(C): Corrected Qp:Qs, (NC): Non-corrected Qp:Qs, WSR: Wilcoxon Signed Rank Test. 1. Null hypothesis: The median of Qp:Qs equals 1:1 (P < 0.05 rejects null hypothesis). 2. Null Hypothesis: The median of distribution between (NC) vs (C) equals "0" (P < 0.05 rejects null hypothesis). 3. Null Hypothesis: There is no significant difference between distribution of dichotomized Qp:Qs into clinically acceptable and not acceptable in (NC) vs. (C) (0.9:1.0 ≤ Qp:Qs ≤ 1.1:1.0 was set as clinically acceptable). 4. Platform 2 and 3 are two different background phase correction algorithms in a same post-processing package, thus sharing the same non-corrected data.