Nam Se Jin, Yoo Jaeheung, Lee Hye Sun, Kim Eun-Kyung, Moon Hee Jung, Yoon Jung Hyun, Kwak Jin Young
Department of Radiology, Severance Hospital, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
Yonsei University, College of Medicine, Seoul, Korea.
J Ultrasound Med. 2016 Apr;35(4):775-82. doi: 10.7863/ultra.15.05055. Epub 2016 Mar 11.
To evaluate the diagnostic value of histogram analysis using grayscale sonograms for differentiation of malignant and benign thyroid nodules.
From July 2013 through October 2013, 579 nodules in 563 patients who had undergone ultrasound-guided fine-needle aspiration were included. For the grayscale histogram analysis, pixel echogenicity values in regions of interest were measured as 0 to 255 (0, black; 255, white) with in-house software. Five parameters (mean, skewness, kurtosis, standard deviation, and entropy) were obtained for each thyroid nodule. With principal component analysis, an index was derived. Diagnostic performance rates for the 5 histogram parameters and the principal component analysis index were calculated.
A total of 563 patients were included in the study (mean age ± SD, 50.3 ± 12.3 years;range, 15-79 years). Of the 579 nodules, 431 were benign, and 148 were malignant. Among the 5 parameters and the principal component analysis index, the standard deviation (75.546 ± 14.153 versus 62.761 ± 16.01; P < .001), kurtosis (3.898 ± 2.652 versus 6.251 ± 9.102; P < .001), entropy (0.16 ± 0.135 versus 0.239 ± 0.185; P < .001), and principal component analysis index (-0.386±0.774 versus 0.134 ± 0.889; P < .001) were significantly different between the malignant and benign nodules. With the calculated cutoff values, the areas under the curve were 0.681 (95% confidence interval, 0.643-0.721) for standard deviation, 0.661 (0.620-0.703) for principal component analysis index, 0.651 (0.607-0.691) for kurtosis, 0.638 (0.596-0.681) for entropy, and 0.606 (0.563-0.647) for skewness. The subjective analysis of grayscale sonograms by radiologists alone showed an area under the curve of 0.861 (0.833-0.888).
Grayscale histogram analysis was feasible for differentiating malignant and benign thyroid nodules but did not show better diagnostic performance than subjective analysis performed by radiologists. Further technical advances will be needed to objectify interpretations of thyroid grayscale sonograms.
评估使用灰阶超声图像的直方图分析对鉴别甲状腺良恶性结节的诊断价值。
纳入2013年7月至2013年10月期间563例接受超声引导下细针穿刺的患者的579个结节。对于灰阶直方图分析，使用内部软件在感兴趣区域测量像素回声值为0至255（0为黑色；255为白色）。为每个甲状腺结节获取五个参数（均值、偏度、峰度、标准差和熵）。通过主成分分析得出一个指数。计算五个直方图参数和主成分分析指数的诊断性能率。
本研究共纳入563例患者（平均年龄±标准差，50.3±12.3岁；范围，15 - 79岁）。在579个结节中，431个为良性，148个为恶性。在五个参数和主成分分析指数中，标准差（75.546±14.153对62.761±16.01；P <.001）、峰度（3.898±2.652对6.251±9.102；P <.001）、熵（0.16±0.135对0.239±0.185；P <.001）和主成分分析指数（-0.386±0.774对0.134±0.889；P <.001）在恶性和良性结节之间有显著差异。根据计算出的临界值，标准差的曲线下面积为0.681（95%置信区间，0.643 - 0.721），主成分分析指数为0.661（0.620 - 0.703），峰度为0.651（0.607 - 0.691），熵为0.638（0.596 - 0.681），偏度为0.606（0.563 - 0.647）。仅由放射科医生对灰阶超声图像进行的主观分析显示曲线下面积为0.861（0.833 - 0.888）。
灰阶直方图分析对鉴别甲状腺良恶性结节是可行的，但与放射科医生的主观分析相比，诊断性能并未更好。需要进一步的技术进步来使甲状腺灰阶超声图像的解读客观化。
