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The in vivo optical and hemodynamic properties of the healthy (n = 22) and pathological (n = 2) human thyroid tissue were measured non-invasively using a custom time-resolved spectroscopy (TRS) and diffuse correlation spectroscopy (DCS) system. Medical ultrasound was used to guide the placement of the hand-held hybrid optical probe. TRS measured the absorption and reduced scattering coefficients (μa, μs') at three wavelengths (690, 785 and 830 nm) to derive total hemoglobin concentration (THC) and oxygen saturation (StO2). DCS measured the microvascular blood flow index (BFI). Their dependencies on physiological and clinical parameters and positions along the thyroid were investigated and compared to the surrounding sternocleidomastoid muscle. The THC in the thyroid ranged from 131.9 μM to 144.8 μM, showing a 25-44% increase compared to the surrounding sternocleidomastoid muscle tissue. The blood flow was significantly higher in the thyroid (BFIthyroid = 16.0 × 10-9 cm2/s) compared to the muscle (BFImuscle = 7.8 × 10-9 cm2/s), while StO2 showed a small (StO2, muscle = 63.8% to StO2, thyroid = 68.4%), yet significant difference. Two case studies with thyroid nodules underwent the same measurement protocol prior to thyroidectomy. Their THC and BFI reached values around 226.5 μM and 62.8 × 10-9 cm2/s respectively showing a clear contrast to the nodule-free thyroid tissue as well as the general population. The initial characterization of the healthy and pathologic human thyroid tissue lays the ground work for the future investigation on the use of diffuse optics in thyroid cancer screening.

The abnormal, uncontrolled production of blood cells in the bone marrow causes hematological malignancies which are common and tend to have a poor prognosis. These types of cancers may alter the hemodynamics of bone marrow. Therefore, noninvasive methods that measure the hemodynamics in the bone marrow have a potential impact on the earlier diagnosis, more accurate prognosis, and in treatment monitoring. In adults, the manubrium is one of the few sites of bone marrow that is rich in hematopoietic tissue and is also relatively superficial and accessible. To this end we have combined time resolved spectroscopy and diffuse correlation spectroscopy to evaluate the feasibility of the noninvasive measurement of the hemodynamics properties of the healthy manubrium in 32 subjects. The distribution of the optical properties (absorption and scattering) and physiological properties (hemoglobin concentration, oxygen saturation and blood flow index) of this tissue are presented as the first step toward investigating its pathology.