Table 1.

RMSE, SNR and CR of the phantom study: C1 (largest sphere) t o C6 (smallest sphere).

	Baseline		Partially sampled			DL
	SNR	CR	RMSE%	SNR	CR	RMSE%	SNR	CR
C1	25.8	1	9.4	23.9	0.86	3.7	25.3	0.97
C2	25.4	0.96	12.3	22.9	0.86	5.6	24.5	0.96
C3	24.8	0.94	11.5	22.6	0.83	1.5	23.8	0.95
C4	21.2	0.71	13.6	18.4	0.73	7.0	17.8	0.81
C5	14.0	0.67	23.1	10.6	0.56	1.3	10.5	0.61
C6	7.9	0.49	21.2	3.2	0.10	4.8	7.4	0.19
Bkg			31.6			17.1
Lung insert		0.73			0.62			0.70

Abbreviations: RMSE, root-mean-square error; Bkg, background; TV, total variation; DL, dictionary learning