Comparison of 133Xenon radiospirometry with quantitative 99mTecnnetium‐macroaggregated albiimin perfusion scintigraphy

Summary. Radiospirometry with 133Xenon and perfusion scintigraphy with 99mTech‐netium‐labelled macroaggregated albumin were compared in 22 patients with lung diseases scheduled for surgery. The tracers were given intravenously and, with a gamma camera coupled to a computer, regional lung function was obtained from the count rate in the upper and lower halves of the lungs. There were no significant differences in regional lung function as estimated from the 99mTc perfusion scintigraphy and from the 133Xe method taking perfusion as well as ventilation into account. When the initial lMXe distribution alone was employed, the regional perfusion was underestimated in the right lower lung region and overestimated in the left lung. This is probably due to difficulties in placing the regions of interest. When a gamma camera is used, perfusion scintigraphy with “Technetium macro‐aggregated albumin is easy to perform aad has good counting statistics. This method is therefore advocated for the pre‐operative assessment of regional lung function.