Craniofacial malformation caused by premature fusion of cranial suture of infants has a serious impact on their growth. The purpose of skull remodeling surgery for infants with craniosynostosis is to expand the skull and allow the brain to grow properly. There are no standardized treatments for skull remodeling surgery at the present, and the postoperative effect can be hardly assessed reasonably. Children with sagittal craniosynostosis were selected as the research objects. By analyzing the morphological characteristics of the patients, the point cloud registration of the skull distortion region with the ideal skull model was performed, and a plan of skull cutting and remodeling surgery was generated. A finite element model of the infant skull was used to predict the growth trend after remodeling surgery. Finally, an experimental study of surgery simulation was carried out with a child with a typical sagittal craniosynostosis. The evaluation results showed that the repositioning and stitching of bone plates effectively improved the morphology of the abnormal parts of the skull and had a normal growth trend. The child’s preoperative cephalic index was 65.31%, and became 71.50% after 9 months’ growth simulation. The simulation of the skull remodeling provides a reference for surgical plan design. The skull remodeling approach significantly improves postoperative effect, and it could be extended to the generation of cutting and remodeling plans and postoperative evaluations for treatment on other types of craniosynostosis.
Complete three-dimensional (3D) tooth model provides essential information to assist orthodontists for diagnosis and treatment planning. Currently, 3D tooth model is mainly obtained by segmentation and reconstruction from dental computed tomography (CT) images. However, the accuracy of 3D tooth model reconstructed from dental CT images is low and not applicable for invisalign design. And another serious problem also occurs,i.e. frequentative dental CT scan during different intervals of orthodontic treatment often leads to radiation to the patients. Hence, this paper proposed a method to reconstruct tooth model based on fusion of dental CT images and laser-scanned images. A complete 3D tooth model was reconstructed with the registration and fusion between the root reconstructed from dental CT images and the crown reconstructed from laser-scanned images. The crown of the complete 3D tooth model reconstructed with the proposed method has higher accuracy. Moreover, in order to reconstruct complete 3D tooth model of each orthodontic treatment interval, only one pre-treatment CT scan is needed and in the orthodontic treatment process only the laser-scan is required. Therefore, radiation to the patients can be reduced significantly.
The medical image registration between preoperative three-dimensional (3D) scan data and intraoperative two-dimensional (2D) image is a key technology in the surgical navigation. Most previous methods need to generate 2D digitally reconstructed radiographs (DRR) images from the 3D scan volume data, then use conventional image similarity function for comparison. This procedure includes a large amount of calculation and is difficult to archive real-time processing. In this paper, with using geometric feature and image density mixed characteristics, we proposed a new similarity measure function for fast 2D-3D registration of preoperative CT and intraoperative X-ray images. This algorithm is easy to implement, and the calculation process is very short, while the resulting registration accuracy can meet the clinical use. In addition, the entire calculation process is very suitable for highly parallel numerical calculation by using the algorithm based on CUDA hardware acceleration to satisfy the requirement of real-time application in surgery.
Non-rigid registration plays an important role in medical image analysis. U-Net has been proven to be a hot research topic in medical image analysis and is widely used in medical image registration. However, existing registration models based on U-Net and its variants lack sufficient learning ability when dealing with complex deformations, and do not fully utilize multi-scale contextual information, resulting insufficient registration accuracy. To address this issue, a non-rigid registration algorithm for X-ray images based on deformable convolution and multi-scale feature focusing module was proposed. First, it used residual deformable convolution to replace the standard convolution of the original U-Net to enhance the expression ability of registration network for image geometric deformations. Then, stride convolution was used to replace the pooling operation of the downsampling operation to alleviate feature loss caused by continuous pooling. In addition, a multi-scale feature focusing module was introduced to the bridging layer in the encoding and decoding structure to improve the network model’s ability of integrating global contextual information. Theoretical analysis and experimental results both showed that the proposed registration algorithm could focus on multi-scale contextual information, handle medical images with complex deformations, and improve the registration accuracy. It is suitable for non-rigid registration of chest X-ray images.
By dividing the evolution of the U.S. clinical trial registration system into three phases—emergence, inception, and maturity—this study systematically traces its half-century development and reveals the underlying tensions and institutional logic. The U.S. clinical trial registration system is not merely a technical instrument, but a comprehensive institutional platform reconciling the conflicts among scientific rationality, commercial interests, and the public’s right to know. The emergence phase (1971—1985) originated from the establishment and public disclosure of the International Cancer Database to meet cancer research needs and safeguard patients’ survival rights. The inception phase (1986—2004) unfolded against the backdrop of the FDA’s drug approval crisis, with the construction of major disease registration systems breaking the regulatory deadlock and achieving an "incremental revolution". The maturity phase (2004—2016) centered on controlling publication bias and advancing institutionalization and legalization. The 2004 paroxetine incident galvanized global consensus on trial registration, and the 2007 U.S. Congressional mandate marked the pivotal turning point toward a fully mature system. Today, China still faces low registration rates and insufficient legal constraints. Drawing on the U.S. experience, China should prioritize institutional publicness, legal enforceability, and the containment of publication bias to strategically upgrade its clinical trial registration system.
ObjectiveTo explore the function of information system platform in the management of outpatient registration source. MethodsOn the basis of registration appointment system, we surveyed again on outpatients traffic between February 6th and 10th in 2012 to find out find out the disadvantages of outpatient service procedures. Certain measures were taken for improvement, especially the management of registration source. ResultsAfter improvement by certain measures, queuing phenomenon and the degree of congestion in the waiting area were improved. To some extent, the satisfaction of patients and doctors was raised from 91% to 93%. ConclusionStandardizing outpatient administration and behavior of patients by information system platform has a good effect and is worth promoting.
