What are the criteria for an AP sacrum?
Sacrum, SI joints, and L5/S1 intervertebraljoint space. No rotation indicated by alignment of the median sagittal crestsand coccyx with the symphysis pubis. Correct alignment of the sacrum and CRdemonstrated the sacrum free of foreshortening and the pubis and sacralforamina are not superimposed. Collimation to area of interest