To determine the accumulation rate of a radiopharmaceutical in a tumor, the coun

Question

To determine the accumulation rate of a radiopharmaceutical in a tumor, the count rate (number of photons detected per unit time) obtained when a real tumor is imaged is compared to the count rate obtained when calibration standard is imaged under the same conditions. Consider a calibration standard imaged 24 hours after injection of0.5MBq of 1-123. The count rate is 96, 450 per minute. The half-life of I- 123 is 13.2 hours. Calculate the total number of photons emitted per minute. A', and the fraction (in %) of the photons that are counted, relative to the total number of photons emitted per minute.

Explanation / Answer

ccording to quantum picture, light radiation consists of packet of energy called photons. Each photon has energy of hh where h is planks constant and is the frequency of light.

If there are N photons emitted then the total energy radiated is NhNh.

Average power is given by P=Energytime=Et=Nht=NthP=Energytime=Et=Nht=Nth. But Nt=nNt=n is the number of photons emitted per second.

Therefore, n=Phn=Ph.

As frequency is related to wavelength and speed c as c=c= we can write =c=c

So, n=Phcn=Phc

If all the power is not radiated then the effective power = rated power x efficiency.

So the number of photons emitted per second n=Peff/c=P×/hc,where is the efficiency.

{I think in this Problem is not Given Power value and voltage value and Lamda Valus also}

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