According to the beam divergence rule, at a distance of 40 inches, moving away from the central ray in any direction results in approximately how many degrees of beam divergence per inch?

An AP axial cervical projection demonstrates the third cervical vertebra superimposed by the lower jaw. How should the positioning setup be adjusted for an optimal projection to be ob-tained?

1. Decrease the degree of central ray angulation. 2. Rotate the patient toward the left side. 3. Elevate the chin. 4. Align the acanthiomeatal line perpendicular to the IR. a. 1 and 2 only b. 3 only c. 3 and 4 only d. 1, 3, and 4 only

Which of the following statements is true concerning the operation of a transcutaneous carbon dioxide electrode?

a. PtcCO2 readings are slightly lower than the PaCO2 value. b. Electrodes should be calibrated when they are repositioned. c. Heating the transcutaneous PCO2 (PtcCO2) to 43°C will adversely affect its operation. d. Before its use, the electrode should be calibrated to 20% and 40% CO2.