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 Hos...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 13470 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 Deeplabv 3+models,which must be trained beforehand.RESULTS:The test dataset included 1348 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.展开更多
Recently,many researchers have tried to develop a robust,fast,and accurate algorithm.This algorithm is for eye-tracking and detecting pupil position in many applications such as head-mounted eye tracking,gaze-based hu...Recently,many researchers have tried to develop a robust,fast,and accurate algorithm.This algorithm is for eye-tracking and detecting pupil position in many applications such as head-mounted eye tracking,gaze-based human-computer interaction,medical applications(such as deaf and diabetes patients),and attention analysis.Many real-world conditions challenge the eye appearance,such as illumination,reflections,and occasions.On the other hand,individual differences in eye physiology and other sources of noise,such as contact lenses or make-up.The present work introduces a robust pupil detection algorithm with and higher accuracy than the previous attempts for real-time analytics applications.The proposed circular hough transform with morphing canny edge detection for Pupillometery(CHMCEP)algorithm can detect even the blurred or noisy images by using different filtering methods in the pre-processing or start phase to remove the blur and noise and finally the second filtering process before the circular Hough transform for the center fitting to make sure better accuracy.The performance of the proposed CHMCEP algorithm was tested against recent pupil detection methods.Simulations and results show that the proposed CHMCEP algorithm achieved detection rates of 87.11,78.54,58,and 78 according to´Swirski,ExCuSe,Else,and labeled pupils in the wild(LPW)data sets,respectively.These results show that the proposed approach performs better than the other pupil detection methods by a large margin by providing exact and robust pupil positions on challenging ordinary eye pictures.展开更多
AIM： To evaluate the value of ultra-wide field（UWF） imaging in the management of traumatic retinopathy under the condition of corneal scar or fixed small pupil after complicated ocular trauma. METHODS： Twenty-eigh...AIM： To evaluate the value of ultra-wide field（UWF） imaging in the management of traumatic retinopathy under the condition of corneal scar or fixed small pupil after complicated ocular trauma. METHODS： Twenty-eight patients（28 eyes） with complicated ocular trauma were enrolled in the study from June 2016 to May 2017, including 19 males and 9 females with age ranged from 11 to 64（43.42±12.62）y. All patients were treated with secondary vitrectomy after emergency operation for wound repair of open ocular trauma. Direct ophthalmoscopy and 45-degree fundus photography were taken at each time point of follow up for comparison of findings with UWF images. Routine eye examination including visual acuity, intraocular pressure, slit lamp examination were performed and analyzed as well.RESULTS： Among the 28 traumatized eyes, the positive rate for identification of traumatic retinopathed was 32.1%（9 cases）, 14.9%（5 cases）, and 85.7%（24 cases） with direct ophthalmoscopy, 45-degree fundus photography, and UWF imaging, respectively. The detective rate of UWF imaging under the condition of corneal scar or fixed small pupil