Segmentation of brain tumor on magnetic resonance images using 3D full-convolutional densely connected convolutional networks / 南方医科大学学报

Accurate segmentation of multiple gliomas from multimodal MRI is a prerequisite for many precision medical procedures. To effectively use the characteristics of glioma MRI and im-prove the segmentation accuracy, we proposes a multi-Dice loss function structure and used pre-experiments to select the good hyperparameters (i.e. data dimension, image fusion step, and the implementation of loss function) to construct a 3D full convolution DenseNet-based image feature learning network. This study included 274 segmented training sets of glioma MRI and 110 test sets without segmentation. After grayscale normalization of the image, the 3D image block was extracted as a network input, and the network output used the image block fusion method to obtain the final segmentation result. The proposed structure improved the accuracy of glioma segmentation compared to a general structure. In the on-line assessment of the open BraTS2015 data set, the Dice values for the entire tumor area, tumor core area, and enhanced tumor area were 0.85, 0.71, and 0.63, respectively.

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.

A new biocompatible microemulsion increases extraction yield and bioavailability of Andrographis paniculata / 中国天然药物

The purpose of this study was to design and prepare a biocompatible microemulsion of Andrographis paniculata (BMAP) containing both fat-soluble and water-soluble constituents. We determined the contents of active constituents of BMAP and evaluated its bioavailability. The biocompatible microemulsion (BM), containing lecithin and bile salts, was optimized in the present study, showing a good physical stability. The mean droplet size was 19.12 nm, and the average polydispersity index (PDI) was 0.153. The contents of andrographolide and dehydroandrographolide in BMAP, as determined by high performance liquid chromatography (HPLC), were higher than that in ethanol extraction. The pharmacokinetic results of BMAP showed that the AUC0-7 and AUC0→∞ values of BMAP were 2.267 and 27.156 μg·mL(-1)·h(-1), respectively, and were about 1.41-fold and 6.30-fold greater than that of ethanol extraction, respectively. These results demonstrated that the bioavailability of and rographolide extracted by BMAP was significantly higher than that extracted by ethanol. In conclusion, the BMAP preparation displayed ann improved dose form for future clinical applications.

Status and analysis of Astragali Radix resource in China / 中国中药杂志

To explore the status of the resources of Astragali Radix, a survey on its germplasm resources was carried out. Some conclusions can be drawn for Astragali Radix: the major source is the cultivated Astragalus mongolicus. The new major cultivation areas for A. mongolicus and A. membranaceus are Shandong and Gansu province. The semi-wildly planting model in Shanxi province maintains the genuine trait of Astragali Radix, but its yield is limited, and now a combination model has been developed. The major problems for Astragali Radix are the selection of planting sites, the rot root and difficulty in collecting and processing. Several developmental proposals for Astragali Radix were put forward including rational distribution of planting areas, establishment of standard system, development and standardization of producing technologies.

A graph cuts-based interactive method for segmentation of magnetic resonance images of meningioma / 南方医科大学学报

For accurate segmentation of the magnetic resonance (MR) images of meningioma, we propose a novel interactive segmentation method based on graph cuts. The high dimensional image features was extracted, and for each pixel, the probabilities of its origin, either the tumor or the background regions, were estimated by exploiting the weighted K-nearest neighborhood classifier. Based on these probabilities, a new energy function was proposed. Finally, a graph cut optimal framework was used for the solution of the energy function. The proposed method was evaluated by application in the segmentation of MR images of meningioma, and the results showed that the method significantly improved the segmentation accuracy compared with the gray level information-based graph cut method.

Three-dimensional low-dose CT volume reconstruction based on non-local weights optimization and GPU acceleration / 南方医科大学学报

Concerns have been raised over x-ray radiation dose associated with repeated computed tomography (CT) scans for tumor surveillance and radiotherapy planning. In this paper, we present a low-dose CT image reconstruction method for improving low-dose CT image quality. The method proposed exploited rich redundancy information from previous normal-dose scan image for optimizing the non-local weights construction in the original non-local means (NLM)-based low-dose image reconstruction. The objective 3D low-dose volume and the previous 3D normal-dose volume were first registered to reduce the anatomic structural dissimilarity between the two datasets, and the optimized non-local weights were constructed based on the registered normal-dose volume. To increase the efficiency of this method, GPU was utilized to accelerate the implementation. The experimental results showed that this method obviously improved the image quality, as compared with the original NLM method, by suppressing the noise-induced artifacts and preserving the edge information.

Automatic detection and diagnosis of lung nodules on CT images based on LDA and SVM / 南方医科大学学报

Based on suspected pulmonary nodule segmentation images obtained previously and with a large-sample training, automatic detection and diagnosis of the pulmonary nodules on CT images was realized by extracting the multi-dimensional features of the pulmonary nodule images and the application of LDA and SVM statistical classifiers. Experimental results showed that this detection and diagnosis method produced better classification results, and is practical for application in CAD systems.

Real-time volume rendering based on gradient adaptive shading / 南方医科大学学报

For medical image volume rendering, it is very difficult to simultaneously visualize interior and exterior structures while preserving clear shape cues. Highly transparent transfer functions produce cluttered images with many overlapping structures, while clipping techniques completely remove possibly important contextual information. To address this issue, A gradient adaptive shading based illumination model is proposed and implemented in CUDA architecture. The coefficients of ambient, diffuse and specular lighting are tuned adaptively according to gradient. The experiments show that our method is capable of preserving 3-D contextual information in medical image dataset while still show clear boundaries with real-time interactive speed.

