Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>A 69-year-old man presented with recurring drops in hemoglobin levels and suspected gastrointestinal bleeding. Endoscopy did not show a site of bleeding so further examinations became necessary. Scintigraphy and SPECT/CT with <jats:sup>99m</jats:sup>TcO<jats:sub>4</jats:sub>
<jats:sup>−</jats:sup>–labeled red blood cells were performed without evidence of a hemorrhage. Based on an established protocol for splenic PET/CT, autologous erythrocytes can be labeled with <jats:sup>68</jats:sup>Ga-oxine and used as a tracer for the localization of active bleeding sites. In the patient, PET/CT with <jats:sup>68</jats:sup>Ga-oxine–labeled undamaged erythrocytes was performed successfully and revealed a hemorrhage of the gastric corpus that was confirmed and treated by endoscopy.</jats:p>