In chest CT, which technique besides breath-hold can help reduce motion artifacts?

In chest CT, which technique besides breath-hold can help reduce motion artifacts?

• A. Gating strategies.
• B. Longer exposure time.
• C. No contrast use.
• D. Lower resolution imaging.

Answer: (A)

Motion during chest CT mainly comes from breathing and heart motion, so beyond breath-holding the trick is to time data acquisition to a phase of the cycle when movement is minimal. Gating strategies do exactly that by synchronizing image collection with a specific point in the respiratory or cardiac cycle. Respiratory gating uses sensors or a navigator to track breathing and trigger or sort data so images are reconstructed from data acquired at a consistent, minimal-motion phase, often near end expiration. Cardiac gating uses an ECG signal to acquire data during a quiescent part of the heartbeat, typically diastole, reducing cardiac-related blur that can affect central chest structures. This approach is especially helpful when the patient can’t hold a breath well or when the scan duration would otherwise introduce more motion blur. In contrast, longer exposure time tends to increase motion blur, and lowering resolution or avoiding contrast doesn’t specifically address motion artifacts.

Motion during chest CT mainly comes from breathing and heart motion, so beyond breath-holding the trick is to time data acquisition to a phase of the cycle when movement is minimal. Gating strategies do exactly that by synchronizing image collection with a specific point in the respiratory or cardiac cycle. Respiratory gating uses sensors or a navigator to track breathing and trigger or sort data so images are reconstructed from data acquired at a consistent, minimal-motion phase, often near end expiration. Cardiac gating uses an ECG signal to acquire data during a quiescent part of the heartbeat, typically diastole, reducing cardiac-related blur that can affect central chest structures. This approach is especially helpful when the patient can’t hold a breath well or when the scan duration would otherwise introduce more motion blur. In contrast, longer exposure time tends to increase motion blur, and lowering resolution or avoiding contrast doesn’t specifically address motion artifacts.