TABLE 2.

Metrics with Corresponding Formulas and Reference Values for Image Quality Assessment

Metric	Formula	Reference value
SNR	20⋅log10 $\text{[math]}$	6 dB
CNR	$\text{[math]}$	1

SNR = signal-to-background noise ratio; S = mean intensity signal; RMSN = root mean square noise calculated as SD from background area; CNR = contrast-to-noise ratio; N = noise calculated as mean background signal.