探索课堂教学策略 提高医学影像学教学效果

本文探讨了通过发挥教师的主导作用，树立“教以学为中心”的思想；把握教学活动中三个主要的环节，优化教学模式；认真处理好课前、课中以及课后三者之间的关系，做到重视课前、突出课中、兼顾课后，使三者相互协调、相互促进；充分调动了学生学习的积极性，增加了学习的兴趣，达到了提高医学影像学教学效果的目标。     

可视化仿真手术在胰腺和脾脏手术中的应用研究

目的 研究基于64排螺旋CT胰腺和脾脏扫描数据的三维重建和可视化仿真手术.方法 采集胰腺和脾脏CT的扫描数据,通过自适应区域生长法对CT序列图像进行程序分割和提取,再采用自行开发的医学图像处理软件对分割后的图像数据进行三维重建,然后利用FreeForm Modeling System和PHANTOM软件进行胰腺和脾脏的可视化仿真手术.结果 利用自适应区域生长法对胰腺和脾脏CT图像进行程序分割速度快、效果好.用自行设计的图像处理软件进行三维重建,图像结构清晰,可真实再现胰腺和脾脏的解剖结构.通过Freeform Modeling System和PHANTOM可以进行和实际手术过程一样的可视化仿真手术.结论 基于螺旋CT数据的三维重建和可视化仿真手术,对胰腺和脾脏等腹部脏器的个体化手术方案制定、风险评估、临床教学训练等方面都有很大的应用价值.     

Differentiation of Benign Pigmented Skin Lesions with the Aid of Computer Image Analysis: A Novel Approach

Background

The differential diagnosis of common pigmented skin lesions is important in cosmetic dermatology. The computer aided image analysis would be a potent ancillary diagnostic tool when patients are hesitant to undergo a skin biopsy.

Objective

We investigated the numerical parameters discriminating each pigmented skin lesion from another with statistical significance.

Methods

For each of the five magnified digital images containing clinically diagnosed nevus, lentigo and seborrheic keratosis, a total of 23 parameters describing the morphological, color, texture and topological features were calculated with the aid of a self-developed image analysis software. A novel concept of concentricity was proposed, which represents how closely the color segmentation resembles a concentric circle.

Results

Morphologically, seborrheic keratosis was bigger and spikier than nevus and lentigo. The color histogram revealed that nevus was the darkest and had the widest variation in tone. In the aspect of texture, the surface of the nevus showed the highest contrast and correlation. Finally, the color segmented pattern of the nevus and lentigo was far more concentric than that of seborrheic keratosis.

Conclusion

We found that the subtle distinctions between nevus, lentigo and seborrheic keratosis, which are likely to be unrecognized by ocular inspection, are well emphasized and detected with the aid of software.     

Comparison between laser scanning tomography and computerised image analysis of the optic disc

AIMS: To study the interchangeability of the measurements of the optic disc topography obtained by one computerised image analyser and one confocal laser tomographic scanner. METHODS: One eye of 28 patients with glaucoma or glaucoma suspects was studied. All cases had simultaneous stereoscopic disc photographs taken with the fundus camera Topcon TRC-SS and optic disc examination with the Heidelberg retina tomograph (HRT) during the same visit. The optic disc photographs were digitised and analysed with the Topcon ImageNet (TI) system. Three variables of the optic disc topography provided by the TI and the HRT were compared--cup volume (CV), rim area (RA), and cup area to disc area ratio (CA/DA). RESULTS: The mean values of CV and RA provided by the TI (0.52 (SD 0.32) mm3 and 1.58 (0.39) mm2, respectively) were greater (p < 0.01) than the mean values of CV and RA determined by the HRT (0.32 (0.25) mm3, and 1.33 (0.47) mm2, respectively). The mean value of CA/DA provided by the TI (0.42 (0.14)) and the HRT (0.42 (0.18)) was similar (p = 0.93). Correlation coefficients between measurements obtained by the two methods ranged from 0.53 to 0.73. CONCLUSION: There was a significant discrepancy in the measurements of rim area and cup volume of the optic disc obtained by a computerised image analyser and a laser scanning tomograph.     

一个先天性眼外肌纤维化综合征家系的影像特征分析

目的:研究一个先天性眼外肌纤维化综合征（CFEOM）家系,发病者眼外肌及眼运动神经的影像学特征,初步探索该病发病机制,为其治疗提供理论基础。方法:对一个常染色体显性遗传病CFEOM1 家系,三代3 例患者进行高分辨率MRI扫描,随机抽取12 个正常人作为对照组,扫描方法:眼眶部行3mm 层厚、T1 加权MRI 扫描;颅内行1mm 层厚、3D FIESTA 扫描。比较两组眼外肌以及眼运动神经的变化。结果:发病者5 条眼外肌体积较正常对照组小,尤以上直肌明显,差异有统计学意义（P＜0.05）;眼运动神经（动眼神经、外展神经）的颅内段截面积较正常对照组小,差异有统计学意义（P＜0.05）。结论:CFEOM 病患者各条眼外肌较正常人萎缩,颅内眼运动神经有发育不良。提示该病可能为眼运动神经核发育不良引起。     

