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Radiopharmaceutical Questions

The following questions involve radiochemistry. Concepts covered include radiopharmaceutical question: looking at radionucleotide accumulation in the brain and mammogram photons.

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attenuation coefficient for bone, mu_b =0.29 /cm
attenuation coefficient for tissue, mu_t = 0.15 /cm

thickness of skull, x_b = 0.8 cm
thickness of tissue outside skull, x_to = 0.2 cm
brains size, x_tbr = 15 cm

Left side activity measured,
A_l = 3.0MBq == 3.0*10^6 Bq

Right side activity measured,
A_r = 4.2 MBq == 4.2*10^6 Bq

Let us assume original activity is Ao
Detected activity,
A = Ao*exp(- sum(mu* x))

Here, sum(mu*x) corresponding to bones and tissues attenuation.

=>ln(A/Ao) = - sum(mu * x)

Let us assume, the Tc is accumulated inside the brain, at distance x right side of the centre.

for left side,
tissue thickness, ...

Solution Summary

There are answers to 3 questions related to radio-therapy. In first question, using SPECT observation it estimated where the Tc is accumulated. In second question, which is related to mammography, dose equivalent is estimated. In the last question, based on obstructions due to bone and muscle, percentage change in transmitted X-rays is estimated.