Segmentation of the prostate on magnetic resonance images using an ellipsoidal shape prior constraint algorithm / 南方医科大学学报

We propose a novel strategy for multi-atlas-based image segmentation of the prostate on magnetic resonance (MR) images using an ellipsoidal shape prior constraint algorithm. An ellipsoidal shape prior constraint was incorporated into the process of multi-atlas based segmentation to restrict the regions of interest on the prostate images and avoid the interference by the surrounding tissues and organs in atlas selection. In the subsequent process of atlas fusion, the ellipsoidal shape prior constraint calibrated and compensated for the shape prior obtained by the registration technique to avoid incorrect segmentation caused by registration errors. Evaluation of this proposed method on prostate images from 50 subjects showed that this algorithm was effective and yielded a mean Dice similarity coefficients of 0.8812, suggesting its high accuracy and robustness to segment the prostate on MR images.

Biocompatibility of electrospun poly(lactide-co-glycolide)/polyethylene glycol nanofibrous scaffold with mouse neural stem cells / 中国组织工程研究

BACKGROUND:Poly(lactide-co-glycolide) (PLGA) scaffold is widely used in tissue engineering, but its poor cel adhesion ability and strong hydrophobicity limit its further development and application. OBJECTIVE: To study the biocompatibility of electrospun poly (lactide-co-glycolide)/polyethylene glycol (PLGA-PEG) nanofibrous scaffolds with mouse neural stem celsin vitro. METHODS:Neural stem cels were isolated from embryos of CD-1 mice at 15 embryonic days. Electrospinning was used to prepare PLGA and PLGA-PEG nanofibrous scaffolds. Scanning electron microscope was used for scanning observation of scaffolds. The 5th passage neural stem cels were seeded onto PLGA and PLGA-PEG scaffolds respectively, and culturedin vitro. RESULTS AND CONCLUSION: Interconnected porous network structure was observed in both two kinds of scaffolds under the scanning electron microscope. Fiber diameters and porosities of PLGA and PLGA-PEG scaffolds showed no significant differences (P > 0.05). Cel Counting Kit-8 detection showed neural stem cels grew wel on both two kinds of scaffolds and the absorbance value of two groups increased continuously with incubation time (1, 3, 5, 7, 9, 11 days). And there were statisticaly significant differences in the absorbance values between two groups at each time point (P < 0.05). Moreover, the cel adhesion rate was significantly higher in the PLGA-PEG group than in the PLGA group at 3, 6, 9 hours of culture (P < 0.05). Hoechst 33342 staining showed normal morphology and quality of the nuclei, and significantly more cels were observed in the PLGA-PEG group than the PLGA group (P < 0.05). Under the scanning electron microscope, compared with the PLGA scaffold, the PLGA-PEG scaffold was better for growth and matrix secretion of neural stem cels. In conclusion, PLGA-PEG nanofibrous scaffolds prepared by electrospinning are safe, non-toxic and suitable for neural stem cels growth with wel biocompatibility, appropriate aperture and porosity.