Fig. 3.

a Hypercellular bone marrow. On the ¹¹¹In-labeled leukocyte image (left), acquired 24 h after injection of autologous labeled leukocytes, there is focally increased activity in the left shoulder of a patient with sickle cell disease, who presented with fever and left shoulder pain. The distribution of activity is virtually identical on the bone marrow image (right), which was performed immediately after the labeled leukocyte imaging, and 1 h after injection of ^99mTc-sulfur colloid and hence the test is negative for osteomyelitis. The increased activity in the left shoulder is the result of localized marrow hyperplasia. b Osteomyelitis, left shoulder. On the ^99mTc-exametazime image (left), acquired approximately 16 h after injection of labeled autologous leukocytes, there is focally increased activity in the left shoulder (arrow) of a patient who presented with shoulder pain, fever and positive blood cultures. On the bone marrow image (right), which was performed 1 h after injection of ^99mTc-sulfur colloid and 2 days after the labeled leukocyte study, the left shoulder is photopenic (arrow) and the test is positive for osteomyelitis