Fiber direction estimation using constrained spherical deconvolution based on multi-model response function / 生物医学工程学杂志

Constrained spherical deconvolution can quantify white matter fiber orientation distribution information from diffusion magnetic resonance imaging data. But this method is only applicable to single shell diffusion magnetic resonance imaging data and will provide wrong fiber orientation information in white matter tissue which contains isotropic diffusion signals. To solve these problems, this paper proposes a constrained spherical deconvolution method based on multi-model response function. Multi-shell data can improve the stability of fiber orientation, and multi-model response function can attenuate isotropic diffusion signals in white matter, providing more accurate fiber orientation information. Synthetic data and real brain data from public database were used to verify the effectiveness of this algorithm. The results demonstrate that the proposed algorithm can attenuate isotropic diffusion signals in white matter and overcome the influence of partial volume effect on fiber direction estimation, thus estimate fiber direction more accurately. The reconstructed fiber direction distribution is stable, the false peaks are less, and the recognition ability of cross fiber is stronger, which lays a foundation for the further research of fiber bundle tracking technology.

Perioperative blood pressure management in patients with acute ischemic stroke treated with endovascular therapy / 国际脑血管病杂志

Acute ischemic stroke is characterized by high morbidity, high disability and high mortality. The effectiveness and safety of endovascular therapy in the treatment of acute ischemic stroke have been recognized, but there are few studies on perioperative blood pressure control, and the best blood pressure control management strategy has not yet reached a consensus. This article reviews the blood pressure management during the perioperative period of endovascular treatment.

Risk factors analysis and nomogram prediction of sarcopenia in elderly inpatients / 中国实用护理杂志

Objective:To establish an individualized nomogram model to predict the risk of sarcopenia by analyzing the related factors of myopenia in elderly inpatients.Methods:Inpatients in the department of Affiliated Hospital of Qinghai University from January 2017 to December 2018, aged ≥ 60 years old, were included by the diagnostic criteria of Asian sarcopenia working group, and the independent risk factors were screened by logistic regression for the occurrence of sarcopenia. According to the independent risk factors, a nomogram model was established to predict the risk of sarcopenia. Bootstrap method was used to verify the model. C-index and calibration curve were used to evaluate the differentiation and calibration of the prediction model.Results:Totally 83 of 268 elderly patients had sarcopenia, the incidence was 30.9%. Age ( OR = 1.726, 95% CI 1.244-2.432), body mass index ( OR = 0.753, 95% CI 0.621-0.969), current smoking ( OR = 1.081, 95% CI 1.048-3.297), osteoporosis ( OR = 2.031, 95% CI 1.201-4.193) were all independent risk factors of myopenia in elderly patients. The concordance index for predicting the risk of myopenia was 0.775 (95% CI 0.722-0.827). Conclusion:Age, body mass index, osteoporosis, smoking are the independent risk factors of myopenia in elderly patients. The nomogram model can more directly evaluate the risk of sarcopenia in elderly patients.

Progress in the study of the imaging genomics of Alzheimer's disease / 生物医学工程学杂志

With the exacerbation of aging population in China, the number of patients with Alzheimer's disease (AD) is increasing rapidly. AD is a chronic but irreversible neurodegenerative disease, which cannot be cured radically at present. In recent years, in order to intervene in the course of AD in advance, many researchers have explored how to detect AD as early as possible, which may be helpful for effective treatment of AD. Imaging genomics is a kind of diagnosis method developed in recent years, which combines the medical imaging and high-throughput genetic omics together. It studies changes in cognitive function in patients with AD by extracting effective information from high-throughput medical imaging data and genomic data, providing effective guidance for early detection and treatment of AD patients. In this paper, the association analysis of magnetic resonance image (MRI) with genetic variation are summarized, as well as the research progress on AD with this method. According to complexity, the objects in the association analysis are classified as candidate brain phenotype, candidate genetic variation, genome-wide genetic variation and whole brain voxel. Then we briefly describe the specific methods corresponding to phenotypic of the brain and genetic variation respectively. Finally, some unsolved problems such as phenotype selection and limited polymorphism of candidate genes are put forward.

