Accuracy and reproducibility of phase-contrast MR imaging measurements for CSF flow

Abstract

BACKGROUND AND PURPOSE: PCMR, widely used for the evaluation of blood flow, has been adopted for the assessment of cerebrospinal fluid flow in a variety of disorders. The purpose of this study was to evaluate the accuracy and reproducibility of 2 fast PCMR techniques for measuring CSF flow. MATERIALS AND METHODS: Velocities were calculated from RPC and CPC images of fluid flowing in a tube at a constant velocity. Error and the COV were computed for average and peak velocities. Additionally, measurements of sinusoidally fluctuating flow and of CSF flow in 5 healthy volunteers were acquired with the RPC and CPC acquisitions. RESULTS: For constant velocity experiments, error for the RPC and CPC acquisitions averaged +1.15% and +8.91% and COVs averaged 1.29% and 3.01%, respectively. For peak velocities of ≥12.6 cm/s, error with RPC or CPC ranged from -33.3% to -36.9% and COVs were 0%-4% for RPC and 1%-7% for CPC. For peak velocities of ≤6.4 cm/s, RPC and CPC overestimated velocity by >250%. For fluctuating flow, both acquisitions showed similar flow patterns. In volunteer studies, peak systolic and diastolic velocities were not significantly different. CONCLUSIONS: The RPC and CPC sequences measure velocities on the order of CSF flow with an average error of ≥9%. The 2 techniques significantly overestimate peak velocities <6.4 cm/s, with maximum errors of 209% and 276% and maximum COVs of 100% and 73% for the RPC and CPC sequences, respectively. Measurements of CSF velocities in human volunteers and of sinusoidally fluctuating phantom velocities did not differ significantly between the 2 techniques.