[Ventilation scintigraphy of the lung with 99mTc-DTPA or with 99mTc-sulfur colloid?]

Ventilation scintigraphy of the lung, obtained with sufficiently small 99mTc-labelled aerosol particles, provides an image of ventilation distribution that is acceptable in clinical routine. Whether 99mTc-DTPA or 99mTc-sulfur colloid is more suitable as a carrier was studied in 6 smokers and 8 non-smokers with chronic obstructive pulmonary disease. 99mTc-sulfur colloid was not absorbed by the bronchial mucosa and therefore appears to be an almost ideal agent. In contrast, 99mTc-DTPA was absorbed by the bronchial mucosa in all smoking patients more rapidly and inhomogenously than in non-smokers. The quantitative and qualitative comparison of the two dorsal ventilation scans taken both immediately after inhalation and 20 min later, showed in all 6 smoking patients after 20 min significant differences which influenced the diagnosis result. 99mTC-DTPA is therefore not recommended for use in ventilation lung scintigraphy, especially in smoking patients.