Choline-containing compounds quantification by 1H NMR spectroscopy using external reference and noise measurements.

Area of Science:

• Medical Imaging
• Biophysics
• Oncology

Background:

• Proton magnetic resonance spectroscopy ((1)H-MRS) is a non-invasive technique used to analyze chemical compounds in human tissues.
• Elevated choline compounds are indicative of active tumors, aiding in cancer diagnosis and treatment monitoring.
• Differentiating benign from malignant lesions requires accurate choline quantification due to potential choline peaks in benign conditions.

Purpose of the Study:

• To develop and validate an external reference procedure for absolute choline quantification in standard units.
• To implement a noise-based method for choline quantification that minimizes scanner-dependent variations.
• To assess the accuracy and precision of the proposed method in both phantom and in vivo studies.

Main Methods:

• Acquisition of spectra using a 1.5 T scanner with a PRESS sequence on phantoms and healthy volunteers.
• Implementation of a quantification procedure utilizing metabolite and noise measurements from spectra.
• Comparison of the noise-based method with a standard quantification approach.

Main Results:

• In vitro quantification demonstrated high accuracy (95-99%) and precision (5-13%).
• In vivo studies on healthy volunteers yielded choline concentrations of (1.73 ± 0.24) mmol/l.
• The method proved effective for quantifying choline in phantoms and human tissues like the brain.

Conclusions:

• The proposed method accurately quantifies choline content in biological samples.
• This technique is user-friendly, computationally inexpensive, and easily implementable across different centers.
• The absolute quantification of choline can significantly improve the diagnostic accuracy in oncology.