19
Rev 05
SNR
Calulations
1.Select the reconstructed image from Channel 2, and display an eliptical ROI
with a total pixel area of 1300 mm squared. Refer to Philips Gyroscan Intera
Instructions Manual for ROI help.
2. Position ROI in the center of the phantom bottle, as shown below.
3. Bring up the Statistics for ROI, right-mouse select over the ROI number
(arbitrary number next to the ROI), left-mouse select on Statistics from the drop-
down box, and select Statistics again from drop box.
4. Record the Signal Mean value.
5. Move ROI to background noise as shown below.
6. Record the noise standard deviation.
7. Divide the signal mean by the noise standard deviation.
8. Record this SNR value for future reference.
9. Spec > 50.
Example