Diffusion magnetic resonance imaging (MRI) is a powerful noninvasive technique for studying cerebrospinal fluid (CSF) dynamics in the brain. CSF plays a critical role in metabolic waste clearance and circulates through various brain pathways, including the ventricular system, subarachnoid spaces, para-arterial spaces, interstitial spaces, and para-venous spaces. Diffusion MRI, particularly using pulsed-gradient spin-echo (PGSE) sequences, provides high sensitivity to incoherent water movement, making it suitable for assessing CSF dynamics. This review discusses established and emerging diffusion MRI techniques for measuring CSF dynamics and their potential clinical applications. It emphasizes the importance of optimizing diffusion MRI acquisition parameters to enhance sensitivity and specificity for CSF dynamics. The review also highlights the challenges of interpreting diffusion-based imaging, especially when differentiating between tissue- and fluid-related changes or structural versus functional alterations. The glymphatic system, a proposed pathway for CSF to clear metabolic waste, has been studied using diffusion MRI. CSF flows from the subarachnoid spaces into the brain through para-arterial spaces, exchanges with interstitial fluid (ISF), and drains waste from para-venous or perineural spaces. Diffusion MRI has been used to investigate CSF circulation pathways, including ventricles, subarachnoid spaces, para-arterial spaces, interstitial spaces, and para-venous spaces. Various diffusion models and acquisition parameters have been developed to assess these distinct pathways. The review discusses current diffusion MRI approaches, including mono-compartment and multi-compartment models, as well as intravoxel incoherent motion (IVIM) and neurite orientation dispersion and density imaging (NODDI). These techniques have been applied to study CSF dynamics in various brain regions, including the ventricles, subarachnoid space, and parenchyma. IVIM has been used to assess CSF flow in the ventricles and subarachnoid space, while NODDI has been used to assess axonal density and dendrite fanning. These techniques have shown promise in detecting changes in CSF dynamics and their relationship to neurodegenerative diseases. The review also discusses the challenges of interpreting diffusion-based imaging, including the limitations of diffusion metrics in quantifying flow velocity and the potential for partial volume effects to influence results. The review concludes that diffusion MRI has significant potential for studying CSF dynamics and their relationship to neurodegenerative diseases, but careful interpretation is required to avoid misinterpretation of results.Diffusion magnetic resonance imaging (MRI) is a powerful noninvasive technique for studying cerebrospinal fluid (CSF) dynamics in the brain. CSF plays a critical role in metabolic waste clearance and circulates through various brain pathways, including the ventricular system, subarachnoid spaces, para-arterial spaces, interstitial spaces, and para-venous spaces. Diffusion MRI, particularly using pulsed-gradient spin-echo (PGSE) sequences, provides high sensitivity to incoherent water movement, making it suitable for assessing CSF dynamics. This review discusses established and emerging diffusion MRI techniques for measuring CSF dynamics and their potential clinical applications. It emphasizes the importance of optimizing diffusion MRI acquisition parameters to enhance sensitivity and specificity for CSF dynamics. The review also highlights the challenges of interpreting diffusion-based imaging, especially when differentiating between tissue- and fluid-related changes or structural versus functional alterations. The glymphatic system, a proposed pathway for CSF to clear metabolic waste, has been studied using diffusion MRI. CSF flows from the subarachnoid spaces into the brain through para-arterial spaces, exchanges with interstitial fluid (ISF), and drains waste from para-venous or perineural spaces. Diffusion MRI has been used to investigate CSF circulation pathways, including ventricles, subarachnoid spaces, para-arterial spaces, interstitial spaces, and para-venous spaces. Various diffusion models and acquisition parameters have been developed to assess these distinct pathways. The review discusses current diffusion MRI approaches, including mono-compartment and multi-compartment models, as well as intravoxel incoherent motion (IVIM) and neurite orientation dispersion and density imaging (NODDI). These techniques have been applied to study CSF dynamics in various brain regions, including the ventricles, subarachnoid space, and parenchyma. IVIM has been used to assess CSF flow in the ventricles and subarachnoid space, while NODDI has been used to assess axonal density and dendrite fanning. These techniques have shown promise in detecting changes in CSF dynamics and their relationship to neurodegenerative diseases. The review also discusses the challenges of interpreting diffusion-based imaging, including the limitations of diffusion metrics in quantifying flow velocity and the potential for partial volume effects to influence results. The review concludes that diffusion MRI has significant potential for studying CSF dynamics and their relationship to neurodegenerative diseases, but careful interpretation is required to avoid misinterpretation of results.