Kolios M C, Czarnota G J, Lee M, Hunt J W, Sherar M D
Department of Mathematics, Physics and Computer Science, Ryerson University, Toronto, Ontario, Canada.
Ultrasound Med Biol. 2002 May;28(5):589-97. doi: 10.1016/s0301-5629(02)00492-1.
Ultrasound (US) spectral analysis methods are used to analyze the radiofrequency (RF) data collected from cell pellets exposed to chemotherapeutics that induce apoptosis and other chemicals that induce nuclear transformations. Calibrated backscatter spectra from regions-of-interest (ROI) were analyzed using linear regression techniques to calculate the spectral slope and midband fit. Two f/2 transducers, with operating frequencies of 30 and 34 MHz (relative bandwidths of 93% and 78%, respectively) were used with a custom-made imaging system that enabled the collection of the raw RF data. For apoptotic cells, the spectral slope increased from 0.37 dB/MHz before drug exposure to 0.57 dB/MHz 24 h after, corresponding to a change in effective scatterer radius from 8.7 to 3.2 microm. The midband fit increased in a time-dependent fashion, peaking at 13dB 24 h after exposure. The statistical deviation of the spectral parameters was in close agreement with theoretical predictions. The results provide a framework for using spectral parameter methods to monitor apoptosis in in vitro and in in vivo systems and are being used to guide the design of system and signal analysis parameters.
超声（US）光谱分析方法用于分析从暴露于诱导细胞凋亡的化疗药物及其他诱导核转化的化学物质的细胞沉淀中收集的射频（RF）数据。使用线性回归技术分析来自感兴趣区域（ROI）的校准后向散射光谱，以计算光谱斜率和中频拟合。两个f/2换能器，工作频率分别为30和34MHz（相对带宽分别为93%和78%），与一个定制成像系统一起使用，该系统能够收集原始RF数据。对于凋亡细胞，光谱斜率从药物暴露前的0.37dB/MHz增加到24小时后的0.57dB/MHz，对应有效散射体半径从8.7微米变化到3.2微米。中频拟合以时间依赖的方式增加，在暴露后24小时达到13dB的峰值。光谱参数的统计偏差与理论预测密切一致。这些结果为使用光谱参数方法监测体外和体内系统中的细胞凋亡提供了一个框架，并正被用于指导系统和信号分析参数的设计。
