Tc-99m HMPAO labelled WBCs in the detection of occult sepsis in the intensive care unit.

In a retrospective study involving 25 patients with occult sepsis in the ICU of Taichung Veterans General Hospital, the sensitivity and specificity of the new diagnostic method, Tc-99m HMPAO labelled white blood cells (WBCs) scan, were compared with other evaluating methods including clinical information, radiograph, ultrasound, bacterial culture, operative findings and pathological report. It was found that Tc-99m HMPAO labelled WBCs scans gave a sensitivity of 96.0%, a specificity of 84.4% and an overall accuracy of 87.3%, as well as the probable causes of false positive and false negative diagnoses were discussed. In conclusion, Tc-99m HMPAO labelled WBCs scans provide a reliable method for imaging of occult sepsis in the ICU.