Prior to a scan, a patient receives a 100 Mbq of a compound labeled with an isotope having a physical half-life of one hour. The clearance of this compound by the kidneys is 20% per hour After one hour the patient urinates. How many MBq remain in the patient at this time? A. 36 B. 40 C. 50 D. 54 E. 80 It is determined that 60 I seeds, of a specified activity, are needed for an implant. The case is then postponed for 10 days. How many of these same seeds would you need to implant on the new date? (Half-life of 1-60 days.) A. 60 B, 67 C. 70 D. 77