Two ultrasound measurements were associated with a history of enlargement in very small ACR TI-RADS 5 thyroid nodules, according to a retrospective study. Nodules with visible blood flow inside them were more often in the enlarged group, while a lower shear wave velocity ratio was also linked to enlargement. The findings suggest these measurements may help identify nodules that have grown before, but they do not show that the imaging causes or changes growth.
What the researchers compared
The researchers examined whether superb microvascular imaging, or SMI, and shear wave elastography, or SWE, could distinguish nodules with previous enlargement from stable nodules. The study involved ACR TI-RADS 5 nodules measuring at most 10 millimeters. Each nodule underwent ultrasound with both techniques. The researchers recorded intra-nodular vascularity, the largest vascular index between transverse and longitudinal views, called VImax, and the ratio of the nodule's shear wave velocity to the value measured in the surrounding thyroid tissue, called the SWV ratio.
The study classified a nodule as enlarged if its growth rate was above 2 millimeters per year or if its largest dimension increased by more than 3 millimeters. Among 51 nodules, 25, or 49.0 percent, met that definition. The supplied results do not give a separate count for the stable-nodule group.
Blood flow was more common in nodules that had grown
Intra-nodular vascularity was reported in 80.0 percent of enlarged nodules, compared with 46.2 percent of stable nodules. The reported difference had a p-value of 0.03. In plain terms, the groups differed on this measure, although the result describes an association within this study sample rather than a cause of enlargement.
The average VImax was also higher among enlarged nodules: 21.18 with a standard deviation of 8.31, compared with 15.77 with a standard deviation of 9.96 in stable nodules. The reported p-value was 0.03. VImax, however, was not a significant independent predictor when the researchers considered several measurements together.
The groups also differed on the SWV ratio. Its mean was 1.27, with a standard deviation of 0.38, in enlarged nodules and 1.66, with a standard deviation of 0.37, in stable nodules. The reported p-value was below 0.001.
A three-part model showed promise within the sample
A multivariable logistic regression analysis identified the mean SWV ratio, the nodule's initial size and intra-nodular vascularity as independent predictors of growth in the reported analysis. The regression coefficients were minus 3.35 for the mean SWV ratio, minus 1.06 for initial size and 1.97 for intra-nodular vascularity, with reported p-values of 0.005, 0.003 and 0.049, respectively. VImax was not significant in that analysis.
The model combining those three variables had an area under the receiver operating characteristic curve of 0.882, with a 95 percent confidence interval from 0.786 to 0.977. This measure summarizes how well a model separates two groups, here nodules classified as enlarged and stable. The estimate was based on 2,000 bootstrap iterations.
The result is not ready to guide care on its own
The study was retrospective and had a small sample, limitations the authors highlighted themselves. The supplied analysis also does not report the stable-nodule count, selection criteria, follow-up duration or handling of missing data. It does not report external validation or model calibration, so it remains uncertain how the measurements would perform in a different group of patients or in prospective follow-up.
The results do not establish diagnostic performance for malignancy, patient outcomes or the value of changing treatment decisions. They apply to the studied ACR TI-RADS 5 nodules measuring 10 millimeters or less, and the authors called for larger prospective studies to assess whether SMI and SWE can help manage suspicious thyroid nodules. The protocol was reviewed and approved by the hospital ethics committee under approval JS-2881.
The publication record lists the article as published on 20 August 2026. The study was funded by National High Level Hospital Clinical Research Funding under grant No. 2022-PUMCH-B-066. The authors declared no financial interests or personal relationships that could have appeared to influence the work, and said the dataset is available from the corresponding author on reasonable request.
Paper data and sources
Original title: Could superb microvascular imaging or shear wave elastography tell us the growth record of suspicious thyroid nodules measuring ≤ 10 mm? A retrospective study.
Authors: Xinlong Shi, Ruifeng Liu, Yu Xia et al.
Journal/Repository: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery
Status: Peer-reviewed
First online: 2026-08-20
DOI: 10.1007/s00405-026-10511-6
Original paper · Full text