title: Muscle MRI in patients with long-chain fatty acid oxidation disorders.
abstract: BACKGROUND
  Muscle magnetic resonance imaging (MRI) is a useful tool for visualizing abnormalities in neuromuscular disorders. The value of muscle MRI has not been studied in long-chain fatty acid oxidation (lcFAO) disorders. LcFAO disorders may present with metabolic myopathy including episodic rhabdomyolysis.
  
  
  OBJECTIVE
  To investigate whether lcFAO disorders are associated with muscle MRI abnormalities.
  
  
  METHODS
  Lower body MRI was performed in 20 patients with lcFAO disorders, i.e. three carnitine palmitoyltransferase 2 deficiency (CPT2D), 12 very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), three mitochondrial trifunctional protein deficiency (MTPD) and two isolated long-chain hydroxyacyl-CoA dehydrogenase deficiency (LCHADD).
  
  
  RESULTS
  At the time of MRI, four patients had muscle weakness, 14 had muscle pain and 13 were exercise intolerant. Median creatine kinase (CK) level of patients at the day of MRI was 398 U/L (range 35-12,483). T1W and STIR signal intensity (SI) were markedly increased in MTPD patients from girdle to lower leg. VLCADD patients showed predominantly proximal T1W SI changes, whereas LCHADD patients mostly showed distal T1W SI changes. Prominent STIR weighted signal intensity increases of almost all muscle groups were observed in patients with VLCADD and LCHADD with very high CK (>11.000) levels.
  
  
  CONCLUSIONS
  lcFAO disorders are associated with specific patterns of increased T1W and STIR signal intensity. These patterns may reflect lipid accumulation and inflammation secondary to lcFAO defects and progressive muscle damage. Future studies are needed to investigate whether muscle MRI might be a useful tool to monitor disease course and to study pathogenesis of lcFAO related myopathy.
authors.affiliation: Department of Paediatric Gastroenterology and Metabolic Diseases, Wilhelmina Children's Hospital, UMC Utrecht, KC 03.063.0, Lundlaan 6, 3584 EA, Utrecht, The Netherlands.
authors.forename: Eugene F
authors.initials: EF
authors.lastname: Diekman
authors.forename: W Ludo
authors.initials: WL
authors.lastname: van der Pol
authors.forename: Rutger A J
authors.initials: RA
authors.lastname: Nievelstein
authors.forename: Sander M
authors.initials: SM
authors.lastname: Houten
authors.forename: Frits A
authors.initials: FA
authors.lastname: Wijburg
authors.forename: Gepke
authors.initials: G
authors.lastname: Visser
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000172:deficiency*; D044942:Acyl-CoA Dehydrogenase, Long-Chain / Q000172:deficiency*; D000293:Adolescent; D000328:Adult; D009202:Cardiomyopathies / Q000473:pathology*; D002334:Carnitine O-Palmitoyltransferase / Q000172:deficiency*; D002648:Child; D002675:Child, Preschool; D000080984:Congenital Bone Marrow Failure Syndromes; D003402:Creatine Kinase / Q000097:blood; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D006801:Humans; D008052:Lipid Metabolism, Inborn Errors / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008661:Metabolism, Inborn Errors / Q000473:pathology*; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000473:pathology*; D017240:Mitochondrial Myopathies / Q000473:pathology*; D063991:Mitochondrial Trifunctional Protein / Q000172:deficiency; D018482:Muscle, Skeletal / Q000473:pathology*; D009135:Muscular Diseases / Q000473:pathology*; D009422:Nervous System Diseases / Q000473:pathology*; D010084:Oxidation-Reduction; D012206:Rhabdomyolysis / Q000473:pathology*
chemical_list: D005227:Fatty Acids; D015094:3-Hydroxyacyl CoA Dehydrogenases; D044942:Acyl-CoA Dehydrogenase, Long-Chain; D063991:Mitochondrial Trifunctional Protein; D002334:Carnitine O-Palmitoyltransferase; D003402:Creatine Kinase