MR susceptibility contrast imaging using a 2D simultaneous multi-slice gradient-echo sequence at 7T.

PURPOSE: To develop a 7T simultaneous multi-slice (SMS) 2D gradient-echo sequence for susceptibility contrast imaging, and to compare its quality to 3D imaging. METHODS: A frequency modulated and phase cycled RF pulse was designed to simultaneously excite multiple slices in multi-echo 2D gradient-echo imaging. The imaging parameters were chosen to generate images with susceptibility contrast, including T2*-weighted magnitude/phase images, susceptibility-weighted images and quantitative susceptibility/R2* maps. To compare their image quality with 3D gradient-echo imaging, both 2D and 3D imaging were performed on 11 healthy volunteers and 4 patients with multiple sclerosis (MS). The signal to noise ratio (SNR) in gray and white matter and their contrast to noise ratio (CNR) was simulated for the 2D and 3D magnitude images using parameters from the imaging. The experimental SNRs and CNRs were measured in gray/white matter and deep gray matter structures on magnitude, phase, R2* and QSM images from volunteers and the visibility of MS lesions on these images from patients was visually rated. All SNRs and CNRs were compared between the 2D and 3D imaging using a paired t-test. RESULTS: Although the 3D magnitude images still had significantly higher SNRs (by 13.0~17.6%), the 2D magnitude and QSM images generated significantly higher gray/white matter or globus pallidus/putamen contrast (by 13.3~87.5%) and significantly higher MS lesion contrast (by 5.9~17.3%). CONCLUSION: 2D SMS gradient-echo imaging can serve as an alternative to often used 3D imaging to obtain susceptibility-contrast-weighted images, with an advantage of providing better image contrast and MS lesion sensitivity.

[Serum levels of ferritin and neuron-specific enolase in children with hand-foot-mouth disease complicated by acute viral encephalitis].

OBJECTIVE: To study serum ferritin and neuron-specific enolase (NSE) levels in children with hand-foot-mouth disease (HFMD) complicated by acute viral encephalitis and their clinical significance. METHODS: Serum levels of ferritin and NSE were measured using ELISA and electrochemical luminescence in 20 children with HFMD complicated by viral encephalitis (encephalitis group), 20 children with HFMD only (simple HFMD group) and 20 healthy children (control group). RESULTS: Serum levels of ferritin in the encephalitis group (212 ± 71 µg/L) were significantly higher than in the simple HFMD group (85 ± 18 µg/L) and control group (70 ± 15 µg/L) (P<0.01). Serum levels of NSE in the encephalitis group (8.6 ± 2.6 µg/L) were also significantly higher than in the simple HFMD group (6.0 ± 1.3 µg/L) and control group (5.6 ± 1.8 µg/L) (P<0.01). Significantly decreased serum ferritin (126 ± 37 µg/L) and NSE levels (6.8 ± 1.9 µg/L) were found in the encephalitis group (P<0.01) after treatment. CONCLUSIONS: Serum levels of ferritin and NSE in children with HFMD complicated by acute viral encephalitis increase, suggesting that serum ferritin and NSE measurement is useful in the early diagnosis of HFMD complicated by acute viral encephalitis.