Romijn R L, Thijssen J M, Oosterveld B J, Verbeek A M
Biophysical Laboratory, University of Nijmegen, The Netherlands.
Ultrason Imaging. 1991 Jan;13(1):27-55. doi: 10.1177/016173469101300102.
In this study, the estimation of ultrasound parameters is evaluated for in vivo differentiation of intraocular melanomas. For this purpose, both tissue and image parameters of the ultrasound signal are considered. These parameters comprised, respectively, the frequency dependent attenuation and backscattering coefficient of the melanoma tissue, and the first and second-order statistics of the amplitude-modulated and phase-derivative images of the melanomas. A diffraction correction procedure has been applied prior to the estimation of the parameters to correct the ultrasound signals for the echographic equipment used and for the various distances of the region-of-interest to the transducer. In addition, a pre-processing to select a homogeneous region from the tumours was implemented to obtain consistent estimates of the ultrasound parameters, because the accuracy and the precision of the parameters would be greatly reduced by the inhomogeneity of the melanoma tissue. The estimation methods are evaluated by means of the accuracy and precision of the parameters estimated from simulated ultrasound data and data obtained from a tissue-mimicking phantom. The mutual correlations of the parameters are discussed for the ultrasound data obtained from the melanomas. This study enabled a preselection of the independent ultrasound parameters that could be used in a discriminant analysis to perform a differentiation of intraocular melanomas. The sensitivity and specificity of differentiating spindle cell type from mixed-epitheloid meleanomas were 92 and 89 percent, respectively.
在本研究中，评估了超声参数估计用于眼内黑色素瘤的体内鉴别。为此，考虑了超声信号的组织和图像参数。这些参数分别包括黑色素瘤组织的频率依赖性衰减和背向散射系数，以及黑色素瘤调幅图像和相位导数图像的一阶和二阶统计量。在参数估计之前应用了衍射校正程序，以针对所使用的超声设备以及感兴趣区域到换能器的不同距离对超声信号进行校正。此外，实施了从肿瘤中选择均匀区域的预处理，以获得超声参数的一致估计，因为黑色素瘤组织的不均匀性会大大降低参数的准确性和精度。通过从模拟超声数据和从组织模拟体模获得的数据估计的参数的准确性和精度来评估估计方法。讨论了从黑色素瘤获得的超声数据中参数的相互相关性。本研究实现了对可用于判别分析以进行眼内黑色素瘤鉴别的独立超声参数的预选。区分梭形细胞型与混合上皮样黑色素瘤的敏感性和特异性分别为92%和89%。
