Biomarkers.

Background: Arterial spin labelling (ASL) is a non-invasive MRI technique for quantifying cerebral blood flow (CBF), used for monitoring changes over the course of a disease or treatment. A crucial parameter in ASL is the post-labelling delay (PLD), determined by the time it takes for blood to travel from the labeling location to the tissue under investigation. Time-encoded ASL (te-ASL) utilizes multiple PLDs for more accurate quantification.

Noninvasive blood-brain barrier integrity mapping in patients with high-grade glioma and metastasis by multi-echo time-encoded arterial spin labeling.

Purpose: In brain tumors, disruption of the blood-brain barrier (BBB) indicates malignancy. Clinical assessment is qualitative; quantitative evaluation is feasible using the K leakage parameter from dynamic susceptibility contrast MRI. However, contrast agent-based techniques are limited in patients with renal dysfunction and insensitive to subtle impairments.

BOLD-CSF dynamics assessed using real-time phase contrast CSF flow interleaved with cortical BOLD MRI.

Background: Cerebrospinal fluid (CSF) motion and pulsatility has been proposed to play a crucial role in clearing brain waste. Although its driving forces remain debated, increasing evidence suggests that large amplitude vasomotion drives such CSF fluctuations. Recently, a fast blood-oxygen-level-dependent (BOLD) fMRI sequence was used to measure the coupling between CSF fluctuations and low-frequency hemodynamic oscillations in the human cortex.

The Road to a Realistic 3D Model for Estimating R and R* Relaxation Versus Gd-DTPA Concentration in Whole Blood and Brain Tumor Vasculature.

Dynamic susceptibility contrast (DSC) MRI is commonly part of brain tumor imaging. For quantitative analysis, measurement of the arterial input function and tissue concentration time curve is required. Usually, a linear relationship between the MR signal changes and contrast agent concentration ([Gd]) is assumed, even though this is a known simplification.

Exploring the need for a preload on the estimation of permeability, vessel radius, and relative cerebral blood volume in MR vascular fingerprinting-based dynamic susceptibility contrast perfusion imaging.

Purpose: Dynamic susceptibility contrast (DSC) MRI is commonly part of the clinical brain tumor imaging protocol. Usually, a preload of contrast agent is administered to minimize contrast-leakage T effects. However, recent studies have indicated that with adaptation of scan parameters (in particular, low flip angle), a preload is not required.