USE OF MACROAGGREGATED ALBUMIN LUNG PERFUSION SCAN TO DIAGNOSE HEPATOPULMONARY SYNDROME - A NEW APPROACH

Background & Aims: We have reported that contrast echocardiography is a sensitive screening test for the hepatopulmonary syndrome (HPS). How ever, Contrast echocardiography lacks specificity because many cirrhot ic patients have positive study results with normal arterial blood gas es and therefore do not fulfill criteria for HPS, The aim of this stud y was to assess the role of macroaggregated albumin lung perfusion sca ns (MAA scans) in the diagnosis of HPS, Methods: MAA scans were perfor med in 25 patients with HPS, 25 cirrhotic patients without HPS, and 15 hypoxemic subjects with intrinsic lung disease alone, An MAA shunt fr action was calculated from brain and lung counts. Results: MAA scan re sults were positive in 21 of 25 patients with HPS and negative in all controls, All 21 patients with positive MAA scans had P-O2 values of < 60 mm Hg, There was a strong inverse correlation between the degree of the MAA shunt fraction and arterial hyperemia (r = -0.726), Conclusio ns: A positive MAA scan result in cirrhosis is specific for the presen ce of moderate to severe HPS, We speculate that MAA scans may be parti cularly useful in evaluating the contribution of HPS to the hypoxemia in cirrhotic patients with intrinsic lung disesase.