Grading static versus dynamic images of contact lens complications

Background: This study was conducted to investigate grading performance when estimating the severity of static versus dynamic images of contact lens‐related ocular pathology. Methods: Thirty‐eight subjects used the Efron Grading Scales for Contact Lens Complications to grade the severity of ocular pathological changes depicted in static and dynamic (movie clip) computer‐displayed images of each of the following contact lens complications: bulbar conjunctival redness, limbal redness, papillary conjunctivitis, corneal staining, corneal infiltrates and meibomian gland dysfunction. The viewing of static and dynamic images was separated by seven weeks. Results: Grades assigned to dynamic images were 0.6 and 0.7 grading scale units higher than those assigned to static images for limbal redness and papillary conjunctivitis, respectively (p < 0.0001 for both). No difference was observed for the other four complications. There was an apparent trend for grading variability to be reduced (that is, observers grading in closer agreement) when grading dynamic versus static images. Conclusions: Absolute grades based on an assessment of signs of pathology represented in static images may, in some instances, underestimate the true severity of the condition.     

计算机图像分析在轻度皮肤刺激反应评判中的运用研究

作者借助Ｐｈｏｌｔｏｓｈｏｐ来分析评判轻度皮肤刺激反应。每个受试区用皮肤分光光度测量仪检测,并在试验前后在设定的条件下摄取图像,临床评估则按照ＩＧＤＲＧ标准。所有图像用图像分析表在ＧｒｅｙｓｃａｌｅＲＧＢ,ＣＭＹＫ和Ｌａｂ模式颗各个光亮度或灰度值同皮肤反应程度呈 线性相关。同样皮肤分光光度测量仪所测Ｌ和值与各种模式的光亮度和ＲＧＢ模式和Ｒ和Ｌａｂ的ａ值也是呈很好的线性相关。作者认为用Ｐｈｏｔｏｓｈ     

Development of a digital imaging system for objective measurement of hyperpigmented spots on the face

Background/aims: There are few available methods that can be used to quantify hyperpigmented spots on a wide area of the face. The objective of this study was to develop such a method through the use of specialized image analysis technologies. Methods: This imaging system was composed of a source of illumination whose light intensity was controlled with a dimmer, a 3-CCD video camera connected to a computer, and a positioning device used to correctly align the subject's face. This system was calibrated by adjusting the light intensity, the camera position, and white balance of the camera in order to acquire reproducible images. Using a specific algorithm for the image analysis, this system enabled us to measure both the total area of hyperpigmented spots (mm²) and the averaged skin colour tone (quasi L*a*b*) excluding the area of those hyperpigmented spots in a wide area of the face. The accuracy and reproducibility of the system was validated using a mannequin head with six standard colour chips obtained from the GretagMacbeth ColorChecker^®, and brown-coloured patches that simulated hyperpigmented spots whose colour and area were both known. The correlation between CIE L*a*b* and quasi L*a*b* values was examined by conducting simultaneous measurements of the facial skin colour of 187 subjects with a tristimulus colourimeter (Minolta Chromameter) and our imaging system. Results: The measurement errors in quasi L*a*b* values of colour chips and the area of brown patches were less than 2 and 5%, respectively, unless these chips or patches were located in the peripheral zone of the mannequin head. The variation in quasi L*a*b* values and the area of hyperpigmented spots (mm²) in five repeated measurements performed once every hour was less than 2%. There was an excellent correlation between the CIE L*a*b* and quasi L*a*b* values, and the Pearson's correlation coefficient between CIE L* and quasi L* value, for instance, was 0.908. Conclusions: As long as the region to be evaluated is limited to the cheek and periorbital areas, this system enables automatic detection of hyperpigmented spots in a wide area of the face, as well as the correct measurement of those areas and determination of skin colours.     

Increased regional homogeneity in internet addiction disorder: a resting state functional magnetic resonance imaging study

Background Internet addition disorder （lAD） is currently becoming a serious mental health problem among Chinese adolescents. The pathogenesis of lAD, however, remains unclear. The purpose of this study applied regional homogeneity （ReHo） method to analyze encephalic functional characteristic of lAD college students under resting state. Methods Functional magnetic resonanc image （fMRI） was performed in 19 lAD college students and 19 controls under resting state. ReHo method was used to analyze the differences between the average ReHo in two groups. Results The following increased ReHo brain regions were found in lAD group compared with control group： cerebellum, brainstem, right cingulate gyrus, bilateral parahippocampus, right frontal lobe （rectal gyrus, inferior frontal gyrus and middle frontal gyrus）, left superior frontal gyrus, left precuneus, right postcentral gyrus, right middle occipital gyrus, right inferior temporal gyrus, left superior temporal gyrus and middle temporal gyrus. The decreased ReHo brain regions were not found in the lAD group compared with the control group. Conclusions There are abnormalities in regional homogeneity in lAD college students compared with the controls and enhancement of synchronization in most encephalic regions can be found. The results reflect the functional change of brain in lAD college students. The connections between the enhancement of synchronization among cerebellum, brainstem, limbic lobe, frontal lobe and apical lobe may be relative to reward pathways.