was statistically greater than that of 45-degree fundus photography and direct ophthalmoscopy（Bonferroni correction, P〈0.001）. UWF image was obtained in 19 eyes with opaque corneal scar, otherwise their fundus could not be seen by conventional methods. The additional findings of traumatic retinopathies by UWF imaging included periretinal membranes or pre-retinal proliferating strip, retinal holes, hemorrhage in the vitreous or sub-retinal space.CONCLUSION： UWF imaging is superior to traditional fundus photography in the evaluation of traumatic retinopathies under the condition of corneal scar or fixed small pupil after complicated ocular trauma.展开更多
In this paper, we present an elongated speckle images produced from diffusers using sharp elliptical apertures. The orientation of the elliptic aperture is recognized from the direction of the elongation in the speckl...In this paper, we present an elongated speckle images produced from diffusers using sharp elliptical apertures. The orientation of the elliptic aperture is recognized from the direction of the elongation in the speckle images. The aperture tilting out of the plane is investigated. Three models of elliptical apertures are considered and the corresponding speckle images are obtained. The 1st model is composed of two orthogonal ellipses or plus symbol pupil;the 2nd has four symmetric ellipses with an angle of 45° between each of them or in the form of a snow flake pupil and the 3rd model looks like an airplane. Also, the autocorrelation profiles of the speckle images corresponding to the diffused airplane are obtained from which the average speckle size is computed. Finally, the reconstructed images of the described elliptical models and its autocorrelation images, making use of Mat lab code, are obtained.展开更多
目的采用非对称采集与迭代最小二乘估算法迭代水脂分离(iteraterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation,IDEAL-IQ)方法定量评估冈上肌腱损伤的严重程度与肩袖肌群脂肪...目的采用非对称采集与迭代最小二乘估算法迭代水脂分离(iteraterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation,IDEAL-IQ)方法定量评估冈上肌腱损伤的严重程度与肩袖肌群脂肪浸润程度及受试者特征之间的关系。材料与方法回顾性分析2022年8月至2024年6月本院经肩关节镜证实的33例冈上肌腱部分撕裂患者及89例完全撕裂患者,均进行了常规MRI扫描及IDEAL-IQ序列扫描。由两名放射科医生分别对所有受试者的MRI图像进行独立评估,根据常规MRI图像的冈上肌腱损伤表现,将完全撕裂组的冈上肌腱按照Patte分型分为Patte 1型(Ⅱ级)、Patte 2型(Ⅲ级)、Patte 3型(Ⅳ级),将部分撕裂组定义为Ⅰ级。同时在斜矢状位上进行Goutallier分级及Thomazeau萎缩分级,并通过GE ADW 4.7工作站后处理软件在IDEAL-IQ序列生成的脂肪分数图像上测量冈上肌、冈下肌、肩胛下肌及小圆肌脂肪分数(fat fraction,FF)。用组内相关系数(intra-class correlation coefficient,ICC)及Kappa一致性检验评估观察者间及观察者内的一致性。采用Kruskal-Wallis H检验、单因素ANOVA检验分析FF值在不同分组之间的差异,组间两两比较用Bonferroni检验。采用Pear_(s)on相关性分析肩袖肌肉FF值与年龄、症状持续时间的相关性(相关系数r),Spearman相关性分析冈上肌腱损伤分级与肩袖肌群FF值、Goutallier分级及Thomazeau萎缩分级之间的相关性(相关系数r_(s))。结果(1)冈上肌、冈下肌、肩胛下肌的FF值在冈上肌腱损伤Ⅳ级中显著高于Ⅲ级,高于Ⅱ级和Ⅰ级,差异有统计学意义(P值分别为<0.001、<0.001、0.005);小圆肌的FF值在不同分级之间差异无统计学意义(P=0.073)。组内比较Ⅰ级和Ⅱ级的冈上肌、冈下肌、肩胛下肌、小圆肌FF值差异无统计学意义(P值分别为0.026、0.102);Ⅲ级和Ⅳ级的FF值差异有统计学意义(P<0.001)。(2)冈上肌、冈下肌、小圆肌的FF值与年龄呈中等相关(r值分别为0.381、0.339、0.349,P均<0.001),肩胛下肌的FF值与年龄呈弱相关(r=0.216,P=0.017);冈上肌、冈下肌、肩胛下肌FF值与症状持续时间呈中等程度相关(r分别为0.442、0.412、0.314,P均<0.001),小圆肌的FF值与症状持续时间呈弱相关(r=0.277,P=0.002);冈上肌腱损伤程度与冈上肌FF值呈显著相关(r_(s)=0.740,P<0.001),与冈下肌的FF值呈强相关性(r_(s)=0.596,P<0.001),与肩胛下肌、小圆肌的FF值呈弱相关(r_(s)分别为0.257、0.212,P值分别为0.004、0.019);冈上肌损伤程度分级与Goutallier分级、Thomazeau分级之间呈显著正相关(r_(s)分别为0.757、0.737,P均<0.001),且冈上肌FF值在Goutallier和Thomazeau的分级中差异具有统计学意义(P均<0.001)。结论3.0 T MR IDEAL-IQ序列能量化和客观评估肩袖肌群脂肪浸润程度,肩袖肌群脂肪浸润程度与冈上肌腱损伤分级呈正相关,与年龄、症状持续时间呈正相关。展开更多
