John S, Sujana H, Suresh S, Swarnamani S, Biswas J, Gopal L
Medical Research Foundation, Sankara Nethralaya, India.
Indian J Ophthalmol. 1998 Sep;46(3):153-7.
An in-vitro study of wave spectral analysis in 8 enucleated eyes was conducted in order to differentiate histological subtypes of malignant melanoma. To obtain the backscattering coefficient for the tissues, we used a broadband focussed transducer with a frequency range of 7-12 MHz and a centre frequency of 10 MHz. Experimental measurement of backscattering coefficient and attenuation coefficient at various frequencies was done by substitution techniques. The backscattering coefficient, scatterer size, and root mean square velocity fluctuation were derived by the numerical method, while the attenuation coefficient at 1 MHz was derived from attenuation coefficient at different frequencies. This study revealed that backscattering coefficient and attenuation coefficient, over a frequency range of 7-12 MHz, show an increase in the spindle cell type compared to the mixed cell type of malignant melanoma. Particularly, the scatterer size was significantly higher in the spindle cell group (p = 0.013) in contrast to the mixed cell type. Spindle cells have uniform and compact histological pattern which contributes to an increase in scatterer size and root mean square velocity fluctuation. The ultrasonically obtained parameters have been shown to have a good correlation with the histology of malignant melanoma.
为了区分恶性黑色素瘤的组织学亚型，对8只摘除的眼球进行了波谱分析的体外研究。为了获得组织的背向散射系数，我们使用了频率范围为7 - 12 MHz、中心频率为10 MHz的宽带聚焦换能器。通过替代技术对不同频率下的背向散射系数和衰减系数进行了实验测量。背向散射系数、散射体大小和均方根速度波动通过数值方法得出，而1 MHz时的衰减系数则从不同频率下的衰减系数推导得出。这项研究表明，在7 - 12 MHz的频率范围内，与恶性黑色素瘤的混合细胞类型相比，梭形细胞类型的背向散射系数和衰减系数有所增加。特别是，与混合细胞类型相比，梭形细胞组的散射体大小显著更高（p = 0.013）。梭形细胞具有均匀且紧密的组织学模式，这导致散射体大小和均方根速度波动增加。超声获得的参数已被证明与恶性黑色素瘤的组织学有良好的相关性。
