Normal Images
Male 72 y/o with intermitent lower gastrointestinal bleeding. It can be see aorta, vena cava, liver and heart blood pool activity. There is no GI extravasation. Endoscopy was normal. No specific diagnosis was made and the patient was discharged in good condition. 99mTc-labeled erythrocyte scans are performed by acquiring flow images, followed by sequential static or dynamic images for 60 to 90 minutes or until bleeding is confirmed. These scans demonstrate bleeding rates as low as 0.1 to 0.2 ml per minute. To detect intermittent bleeding, delayed imaging may be done as long as 24 hours after the 99mTc-RBC is administered. The sensitivity of the 99mTc-RBC scans was 93%, specificity 95%, and accuracy 94%.
1 Holder L. E.. Radionuclide Imaging in the Evaluation of Acute Gastrointestinal Bleeding. RadioGraphics 2000; 20:1153–1159.
2 Howarth D. The Role of Nuclear Medicine in the Detection of Acute Gastrointestinal Bleeding.Seminars in nuclear medicine 2006;Vol36,2:133-146.