目的探讨IDEAL(etry and the least-squares estimation)联合FRFSE序列在节后臂丛神经成像中的应用价值。方法 30名颈椎MR检查的成人患者,均无臂丛神经损伤病史,分成两组(每组男性8位,女性7位),用GE signa HDx3.0T磁共振机行臂丛神经成...目的探讨IDEAL(etry and the least-squares estimation)联合FRFSE序列在节后臂丛神经成像中的应用价值。方法 30名颈椎MR检查的成人患者,均无臂丛神经损伤病史,分成两组(每组男性8位,女性7位),用GE signa HDx3.0T磁共振机行臂丛神经成像,采用冠状位薄层扫描,分别扫描IDEAL-FRFSE序列和STIR序列。对IDEAL及STIR原始图像在SUN ADW4.4工作站上进行多平面重组(Multi-Plane Reconstruction,MPR)及最大信号投影(Maximum Intensity Projection,MIP)后处理。观察分析各序列可清晰显示的臂丛神经节、锁骨上神经、锁骨下神经数目。结果每组30侧臂丛神经,STIR序列清晰显示神经节16、锁骨上神经24、锁骨下神经17,信噪比(38.3±2.30),对比噪声比(21.5±1.30)。IDEAL序列清晰显示神经节27、锁骨上神经30、锁骨下神经23,信噪比(56.5±3.20),对比噪声比(32.4±2.10)。结论 IDEAL序列可以清楚地显示节后臂丛神经,与STIR序列比较具有明显优势,具有良好应用前景。展开更多
By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize f...By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize for the best pupil phase mask in ideal condition. Here one simple point spread function (PSF) based method with only the standard deviation method used to evaluate the PSF stability over the depth of focus is taken to optimize for the best coefficients of pupil phase mask in practical optical systems. Results of imaging simulations for optical systems with and without pupil phase mask are presented, and the sharpness of image is calculated for comparison. The optimized results showed better and much more stable imaging quality over the original system without changing the position of the image plane.展开更多
目的探讨磁共振非对称回波的最小二乘估算法迭代水脂分离(iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification,IDEAL-IQ)序列在甲胎蛋白(alpha fetoprotein,AFP)阴性肝细胞癌(...目的探讨磁共振非对称回波的最小二乘估算法迭代水脂分离(iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification,IDEAL-IQ)序列在甲胎蛋白(alpha fetoprotein,AFP)阴性肝细胞癌(hepatocellular carcinoma,HCC)和肝脏局灶性结节性增生(focal nodular hyperplasia,FNH)诊断和鉴别诊断中的价值。材料与方法回顾性分析AFP阴性HCC 28例和FNH 15例患者资料,所有患者术前均行MRI肝脏常规扫描及IDEAL-IQ序列扫描,在后处理工作站测量病灶及背景肝组织弛豫率值(R2;)、脂肪分数(fat fraction,FF)值,统计学分析比较FF值、R2;值之间的差异,采用受试者工作特征(receiver operating characteristic,ROC)曲线分析比较相关参数在两组病变中的诊断效能。结果HCC组和FNH组FF;值、R2^(*)_(肝脏)/R2^(*)_(病灶)分别为8.28%±5.76%、2.98±1.08和2.56%±1.25%、1.90±0.50,两者之间差异具有统计学意义(P<0.05);两组病灶R2^(*)_(病灶)值、背景肝组织FF_(肝脏)值分别为(21.15±5.80)Hz、4.02%±2.54%和(22.79±6.07)Hz、4.23%±3.32%,差异无统计学意义(P>0.05)。FF_(病灶)值及R2^(*)_(肝脏)/R2^(*)_(病灶)曲线下面积(area under the curve,AUC)分别为0.923(P<0.001)、0.883(P=0.56)。结论FF;值及R2^(*)_(肝脏)/R2^(*)_(病灶)对于两者均具有鉴别诊断价值,FF;值AUC大于R2^(*)_(肝脏)/R2^(*)_(病灶)。展开更多
The aberration field of an optical system with a tilted pupil is explored through expanding the vector expressions of the third-order wavefront aberrations. First, the vector forms of the wavefront aberrations are mod...The aberration field of an optical system with a tilted pupil is explored through expanding the vector expressions of the third-order wavefront aberrations. First, the vector forms of the wavefront aberrations are modified to obtain the aberration expressions with the pupil tilted; full field displays of coma and astigmatism in this situation are given. Then, the third-order aberration formulas with the pupil decentered and tilted simultaneously are derived and discussed. Finally, an example is taken to certify the validity of aberration distribution properties.展开更多
文摘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 13470 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 Deeplabv 3+models,which must be trained beforehand.RESULTS:The test dataset included 1348 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.
基金This research was funded by“TAIF UNIVERSITY RESEARCHERS SUPPORTING PROJECT,grant number TURSP-2020/345”,Taif University,Taif,Saudi Arabia.
