Quantitative phase-contrast flow MRI measurements in the presence of a second vessel closely positioned to the examined vessel.

Purpose: To examine the influence of the truncated sampling of k-space data on the accuracy of phase-contrast (PC) flow quantifications in the presence of nearby vessels.

Materials And Methods: Computer simulations were performed along with some experimental validations on a flow phantom and a normal subject.

Results: The accuracy of the PC flow quantification decreased when a second vessel was positioned closely to the examined vessel. The effect strongly depended on the peak flow velocity in the second vessel relative to the velocity encoding (venc) level of the MRI acquisition, and on the position and area of the second vessel.

Conclusion: Due to the truncated sampling of the k-space data, signal leaked from nearby vessels and distorted the PC flow quantification in the examined vessel. The presented results suggest specific experimental conditions to minimize this flow quantification error.