Ectopic thyroid: The great mimicker

Ectopic thyroid tissue is very rare, but its prevalence increases in those with thyroid pathology. It typically occurs due to aberrant development of the thyroid gland during its migration to the pretracheal region. In this report, there are two cases of mediastinal ectopic thyroid tissue discussed, which were initially considered to be malignancies. The hospital course, diagnostic workup, including the use of computed tomography and positron emission tomography scans, and the characteristic features of the tissue are examined here. Due to the imaging characteristics, it is important to consider ectopic thyroid tissue as a differential diagnosis for mediastinal masses as encountered in these cases. Asymptomatic ectopic thyroid tissue is usually treated medically; however, patients in both of our cases opted for surgical resection of the masses even after confirmation of the origin of the tissues

Phase-contrast micro-computed tomography measurements of the intraocular pressure-induced deformation of the porcine lamina cribrosa

The lamina cribrosa (LC) is a complex mesh-like tissue in the posterior eye. Its biomechanical environment is thought to play a major role in glaucoma, the second most common cause of blindness. Due to its small size and relative inaccessibility, high-resolution measurements of LC deformation, important in characterizing LC biomechanics, are challenging. Here we present a novel noninvasive imaging method, which enables measurement of the three-dimensional deformation of the LC caused by acute elevation of intraocular pressure (IOP). Posterior segments of porcine eyes were imaged using synchrotron radiation phase contrast micro-computed tomography (PC μCT) at IOPs between 6 and 37 mmHg. The complex trabecular architecture of the LC was reconstructed with an isotropic spatial resolution of 3.2 μm. Scans acquired at different IOPs were analyzed with digital volume correlation (DVC) to compute full-field deformation within the LC. IOP elevation caused substantial tensile, shearing and compressive devformation within the LC, with maximum tensile strains at 30 mmHg averaging 5.5%, and compressive strains reaching 20%. We conclude that PC μCT provides a novel high-resolution method for imaging the LC, and when combined with DVC, allows for full-field 3D measurement of ex vivo LC biomechanics at high spatial resolution