Objective To investigate the number of Chinese clinical trials and the completeness of registered information on the source of their funding. Methods We searched the five primary registers in the World Health Organization’s International Clinical Trial Registration Platform to identify Chinese clinical trials, calculated the number Chinese clinical trials with specific funding and evaluated the completeness of the information on the source of this funding. Results We identified 383 registered Chinese clinical trials, of which 219 (27 trials per year on average) were registered in clinicaltrials.gov, 94 in the Chinese Clinical Trial Register Center (113 per year on average), 62 in controlled-trials.com (12.4 per year on average) and 8 (1.6 per year on average) in the Australian and New Zealand Clinical Trials Registry. 360 trials had some information on their source of funding: 230 from the mainland of China (62 funded by colleges/universities, 47 by national/local organizations, 47 by the Ministry of Science and Technology, 34 by hospitals, 28 by commercial organizations, 9 by international foundations, and 3 by the Ministry of Health), 117 from Hongkong and 13 from Taiwan. The information in the registers on the source of funding was incomplete. Conclusion The number of funded Chinese clinical trials in these registers is too small. The registrations should be improved to improve the completeness of information on the source of funding. It is important to disseminate the importance of registering clinical trials and doing so in a local register to promote the transparency and accessibility of trial registration.
ObjectivesTo analyze the research status and hot spots of hypertension-related clinical trials in special Chinese population registered on the Chinese Clinical Trial Registry (ChiCTR), so as to provide a basis for the development of hypertension-related research in special population in China.MethodsThe ChiCTR was searched online (up to August 31st, 2019, no limitation in the status of trial registration), all clinical trials on hypertension in special population were collected, and the general characteristics, researched diseases, research types, intervention measures and main outcomes of the trials were analyzed.ResultsA total of 64 hypertension-related clinical trials in special population registered in the ChiCTR were included, including 41 (64.1%) trials registered in last 3 years. The registration status of 46 (71.9%) trials was pre-registration. The registered authors were mainly from colleges and universities or medical institutions (n = 61, 95.3%), of which 60.9% were registered in Beijing, Shanghai, Guangdong, Zhejiang, Jiangsu and Hebei. The researched diseases mainly included elderly hypertension and hypertensive stroke, accounting for 50% of the total. Additionally, 37 (57.8%) clinical trials were intervention studies, of which 21 (56.7%) were drug-based intervention studies. Blood pressure, blood glucose, cardiovascular and cerebrovascular events, blood lipid, cranial MRI and Glasgow Coma Scale were the commonly used outcomes, accounting for 58.5% of the total outcomes. Most blood pressure measurements did not indicate the measurement method (n = 22, 64.7%).ConclusionsThe quantity of hypertension-related clinical trials in special population registered on the ChiCTR is increasing, however, there exists regional imbalance. The drug intervention-related clinical trials of elderly hypertension have become a research hot spot. However, blood pressure measurement method is not indicated in most trials, and some researchers do not register in time. Therefore, it is suggested that researchers should further strengthen the awareness of carrying out high-quality clinical trials.
Image registration is of great clinical importance in computer aided diagnosis and surgical planning of liver diseases. Deep learning-based registration methods endow liver computed tomography (CT) image registration with characteristics of real-time and high accuracy. However, existing methods in registering images with large displacement and deformation are faced with the challenge of the texture information variation of the registered image, resulting in subsequent erroneous image processing and clinical diagnosis. To this end, a novel unsupervised registration method based on the texture filtering is proposed in this paper to realize liver CT image registration. Firstly, the texture filtering algorithm based on L0 gradient minimization eliminates the texture information of liver surface in CT images, so that the registration process can only refer to the spatial structure information of two images for registration, thus solving the problem of texture variation. Then, we adopt the cascaded network to register images with large displacement and large deformation, and progressively align the fixed image with the moving one in the spatial structure. In addition, a new registration metric, the histogram correlation coefficient, is proposed to measure the degree of texture variation after registration. Experimental results show that our proposed method achieves high registration accuracy, effectively solves the problem of texture variation in the cascaded network, and improves the registration performance in terms of spatial structure correspondence and anti-folding capability. Therefore, our method helps to improve the performance of medical image registration, and make the registration safely and reliably applied in the computer-aided diagnosis and surgical planning of liver diseases.
Objective The baseline, clinical characteristics, and risk factors were analyzed in the stroke registry program of the Xinjiang Production Constraction Corp’s Hospital aimed to aid the clinical management and stroke prevention. Method A single center prospective method based on Lausanne Stroke Registry was used in this study. Patients generally, past history, living conditions, onset to treatment time, the stroke scale were collected with 1 year follow up. The investigators of follow up were single blinded. Result Eight hundred and ten ischemic stroke patients were included, of which 478 (59.01%) were male, 332 (40.99%) were female. The average age of these patients was 66.50±10.66 years. One year loss rate of follow up was 4.64%. Seven hundred and sixty-nine patients were diagnosis as acute cerebral infarction, 41 patients were TIA. The median time from onset to treatment was 15 hours. Lacunar infarction was the most common type with 334 (43.43%) patients. The average score of the National Institutes of Heath Stroke Scale was 5.55±7.24. The incidence of carotid artery plaque was 82.2%. Conclution Xinjiang region has its own characteristics of stroke with a higher carotid artery plaque rate and thrombolytic therapy ratio. Good stroke registration system could standardize the clinical behavior and promote the continuous improvement of medical quality.