Characterizing Protein Concentration in Cerebrospinal Fluid with T₂ Component Analysis.

Area of Science:

• Biomedical Imaging
• Magnetic Resonance Imaging (MRI)
• Cerebrospinal Fluid (CSF) Analysis

Background:

• Protein accumulation in CSF is associated with neurological conditions.
• T2 values in MRI are hypothesized to decrease with increased protein concentration.
• Accurate visualization of protein distribution is crucial for diagnosis.

Purpose of the Study:

• To validate the accuracy of Carr-Purcell-Meiboom-Gil (CPMG) pulses and non-negative least squares (NNLS) analysis for mapping T2 values.
• To assess the ability of this method to visualize and quantify protein concentrations in CSF.

Main Methods:

• Prepared albumin solutions with varying concentrations (0.002-4.5 mM) in artificial CSF.
• Acquired data using CPMG pulses and NNLS analysis to decompose T2 values per pixel.
• Derived 25 T2 component values and assessed changes with varying albumin concentrations.
• Applied the method to clinical cases involving subdural hematoma and a cystic tumor.

Main Results:

• Distinct T2 peaks were observed for albumin concentrations from 0.056 to 4.55 mM, with overlapping peaks at lower concentrations.
• Color maps effectively represented T2 value changes and differentiated albumin concentrations within single voxels.
• Clinical cases showed T2 component maps reflecting differences in albumin concentrations, consistent with experimental findings.

Conclusions:

• The combined CPMG sequences and NNLS analysis provide effective imaging for differentiating protein accumulation in CSF.
• This technique offers high resolution, capable of detecting protein concentration differences at the single-pixel level.
• The method shows promise for improved diagnostic capabilities in neurological conditions involving CSF protein abnormalities.