Purpose: Functional changes have been observed between diseased and healthy subjects, and functional brain atlases derived from healthy populations may fail to reflect functional characteristic of the diseased brain. Therefore the aim of this study was to generate a visual atlas based on functional connectivity from primary open-angle glaucoma (POAG) patients and to prove the applicability of the visual atlas in functional connectivity and network analysis. Methods: Functional magnetic resonance images were acquired from 36 POAG patients and 20 healthy controls. Two data-driven approaches, K-means and Ward clustering algorithms, were adopted for visual cortices parcellation. Dice coefficient and adjusted Rand index were used to assess reproducibility of the two approaches. Homogeneity index, silhouette coefficient, and network properties were adopted to assess functional validity for the data-driven approaches and frequently used brain atlas. Graph theoretical analysis was adopted to investigate altered network patterns in POAG patients based on data-driven visual atlas. Results: Parcellation results demonstrated asymmetric patterns between left and right hemispheres in POAG patients compared with healthy controls. In terms of evaluating metrics, K-means performed better than Ward clustering in reproducibility. Data-driven parcellations outperformed frequently used brain atlases in terms of functional homogeneity and network properties. Graph theoretical analysis revealed that atlases generated by data-driven approaches were more conducive in detecting network alterations between POAG patients and healthy controls. Conclusions: Our findings suggested that POAG patients experienced functional alterations in the visual cortices. Results also highlighted the necessity of data-driven atlases for functional connectivity and functional network analysis of POAG brain.
Abstract Purpose To evaluate the effects of high intraocular pressure ( IOP ) on central nervous system in patients with high‐tension glaucoma ( HTG ) by using resting‐state functional magnetic resonance imaging (rs‐ fMRI ). Methods Thirty‐six patients with HTG and twenty age‐ and gender‐matched healthy controls ( HC s) were recruited and underwent IOP measurement and rs‐ fMRI scan. The whole brain regional homogeneity (ReHo) value was calculated among the enrolled subjects. Two‐sample t tests with permutation test and threshold‐free cluster enhancement was performed between HTG group and HC s. Correlation analyses between IOP and ReHo values were conducted. Results Compared with HC s, HTG group showed increased ReHo values in the left lobule 8 of cerebellar hemisphere, left lobule 4 and 5 of cerebellar hemisphere and left fusiform gyrus ( FG ) (p < 0.05). HTG group showed decreased ReHo value in the left middle frontal gyrus ( MFG ) (p < 0.05). Intraocular pressure of the left eye in HTG group experienced a significant positive correlation with ReHo value of the left FG ( r = 0.370, p = 0.026), IOP of the right eye in HTG group showed a significant negative correlation with ReHo value in the left MFG ( r = −0.421, p = 0.011). Conclusion Resting‐state fMRI ReHo analyses associated elevated IOP with abnormal regional activity in several brain regions related to higher visual function and visual memory consolidation. High‐tension glaucoma patients also showed diminished integration of visual information and cerebellar function. These results may provide imaging support for pathophysiological research of HTG and may reveal new targets for the accurate treatment of HTG .
Aiming at the problem that the image generated by Millimeter Wave(MMW) focal plane imaging system is contaminated by much unknown noise and has lower resolution,a novel image denoising method,combined with Human Visual System(HVS) based self-adaptive median filtering and contourlet transformation,is proposed in this paper.The noise is self-adaptively detected and filtered by using the method of HVS-based adaptive median filtering,and pulse noise is filtered efficiently.Utilizing the contourlet decomposition orientation and the energy variation to transform the median filtering result,the high frequency sub-bands are obtained,and they are further denoised by the threshold,which retains more image contour in degree.Experimental results show that that the proposed method has better denoising performance than other methods.
Objective: To study the effect of Triamcinolone acetonide to treat patients with uveitis and cataract after surgery.Methods: 48 cases with uveitis and cataract after surgery were collected and divided into control group and observation group according to numbers,each group had 24 cases.The observation group was given Triamcinolone acetonide combined with Prednisolone,while the control group was given Prednisolone only.The recovery of visual acuity,intraocular pressure changes,anterior chamber inflammation,complications occurrence were compared and the recurrence was observed at the follow-up visit after 3 months.Results: The recovery of visual acuity after surgery in the observation group was better than the control group,the result of the first postoperative day was no significant(P0.05),but the results after a week and a month in the observation group were respectively 15 cases and 18 cases,while the control group were 11 cases and 12 cases,the differences were significant(P0.05);the preoperative intraocular pressure between the two groups were all lower than postoperation,but there were no significant differences compared with the results of one day and one week after surgery(P0.05);the level of anterior chamber inflammation of the observation group was lower than the control group,the level of 1 day and 1 week after surgery compared between the two groups were significantly different(P0.05);the rate of complications and recurrence in the observation group was respectively 20.83%,12.50%,lower than the control group(37.50%,25.00%).The difference was statistically significant(P0.05).Conclusion: The effect of Triamcinolone acetonide to treat patients with uveitis and cataract after surgery is conformed.Not only the visual recovery is faster,the anterior chamber inflammation is mild,but also the rate of complications and recurrence is lower.It is worthy to be widely used in the clinical.
It is the key to select the appropriate structure elements in the edge detection using morphological gradient operator. A new quantum measurement is proposed in this paper based on quantum collapsing theory in which the possible noisy pixels are collapsed to state 0 while no participating in morphological operation. As the noise intensity increases, the size of the window of the structural elements of superposition states is adaptively increased and quantum collapsing morphological gradient operator is created. The experimental results on the edge detection of the image corrupted with impulse noise show that the proposed algorithm has strongly ability of anti-noise. The normalized mean square error of the new algorithm increases slowly with impulse noise intensity. Further more, the new algorithm is consistent with the traditional morphological gradient operator on noise-free image edge detection.
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