Study on Quantitative Echography of Ocular Lesions with A Newly Developed Ultrasonic Diagnostic Equipment

在眼眶病变的超声诊断中，评估目标组织的超声反射率是非常重要的。用于此目的的方法称为定量超声。可分为两大类：一类是从表面反射率来判断点状或膜状病变的性质，另一类是从内部反射率来判断占位性病变的组织学特征。前者为眼内点状或膜状病变，眼窝点状病变则根据超声对靶组织的反射率进行诊断。我们使用Kretztechnik 7200ma对许多眼膜样病变如视网膜脱离、玻璃体出血和增生膜形成进行了研究。根据这些结果，定量超声成像中存在的两个问题成为研究的主题。其中一个问题是，a型超声波束通过靶的方向无法在监视器上显示更多的组织。现代超声诊断设备的出现解决了这一问题，在b型图像上可以显示a型超声波束的方向。将超声波束垂直于病灶表面或病灶中心，既方便又精确。第二个问题是，为了确定某些膜样病变的反射率，有必要与标准组织，巩膜的反射率进行比较。通常反射率判断至少要做两次，一次来自目标组织，另一次来自标准组织。在新开发的设备中，a模式图像可以在屏幕上扩展和放大。单个峰的反射率可以用刻度表示。因此可以直接读取以dB为单位的反射率值。唯一需要询问的一点是，增益最初应该设置在什么水平上。有几种方法可以确定增益的初始水平。首先，对我们用Kretztechnic 7200ma获得的数据进行了确定。其次，从四幅不同增益水平的b模图像中进行判断。第三，考虑正常眼巩膜反射率的结果。需要进一步调查才能确定最佳方法。在眼病变的定量超声检查中，最重要的是将脱离的视网膜与其他病变区分开来。这是极其重要的，在某些情况下，脱离视网膜不能显示高反射率的超声光束。以下是案例。1)发病后的时间间隔。随着时间的流逝，萎缩的变化发展。结果，脱离视网膜特有的高反射率消失了。(2)脱离视网膜的延伸。在部分小范围视网膜脱离病例中，图像呈大泡状，由于反射角度的原因，超声反射率错误地认为低。在很大程度上，萎缩过程经常发生。(3) Retinoschisis。它是与视网膜脱离相鉴别的病变之一。其他特征，如尺寸、形状或厚度也应考虑在内。(4)炎症。继发性视网膜脱离的反射率通常较低。(5)增殖过程。在玻璃体增生的情况下，如糖尿病性玻璃体视网膜病变，超声反射性受到很大影响。(6)不同定位下反射率的差异。据说，在离体视网膜中，周围的反射率与后部相同或更高。(7)与前巩膜层比较。有时巩膜前层的反射率有助于区分离体视网膜。(8)的年龄。据说年龄是用来评价反射率的。在此基础上，对各种类型的视网膜脱离进行了研究，包括新鲜的和旧的，简单的或复杂的，特发性的或继发性的。部分结果或意见已在国际和国内会议上提出。少

In ultrasonic diagnosis of ocular and orbital lesions it is important to evaluate the ultrasonic reflectivity of the target tissue. The method used for the purpose, is termed as quantitative echography. It can be divided into two categories: the one is to estimate the nature of point-like or membrane-like lesions from their surface reflectivity, and the other is to estimate the histologic characteristics of space-occupying lesions from their internal reflectivity. In the former point-like or membrane-like lesions in the eye, and point-like lesions in the orbit are diagnosed on the reflectivity of ultrasound to the target tissue. We have studied many cases of ocular membrane-like lesions such as retinal detachment, vitreous hemorrahge and proliferative membrane formation using Kretztechnik 7200 MA. From those results two problems in doing quantitative echography have become the subject of investigation. One of the problems is that the direction of A-mode ultrasonic beam through the targ … More et tissue could not be displayed on the monitor. The problem has been solved after the advent of the modern ultrasonic diagnostic equipment, in which the direction of A-mode ultrasonic beam can be displayed on the B-mode image. It is easily and precisely to apply the ultrasonic beam perpendicularly to the surface or to the center of the lesion. The second problem is that for determining the reflectivity of a ceratin membrane-like lesion, it is necessary to have the reflectivity from the standard tissue, the sclera to compare with. Ordinarily reflectivity judgment should have been done twice at least, the one from the target tissue and the other from the standard tissue. In the newly developed equipment A-mode image can be extended and enlarged on the screen. Reflectivity of the individual peaks can be shown with the scale. Therefore the value of reflectivity with the unit of dB can be directly read. The only point to be inquired is on what level the gain should be initially set. There are several ways to decide the initial level of the gain. First, it is decided on the data of ours obtained with Kretztechnic 7200 MA. Second, it is judged from four B-mode images of different level of gain. Third, the results of reflectivity of the sclera in the normal eyes would be considered. Further investigation is necessary to decide the best way.The most important thing in quantitative echography in the ocular lesion is to differentiate the detached retina from other lesions. It is extremely important that in some case the detached retina fail to show high reflectivity to the ultrasonic beam. The followings are the cases. 1) The time interval after the onset. As the time passes, atrophic changes develop. As the result, the characteristic high reflectivity of the detached retina become absent. (2) Extension of the detached retina. In some cases of the detached retina of small extent, the figure is bullous, and the ultrasonic reflectivity is erroneously as low, because of the angle of reflection. In the cases of large extent the atrophic processes frequently develop. (3) Retinoschisis. It is one of the lesions to be differentiated from the detached retina. Other characteristics such as size, figure or thickness should be considered. (4) Inflammation. In secondary retinal detachment the reflectivity is often low. (5) Proliferative processes. In cases of proliferative processes in the vitreous such as diabetic vitreoretinopathy the ultrasonic reflectivity is much effected. (6) Difference of the reflectivity in the different localization. It is said that in detached retina the reflectivity in the periphery is the same or higher, compared with that in the posterior. (7) Comparison to the prescleral layer. Sometimes reflectivity of the prescleral layer is useful to differentiate the detached retina. (8) Age. Age is said to be considered to evaluate the reflectivity.Upon those points mentioned above, investigation in many kinds of retinal detachment, fresh and old, simple or complicated, idiopathic or secondary, are going on. A part of the results or opinions have been presented in international and domestic meetings. Less