Table 1. The criteria of visual grading method to assess the degree of liver iron overload.

Grade	Description	Criteria
		In-phase images	In-phase and out-of-phase images
0	Normal iron concentration	Liver signal intensity (SI) is greater than muscle SI	Liver SI of in-phase images and out-of-phase images is about the same
1	Minor iron overload	Liver SI is about as low as muscle SI	Liver SI of in-phase images is slightly lower than out-of-phase images
2	Moderate iron overload	Liver SI is lower than muscle SI, although not as low as the background noise	Liver SI of in-phase images is clearly lower than out-of-phase images
3	Severe iron overload	Liver SI is lower than muscle SI, and about as low as background noise	Liver SI of in-phase images is clearly lower than in out-of-phase images