Real-time X-ray Imaging of Lung Fluid Volumes in Neonatal Mouse Lung.

At birth, the lung undergoes a profound phenotypic switch from secretion to absorption, which allows for adaptation to breathing independently. Promoting and sustaining this phenotype is critically important in normal alveolar growth and gas exchange throughout life. Several in vitro studies have characterized the role of key regulatory proteins, signaling molecules, and steroid hormones that can influence the rate of lung fluid clearance. However, in vivo examinations must be performed to evaluate whether these regulatory factors play important physiological roles in regulating perinatal lung liquid absorption. As such, the utilization of real time X-ray imaging to determine perinatal lung fluid clearance, or pulmonary edema, represents a technological advancement in the field. Herein, we explain and illustrate an approach to assess the rate of alveolar lung fluid clearance and alveolar flooding in C57BL/6 mice at post natal day 10 using X-ray imaging and analysis. Successful implementation of this protocol requires prior approval from institutional animal care and use committees (IACUC), an in vivo small animal X-ray imaging system, and compatible molecular imaging software.

Bacterial infection probes and imaging strategies in clinical nuclear medicine and preclinical molecular imaging.

At present, a limited number of strategies exist for diagnostic imaging of patients with bacterial infection. While radiolabeled probes and white blood cells provide robust solutions to detect bacteria in humans, they also give false positives in cases of sterile inflammation. With the onset of bacterial drug resistance, and a clinical trend toward reducing the prescription of antibiotics, the need for highly specific infection detection protocols has been renewed. The preclinical research community has recently utilized new optical imaging strategies, alongside traditional radioimaging research, to develop novel infection probes with translational potential. Here we review the current clinical methods for imaging bacteria in humans, and discuss the efforts within the preclinical community to validate new strategies. The review of preclinical infection imaging probes is limited to those probes that could be feasibly adapted for use in humans with currently available clinical modalities.