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Table 4 Number of animals required per group to reach statistical significance in relation to the expected difference between control and treatment/disease groups and the variability of the measured data. Data were computed using G*Power by a two-tailed unpaired Student’s t test assuming equality of variance in both groups and normal distributions. Furthermore, a false positive rate (type I error) of 5 % was selected, together with a false negative rate (type II error) of 20 %, corresponding to a power of 80 %

From: Accurate molecular imaging of small animals taking into account animal models, handling, anaesthesia, quality control and imaging system performance

Expected change between control and treatment/disease groups in % Intra-animal variability of the SPECT/PET data in % Number of animals required per group
20 10 6
20 15 10
20 20 17
25 10 4
25 15 7
25 20 12
30 10 4
30 15 6
30 20 9