Table 2. MR imaging and spectroscopy phenotypes in dystrophinopathies.

Reference	Study Description	Assay	Study population	Findings in dystrophy	Our findings in mdx
Banerjee [57]	DMD vs. controls; effects of creatine	31P NMR Spectroscopy	DMD; 27 patients, 8 controls	PCr is lower & Pi is higher in DMD	PCr is lower and Pi higher in 6 week mdx
Forbes [58]	Ambulant DMD vs. controls	T2 MR Imaging	DMD; 30 patients, 10 controls	CSAmax higher in DMD (MG, Sol, ST)	CSAmax up for mdx in all weeks (leg & thigh)
Kinali [13]	Leg muscle of DMD	T2 MR Imaging	DMD; 34 patients	Non-muscle content and fat higher in DMD	Non-muscle higher in mdx muscle in all weeks
Newman [15]	Forearms of DMD vs. controls	1H NMR Spectroscopy	DMD; 6 patients aged 9–15 years	Fat content higher in DMD	No fatty infiltration visible in mdx
Kim [12]	T1 and FS imaging of DMD pelvic muscles	Fat-Suppressed T2 Imaging	DMD; 42 patients	DMD Edema; GMa, VL, GMe most frequent	Inflammation and muscle damage present in mdx
Dunn [53]	Quantitative MRI of mdx vs. WT	T2 Mapping	mdx; 32–48 weeks	T2 decrease, 1H density & water increase	Inflammation and muscle damage present in mdx
Zhang [29]	Cardiac function and metabolism in mdx	MRI & ex vivo 31P NMR Spec	mdx and WT; 32 weeks	Decreased PCr in heart; RV & LV defects	Decreased PCr in skeletal muscle
McIntosh [34]	Crush injury and mdx vs. controls	T2 images	mdx; 8–10 weeks	Dystrophic foci seen; muscle changes over 21 days post-injury	Changes in natural mdx lesions between 2 to 4 week intervals
Stuckey [45]	Cardiac morphology and function in mdx vs. controls	Longitudinal cardiac & Gd MRI	mdx; 4–52 weeks	RV Dysfunction by 1 & LV by 12 months; fibrosis by 6 months	Heart fibrosis after 6 months; 8 weeks if dosed with prednisone[4]
Pratt [55]	Case study of a single mdx leg	MRI	One single mdx mouse; 5–80 weeks	Peak in MRI hetero-geneity, recovery after 13 weeks	Peak phenotypes in necrotic phase, damage persists at 8–12 weeks
Straub [46]	Agent-enhanced MRI of mdx and Sgca−/− mice	MS-325 agent MRI	mdx & Sgca−/−; 8–10 weeks	Enhances dystrophic muscle contrast
Amthor [47]	Albumin targeting of dystrophic muscle	Gd enhanced MRI	mdx; 11–13 weeks	HSA targets to dystrophic muscle
Odintsov [48]	MRI detection of transplanted stem cells	MRI of labeled stem cells	mdx and dKO; 5–30 weeks	MRI tracks Fe-labeled stem cells short-term
Martins-Bach [51]	Metabolic profiling of mdx muscle	In vitro 1H NMR Spec	Lysates of mdx muscle; 12–24 weeks	Identified metabolites altered in mdx lysates
Xu [52]	Metabolic changes in muscle after injury	1H NMR Spec	Injured WT & mdx TAs; 8 weeks	Intramuscular lipids increase post injury	Energetics deficit in necrotic phase
Mathur [54]	Effects of exercise on T2 values in muscle	T2 Mapping	mdx and WT; 20–60 weeks	T2, affected area up in mdx & after running	Affected area increased in necrotic phase
Walter [33]	Gene therapy effects on dystrophic muscle	T2 Mapping	mdx & γsg−/−mice; 1 year post-therapy	MRI tracks gene therapy efficacy in mdx	6 week mdx leg provides best stat power

Abbreviations: CSAmax, maximum cross-sectional area; FS, fat suppressed T2; Gd, gadolinium; GMa, gluteus maximus; GMed, gluteus medius; HSA, human serum albumin; MR, Magnetic Resonance; MG, medial gastrocnemius; PCr, phosphocreatine; RV, right ventricular; Sg, Sarcoglycan; Sgca, Sarcoglycan alpha; Sol, soleus; ST, semitendinosus; tATP, total adenosine triphosphate; VL, vastus lateralis; WT, wild-type.