Optical coherence tomography for the qualitative analysis of thyroid tissue images: Feasibility, features, and clinical potential

The most important steps in thyroid surgery include distinguishing benign from malignant lesions and identifying the parathyroid glands. Optical coherence tomography (OCT) provides technical support for intraoperative guidance owing to its real-time, three-dimensional imaging capability. Benign and malignant diagnoses can be confirmed with intraoperative frozen sections; however, current approaches are time-consuming and labor-intensive and do not allow comprehensive, nondestructive tissue assessments. This study aimed to explore the use of OCT for imaging the thyroid tissue by verifying its clinical feasibility and qualitatively analyzing the OCT imaging characteristics of pathological thyroid glands. A customized swept-source OCT (SS-OCT) system was used to collect OCT data corresponding to the pathologies of 61 freshly excised tissue blocks containing either benign or malignant lesions from 45 patients. The OCT images were highly consistent with the H&E histological images, verifying the feasibility of OCT in producing suitable images for analysis. The OCT-derived characteristics of the thyroid tissue were as follows: normal thyroid follicles presented with regularly arranged honeycomb structures; follicular nodular disease (FND) was characterized by heterogeneous nodules composed of follicles of different sizes, with multiple nodules also differing in size and consisting of varied reticular structures and a focally solid appearance; lymphocyte aggregation led to a gray‒black appearance in Hashimoto's thyroiditis tumors; and papillary thyroid carcinoma lesions were characterized by a heterogeneous texture and a low penetration depth. These results demonstrate the imaging capabilities of OCT for thyroid tissue with different pathological conditions and its broad prospects for clinical application.