Park Ko Woon, Shin Jung Hee, Hahn Soo Yeon, Kim Jae-Hun, Lim Yaeji, Choi Joon Young
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine.
Department of Applied Statistics, Chung-Ang University, 221, Heukseok-dong, Dongjak-gu.
Medicine (Baltimore). 2020 Nov 25;99(48):e23252. doi: 10.1097/MD.0000000000023252.
The role of histogram based on ultrasound (US) images for thyroid nodules found in fluorine-18 fluorodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET-CT) is unknown. We aimed to assess whether histogram analysis using gray scale US could differentiate thyroid nodules detected by PET-CT.In this study, 71 thyroid nodules ≥1 cm were identified in 71 patients by conducting 18F-FDG PET-CT, from January 2010 to June 2013. Subsequently, either grayscale US-guided fine needle aspirations or core needle biopsies were performed on each patient. Each grayscale US feature was categorized according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS). Histogram parameters (skewness, kurtosis, intensity, uniformity, and entropy) were extracted from the grayscale US images followed by statistical analysis using the Chi-Squared or Mann-Whitney U tests.The 71 nodules comprised 30 (42.3%) benign nodules, 30 (42.3%) primary thyroid malignancies, and 11 (15.4%) metastatic lesions. Tumor size, US findings, and histogram parameters were significantly different between the benign and malignant thyroid nodules (P = .011, P = .000, and P < .02, respectively). A comparison showed that parallel orientation and an absence of calcifications were found more frequently in metastatic thyroid nodules than in primary thyroid malignancies (P = .04, P < .000, respectively). However, histogram parameters and K-TIRADS were not significantly different between primary thyroid malignancies and metastatic lesions.There is a limit to replacing cytopathological confirmation with texture analysis for the differentiation of thyroid nodules detected by PET-CT. Therefore, cytopathological confirmation of nodules appearing malignant on US images cannot be avoided for an ultimate diagnosis of metastasis.
基于超声（US）图像的直方图在氟-18氟脱氧葡萄糖（18F-FDG）正电子发射断层扫描/计算机断层扫描（PET-CT）中发现的甲状腺结节中的作用尚不清楚。我们旨在评估使用灰阶超声的直方图分析能否区分PET-CT检测到的甲状腺结节。在本研究中，2010年1月至2013年6月期间，通过18F-FDG PET-CT在71例患者中识别出71个直径≥1 cm的甲状腺结节。随后，对每位患者进行灰阶超声引导下细针穿刺或粗针活检。根据韩国甲状腺影像报告和数据系统（K-TIRADS）对每个灰阶超声特征进行分类。从灰阶超声图像中提取直方图参数（偏度、峰度、强度、均匀性和熵），然后使用卡方检验或曼-惠特尼U检验进行统计分析。这71个结节包括30个（42.3%）良性结节、30个（42.3%）原发性甲状腺恶性肿瘤和11个（15.4%）转移灶。良性和恶性甲状腺结节之间的肿瘤大小、超声表现和直方图参数存在显著差异（分别为P = 0.011、P = 0.000和P < 0.02）。比较显示，与原发性甲状腺恶性肿瘤相比，转移性甲状腺结节中平行取向和无钙化的情况更常见（分别为P = 0.04、P < 0.000）。然而，原发性甲状腺恶性肿瘤和转移灶之间的直方图参数和K-TIRADS无显著差异。用纹理分析替代细胞病理学确认来区分PET-CT检测到的甲状腺结节存在局限性。因此，对于转移的最终诊断，不能避免对超声图像上表现为恶性的结节进行细胞病理学确认。
