UNILATERAL ABSENCE OF RIGHT-LUNG PERFUSION WITH NORMAL VENTILATION ONRADIONUCLIDE LUNG-SCAN AS A SIGN OF AORTIC DISSECTION

A case of aortic dissection with unilateral absence of right-lung perf usion and normal ventilation on radionuclide ventilation/perfusion (V/ Q) lung scan is presented with a review of the literature. Anticoagula tion or thrombolytic therapy for presumed pulmonary embolism may be ca tastrophic if the clinical syndrome and V/Q scan appearance are instea d due to aortic dissection. With this V/Q scan appearance, these thera pies should not be instituted unless pulmonary embolism is diagnosed b y pulmonary arteriography.