文摘Recently,many researchers have tried to develop a robust,fast,and accurate algorithm.This algorithm is for eye-tracking and detecting pupil position in many applications such as head-mounted eye tracking,gaze-based human-computer interaction,medical applications(such as deaf and diabetes patients),and attention analysis.Many real-world conditions challenge the eye appearance,such as illumination,reflections,and occasions.On the other hand,individual differences in eye physiology and other sources of noise,such as contact lenses or make-up.The present work introduces a robust pupil detection algorithm with and higher accuracy than the previous attempts for real-time analytics applications.The proposed circular hough transform with morphing canny edge detection for Pupillometery(CHMCEP)algorithm can detect even the blurred or noisy images by using different filtering methods in the pre-processing or start phase to remove the blur and noise and finally the second filtering process before the circular Hough transform for the center fitting to make sure better accuracy.The performance of the proposed CHMCEP algorithm was tested against recent pupil detection methods.Simulations and results show that the proposed CHMCEP algorithm achieved detection rates of 87.11,78.54,58,and 78 according to´Swirski,ExCuSe,Else,and labeled pupils in the wild(LPW)data sets,respectively.These results show that the proposed approach performs better than the other pupil detection methods by a large margin by providing exact and robust pupil positions on challenging ordinary eye pictures.
基金Supported by Sichuan Province Scientific Research Project of Institutions of Higher Education (No.2017ZRQN-108)
文摘AIM： To evaluate the value of ultra-wide field（UWF） imaging in the management of traumatic retinopathy under the condition of corneal scar or fixed small pupil after complicated ocular trauma. METHODS： Twenty-eight patients（28 eyes） with complicated ocular trauma were enrolled in the study from June 2016 to May 2017, including 19 males and 9 females with age ranged from 11 to 64（43.42±12.62）y. All patients were treated with secondary vitrectomy after emergency operation for wound repair of open ocular trauma. Direct ophthalmoscopy and 45-degree fundus photography were taken at each time point of follow up for comparison of findings with UWF images. Routine eye examination including visual acuity, intraocular pressure, slit lamp examination were performed and analyzed as well.RESULTS： Among the 28 traumatized eyes, the positive rate for identification of traumatic retinopathed was 32.1%（9 cases）, 14.9%（5 cases）, and 85.7%（24 cases） with direct ophthalmoscopy, 45-degree fundus photography, and UWF imaging, respectively. The detective rate of UWF imaging under the condition of corneal scar or fixed small pupil was statistically greater than that of 45-degree fundus photography and direct ophthalmoscopy（Bonferroni correction, P〈0.001）. UWF image was obtained in 19 eyes with opaque corneal scar, otherwise their fundus could not be seen by conventional methods. The additional findings of traumatic retinopathies by UWF imaging included periretinal membranes or pre-retinal proliferating strip, retinal holes, hemorrhage in the vitreous or sub-retinal space.CONCLUSION： UWF imaging is superior to traditional fundus photography in the evaluation of traumatic retinopathies under the condition of corneal scar or fixed small pupil after complicated ocular trauma.
