Department of Clinical Radiology, University of Muenster, 48129 Muenster, Germany.
AJR Am J Roentgenol. 2010 Oct;195(4):979-85. doi: 10.2214/AJR.10.4010.
The purpose of this study was to assess the measurement accuracy and reproducibility of semiautomated metric and volumetric lymph node analysis in MDCT.
Whole-body CT with IV contrast administration was performed on 112 patients. Peripheral (cervical, axillary, and inguinal), abdominal, and thoracic lymph nodes were evaluated independently by two radiologists both manually and with semiautomated segmentation software. Long-axis diameter, short-axis diameter, and volume were measured. Agreement between the semiautomated and manual measurements (measurement error), need for manual correction, and relative interobserver differences were determined. Statistical analysis encompassed the variance inhomogeneity test, intraclass correlation coefficients, and Bland-Altman plots.
In total, 742 peripheral (cervical, axillary, and inguinal), abdominal, and thoracic lymph nodes (mean diameter, 13.2 ± 4.3 mm; range, 4-37 mm) were evaluated. Semiautomatic segmentation without need for further correction was possible for 480 of 742 lymph nodes (64.7%). Calculation of intraclass correlation coefficients revealed high correlation between manual and semiautomatic measurements (r = 0.70-0.81) with a slight trend toward size overestimation for semiautomatic short-axis diameter (14.3%; limits of agreement, -34.3%, 62.9%) and long-axis diameter (11.7%; limits of agreement, -25.2%, 48.5%). Bland-Altman plots showed significantly (p < 0.0001) lower interobserver differences for semiautomated short-axis diameter (1.2%; 95% CI, -39.9% to 42.3%) compared with the manual measurement (7.6%; 95% CI, -38.7% to 53.9%). Among all locations, the relative interobserver difference for semiautomatic volume (2.9%; 95% CI, -31.4% to 37.3%) was significantly lower than that for manual short-axis diameter (p < 0.0001), manual long-axis diameter (0.0178), and semiautomatic short-axis diameter (p < 0.0001).
Semiautomatic short-axis diameter, particularly volume measurements, of lymph nodes are, irrespective of location, precise in terms of reproducibility and appear to be considerably more reliable than manual lymph node assessment.
本研究旨在评估 MDCT 中半自动测量和容量分析在淋巴结方面的测量准确性和可重复性。
对 112 例患者进行全身 CT 增强检查。由两位放射科医生分别独立手动和使用半自动分割软件对外周（颈部、腋窝和腹股沟）、腹部和胸部淋巴结进行评估。测量长轴直径、短轴直径和体积。确定半自动和手动测量之间的一致性（测量误差）、是否需要手动校正以及相对观察者间差异。统计分析包括方差非均一性检验、组内相关系数和 Bland-Altman 图。
总共评估了 742 个外周（颈部、腋窝和腹股沟）、腹部和胸部淋巴结（平均直径，13.2 ± 4.3mm；范围，4-37mm）。742 个淋巴结中，有 480 个无需进一步校正即可进行半自动分割（64.7%）。计算组内相关系数显示，手动和半自动测量之间具有高度相关性（r = 0.70-0.81），半自动短轴直径存在轻微的尺寸高估趋势（14.3%；一致性界限，-34.3%，62.9%）和长轴直径（11.7%；一致性界限，-25.2%，48.5%）。Bland-Altman 图显示，半自动短轴直径的观察者间差异明显（p < 0.0001）低于手动测量（7.6%；95%CI，-38.7%，53.9%）。在所有部位中，半自动体积的观察者间相对差异（2.9%；95%CI，-31.4%，37.3%）明显低于手动短轴直径（p < 0.0001）、手动长轴直径（0.0178）和半自动短轴直径（p < 0.0001）。
无论位置如何，半自动短轴直径，特别是淋巴结的体积测量，在重复性方面都非常精确，并且似乎比手动淋巴结评估可靠得多。
