Table 4.

Longitudinal changes in the osteonecrotic lesions in children observed with magnetic resonance imaging during the second year after alloHCT.

One year post alloHCT MR imaging results		Two year post alloHCT MR imaging results				Total
		Not done/Missing	Not Involved	ON; < 30% Epiphyseal involvement	ON; ≥ 30% Epiphyseal involvement
Hips:	Not done/Missing	12	2	0	0	14
	Not Involved	58	55	0	1∞	114
	ON; < 30% Epiphyseal involvement	0	0	1	0	1
	ON; ≥ 30% Epiphyseal involvement	3	0	1±	5	9
	Total	73	57	2	6	138
Knees:	Not done/Missing	6	2	0	1∞	9
	Not Involved	53	38	4∞	0	95
	ON; < 30% Epiphyseal involvement	7	4•	11	1	23
	ON; ≥ 30% Epiphyseal involvement	2	0	1±	8	11
	Total	68	44	16	10	138

Abbreviations: MR, magnetic resonance imaging; ON, osteonecrosis

^∞New cases identified with osteonecrosis during second year after allogeneic HCT

^±Case that showed regression in the size of the osteonecrosis lesions after allogeneic HCT

^•Cases that showed complete resolution