A tooth cone beam computer tomography image segmentation method based on the local Gaussian distribution fitting / 生物医学工程学杂志

Oral teeth image segmentation plays an important role in teeth orthodontic surgery and implant surgery. As the tooth roots are often surrounded by the alveolar, the molar's structure is complex and the inner pulp chamber usually exists in tooth, it is easy to over-segment or lead to inner edges in teeth segmentation process. In order to further improve the segmentation accuracy, a segmentation algorithm based on local Gaussian distribution fitting and edge detection is proposed to solve the above problems. This algorithm combines the local pixels' variance and mean values, which improves the algorithm's robustness by incorporating the gradient information. In the experiment, the root is segmented precisely in cone beam computed tomography (CBCT) teeth images. Segmentation results by the proposed algorithm are then compared with the classical algorithms' results. The comparison results show that the proposed method can distinguish the root and alveolar around the root. In addition, the split molars can be segmented accurately and there are no inner contours around the pulp chamber.

Research progress of details enhancement methods in medical images / 生物医学工程学杂志

Effective medical image enhancement method can not only highlight the interested target and region, but also suppress the background and noise, thus improving the quality of the image and reducing the noise while keeping the original geometric structure, which contributes to easier diagnosis in disease based on the image enhanced. This article carries out research on strengthening methods of subtle structure in medical image nowadays, including images sharpening enhancement, rough sets and fuzzy sets, multi-scale geometrical analysis and differential operator. Finally, some commonly used quantitative evaluation criteria of image detail enhancement are given, and further research directions of fine structure enhancement of medical images are discussed.

An Improved Empirical Mode Decomposition Algorithm for Phonocardiogram Signal De-noising and Its Application in S1/S2 Extraction / 生物医学工程学杂志

In this paper, an improved empirical mode decomposition (EMD) algorithm for phonocardiogram (PCG) signal de-noising is proposed. Based on PCG signal processing theory, the S1/S2 components can be extracted by combining the improved EMD-Wavelet algorithm and Shannon energy envelope algorithm. Firstly, by applying EMD-Wavelet algorithm for pre-processing, the PCG signal was well filtered. Then, the filtered PCG signal was saved and applied in the following processing steps. Secondly, time domain features, frequency domain features and energy envelope of the each intrinsic mode function's (IMF) were computed. Based on the time frequency domain features of PCG's IMF components which were extracted from the EMD algorithm and energy envelope of the PCG, the S1/S2 components were pinpointed accurately. Meanwhile, a detecting fixed method, which was based on the time domain processing, was proposed to amend the detection results. Finally, to test the performance of the algorithm proposed in this paper, a series of experiments was contrived. The experiments with thirty samples were tested for validating the effectiveness of the new method. Results of test experiments revealed that the accuracy for recognizing S1/S2 components was as high as 99.75%. Comparing the results of the method proposed in this paper with those of traditional algorithm, the detection accuracy was increased by 5.56%. The detection results showed that the algorithm described in this paper was effective and accurate. The work described in this paper will be utilized in the further studying on identity recognition.

Relationship Between Plasma Level of NT-proBNP and Ventricular Diastolic Dysfunction in Elder Hypertensive Patients Without Target Organ Damage / 中国循环杂志

Objective: To study the relationship between plasma level of N-terminal B-type natriuretic peptide (NT-proBNP) and ventricular diastolic dysfunction in elder hypertensive patients without target organ damage. Methods: A total of 66 relevant patients treated in our hospital from 2012-03 to 2014-03 were studied. According to the standard of ventricular diastolic dysfunction, the patients were divided into 2 groups: Study group, n=27 patients with diastolic dysfunction and Control group, n=39 patients without diastolic dysfunction. The patients in Study group were further divided into 3 sub-groups based on Doppler classification of diastolic dysfunction:Grade 1, the patients with E/A90 ms, n=8. Grade 2, the patients with E/A>1.5, DT (150-220) ms, IVRT1.5, DT≤150 ms, IVRT NT-proBNP and ventricular diastolic dysfunction. Results: Plasma level of NT-proBNP was higher in Study group than that in Control group. NT-proBNP level in Grade 3-4 sub-group was obviously higher than those in Grade 1 and Grade 2 sub-groups, NT-proBNP level in Grade 2 sub-group was higher than that in Grade 1 sub-group. Pearson correlation analysis indicated that NT-proBNP level was positively related to systolic blood pressure, diastolic function and E/E’ (r=0.211, P=0.037, r=0.442, P=0.004 and r=0.556, P=0.000), while negatively related to E’/A’ (r=-0.372, P=0.000). Conclusion: The increased plasma level of NT-proBNP are highly support for ventricular diastolic dysfunction in elder hypertensive patients without target organ damage, NT-proBNP level is related to ventricular diastolic function.

