Cover Imaging for Physicists

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Count Rate Performance
 Ratio Trues/Randoms unbalanced for high Activities
 Processing of detected photons takes finite time
 Noise Equivalent Count Rate:
ESTRO Teaching Course Advanced Imaging: PET – Basic Principles 30
Count rate curves for
true, random and
multiple coincidences.
Derived curves for
expected and noise
equivalent count rate
[2]. Data recorded on a
CTI ECAT 953B PET
using a 11C-filled
cylinder in water.
fR ST
T
NECR
2
2
++
=
T: trues
S: scattered
R: randoms
f: rel. area of
object on
proj. surface
Noisy image
Maximum
image
quality Low image
contrast