1.MRI volumetric analysis of olfaction-related cortex in olfactory dysfunction patients after upper respiratory tract infections
Guangzheng DAI ; Jianlin WU ; Shiyu ZHOU ; Jing SHEN
Chinese Journal of Radiology 2014;48(4):270-274
Objective To measure the volume of olfaction-related cortex in olfactory dysfunction patients after upper respiratory tract infections via MRI,and to analyze the differences in the volume of olfaction-related cortex.Methods Fifteen olfactory dysfunction patients after upper respiratory tract infections (patient group) and fifteen age-and gender-matched normal volunteers (control group) were enrolled in this study to undergo 1.5 Tesla MR scanning.The volumes of olfaction-related cortex,including entorhinal cortex (EC),perirhinal cortex (PRC) and insular cortex (IC),were drawn and computed with Dr.View software.Olfactory function test was performed with the Sniffin' Sticks method which consisted of three tests:odor threshold (THR),odor discrimination (DIS),odor identification (ID),and their sum score (TDI).Statistical differences in the volumetric measures of bilateral EC,PRC,and IC between patient and control group were analyzed by analysis of covariance (ANCOVA) with age and intracranial volume (ICV) as covariates.Statistical differences in the olfactory function between patient and control group were analyzed by ANCOVA with age as a covariate.Results (1) The EC volume of patient group in the left and right side were (1.5 ± 0.3),(1.6 ± 0.1) cm3,while the control group were (1.7 ± 0.2),(1.8 ± 0.3) cm3 ; The PRC volume of patient group in the left and right side were (1.9 ± 0.4),(1.9 ± 0.3) cm3,and the control group were (2.5 ± 0.8),(2.3 ± 0.7) cm3 ; The IC volume of patient group in the left and right side were (5.2 ± 0.4),(5.8 ± 0.5) cm3,and the control group were (5.8 ± 0.8),(6.7 ± 0.2) cm3.EC,PRC and IC volumes of patient group and control group were measured and the results showed that the olfaction-related cortex volume was decreased in patient group showing significant statistical difference (F =4.913,4.793,7.832,5.574,9.842,7.221,P < 0.05).(2) Olfactory function test of patient group and control group was performed and the results showed that the scores of patient group were lower than that of control group,and the differences were significant (F =54.508,118.774,93.039,53.692,74.139,53.626,91.842,91.696,P < 0.01).Conclusions It is feasible to measure the volumes of olfaction-related cortex with MRI,and the volumes of EC,PRC and IC decreased in olfactory dysfunction patients after upper respiratory tract infections compared with normal people.
2.Corneal Nerves Alteration Associated with Corneal Complications after Pars Plana Vitrectomy
Tiezhu LIN ; Hong YE ; Emmanuel Eric PAZO ; Guangzheng DAI ; Yang XIA ; Wei HE
Korean Journal of Ophthalmology 2021;35(4):255-260
Purpose:
To evaluate the effect of corneal nerves assessment on predicting corneal complications following pars plana vitrectomy (PPV).
Methods:
In this prospective single-center cohort study, 94 patients (94 eyes) received PPV, and were divided into postoperative groups with and without corneal complications. All eyes had corneal nerve fiber length (CNFL), corneal nerve fiber density, and branch density of corneal nerve fibers assessed and calculated with Image J preoperatively. Multivariate logistic regression analysis was used to identify corneal nerve fiber parameters that correlated to post-operative corneal complications. Receiver operator characteristic curve analysis was performed to identify the optimal cut-off point of the corneal fibers’ parameters for predicting corneal complications after PPV.
Results:
Eleven eyes (11.70%) developed corneal complications at 1 week after PPV. There was significant difference between CNFL (19.44 ± 6.88 vs. 26.84 ± 7.53, p = 0.003), corneal nerve fiber density (28.82 ± 9.91 vs. 37.10 ± 10.16, p = 0.013) and branch density of corneal nerve fibers (55.84 ± 21.08 vs. 82.04 ± 31.89, p = 0.01) in two groups, respectively. Receiver operator characteristic analysis showed that the optimal cutoff value of CNFL to predict corneal complications following PPV was <26.495 mm/mm2.
Conclusions
The decrease of CNFL may predict corneal complications following PPV. Regular preoperative corneal confocal microscopy test in PPV patients could be considered.
3.Corneal Nerves Alteration Associated with Corneal Complications after Pars Plana Vitrectomy
Tiezhu LIN ; Hong YE ; Emmanuel Eric PAZO ; Guangzheng DAI ; Yang XIA ; Wei HE
Korean Journal of Ophthalmology 2021;35(4):255-260
Purpose:
To evaluate the effect of corneal nerves assessment on predicting corneal complications following pars plana vitrectomy (PPV).
