Figure 1

Concept of multi-component phasor analysis and the effect of undersampling. (a) For modelled datasets of mono-exponential decays with different time constants the phasors end up on the semicircle (red dots) between 0 for slow and 1 for fast decays, while for bi-exponential decays with different ratios of their total integral the phasors reside on a line (blue dots) between the phasors on the semicircle of the two mono-exponential decays comprising the signal. (b) For three components, the combined phasors are located inside a triangle connecting the three references. Comparison of (c) the phasor plot for the full 2D quantitative T ₂ dataset consisting of 64 echo time steps of the cross section of the stem of a tomato plant to (d) the phasor plot of a subset of 16 echo times with reduced SNR by extracting echo step 2, 6, 10, …, 62 from the full dataset and (e) the phasor plot of a subset of 4 echo times with further reduced SNR by extracting echo time steps 4, 20, 36 and 52 from the full dataset.