Quantitation of right-to-left shunt ratio in patients with pulmonary telangiectasia by technetium-99m MAA lung perfusion imaging.

Two cases of pulmonary telangiectasia have been presented. Using lung perfusion scans, two quantitative estimation methods for right-to-left (R-L) shunt ratios have been described. The R-L shunt ratios estimated by lung perfusion imaging correlate well with those derived by the Fick method. The methods described are simple and accurate, and seem to be useful for evaluation and follow-up of the patients.