Contrast Media & Molecular Imaging / 2019 / Article / Fig 3

Review Article

A Window on the Lung: Molecular Imaging as a Tool to Dissect Pathophysiologic Mechanisms of Acute Lung Disease

Figure 3

[13N]nitrogen (13N2) positron emission tomography images from a sheep with lavage-induced lung injury. A bolus of 13N2 in saline solution was infused intravenously over 3 seconds at the beginning of a 60-second apnea. The distribution of 13N2 during early apnea (between 5 and 10 seconds) reflects regional perfusion (peak apnea image). The distribution of 13N2 at the end of apnea (between 40 and 60 seconds) is proportional to perfusion only to aerated alveolar units, which retain 13N2 during apnea (end-apnea image). The decrease in tracer activity between peak and end-apnea images in the dorsal, dependent lung (arrowheads) reflects the presence of shunt in this part of the lung because alveoli that are perfused but not aerated do not retain 13N2 during apnea. Modified from Musch et al (Reference [12]).

We are committed to sharing findings related to COVID-19 as quickly and safely as possible. Any author submitting a COVID-19 paper should notify us at to ensure their research is fast-tracked and made available on a preprint server as soon as possible. We will be providing unlimited waivers of publication charges for accepted articles related to COVID-19. Sign up here as a reviewer to help fast-track new submissions.