文摘In this paper, we present an elongated speckle images produced from diffusers using sharp elliptical apertures. The orientation of the elliptic aperture is recognized from the direction of the elongation in the speckle images. The aperture tilting out of the plane is investigated. Three models of elliptical apertures are considered and the corresponding speckle images are obtained. The 1st model is composed of two orthogonal ellipses or plus symbol pupil;the 2nd has four symmetric ellipses with an angle of 45° between each of them or in the form of a snow flake pupil and the 3rd model looks like an airplane. Also, the autocorrelation profiles of the speckle images corresponding to the diffused airplane are obtained from which the average speckle size is computed. Finally, the reconstructed images of the described elliptical models and its autocorrelation images, making use of Mat lab code, are obtained.
文摘目的采用非对称采集与迭代最小二乘估算法迭代水脂分离(iteraterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation,IDEAL-IQ)方法定量评估冈上肌腱损伤的严重程度与肩袖肌群脂肪浸润程度及受试者特征之间的关系。材料与方法回顾性分析2022年8月至2024年6月本院经肩关节镜证实的33例冈上肌腱部分撕裂患者及89例完全撕裂患者,均进行了常规MRI扫描及IDEAL-IQ序列扫描。由两名放射科医生分别对所有受试者的MRI图像进行独立评估,根据常规MRI图像的冈上肌腱损伤表现,将完全撕裂组的冈上肌腱按照Patte分型分为Patte 1型(Ⅱ级)、Patte 2型(Ⅲ级)、Patte 3型(Ⅳ级),将部分撕裂组定义为Ⅰ级。同时在斜矢状位上进行Goutallier分级及Thomazeau萎缩分级,并通过GE ADW 4.7工作站后处理软件在IDEAL-IQ序列生成的脂肪分数图像上测量冈上肌、冈下肌、肩胛下肌及小圆肌脂肪分数(fat fraction,FF)。用组内相关系数(intra-class correlation coefficient,ICC)及Kappa一致性检验评估观察者间及观察者内的一致性。采用Kruskal-Wallis H检验、单因素ANOVA检验分析FF值在不同分组之间的差异,组间两两比较用Bonferroni检验。采用Pear_(s)on相关性分析肩袖肌肉FF值与年龄、症状持续时间的相关性(相关系数r),Spearman相关性分析冈上肌腱损伤分级与肩袖肌群FF值、Goutallier分级及Thomazeau萎缩分级之间的相关性(相关系数r_(s))。结果(1)冈上肌、冈下肌、肩胛下肌的FF值在冈上肌腱损伤Ⅳ级中显著高于Ⅲ级,高于Ⅱ级和Ⅰ级,差异有统计学意义(P值分别为<0.001、<0.001、0.005);小圆肌的FF值在不同分级之间差异无统计学意义(P=0.073)。组内比较Ⅰ级和Ⅱ级的冈上肌、冈下肌、肩胛下肌、小圆肌FF值差异无统计学意义(P值分别为0.026、0.102);Ⅲ级和Ⅳ级的FF值差异有统计学意义(P<0.001)。(2)冈上肌、冈下肌、小圆肌的FF值与年龄呈中等相关(r值分别为0.381、0.339、0.349,P均<0.001),肩胛下肌的FF值与年龄呈弱相关(r=0.216,P=0.017);冈上肌、冈下肌、肩胛下肌FF值与症状持续时间呈中等程度相关(r分别为0.442、0.412、0.314,P均<0.001),小圆肌的FF值与症状持续时间呈弱相关(r=0.277,P=0.002);冈上肌腱损伤程度与冈上肌FF值呈显著相关(r_(s)=0.740,P<0.001),与冈下肌的FF值呈强相关性(r_(s)=0.596,P<0.001),与肩胛下肌、小圆肌的FF值呈弱相关(r_(s)分别为0.257、0.212,P值分别为0.004、0.019);冈上肌损伤程度分级与Goutallier分级、Thomazeau分级之间呈显著正相关(r_(s)分别为0.757、0.737,P均<0.001),且冈上肌FF值在Goutallier和Thomazeau的分级中差异具有统计学意义(P均<0.001)。结论3.0 T MR IDEAL-IQ序列能量化和客观评估肩袖肌群脂肪浸润程度,肩袖肌群脂肪浸润程度与冈上肌腱损伤分级呈正相关,与年龄、症状持续时间呈正相关。
