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Abstract #3346

Probabilistic Averaging: An Instinctive Method of Averaging According to Data Confidence Applied to Cardiac 31P MRS

Lowri E. Cochlin1, Kieran Clarke1

1Cardiac Metabolism Research Group, University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford, United Kingdom


This work demonstrates an intuitive approach to weighting data according to precision achieved during quantification. Cardiac 31P-MRS is used as an example of data whose accurate fitting is often challenged by low SNR. The 1:1:1 ratio of ::-ATP peaks (excited uniformly with optimized RF-pulse, NAD and T1 corrected) constitutes three measures of the same molecule. Probability density functions generated for each integrated peak therefore combine as a weighted average representing a maximum likelihood estimate of the true value. Data from 11 healthy volunteers processed probabilistically demonstrated reduced variance in every PCr/ATP, and reduced inter-subject PCr/ATP spread, compared to standard weighting.