Repeatability assessment of sodium (23Na) MRI at 7.0 T in healthy human calf muscle and preliminary results on tissue sodium concentrations in subjects with Addison’s disease

Table 4 Tissue sodium concentration (TSC) determined after external (B₀) and local (B₁) field inhomogeneity corrections and partial volume effect (PVE) in healthy subjects in different muscle regions and during three imaging sessions (measurements), M1, M2, and M3

Subject number↓ Muscle type →	TSC [mmol/L]—M1			TSC [mmol/L]—M2			TSC [mmol/L]—M3
Subject number↓ Muscle type →	GM	TA	S	GM	TA	S	GM	TA	S
1	20.2 ± 0.8	13.4 ± 0.7	12.2 ± 0.8	21.0 ± 0.8	13.2 ± 0.2	12.7 ± 0.3	20.0 ± 0.3	13.2 ± 0.2	12.8 ± 0.3
2	20.5 ± 0.9	13.7 ± 0.9	12.9 ± 0.9	20.8 ± 0.4	14.0 ± 0.8	12.5 ± 0.2	20.5 ± 1.0	13.2 ± 1.0	12.7 ± 1.0
3	19.9 ± 0.2	14.6 ± 1.0	13.2 ± 0.4	19.8 ± 0.6	14.8 ± 1.0	13.0 ± 1.0	19.6 ± 2.0	14.6 ± 0.8	12.6 ± 0.7
4	20.8 ± 0.5	14.0 ± 0.4	12.5 ± 0.9	20.5 ± 1.0	14.5 ± 0.6	12.8 ± 0.9	20.0 ± 0.8	13.9 ± 0.9	13.1 ± 0.7
5	20.0 ± 0.8	14.9 ± 0.2	13.1 ± 1.0	19.6 ± 0.8	14.0 ± 0.5	12.2 ± 0.2	19.4 ± 1.0	13.5 ± 0.5	12.5 ± 0.2
6	19.5 ± 1.0	13.8 ± 1.0	13.9 ± 0.5	20.0 ± 2.0	13.1 ± 0.1	13.5 ± 0.5	20.8 ± 0.9	13.7 ± 0.7	13.4 ± 0.4
7	19.9 ± 0.9	13.5 ± 0.5	12.9 ± 1.0	19.6 ± 1.0	13.6 ± 0.6	12.7 ± 0.7	19.7 ± 0.6	13.3 ± 0.6	12.0 ± 0.5
8	19.5 ± 0.8	13.7 ± 1.0	12.1 ± 0.4	19.5 ± 0.9	13.0 ± 0.7	11.7 ± 0.8	19.4 ± 2.0	13.5 ± 0.1	11.1 ± 0.3
9	19.0 ± 0.2	14.1 ± 0.7	11.5 ± 0.8	19.5 ± 1.0	14.2 ± 0.6	12.6 ± 0.2	19.0 ± 0.5	13.5 ± 0.4	11.0 ± 0.6
10	19.8 ± 0.5	14.4 ± 0.8	12.2 ± 0.2	19.0 ± 0.7	14.0 ± 0.2	12.9 ± 1.0	19.8 ± 0.9	14.3 ± 1.0	12.8 ± 1.0
11^a	9.6 ± 0.6	7.7 ± 0.7	7.2 ± 0.8
12^a	10.7 ± 0.8	8.0 ± 0.8	7.1 ± 1.0
13^a	11.1 ± 0.8	9.0 ± 1.0	7.1 ± 2.0
14^a	10.8 ± 0.9	8.8 ± 2.0	7.4 ± 0.5
15^a	8.8 ± 1.0	8.7 ± 0.9	7.3 ± 0.4

G Gastrocnemius, M1, M2, M3 the first session, the second, and the third imaging session, respectively, S Soleus, TA Tibialis anterior, TSC Tissue sodium concentration
^aAddison’s patient

ISSN: 1471-2474