Table 4. Summary of the serial age-corrected QSM observations. Statistical significance measured with Wilcoxon signed rank test (two-tailed). The assumption of paired sample was considered while calculating the effect sizes.

ROI	QSM (ppb)			Baseline ALS vs. 6 months
	Baseline ALS, mean ± SEM	6 months ALS, mean ± SEM		P value	Cohen’s d
Left primary motor area (anterior)	30±1.3	29.9±1.3		1	−0.03
Right primary motor area (anterior)	33.7±1.2	34.4±1.9		0.73	0.23
Left primary motor area (posterior)	31.2±1.6	29.9±1.4		0.05	−0.77
Right primary motor area (posterior)	31±1.5	31.3±2		0.91	0.13
Left pre-motor area	24.6±1.2	25.2±1.3		0.3	0.56
Right pre-motor area	25.1±1.4	25.7±1.4		0.05	0.76

QSM, quantitative susceptibility mapping; ALS, amyotrophic lateral sclerosis; SEM, standard error of the mean; ROI, region of interest.