A simple separator to generate half micron aqueous particles for lung imaging.

Area of Science:

• Medical Imaging
• Respiratory Medicine
• Particle Technology

Background:

• Radioactive rare gases are standard for ventilation imaging.
• Optimal imaging requires minimal particle deposition in the upper airways.
• Particles larger than 2 microns can compromise image quality.

Purpose of the Study:

• To develop and evaluate a separator for nebulized aerosols.
• To reduce the proportion of large particles in aerosols for lung imaging.
• To compare imaging quality using a modified aerosol system versus radioactive gases.

Main Methods:

• A separator device was designed using inert spheres in a perspex cylinder.
• The separator modified the output of an Acorn jet nebulizer.
• Imaging and particle deposition were compared between the modified aerosol (99TcmDTPA) and 81Krm in eight subjects.

Main Results:

• The separator reduced particles >2 micron aerodynamic diameter from 60% to 6%.
• Images from the modified aerosol system were comparable to 81Krm in normal subjects.
• Abnormal lung ventilation patterns were discernible with the modified system using a penetration index.

Conclusions:

• The developed separator effectively optimizes aerosol particle size for ventilation imaging.
• This aerosol delivery system provides comparable imaging quality to radioactive gases.
• The modified aerosol system shows promise as a clinical alternative for lung ventilation imaging.