Comparison of Preoperative MRI With Intraoperative Findings for Peroneal Tendon Pathologies.

Magnetic resonance imaging (MRI) is commonly used to evaluate soft tissue pathology of the foot and ankle. Prior investigations have reported limitations of this modality, however, in evaluation of pathologies related to the peroneal tendons. This article investigates the correlation of pre-operative MRI studies with intraoperative findings. Five board-certified radiologists interpreted MRIs of 80 ankles that subsequently underwent surgical procedures performed by one board-certified foot and ankle surgeon, after which comparison was made between their findings. Statistically significant disagreement was found between radiologist and surgeon findings of a normal peroneus brevis (PB), PB and peroneus longus (PL) tendinosis, PB and PL hypertrophy, PB and PL partial linear tears, PB and PL flattening, PB longitudinal split tears, and the PB attritional spectrum (combined analysis of flattening, partial linear tearing, and longitudinal split tears). These results suggest that given the disconcordance between MRI and intraoperative findings, surgeons should remain cautious in their reliance upon this imaging modality when evaluating this anatomic region.

Microstructured Hydrogels to Guide Self-Assembly and Function of Lung Alveolospheres.

Epithelial cell organoids have increased opportunities to probe questions on tissue development and disease in vitro and for therapeutic cell transplantation. Despite their potential, current protocols to grow these organoids almost exclusively depend on culture within 3D Matrigel, which limits defined culture conditions, introduces animal components, and results in heterogenous organoids (i.e., shape, size, composition). Here, a method is described that relies on hyaluronic acid hydrogels for the generation and expansion of lung alveolar organoids (alveolospheres). Using synthetic hydrogels with defined chemical and physical properties, human-induced pluripotent stem cell (iPSC)-derived alveolar type 2 cells (iAT2s) self-assemble into alveolospheres and propagate in Matrigel-free conditions. By engineering predefined microcavities within these hydrogels, the heterogeneity of alveolosphere size and structure is reduced when compared to 3D culture, while maintaining the alveolar type 2 cell fate of human iAT2-derived progenitor cells. This hydrogel system is a facile and accessible system for the culture of iPSC-derived lung progenitors and the method can be expanded to the culture of primary mouse tissue derived AT2 and other epithelial progenitor and stem cell aggregates.