Table 2.

Similarity Measurements rs-EPI trace-weighted single-contrast—rs-EPI trace-weighted SMC (T₂*W $\alpha$ = 20°)^a

TrW	TR = 4500 ms				TR = 2250 ms
	PCC		SSIMb		PCC		SSIMb
Subject #	mean	stdev	mean	stdev	mean	stdev	mean	stdev
1	0.94	0.03	0.82	0.03	0.97	0.01	0.80	0.03
2	0.97	0.02	0.82	0.03	0.98	0.01	0.77	0.03
3	0.96	0.01	0.80	0.05	0.98	0.01	0.80	0.04
4	0.94	0.01	0.83	0.03	0.97	0.01	0.79	0.03

T2*W	TR = 4500 ms				TR = 2250 ms
	PCC		SSIMb		PCC		SSIMb
Subject #	Mean	stdev	Mean	stdev	Mean	stdev	Mean	stdev
1	0.95	0.04	0.74	0.04	0.97	0.01	0.73	0.05
2	0.94	0.05	0.73	0.06	0.97	0,01	0.72	0.05
3	0.92	0.07	0.68	0.07	0.97	0,01	0.72	0.06
4	0.95	0.03	0.70	0.04	0.97	0,01	0.71	0.05

^aCropped images in readout direction were used to limit influence of background noise

^bRegistered images were used for analysis

All p-values are < 0.0001, and therefore the measured similarity is significant at p < 0.05

PCC Pearson correlation coefficient, SSIM structural similarity index measure