 791 × 10 mm/s or chiasm involvement" showed the optimal sensitivity (77.8%) for differentiating NMO-related from MS-related acute ON. CONCLUSIONS: Conventional MRI RESOLVE-DWI is helpful for differentiating NMO-related acute ON from MS-related acute ON. The combination of the ADC value chiasm involvement appears to be effective for discriminating these 2 types of acute ON.

Water-soluble CdTe quantum dots as an anode interlayer for solution-processed near infrared polymer photodetectors.

Water-soluble cadmium telluride (CdTe) quantum dots (QDs) used as an anode interlayer in solution-processed near infrared (NIR) polymer photodetectors (PDs) were demonstrated. Polymer PDs incorporated with CdTe QDs as an anode interlayer exhibited 10-fold suppressed dark current density and analogous photocurrent density relative to poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), which resulted in enhanced detectivities over 10(11) Jones in the spectral range from 350 nm to 900 nm. Moreover, with the substitution of PEDOT:PSS by CdTe QDs, the stability of unencapsulated NIR polymer PDs was extended up to 650 hours, which is more than 3 times longer than those with PEDOT:PSS as an anode interlayer. These results indicated that CdTe QDs can be utilized as a solution-processable alternative to PEDOT:PSS as an anode interlayer for high performance NIR polymer PDs.

Solution-processed ultrasensitive polymer photodetectors with high external quantum efficiency and detectivity.

Operating at room temperature, polymer photodetectors (PDs) with external quantum efficiency approximately 80%, detectivity over 10(13) Jones, linear dynamic range over 120 dB, and dark current a few decades of nA/cm(2) were demonstrated. All these performance parameters were achieved by combined treatment of active layer with solvent vapor annealing and of polymer PDs with postproduction thermal annealing. These high performance parameters demonstrated that polymer PDs is comparable to or better than inorganic counterparts.

Experimental studies with foot-and-mouth disease virus type Asia-1, responsible for the 2005 epidemic in China.

This study was carried out to investigate the biological characteristics of the foot-and-mouth disease (FMD) virus strain Asia-1 China/2005, which is responsible for the 2005 epidemic in China. The result showed that this strain is not host restricted, and could not only cause FMD in cattle and sheep but also in pigs by either inoculation or direct contact.