Cardiac-gated intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for the investigation of intracranial cerebrospinal fluid dynamics in the lateral ventricle: a feasibility study

• Published in: Neuroradiology Vol. 60; no. 4; pp. 413 - 419
• Main Authors: Surer, Eddie, Rossi, Cristina, Becker, Anton S., Finkenstaedt, Tim, Wurnig, Moritz C., Valavanis, Antonios, Winklhofer, Sebastian
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2018; Springer Nature B.V
• Subjects: Adult; Cardiac-Gated Imaging Techniques - methods; Cerebrospinal fluid; Cerebrospinal Fluid Pressure - physiology; Coding; Diastole; Diffusion coefficient; Diffusion Magnetic Resonance Imaging - methods; Diffusion rate; Feasibility Studies; Female; Fluid dynamics; Functional Neuroradiology; Healthy Volunteers; Heart; Heart diseases; Humans; Hydrodynamics; Image processing; Imaging; Lateral Ventricles - diagnostic imaging; Lateral Ventricles - physiology; Magnetic resonance imaging; Male; Males; Mathematical analysis; Medicine; Medicine & Public Health; Molecular diffusion; Neurological diseases; Neurology; Neuroradiology; Neurosciences; Neurosurgery; NMR; Nuclear magnetic resonance; Parameters; Radiology; Resonance; Systole; Ventricle; Ventricle (lateral); Ventricles (cerebral); Diffusion-weighted imaging; Brain imaging; Cerebrospinal fluid; Magnetic resonance imaging; Circulation; Intravoxel incoherent motion
• ISSN: 0028-3940; 1432-1920
• DOI: 10.1007/s00234-018-1995-3

Purpose Intravoxel incoherent motion (IVIM) in diffusion-weighted magnetic resonance imaging (DW-MRI) attributes the signal attenuation to the molecular diffusion and to a faster pseudo-diffusion. Purpose of the study was to demonstrate the feasibility of IVIM for the investigation of intracranial cerebrospinal fluid (CSF) dynamics. Methods Cardiac-gated DW-MRI images with fifteen b -values (0–1300s/mm 2 ) along three orthogonal directions (mediolateral (ML), anteroposterior (AP), and craniocaudal (CC)) were acquired during maximum systole and diastole in 10 healthy volunteers (6 males, mean age 36 ± 15 years). A pixel-wise bi-exponential fitting with an iterative nonparametric algorithm was carried out to calculate the following parameters: diffusion coefficient ( D ), fast diffusion coefficient ( D *), and fraction of fast diffusion ( f ). Region of interest measurements were performed in both lateral ventricles. Comparison of IVIM parameters was performed among two cardiac cycle acquisitions and among the diffusion-encoding directions using a paired Student’s t test. Results f significantly ( p  < 0.05) depended on the diffusion-encoding direction and on the cardiac cycle (diastole AP 0.30 ± 0.13, ML 0.22 ± 0.12, CC 0.26 ± 0.17; systole AP 0.45 ± 0.17, ML 0.34 ± 0.15, CC 0.40 ± 0.21). Neither a cardiac cycle nor a direction dependency was found among mean D values (which is in line with the expected intraventricular isotropic diffusion) and D * values ( p  > 0.05 each). Conclusion The fraction of fast diffusion from IVIM is feasible to detect a direction-dependent and cardiac-dependent pulsatile CSF flow within the lateral ventricles allowing for quantitative monitoring of CSF dynamics. This technique might provide opportunities to further investigate the pathophysiology of various neurological disorders involving altered CSF dynamics.