Intravenous furosemide injection during 18F-FDG PET acquisition.

Unlabelled: Urinary-system elimination of (18)F-FDG can be mistaken for pathologic uptake. Furosemide helps eliminate this artifact. Unnecessary administration should be avoided. Our approach obviates furosemide administration and other invasive procedures in many cases.

Methods: Thirty-seven cancer patients referred for PET to evaluate treatment response or suspected recurrence were prospectively studied using whole-body scanning, with (18)F-FDG injected via dorsal hand catheter beforehand. The catheter was left in place to enable injection of furosemide while the patient was inside the scanner. After abdominopelvic scanning, physicians evaluated the need to inject furosemide. Thirty minutes after furosemide injection, another abdominopelvic scan was obtained to detect postinjection urinary tract changes.

Results: Postfurosemide images showed effects due to physiologic elimination in 24 patients (64.9%), of whom 11 patients (45.8%) had more than one inconclusive prefurosemide finding. In 13 patients (35.1%), delayed images confirmed persistent lymph node uptake, including 3 patients (23.1%) with 1 lesion.

Conclusion: Furosemide injection during scanning reduces artifacts, shortens examinations, and helps avoid invasive procedures.