In vitro evaluation of cerebrospinal fluid velocity measurement in type I Chiari malformation: repeatability, reproducibility, and agreement using 2D phase contrast and 4D flow MRI

Abstract

Background Phase contrast magnetic resonance imaging, PC MRI, is a valuable tool allowing for non-invasive quantification of CSF dynamics, but has lacked adoption in clinical practice for Chiari malformation diagnostics. To improve these diagnostic practices, a better understanding of PC MRI based measurement agreement, repeatability, and reproducibility of CSF dynamics is needed. Methods An anatomically realistic in vitro subject specific model of a Chiari malformation patient was scanned three times at five different scanning centers using 2D PC MRI and 4D Flow techniques to quantify intra-scanner repeatability, inter-scanner reproducibility, and agreement between imaging modalities. Peak systolic CSF velocities were measured at nine axial planes using 2D PC MRI, which were then compared to 4D Flow peak systolic velocity measurements extracted at those exact axial positions along the model. Results Comparison of measurement results showed good overall agreement of CSF velocity detection between 2D PC MRI and 4D Flow (p = 0.86), fair intra-scanner repeatability (confidence intervals ± 1.5 cm/s), and poor inter-scanner reproducibility. On average, 4D Flow measurements had a larger variability than 2D PC MRI measurements (standard deviations 1.83 and 1.04 cm/s, respectively). Conclusion Agreement, repeatability, and reproducibility of 2D PC MRI and 4D Flow detection of peak CSF velocities was quantified using a patient-specific in vitro model of Chiari malformation. In combination, the greatest factor leading to measurement inconsistency was determined to be a lack of reproducibility between different MRI centers. Overall, these findings may help lead to better understanding for application of 2D PC MRI and 4D Flow techniques as diagnostic tools for CSF dynamics quantification in Chiari malformation and related diseases.

Cerebrospinal fluid dynamics along the optic nerve

“…These techniques include magnetic resonance imaging (MRI), two-photon imaging, computer-assisted cisternography (CT cisternography), and scanning electron microscopy (SEM). Moreover, phase contrast techniques are also widely used in the CSF study ( 63 ).…”

Quality Control for 4D Flow MR Imaging

“…Williams et al performed 4D flow MRI (3T; spatial resolution, 1.5 × 1.5 × 1.5 mm 3 ; and VENC, 15 cm/s) on an in vitro model of Chiari malformation and compared the CSF velocities with those obtained by 2D cine PC MRI, and reported that the CSF velocities showed good accuracy in each case. 82 Currently, it is difficult to accurately reproduce the geometry of the SSS in CFD and in vitro models due to its detailed and complex structure, and these are not considered to be the ideal true value for human 4D flow MRI measurements for SSS. Therefore, at this time, the measurement accuracy of 4D flow MRI for the human SSS should be examined using existing 2D cine PC MR, whose accuracy has been confirmed.…”

“…34 On the other hand, in an in vitro experiment using a subject-specific CSF flow model of a Chiari malformation patient, 4D flow MRI was performed three times with five different devices at five centers, and the test-retest repeatability was good, but inter-scanner reproducibility was poor. 82 The reason raised in that paper was that the imaging parameters could not be sufficiently matched.…”

A subject‐specific assessment of measurement errors and their correction in cerebrospinal fluid velocity maps using 4D flow MRI

“…A benefit of 4D flow MRI is that it is not influenced by the placement of the acquisition plane and, thus, enables efficient provision of complex CSF movements in all three spatial directions. Taking advantage of these benefits, several studies have reported on 4D flow MRI measurements of the CSF flow pattern over the past decade 11–16 …”

“…Taking advantage of these benefits, several studies have reported on 4D flow MRI measurements of the CSF flow pattern over the past decade. [11][12][13][14][15][16] Flow velocity measurement using PC-MRI is, however, impaired by several potential sources of error, as summarized in Refs. [17][18][19].…”