Sparse angular CT projection onto convex set reconstruction using nonlocal means iterative modification / 南方医科大学学报

Based on the fact that nonlocal means (NL-means) filtered image can likely produce an acceptable priori solution, we propose a sparse angular CT projection onto convex set (POCS) reconstruction using NL-means iterative modification. The new reconstruction scheme consists of two components, POCS and NL-means filter. In each phase of the sparse angular CT iterative reconstruction, we first used POCS algorithm to meet the identity and non-negativity of projection data, and then performed NL-means filter to the image obtained by POCS method for image quality improvement. Simulation experiments showed that the proposed POCS scheme can significantly improve the quality of sparse angular CT image by suppressing the noise and removing the streak-artifacts.

Study on absorption mechanism of genistein self-microemulsifying system in rat intestines / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the absorption mechanism of genistein self-microemulsifying system in rat intestines.</p><p><b>METHOD</b>The concentrations of phenol red and genistein by in situ perfusion in rats were determined by UV and HPLC, respectively. The effects of drug concentrations, pH, various intestinal segments and P-glycoprotein (P-gp) inhibitor verapamil on the absorption had been studied.</p><p><b>RESULT</b>The absorption rate constant (Ka) of genistein had no significant difference at concentrations of 0.05-0.5 mg x mL(-1) and pH of 5.4-7.8 in perfusion. It was Ka of jejunum > ileum > duodenum > colon. The absorption of genistein in jejunum had significant difference (P < 0.05) compared with other parts of intestines. Ka was increased obviously when verapamil was coper-fused with genistein (P < 0. 05).</p><p><b>CONCLUSION</b>The absorption of genistein self-microemulsifying system is a first order process with passive diffusion mechanism related to P-gp efflux. It can be absorbed at all segments of rat intestine, and the jejunum is the best absorption segment, pH had no special effect on the absorption of genistein self-microemulsifying system in rat intestine.</p>

A medical image authentication method based on restorable watermarking / 南方医科大学学报

In this paper, a restorable watermarking algorithm is proposed for medical image content authentication. Important DWT coefficients are chosen to be coded with the SPIHT algorithm for generating watermarking. The improved security watermark scrambled by Arnold transformation was then embedded into the lower bits of the image data. Finally, the chain structure was used to detect the watermarking and identify the altered positions. The altered data in an image was restored by SPIHT decoding. The experimental results demonstrated that the watermarked image not only possessed good perceptual transparence but also allowed location and restoration of the tampered content.

Improved reconstruction for PROPELLER data in magnetic resonance imaging based on fuzzy enhancement / 南方医科大学学报

To improve the conventional reconstruction algorithm for PROPELLER MRI data, we propose a new algorithm based on fuzzy enhancement. The motion parameters were extracted from fuzzy enhanced images reconstructed through zero-padding strips. After motion compensation, the image was obtained through gridding reconstruction. The experiment results showed that this algorithm could estimate and compensate the motion more robustly and precisely, and the motion artifacts could be better suppressed to obtain improved image quality.

Automatic extraction and segmentation of the intracranial structure from cerebral computed tomography / 南方医科大学学报

This paper describes a new method for extracting and segmenting intracranial structure from serial images of cerebral computerized tomography automatically. A region growing- and morphology-based approach was first developed to extract intracranial structures from the serial images of cerebral computerized tomography, and focusing on the problems of parameter initialization of the expectation maximization (EM) algorithm, an improved EM algorithm based on parameter- limited GMM was presented to segment the intracranial structures successfully. Experimental results of the algorithm showed that this method was effective for all cerebral computerized tomography images from bottom to top of the cerebrum.

Fuzzy Markov random filed model and a new algorithm for image segmentation / 南方医科大学学报

A fuzzy Markov random field (FMRF) model is established and a new algorithm based on FMRF for image segmentation proposed in this paper. This algorithm simultaneously deals with the fuzziness and randomness for effective acquisition of the prior knowledge of the images. A conventional Markov random field (CMRF) serves as a bridge between the FMRF, obviously a generalization of the CMRF, and the original images. The FMRF degenerates into the CMRF when no fuzziness is considered. The segmentation results are obtained by fuzzifying the image, updating the membership of prior FMRF based on the maximum posteriori criteria, and defuzzifying the image according to the maximum membership principle. The proposed algorithm can effectively filter the noise and eliminate partial volume effect when processing the degraded image to ensure more accurate image segmentation.

Influence of the watery extract of jiangzhining decoction on the genetic expression of hepatocyte LDLR of hyperlipidemic rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the influence of Jiangzhining decoction on the genetic expression of Liver LDLR of the rats suffered from hyperlipemia.</p><p><b>METHOD</b>Laboratory animals were male wister rats with hyperlipemia resulting from high fat feeding. Prescription was the douche of stomach with Jiangzhining decoction (200%) with a dosage of 1.4 g.kg-1, for 15 successive days. Total RNA was extracted from the liver tissue of treated rats and LDLRmRNA was detected by Dot blot hybridization. Expression levels of LDLRmRNA was estimated by a ratio of LDLRmRNA and beta-actin mRNA.</p><p><b>RESULT</b>The difference between expression levels of LDLRmRNA for normal group and those for hyperlipemia group (100% +/- 19% vs 39% +/- 14%) was significant (P < 0.05); and the difference between decoction group (108 +/- 8%) and hyperlipimia group was also highly significant (P < 0.01).</p><p><b>CONCLUSION</b>High fat feeding reduces the expression of liver LDLRmRNA while the decoction can greatly increase it. The study and development of Jiangzhining are significant in preventing and curing cadiocerebral diseases.</p>