An engineer argues: "The detector term in a PET resolution budget is half the crystal…
PHYSICS · Multi-part · Fermi University Physics · Biophysics & Medical Physics · Nuclear medicine, dosimetry and radiotherapy · Nuclear medicine, dosimetry and radiotherapy
The Nucleus Resolved, Ch What it is used for: medicine, dating and analysis
Problem
An engineer argues: "The detector term in a PET resolution budget is half the crystal width, so if we simply keep making the crystals smaller and smaller, the resolution can be made as fine as we like, with no limit." Test this claim for a scanner using 124I (mean positron range in tissue 3.9mm) in a ring of diameter 75cm, taking the three blur terms (detector, non-collinearity, positron range) as independent Gaussian widths that add in quadrature, with the non-collinearity term equal to 0.0022D.
((a)) Find the resolution in the limit that the crystal width goes to zero.
((b)) State whether the engineer's claim is correct, and identify the physical quantity that sets the true floor.