The effects of incomplete breath‐holding on 3D MR Image Quality

The purpose of this study was to investigate how fast three‐dimensional (3D) MR image quality is affected by breath‐holding and to develop an optimal breath‐holding strategy that minimizes artifact in the event of an incomplete breath‐hold. A computer model was developed to study variable‐duration breath‐holds during fast 3D imaging. Modeling was validated by 3D gradient‐echo imaging performed on 10 volunteers. Signal‐to‐noise ratio (SNR) and image blur were measured for both simulated and clinical images. Insights gained were applied to clinical 3D gadolinium‐enhanced MR angiography. Breath‐holding significantly improved abdominal 3D MR image quality. Most of this benefit could be achieved with a breath‐hold fraction of 50% if it occurred during acquisition of central k space. Breath‐holding during peripheral k‐space acquisition, however, had no significant benefit. Respiratory motion artifact on fast 3D MRI occurring when a patient fails to suspend respiration for the entire scan duration can be minimized by collecting central k space first (centric acquisition) so that premature breathing affects only the acquisition of peripheral k space.