What is the appropriate breathing instruction for an AP axial projection of the sacrum?

• A. Suspend breathing
• B. Hold breath
• C. Normal breathing
• D. Breath-hold with deep inspiration

Answer: (A)

The key point is to prevent motion during the exposure. For an AP axial projection of the sacrum, stopping respiration keeps the sacral anatomy steady while the angled CR is applied, producing a sharp image and accurate alignment. Instruct the patient to suspend breathing at the moment of exposure (typically at the end of expiration) so diaphragmatic and abdominal motion don’t blur the sacrum or alter its position. Normal breathing would allow motion blur, and a deep inspiratory breath changes the position of abdominal contents and can degrade the image, while a breath-hold, though effective, is not as precise in this context as a clear suspension of respiration.