文摘By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize for the best pupil phase mask in ideal condition. Here one simple point spread function (PSF) based method with only the standard deviation method used to evaluate the PSF stability over the depth of focus is taken to optimize for the best coefficients of pupil phase mask in practical optical systems. Results of imaging simulations for optical systems with and without pupil phase mask are presented, and the sharpness of image is calculated for comparison. The optimized results showed better and much more stable imaging quality over the original system without changing the position of the image plane.
文摘目的探讨磁共振非对称回波的最小二乘估算法迭代水脂分离(iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification,IDEAL-IQ)序列在甲胎蛋白(alpha fetoprotein,AFP)阴性肝细胞癌(hepatocellular carcinoma,HCC)和肝脏局灶性结节性增生(focal nodular hyperplasia,FNH)诊断和鉴别诊断中的价值。材料与方法回顾性分析AFP阴性HCC 28例和FNH 15例患者资料,所有患者术前均行MRI肝脏常规扫描及IDEAL-IQ序列扫描,在后处理工作站测量病灶及背景肝组织弛豫率值(R2;)、脂肪分数(fat fraction,FF)值,统计学分析比较FF值、R2;值之间的差异,采用受试者工作特征(receiver operating characteristic,ROC)曲线分析比较相关参数在两组病变中的诊断效能。结果HCC组和FNH组FF;值、R2^(*)_(肝脏)/R2^(*)_(病灶)分别为8.28%±5.76%、2.98±1.08和2.56%±1.25%、1.90±0.50,两者之间差异具有统计学意义(P<0.05);两组病灶R2^(*)_(病灶)值、背景肝组织FF_(肝脏)值分别为(21.15±5.80)Hz、4.02%±2.54%和(22.79±6.07)Hz、4.23%±3.32%,差异无统计学意义(P>0.05)。FF_(病灶)值及R2^(*)_(肝脏)/R2^(*)_(病灶)曲线下面积(area under the curve,AUC)分别为0.923(P<0.001)、0.883(P=0.56)。结论FF;值及R2^(*)_(肝脏)/R2^(*)_(病灶)对于两者均具有鉴别诊断价值,FF;值AUC大于R2^(*)_(肝脏)/R2^(*)_(病灶)。
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China （Grant No 61007009）.
文摘The aberration field of an optical system with a tilted pupil is explored through expanding the vector expressions of the third-order wavefront aberrations. First, the vector forms of the wavefront aberrations are modified to obtain the aberration expressions with the pupil tilted; full field displays of coma and astigmatism in this situation are given. Then, the third-order aberration formulas with the pupil decentered and tilted simultaneously are derived and discussed. Finally, an example is taken to certify the validity of aberration distribution properties.
