- Prior imaging studies with: I131 within the last month; In111 or Ga67 within the last 2 weeks; Tc99m labelled RBCs, WBCs or albumin within the last 48 hours; Tc99m or F18 within the last 24 hours; prior non-imaging, non-therapeutic nuclear medicine studies with I131 (eg., 24-hour RAI uptake) within the last 2 weeks.