Pulmonary ventilation and perfusion imaging with dual-energy CT
Objective
To evaluate the feasibility of dual-energy CT (DECT) ventilation imaging in combination with DE perfusion mapping for a comprehensive assessment of ventilation, perfusion, morphology and structure of the pulmonary parenchyma.
Methods
Two dual-energy CT acquisitions for xenon-enhanced ventilation and iodine-enhanced perfusion mapping were performed in patients under artificial respiration. Parenchymal xenon and iodine distribution were mapped and correlated with structural or vascular abnormalities.
Results
In all datasets, image quality was sufficient for a comprehensive image reading of the pulmonary CTA images, lung window images and pulmonary functional parameter maps and led to expedient results in each patient.
Conclusion
With dual-source CT systems, DECT of the lung with iodine or xenon administration is technically feasible and makes it possible to depict the regional iodine or xenon distribution representing the local perfusion and ventilation.
Full text: Eur Radiol. 2010 Jun 23. [Epub ahead of print]
Authors: Thieme SF, Hoegl S, Nikolaou K, Fisahn J, Irlbeck M, Maxien D, Reiser MF, Becker CR, Johnson TR.
What are the requirements for Xenon ventilation? Is it difficult or dangerous?
Many thanks,
CM
Requirements for xenon gas application include, of course, the gas itself, which can only be extracted from the atmosphere in very low concentrations and is therefore quite expensive. AirLiquide holds the license for medical Xenon gas in Europe. Apart from that, a device for administration is needed, i.e. either, in general anesthesia, an anesthesiology apparatus which is specifically designed for xenon based narcosis (for example Tangens from EKU). For awake, freely breathing patients, a respirator can be used (for example Anzai AZ-725). Although xenon does have narcotic effects, a relevant sedation is not expected at concentrations below 30% for a few breaths. Still, close monitoring including pulse oximetry and support from an anesthesiologist are advisable. For more details refer to the respective chapter of the book “Dual Energy CT in Clinical Practice” (Springer, ISBN: 978-3-642-01739-1) which will appear within the next few weeks.