RT Journal Article SR Electronic T1 Characterization of the Generation of Radiolabeled Monodisperse Albuterol Particles Using the Spinning-Top Aerosol Generator JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 69 OP 73 VO 45 IS 1 A1 Usmani, Omar S. A1 Biddiscombe, Martyn F. A1 Underwood, S. Richard A1 Barnes, Peter J. YR 2004 UL http://jnm.snmjournals.org/content/45/1/69.abstract AB Inhaled radiolabeled aerosols provide invaluable information about in vivo drug deposition. Here, we report our methodology for radiolabeling and imaging monodisperse pharmacologic aerosols in order to study basic aerosol science concepts of drug delivery within the human airways. Methods: We used a spinning-top aerosol generator to produce 99mTc-labeled monodisperse albuterol sulfate aerosols of 1.5-, 3-, and 6-μm mass median aerodynamic diameter. Results: In vitro Andersen cascade validation data showed that technetium and albuterol were coassociated on each impactor stage for all 3 aerosols, and the radiolabeling process itself did not affect their particle size distributions. Good-quality γ-camera scintigraphic images of lung and extrathoracic deposition were obtained within an asthmatic patient. Conclusion: We have successfully radiolabeled and imaged monodisperse albuterol aerosols within the human lungs. This novel technique provides an important tool to relate fundamental concepts of aerosol particle behavior, in vivo deposition, and therapeutic clinical response.