A review on the research progress of the computer-aided detection of pulmonary nodule / 生物医学工程学杂志

Computer-aided detection (CAD) of pulmonary nodule technology can effectively assist the radiologist to enhance lung nodule detection efficiency and accuracy rate, so it can lay the foundation for the early diagnosis of lung cancer. In order to provide reference for the scholars and to develop the CAD technology, we in this paper review the technology research and development of CAD of the pulmonary nodules which is based on CT image in recent years both home and abroad. At the same time, we also analyse the advantages and shortcomings of different methods. Then we present the improvement direction for reference. According to the literature in recent years, there still has been large development space in CAD technology for pulmonary nodules. The establishment and improvement of the CAD system in each step would be of great scientific value.

A probability segmentation algorithm for lung nodules based on three-dimensional features / 生物医学工程学杂志

This paper presents a probability segmentation algorithm for lung nodules based on three-dimensional features. Firstly, we computed intensity and texture features in region of interest (ROI) pixel by pixel to get their feature vector, and then classified all the pixels based on their feature vector. At last, we carried region growing on the classified result, and got the final segmentation result. Using the public Lung Imaging Database Consortium (LIDC) lung nodule datasets, we verified the performance of proposed method by comparing the probability map within LIDC datasets, which was drawn by four radiology doctors separately. The experimental results showed that the segmentation algorithm using three-dimensional intensity and texture features would be effective.

A practical multi-modality medical image registration solution / 生物医学工程学杂志

In medical imaging field, doctors often complete the intra-subject registration of multi modality images by choosing a pair of anatomic landmarks. It is hard to choose the same landmark accurately in different imaging modality. For multi-modality image registration, mutual information measure is widely used because it suffers little from the difference among different modalities, but it has disadvantages of large amount of calculation and slow converges. In this paper, considering the convenience in practice, we firstly register different modality images by choosing a pair of corresponding landmarks. In order to decrease the error during choosing the landmarks, we further do the registration using mutual information method. The advantage of this solution is that the landmark based registration presents a good starting point for further mutual information (MI) registration, while the MI method decreases the difficulty of choosing landmarks. Experimental results showed that this registration solution was fast, accurate, and would have a good clinical potential application in the future.

Clinical study of super-early operation combined with traditional Chuanxiongqin on treatment of hypertensive intracerebral hemorrhage / 中国基层医药

Objective To explore an effective treatment for hypertensive intracerebral hemorrhage.Methods By the method of random and control,patients with hypertensive intracerebral hemorrhage were randomly divided into two groups:the treatment group(32 patients)was treated with integrated traditional Chinese and western medicine therapy,including super-early operation,conventional western medicine and Chuanxiongqin injection treatment.The control group(40 patients)was treated with operation and conventional western medicine treatment.The effect was evaluated on 28 th day after treatment.Results The effect of the treatment group was superior to that of the control group(χ~2=4.15,3.26,P＜0.05).The treatment group had lower mortality rate(χ~2=8.04,P＜0.05)and lower morbidity of complications(pulmonary infection:6/16 cases,χ~2=11.37,P=0.01;upper-congestive hemorrhage:8/16 cases,χ~2=4.10,P=0.04)statistical data indicated that there was significant difference between treatment group and control group.Conclusion Super-early operation with traditional Chinese medicine in treatment of hypertensive intracerebral henorrhage has a better effect than the treatment without traditional Chinese medicine.