From 04742ed049f7d0e738335cce5399894c709f1b5a Mon Sep 17 00:00:00 2001 From: Martin Wilson Date: Fri, 13 Dec 2024 12:01:14 +0000 Subject: [PATCH] updated relaxation notes --- R/amp_scaling.R | 64 +++++++++++++++++++++++++++---------------------- 1 file changed, 35 insertions(+), 29 deletions(-) diff --git a/R/amp_scaling.R b/R/amp_scaling.R index bddbe472..1780022d 100644 --- a/R/amp_scaling.R +++ b/R/amp_scaling.R @@ -350,37 +350,43 @@ scale_amp_ratio_value <- function(fit_result, value) { get_corr_factor <- function(te, tr, B0, gm_vol, wm_vol, csf_vol) { # Correction factor calculated according to the method of Gasparovic et al # (MRM 55:1219-1226 2006) - if ((B0 == 3.0) | (B0 == 2.9)) { - # Wanasapura values given in Harris paper - t1_gm <- 1.331 - t2_gm <- 0.110 - t1_wm <- 0.832 - t2_wm <- 0.0792 - t1_csf <- 3.817 - t2_csf <- 0.503 - t1_metab <- 1.15 - t2_metab <- 0.3 - } else if (B0 == 1.5) { - # values from Gasparovic 2006 MRM paper - t1_gm <- 1.304 - t2_gm <- 0.093 - t1_wm <- 0.660 - t2_wm <- 0.073 - t1_csf <- 2.93 - t2_csf <- 0.23 - t1_metab <- 1.15 - t2_metab <- 0.3 + # see online docs for references to these numbers + + if (B0 == 1.5) { + t1_gm <- 1.304 # Gasparovic et al, page 1223 + t2_gm <- 0.093 # Gasparovic et al, page 1223 + t1_wm <- 0.660 # Gasparovic et al, page 1223 + t2_wm <- 0.073 # Gasparovic et al, page 1223 + t1_csf <- 2.39 # Ibrahim et al, Abstract + t2_csf <- 0.23 # Ibrahim et al, Abstract + t1_metab <- 1.153 # Gasparovic et al, page 1223 + # (1.28+1.09+1.09)/3 + t2_metab <- 0.347 # Gasparovic et al, page 1223 + # (0.34+0.35+0.35)/3 + } else if ((B0 == 3.0) | (B0 == 2.9)) { + t1_gm <- 1.331 # Wansapura et al, Table 7 + t2_gm <- 0.110 # Wansapura et al, Table 2 + t1_wm <- 0.832 # Wansapura et al, Table 7 + t2_wm <- 0.0796 # Wansapura et al, Table 2 + t1_csf <- 3.817 # Lu et at, Discussion + t2_csf <- 0.503 # Piechnik et al, Table 1 + t1_metab <- 1.317 # Mlynarik et al, Table 1 + # (1.47+1.46+1.30+1.35+1.24+1.08)/6 + t2_metab <- 0.207 # Mlynarik et al, Table 2 + # (247+152+207+295+156+187)/6000 + } else if (B0 == 7.0) { + t1_gm <- 2.132 # Rooney et al, Table 1 + t2_gm <- 0.050 # Bartha et al, Table 1, LASER + t1_wm <- 1.220 # Rooney et al, Table 1 + t2_wm <- 0.055 # Bartha et al, Table 1, LASER + t1_csf <- 4.425 # Rooney et al, Table 1 + t2_csf <- 1.050 # Spijkerman et al, supp. materials S3, 1x1x4 + t1_metab <- 1.583 # Li et al, Table 1 + # (1.24+1.78+1.73)/3 + t2_metab <- 0.141 # Li et al, Table 1 + # (131+121+170)/3000 } else { warning("Error. Relaxation values not available for this field strength. Assuming values for 3 Telsa.") - # Wanasapura values given in Harris paper - t1_gm <- 1.331 - t2_gm <- 0.110 - t1_wm <- 0.832 - t2_wm <- 0.0792 - t1_csf <- 3.817 - t2_csf <- 0.503 - t1_metab <- 1.15 - t2_metab <- 0.3 } # MR-visible water densities