In thyroid nodule volume measurements, the transverse direction is usually measured first, followed by the longitudinal direction. A nodule measuring 6x4mm, with 6mm as the transverse measurement length and 4mm as the longitudinal measurement length, has an aspect ratio of 4mm/6mm, which is approximately 0.67. An aspect ratio greater than 1 suggests that the nodule may be malignant. The aspect ratio of thyroid nodules is an important indicator for determining the benign or malignant nature of thyroid nodules, and has a certain reference value for the diagnosis and treatment of thyroid nodules. Clinically, the condition of thyroid nodules is usually judged according to the aspect ratio of the nodule, if the aspect ratio is <1, it is common in benign nodules; if the aspect ratio is >1, it is common in malignant nodules. Therefore, a nodule with a 6x4mm aspect ratio of less than 1 suggests that it may be a benign nodule. However, the aspect ratio is only a reference value and cannot be used as a diagnostic basis. Pathologic analysis is needed to determine whether the nodule is malignant, and patients are advised to go to the hospital for consultation.