Sepsis is a dangerous condition commonly seen in the intensive care unit (ICU) of hospitals. It causes the thymus, a crucial immune organ, to shrink. This process is known as thymus involution. Although thymus involution is a natural process that occurs as we age, it is accelerated during sepsis. This process is associated with poor outcomes in septic patients, yet it had never been studied using ultrasonography in a septic mouse model. Researchers from the University of Kentucky have validated a non-invasive ultrasound imaging approach to monitor septic thymus involution in a cecum ligation and puncture (CLP) sepsis mouse model. In this study, scientists randomly divided 35 C57BL/6J mice into three groups: baseline, post-CLP at 3 days, and post-CLP at 10 days. In each group, they first obtained estimated thymus area and volumes using 2D and 3D ultrasound imaging. The mice were then euthanized to measure thymus weights ex-vivo. The ex-vivo weights were correlated with the in-vivo 2D and 3D estimated areas and volumes and proved the reliability of this approach for monitoring thymus changes during sepsis. The study, led by Dr. Xiang-An Li, a professor of physiology at the University of Kentucky, was published in Ultrasound in Medicine & Biology. It has paved the way for further studies investigating the mechanism of thymus involution during sepsis, which is a crucial but poorly understood phenomenon that exacerbates immunosuppression in septic patients.