A source of 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?

Question

A source of  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?

Quizplus · Accepted Answer

Solving the differential equation yields the radioactive decay law: A = A₀e^- ^$\lambda$ ^t where A = activity at time t, A₀ = activity at starting time, $\lambda$ = decay constant, t = time since starting time. The decay constant $\lambda$ 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, $\lambda$, t) in the decay equation, requiring that the fourth unknown variable be solved for.

A Source of Is Delivered to the Nuclear Medicine