Rb-82 generator

An Automated Microprocessor-Controlled Rb-82 Generator for Positron Emission Tomography Studies... 

The Rb-82 generator permits serial studies in the same patient as often as every 10 minutes with 20-60 mCi of Rb-82 for rapid bolus intravenous infusion. Inherent in the administration of high levels of Rb-82 activity is the need for precise flow control from an automated system to deliver the desired amount of radioactivity. The development of the alumina column parameters and the elution protocol as well as the automated microprocessor system controller are presented here. Some of the details of this system have been discussed in earlier publications (15,21). Generator produced Rb-82 is used as a diffusible flow tracer in myocardial perfusion studies and as a nondiffusible tracer in brain studies to assess blood brain barrier permeability changes in patients with brain tumors or Alzheimer s type dementia. 

Figure 2. Effects of Al O 1 volumes and NaCl concentration in Rb-82 generator elutions. (Reproduced with permission from Ref. 15 Copyright 1979 Nucl. Med.)...

The potential yield of a Rb-82 generator is dictated by the nature of secular equilibrium. Thus, the activities of parent (Sr-82) and daughter (Rb-82) are nearly equivalent at equilibrium (Rb-82/Sr-82 1.00004). After separation of the Rb-82 by generator elution, equilibrium is re-established quickly. The fractional regeneration of daughter activity is given by (Eq. 1) ... 

The Rb-82 generators thus prepared were evaluated by repetitive, high volume elutions using the infusion system described earlier. Eluent was exclusively sterile, 0.9% sodium chloride solution with collections made into sterile, vented serum vials. 

Figure 6. Steady-state administered activity from a Rb-82 generator as a function of time for three selected flow rates.

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