Hybrid NIR Diffuse Optic, Ultrasound Device Characterizes Thyroids

Thyroid diseases affect approximately 200 million people worldwide. In most thyroid pathologies, the vascularization — the number and structure of blood vessels — and hemodynamics are altered. A better understanding of both could help clinicians improve the diagnosis and plan for therapies and follow-up treatment response, but the monitoring techniques available in clinics are not sensitive enough or are impractical for large-scale use.

In an effort to subvert this, a team of researchers from the Institute of Photonic Sciences (ICFO) led by Turgut Durduran has investigated the use of NIR spectroscopy as a cost-effective and non-invasive tool to quantitatively study the properties of thyroid tissue. Through these efforts, the team developed the LUCA platform, a device that integrates NIR spectroscopy and ultrasound techniques to characterize the thyroid tissue with simultaneous anatomical measurements.

A patient’s thyroid being probed by the ICFO researchers’ LUCA platform. The device characterizes thyroid tissue by integrating NIR spectroscopy and ultrasound techniques. Courtesy of ICFO.

The study evaluated 65 subjects, including 18 healthy volunteers and 47 patients with thyroid nodules admitted to the Hospital Clinic in Barcelona, Spain. Researchers assessed the effects of demographic factors such as age, body mass index, and sex; anatomical variables such as the depth of the thyroid; and pathological conditions such as the presence of nodules on the characteristics of thyroid tissue. They also evaluated the capacity of the device to be integrated into the existing screening procedures.

Clinicians placed the integrated monitoring probe on the patients’ thyroid, guided by ultrasound images. The probe used time-domain and diffuse correlation spectroscopy to measure thyroid light absorption and scattering, tissue oxygenation, blood flow, and oxygen metabolism.

The results showed, for example, that age and body mass index significantly affect optical parameters, reducing the measured oxygen saturation, hemoglobin concentration, and blood flow. A comparison between benign and malignant nodules, limited to the ones evaluated, showed lower oxygen saturation in the benign nodules, a result that is currently being investigated in a larger ongoing clinical campaign.

The researchers believe that the reported analysis can be used in future studies as a comprehensive reference of the absolute values of thyroid properties, the precision in their measurement, the variability within and between subjects, and their dependencies on subject characteristics. In this way, they said, these tools can help to improve diagnostic accuracy, allowing doctors to detect thyroid disorders earlier, reduce the reliance on invasive biopsies, and support personalized treatments.

The research was published in Biomedical Optics Express (www.doi.org/10.1364/BOE.538141).