Methods:
In this prospective single-center cohort study, 94 patients (94 eyes) received PPV, and were divided into postoperative groups with and without corneal complications. All eyes had corneal nerve fiber length (CNFL), corneal nerve fiber density, and branch density of corneal nerve fibers assessed and calculated with Image J preoperatively. Multivariate logistic regression analysis was used to identify corneal nerve fiber parameters that correlated to post-operative corneal complications. Receiver operator characteristic curve analysis was performed to identify the optimal cut-off point of the corneal fibers’ parameters for predicting corneal complications after PPV.
Results:
Eleven eyes (11.70%) developed corneal complications at 1 week after PPV. There was significant difference between CNFL (19.44 ± 6.88 vs. 26.84 ± 7.53, p = 0.003), corneal nerve fiber density (28.82 ± 9.91 vs. 37.10 ± 10.16, p = 0.013) and branch density of corneal nerve fibers (55.84 ± 21.08 vs. 82.04 ± 31.89, p = 0.01) in two groups, respectively. Receiver operator characteristic analysis showed that the optimal cutoff value of CNFL to predict corneal complications following PPV was <26.495 mm/mm2.
Conclusions
The decrease of CNFL may predict corneal complications following PPV. Regular preoperative corneal confocal microscopy test in PPV patients could be considered.
4.Factors Associated with Macular Staphyloma Area on Ultra-widefield Fundus Images
Xinmei ZHANG ; Emmanuel Eric PAZO ; Aoqi ZHANG ; Lanting YANG ; Guangzheng DAI ; Xianwei WU ; Yang XIA ; Amit MESHI ; Wei HE ; Tiezhu LIN
Korean Journal of Ophthalmology 2022;36(3):210-217
Purpose:
To assess the feasibility of applying ultra-widefield fundus (UWF) images for macular staphyloma area (MSA) measurement and investigate the associated factors with MSA.
Methods:
This is a retrospective study. MSA was measured by UWF imaging. Central foveal thickness, subfoveal choroidal thickness, subfoveal scleral thickness were measured on spectral domain optical coherence tomography. Intraclass correlation coefficients of MSA measurement would be evaluated. Multiple linear regression analysis was used to analyze the associated factors with MSA.
Results:
In total, 135 eyes of 92 patients were enrolled. The mean age was 64.73 ± 10.84 years. Mean MSA on UWF image was 279.67 ± 71.70 mm2. Intraclass correlation coefficients of MSA measurement was 0.965 (95% confidence interval [CI], 0.946 to 0.977; p < 0.001). In the multiple linear regression analysis, after adjusting for subfoveal choroidal thickness, best-corrected visual acuity, central foveal thickness, and subfoveal scleral thickness, the factors independently related to MSA were axial length (β = 8.352; 95% CI, 3.306 to 13.398; p = 0.001), sex (β = -26.673; 95% CI, -51.759 to -1.586; p = 0.037), age (β = 1.184; 95% CI, 0.020 to 2.348; p = 0.046).
Conclusions
It is feasible to measure MSA on UWF image. Female, longer axial length, and older age may indicate larger MSA.
5.Advancing automated pupillometry: a practical deep learning model utilizing infrared pupil images
Guangzheng DAI ; Sile YU ; Ziming LIU ; Hairu YAN ; Xingru HE
International Eye Science 2024;24(10):1522-1528
AIM:To establish pupil diameter measurement algorithms based on infrared images that can be used in real-world clinical settings.METHODS:A total of 188 patients from outpatient clinic at He Eye Specialist Shenyang Hospital from Spetember to December 2022 were included, and 13 470 infrared pupil images were collected for the study. All infrared images for pupil segmentation were labeled using the Labelme software. The computation of pupil diameter is divided into four steps: image pre-processing, pupil identification and localization, pupil segmentation, and diameter calculation. Two major models are used in the computation process: the modified YoloV3 and Deeplabv3+ models, which must be trained beforehand.RESULTS:The test dataset included 1 348 infrared pupil images. On the test dataset, the modified YoloV3 model had a detection rate of 99.98% and an average precision(AP)of 0.80 for pupils. The DeeplabV3+ model achieved a background intersection over union(IOU)of 99.23%, a pupil IOU of 93.81%, and a mean IOU of 96.52%. The pupil diameters in the test dataset ranged from 20 to 56 pixels, with a mean of 36.06±6.85 pixels. The absolute error in pupil diameters between predicted and actual values ranged from 0 to 7 pixels, with a mean absolute error(MAE)of 1.06±0.96 pixels.CONCLUSION:This study successfully demonstrates a robust infrared image-based pupil diameter measurement algorithm, proven to be highly accurate and reliable for clinical application.