A source of $ { }^{131} \mathrm{I}\left[\mathrm{t} \frac{1}{2}=8.05 \mathrm{~d}\right] $ is delivered to the nuclear medicine department calibrated for 100 mCi at 8:00 AM on Monday.If this radioactivity is injected into a patient at noon on Tuesday, what radioactivity will the patient receive?

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Quizplus · Accepted Answer

Solving the differential equation yields the radioactive decay law: A = A₀e^-F1F1F1S1^F1F1F10^t where A = activity at time t, A₀ = activity at starting time, F1F1F1S1F1F1F10 = decay constant, t = time since starting time.The decay constant F1F1F1S1F1F1F10 is the fraction of atoms that decay per (small) time interval, and has units of 1 over time (e.g., 1/hr) or inverse time (hr^-¹).The typical radioactive decay calculation required in nuclear medicine specifies three of the four variables (A, A₀, F1F1F1S1F1F1F10, t) in the decay equation, requiring that the fourth unknown variable be solved for.

A Source Of 131I[t12=8.05 d] { }^{131} \mathrm{I}\left[\mathrm{t} \frac{1}{2}=8.05 \mathrm{~d}\right] 131I[t21​=8.05 d] Is Delivered to the Nuclear Medicine Department Calibrated for 100

A Source Of ${ }^{131} \mathrm{I}\left[\mathrm{t} \frac{1}{2}=8.05 \mathrm{~d}\right]$ Is Delivered to the Nuclear Medicine Department Calibrated for 100