Zheng Qiuqing, Lin Chunyi, Xu Dong, Zhao Huicheng, Song Mei, Ou Di, Shi Le
Department of ultrasound, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, Zhejiang, China.
Institute of electronics and information, South China University of technology, Guangzhou, China.
J Cancer. 2022 Jan 1;13(3):793-799. doi: 10.7150/jca.60413. eCollection 2022.
The level of cervical cancer screening in underdeveloped countries is far behind that of developed countries mostly because current cervical cancer screening methods are difficult to implement in underdeveloped countries. The use of non-invasive, repeatable, and low-cost ultrasound needs to be accessed. The Canadian Sonix TOUCH ultrasound system and transvaginal ultrasound probe were used to record ultrasound radio frequency (RF) signals from cervical tissues of 69 patients with cervical cancer and 37 healthy women. The self-compiled RF time series signal analysis software was used to extract 3 different dimensions of parameters of the region of interest (ROI), including time domain, frequency domain, and fractal dimension (FD). Fourteen spectrum characteristic parameters were extracted, of which structure function method FD (SFD) and Higuchi FD belonged to FD parameters; slope, intercept, midbandfit, S1, S2, S3, and S4 were frequency domain parameters; and fuzzy entropy, kurtosis, peak, cross zero count, and cross zero standard deviation (Std) were time domain parameters. The average values of the five time-domain characteristic parameters of cervical cancer tissues were smaller than those of normal cervical tissues (fuzzy entropy: 1.70±0.29 vs. 1.83±0.20; kurtosis: 0.347±0.03 vs. 0.350±0.02; peak: 1989.9±166.8 vs. 2024.69±187.5; cross zero count: 3.77±0.31 vs. 3.81±0.29; cross zero Std: 1.26±0.17 vs. 1.33±0.14), although the differences were not statistically significant ( 0.130, 0.326, 0.618, 0.442, and 0.204, respectively). The average values of the two FD characteristic parameters and the seven frequency domain characteristic parameters of cervical cancer tissues were larger than those of normal tissues (SFD: 1.84±0.28 vs. 1.46±0.39; Higuchi FD: 1.71±0.30 vs. 1.28±0.30; slope: -0.32±0.08 vs. -0.26±0.05; intercept: 0.48±0.02 vs. 0.46±0.02; midbandfit: 0.35±0.03 vs. 0.33±0.03; S1: 15.66±1.01 vs. 13.57±1.69; S2: 10.12±0.69 vs. 9.32±1.27; S3: 9.44±1.12 vs. 8.66±1.09; S4: 7.67±1.01 vs. 6.43±0.65), and the differences were statistically significant ( < 0.05). No effective parameters were found to identify cervical squamous cell carcinoma tissues with different levels of differentiation ( > 0.05). Quantitative analysis of RF time series signals based on ultrasound RF flow is expected to become a simple and non-invasive imaging method for cervical cancer diagnosis. However, whether it can be applied to the identification of early small cervical cancer lesions remains to be determined.
欠发达国家的宫颈癌筛查水平远远落后于发达国家，这主要是因为当前的宫颈癌筛查方法在欠发达国家难以实施。需要探索使用非侵入性、可重复且低成本的超声检查。研究使用加拿大Sonix TOUCH超声系统和经阴道超声探头，记录了69例宫颈癌患者和37名健康女性宫颈组织的超声射频（RF）信号。利用自编的RF时间序列信号分析软件，提取了感兴趣区域（ROI）的3种不同维度的参数，包括时域、频域和分形维数（FD）。共提取了14个频谱特征参数，其中结构函数法分形维数（SFD）和Higuchi分形维数属于分形维数参数；斜率、截距、中频拟合度、S1、S2、S3和S4为频域参数；模糊熵、峰度、峰值、过零计数和过零标准差（Std）为时域参数。宫颈癌组织的5个时域特征参数的平均值均小于正常宫颈组织（模糊熵：1.70±0.29对1.83±0.20；峰度：0.347±0.03对0.350±0.02；峰值：1989.9±166.8对2024.69±187.5；过零计数：3.77±0.31对3.81±0.29；过零Std：1.26±0.17对1.33±0.14），尽管差异无统计学意义（P值分别为0.130、0.326、0.618、0.442和0.204）。宫颈癌组织的2个分形维数特征参数和7个频域特征参数的平均值均大于正常组织（SFD：1.84±0.28对1.46±0.39；Higuchi分形维数：1.71±0.30对1.28±0.30；斜率：-0.32±0.08对-0.26±0.05；截距：0.48±0.02对0.46±0.02；中频拟合度：0.35±0.03对0.33±0.03；S1：15.66±1.01对13.57±1.69；S2：10.12±0.69对9.32±1.27；S3：9.44±1.12对8.66±1.09；S4：7.67±1.01对6.43±0.65），且差异有统计学意义（P<0.05）。未发现能鉴别不同分化程度宫颈鳞状细胞癌组织的有效参数（P>0.05）。基于超声射频血流的RF时间序列信号定量分析有望成为一种简单的非侵入性宫颈癌诊断成像方法。然而，其能否应用于早期小宫颈癌病变的鉴别尚待确定。
