7,763 research outputs found
Segmentation of ultrasound images of thyroid nodule for assisting fine needle aspiration cytology
The incidence of thyroid nodule is very high and generally increases with the
age. Thyroid nodule may presage the emergence of thyroid cancer. The thyroid
nodule can be completely cured if detected early. Fine needle aspiration
cytology is a recognized early diagnosis method of thyroid nodule. There are
still some limitations in the fine needle aspiration cytology, and the
ultrasound diagnosis of thyroid nodule has become the first choice for
auxiliary examination of thyroid nodular disease. If we could combine medical
imaging technology and fine needle aspiration cytology, the diagnostic rate of
thyroid nodule would be improved significantly. The properties of ultrasound
will degrade the image quality, which makes it difficult to recognize the edges
for physicians. Image segmentation technique based on graph theory has become a
research hotspot at present. Normalized cut (Ncut) is a representative one,
which is suitable for segmentation of feature parts of medical image. However,
how to solve the normalized cut has become a problem, which needs large memory
capacity and heavy calculation of weight matrix. It always generates over
segmentation or less segmentation which leads to inaccurate in the
segmentation. The speckle noise in B ultrasound image of thyroid tumor makes
the quality of the image deteriorate. In the light of this characteristic, we
combine the anisotropic diffusion model with the normalized cut in this paper.
After the enhancement of anisotropic diffusion model, it removes the noise in
the B ultrasound image while preserves the important edges and local details.
This reduces the amount of computation in constructing the weight matrix of the
improved normalized cut and improves the accuracy of the final segmentation
results. The feasibility of the method is proved by the experimental results.Comment: 15pages,13figure
Correlation between the peripapillary retinal nerve fiber layer thickness,structure changes in non-proliferative diabetic retinopathy and the changes of visual function
AIM:To study the correlation between and the peripapillary retinal nerve fiber layer(RNFL)thickness,structure changes in non-proliferative diabetic retinopathy(NPDR)and the the changes of visual function <p>METHODS:Eighty cases(80 eyes)of patients with NPDR who were in our hospital from January 2011 to December 2013 as group NPDR, 60 cases of patients(60 eyes)without retinopathy who were in the hospital were selected as non-diabetic retinopathy group(NRD)group, meanwhile, 50 healthy people who had health examination in our hospital as control group. The RNFL thickness and visual electrophysiological testing were performed on the study objects in the three groups, and the results were compared among groups.<p>RESULTS: Group NPDR's above, below, nasal, temporal and average RNFL thickness were 91.52±18.52, 88.63±21.65, 63.62±11.72, 60.42±9.13, 69.36±12.52μm,those of group NPDR were 111.32±21.90, 113.57±22.67, 74.31±11.74, 67.64±12.34, and 97.31±11.43μm,those of group control were 121.65±21.42, 129.32±23.31, 82.42±9.28, 80.32±8.51, 102.54±21.82μm. To compare of average thickness of RNFL of three groups, groups NPDR and NPD were thinner than that of control group; To compare each quadrant phase, above, below, nasal, the RNFL thickness among three groups had statistical significance(<i>P</i><0.05), while nasal sides had no obviously changes(<i>P</i>>0.05); At the same time, 60'P100 latency(MS), 60'P100 amplitude(V), 15'P100 latency(MS)and 15'P100 amplitude(V)of three groups had statistical significance(<i>P</i><0.05). <p>CONCLUSION: The changes of RNFL thickness have occurred in the early time of NPDR, and mainly the above, below and temporal, and it has a significant relevance with the changes of visual function
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Important roles for E protein binding sites within the immunoglobulin kappa chain intronic enhancer in activating Vkappa Jkappa rearrangement.
The immunoglobulin kappa light chain intronic enhancer (iEkappa) activates kappa rearrangement and is required to maintain the earlier or more efficient rearrangement of kappa versus lambda (lambda). To understand the mechanism of how iEkappa regulates kappa rearrangement, we employed homologous recombination to mutate individual functional motifs within iE(kappa) in the endogenous kappa locus, including the NF-kappaB binding site (kappaB), as well as kappaE1, kappaE2, and kappaE3 E boxes. Analysis of the impacts of these mutations revealed that kappaE2 and to a lesser extent kappaE1, but not kappaE3, were important for activating kappa rearrangement. Surprisingly, mutation of the kappaB site had no apparent effect on kappa rearrangement. Comparable to the deletion of the entire iEkappa, simultaneous mutation of kappaE1 and kappaE2 reduces the efficiency of kappa rearrangement much more dramatically than either kappaE1 or kappaE2 mutation alone. Because E2A family proteins are the only known factors that bind to these E boxes, these findings provide unambiguous evidence that E2A is a key regulator of kappa rearrangement
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