Ventilation and perfusion lung imaging--which nebulizer?

Abstract

Three commercially available 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol delivery nebulizers for lung ventilation imaging were investigated. Two were air-jet systems, 'Optimist' (Medicaid) and 'Microcirrus' (Amersham), and one was an ultrasonic device (Europlus). Altogether, 112 consecutive patients were scanned, 37 using the Optimist, 40 using the Microcirrus and 35 the Europlus. The age mix, FEV1, FVC and PEFR measurements of the patients in each group were similar. Each contained a proportion of patients with poor respiratory function, with PEFR rates ranging from 30 to 582 l min-1 for patients studied with all systems. Ease of use, image quality and cost were evaluated as well as radioactive and microbiological contamination. The Optimist system gave the best combination of image quality and cost, and was associated with the lowest level of radioactive contamination. It also proved the most popular. Airborne contamination for all nebulizers was lower than previously reported and was largely dependent on patient compliance. With poorly compliant patients, the contamination levels are sufficient to warrant an extraction device. There was no evidence of bacterial contamination of the nebulizers or tubing on repeated use over 5 days.