You decide to build a PET scanner from a dual-head SPECT camera you own. It has two 30-cm square Anger cameras mounted facing each other 1.5 m apart.

(a) Would you use the low-energy collimators, the high-energy collimators, or no collimators? Explain.

(b) What significant piece of electronics would you have to add to the SPECT circuitry to make this work as a PET scanner?

(c) Explain how you would use the X and Y signals coming out of the opposing Anger cameras. Would you use the Z-pulses? Why or why not

(d) You will have to rotate the Anger cameras at some point during the scan. What is the minimum number of angular positions of the two cameras that would be required in order to get full angular coverage for PET reconstruction?

(e) Consider the radiotracer concentration in the body. Would you expect to require a higher, lower, or about the same dose in this make-shift PET scanner versus a real PET scanner? Explain your rationale.