Assessment of Relative and Absolute Quantification Methods in Phosphorus Magnetic Resonance Spectroscopy

Introduction: Phosphorus (P) MRS measurements are typically reported as relative concentrations and less often as absolute concentrations. Absolute concentration methods include using internal or external references and phantom replacement methods. Relative concentration methods include ratios to PCr, the sum of the three ATP peaks, or the total phosphorus signal. This study compares three different methods of referencing phosphorus data and applies each referencing method to a subset of our control and patient schizophrenia data to test whether different referencing methods can lead to different significant findings.