title: MRI assessment of regional differences in phosphorus-31 metabolism and morphological abnormalities of the foot muscles in diabetes.
abstract: To assess differences in the phosphorus-31 (31P) metabolism and morphology in multiple muscle regions in the forefoot of diabetic patients and normal subjects.
  
  
  
  Fifteen diabetic patients and 15 normal subjects were assessed for muscle atrophy by1H magnetic resonance imaging (MRI) at 3T to grade the flexor hallucis, adductor hallucis, interosseous regions, and entire foot cross-section. Each region and the entire foot were also quantitatively evaluated for metabolic function using31P imaging for spatial mapping of the inorganic phosphate (Pi) to phosphocreatine (PCr) ratio (Pi/PCr). The ratio of viable muscle area to the predefined region areas (31P/1H) was calculated. The variability of each method was assessed by its coefficient of variation (CV).
  
  
  
  Muscle atrophy was significantly more severe in diabetic compared to normal subjects in all regions (P < 0.01). The31P/1H area ratio was significantly larger in the adductor hallucis than in the other two regions (P < 0.05). The Pi/PCr ratio was significantly different between the two groups in the flexor hallucis and interosseous regions (P < 0.05) but not adductor hallucis region. The CV for Pi/PCr ranged from 10.13 to 55.84, while it ranged from 73.40 to 263.90 for qualitative grading.
  
  
  
  Changes in atrophy and metabolism appear to occur unequally between different regions of the forefoot in diabetes. The adductor hallucis region appears more capable of maintaining structural and metabolic integrity than the flexor hallucis or interosseous regions. The CV analysis suggests that the quantitative31P methods have less variability than the qualitative grading. J. Magn. Reson. Imaging 2016;44:1132-1142.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School|Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Keelung and Chang Gung University, Taiwan
authors.forename: Yu-Ching
authors.initials: YC
authors.lastname: Lin
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School
authors.forename: Jim
authors.initials: J
authors.lastname: Wu
authors.affiliation: Microcirculation Laboratory and Joslin‐Beth Israel Deaconess Foot Center, the Beth Israel Deaconess Medical Center
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Baltzis
authors.affiliation: Microcirculation Laboratory and Joslin‐Beth Israel Deaconess Foot Center, the Beth Israel Deaconess Medical Center
authors.forename: Aristidis
authors.initials: A
authors.lastname: Veves
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School|RLG Scientific, Millis. MA
authors.forename: Robert L
authors.initials: RL
authors.lastname: Greenman
mesh_terms: D017719:Diabetic Foot / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D005545:Forefoot, Human / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D057054:Molecular Imaging / Q000379:methods*; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D010758:Phosphorus / Q000493:pharmacokinetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
chemical_list: D010758:Phosphorus
keywords: diabetic foot; magnetic resonance spectroscopy; multinuclear imaging; muscle metabolism; musculosketetal MRI; phosphorus-31 imaging