title: Platypnea-orthodeoxia syndrome: Importance of patient position for correct diagnosis at the time of (99m)Tc-MAA injection.
abstract: A 65-year-old male presented with unexplained hypoxia that became exacerbated by an upright posture (platypnea-orthodeoxia syndrome) secondary to hepatopulmonary syndrome (HPS). A (99m)Tc-macroaggregated albumin pulmonary perfusion scan revealed a right to left shunt of 29% in the sitting position, which had not been previously detected when the radiotracer injection was performed with the patient in supine position, nor was it diagnosed using another non-invasive imaging method (transthoracic contrast echocardiography and angio-CT). A transesophageal echocardiography was contraindicated due to the presence of esophageal varices. The administration of the radiopharmaceutical in sitting position for the study of the pulmonary perfusion allowed us to confirm the presence of the shunt and consider the patient a candidate for liver transplantation.
authors.affiliation: Departamento Medicina Nuclear, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain. Electronic address: drapatriciafierro@gmail.com.
authors.forename: M P
authors.initials: MP
authors.lastname: Fierro Alanis
authors.affiliation: Departamento Gastroenterología, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Bastón Rey
authors.affiliation: Departamento Medicina Nuclear, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Nieves-Maldonado
authors.affiliation: Departamento de Medicina Interna, Complejo Hospitalario Universitario de Santiago, Santiago, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Torre Carballada
authors.affiliation: Departamento Gastroenterología, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: J E
authors.initials: JE
authors.lastname: Domínguez-Muñoz
authors.affiliation: Departamento Medicina Nuclear, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Á
authors.initials: Á
authors.lastname: Ruibal Morell
mesh_terms: D000368:Aged; D000075202:Contraindications; D004417:Dyspnea / Q000000981:diagnostic imaging* / Q000209:etiology; D004452:Echocardiography; D017548:Echocardiography, Transesophageal; D020065:Hepatopulmonary Syndrome / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D016031:Liver Transplantation; D008297:Male; D011187:Posture; D011652:Pulmonary Circulation; D019275:Radiopharmaceuticals; D016683:Supine Position; D013668:Technetium Tc 99m Aggregated Albumin
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin
keywords: Gammagrafía pulmonar de perfusión; Hepatopulmonary syndrome; Lung perfusion scan; Platypnea-orthodeoxia syndrome; Sedestación; Sitting position; Síndrome hepatopulmonar; Síndrome platipnea-ortodeoxia