MRI patterns of thigh muscle involvement in immune-mediated necrotizing myopathy and dermatomyositis

BMC Rheumatology

Table 1 Demographics, clinical features, and diagnostic results of participants

n	Group	Dz dur. ā MRI acqn (m)	Age (y), MRI acqn	Tx, ā/p̄ MRI acqn	Sex	CK (U/L)	Muscle Bx site	Histopathologic features	Ab	MRI seq.
1	IMNM	206	56	ā (17 y)	M	19,699	R VL	moderate MN, no I	SRP	T1W
2	IMNM	1	66	p̄	F	19,734	L quads	severe MN, mild perim. I	SRP	STIR
3	IMNM	74	46	ā (6 y)	F	4694	ND	--	SRP	T1W
4	IMNM	2	70	p̄	F	12,218	L quads	moderate MN, no I	HMGCR	STIR
5	IMNM	27	68	p̄	F	3403	ND	--	HMGCR	T2FS
6	IMNM	2	74	p̄	M	3188	ND	--	SRP	STIR
7	IMNM	3	67	p̄	F	15,530	R quads	mild MN, no I	HMGCR	STIR
8	IMNM	7	52	p̄	F	10,160	L RF	moderate MN, no I	SRP	STIR
9	IMNM	2	65	p̄	F	18,244	ND	--	HMGCR	STIR
10	IMNM	33	70	p̄	M	12,073	L deltoid	severe MN, no I	HMGCR	T1W
11	IMNM	4	72	p̄	F	6017	L quads	moderate MN, no I	HMGCR	T2FS
12	IMNM	2	78	p̄	M	11,025	L biceps	severe MN, no I	HMGCR	T2FS
13	IMNM	3	60	p̄	M	19,856	L quads	mild MN, no I	HMGCR	T2FS
14	IMNM	25	52	p̄	F	964	L deltoid	mild MN, no I	HMGCR	T2FS
15	DM	2	58	p̄	F	1535	L biceps	PA, MxA, MHC-1, moderate perim. I	TIF1-γ	T2FS
16	DM	10	49	p̄	F	178	L deltoid	PA, MxA, MHC-1, no I	SAE	T2FS
17	DM	2	73	p̄	F	4679	R thigh	PA, MHC-1, mod MN, mild perim. I	Mi-2	STIR
18	DM	0.5	43	p̄	F	6985	R thigh	PA, MxA, MHC-I, moderate MN, no I	NXP2	STIR
19	DM	1	65	p̄	F	15,242	L deltoid	PA, MxA, MHC-1, muscle infarct, perim. I	MSA/ MAA(-)	T2FS
20	DM	1	80	p̄	M	10,922	R VL	MxA, MHC-1, moderate MN, no I	NXP2	STIR
21	DM	3	68	p̄	M	7800	R thigh	PA, MxA, MHC-I, severe, MN, no I	Mi-2	T2FS
22	DM	2	73	p̄	F	710	ND	--	TIF1-γ	STIR
23	DM	6	9	p̄	F	273	ND	--	TIF1-γ	T2FS
24	DM	3	42	p̄	F	853	L quads	PA, MxA, MHC-1, mild perim. I	SAE	T2FS
25	DM	3	38	p̄	F	83	L quads	PA, MxA, MHC-1, mild perim. I	TIF1-γ	STIR

ā, before; Ab, antibody; acqn, acquisition; Bx, biopsy; CK, creatine kinase; DM, dermatomyositis; dur., duration; Dz, disease; HMGCR, HMG-CoA reductase; I, inflammation; IMNM, immune-mediated necrotizing myopathy; L, left; m, months; MHC-1, major histocompatibility complex class 1 myofiber upregulation; MAA, myositis-associated autoantibodies; MN, myofiber necrosis; MSA, myositis-specific autoantibodies; MxA, myxovirus resistance protein A staining; ND, not done; p̄, after; PA, perifascicular atrophy; perim., perimysial; quads, quadriceps; R, right; seq., sequence; SRP, signal recognition particle; STIR, short tau inversion recovery; T1W, T1 weighted; T2FS, T2 fat saturated; Tx, treatment; VL, vastus lateralis; y, years

ISSN: 2520-1026