Technetium-99m HMPAO labeled leukocytes as the primary diagnostic tool in a case of brain abscess

The authors present a case in which Tc-99m HMPAO labeled autologous leukocytes were used to demonstrate a brain abscess in a patient undergoing evaluation for fever of unknown origin. The abscess was demonstrated on both 1-hour and 24-hour images. The positive 1-hour image led to CT and MRI studies, which are included for correlation. In addition to its previously identified role as a secondary diagnostic test in the differentiation of tumor and abscess, the authors propose that Tc-99m HMPAO is useful as a primary diagnostic tool in the identification of brain abscess. Furthermore, the authors suggest that Tc-99m HMPAO is preferable to In-111 labeled leukocytes because of its better resolution and earlier imaging characteristics.