Reliability of 3-D ultrasound measurements of cervical lymph node volume

This study was undertaken to evaluate the reliability of three-dimensional (3-D) ultrasound in measuring cervical lymph node volume. Ultrasound examination of the neck was performed on 15 healthy subjects (eight men and seven women). For each subject, the volume of cervical lymph nodes was measured twice with 3-D ultrasound by two operators, to evaluate the reproducibility of measurements (interoperator variability). 3-D ultrasound measurements of cervical node volume were performed with and without using SonoCT and XRES imaging. Each 3-D data set was reviewed and remeasured by the operators to evaluate the repeatability of measurements (intra-operator variability). Results showed that the reproducibility and repeatability of 3-D ultrasound volumetric measurements of cervical nodes was improved when SonoCT and XRES imaging were used. There was a high repeatability of 3-D ultrasound measurements of cervical node volume (> 90%). A high reproducibility of measurements was found in the posterior triangle nodes (90.3% - 90.9%). When SonoCT and XRES imaging were used with the scanning, there was a high reproducibility for parotid node measurements (87.4%) and a satisfactory level of reproducibility for submental (61.8%), submandibular (69.3%) and upper cervical node (79%) measurements. 3-D ultrasound is a useful and reliable method in measuring cervical lymph node volume. However, further studies to improve the reproducibility of 3-D ultrasound measurements of submental, submandibular and upper cervical node volume are suggested.