Which part of the syringe can be described as a piston-type rod?

When using a FOUR-digit Medicare "type of bill" code in form locator 4, the bill classification (type of care) is represented by the:

first digit. second digit. third digit. fourth digit.

An AP axial sacral iliac joint projection with accurate positioning demonstrates the

1. median sacral crest and symphysis pubis in alignment. 2. sacroiliac joints without foreshortening. 3. symphysis pubis superimposed over the inferior sacral segments. 4. second sacral segment at the center of the image. a. 1 and 2 only b. 3 and 4 only c. 1, 2, and 4 d. 1, 2, 3, and 4