title: Oximetric angiosome imaging in diabetic feet.
abstract: To develop a noncontrast oximetric angiosome imaging approach to assess skeletal muscle oxygenation in diabetic feet.
  
  
  
  In four healthy and five subjects with diabetes, the feasibility of foot oximetry was examined using a 3T clinical magnetic resonance imaging (MRI) scanner. The subjects' feet were scanned at rest and during a toe-flexion isometric exercise. The oxygen extraction fraction of skeletal muscle was measured using a susceptibility-based MRI method. Our newly developed MR foot oximetric angiosome model was compared with the traditional angiosome model in the assessment of the distribution of oxygen extraction fraction.
  
  
  
  Using the traditional angiosome during the toe-flexion exercise, the oxygen extraction fraction in the medial foot of healthy subjects increased (4.9 ± 3%) and decreased (-2.7 ± 4.4%) in subjects with diabetes (difference = 7.6%; 95% confidence interval = -13.7 ± 1.4; P = 0.02). Using the oximetric angiosome, the percent difference in the areas of oxygen extraction fraction within the 0.7-1.0 range (expected oxygen extraction fraction during exercise) between rest and exercise was higher in healthy subjects (8 ± 4%) than in subjects with diabetes (4 ± 4%; P = 0.02).
  
  
  
  This study demonstrates the feasibility of measuring skeletal muscle oxygen extraction fraction in the foot muscle during a toe-flexion isometric exercise. Instead of assessing oxygen extraction fraction in a foot muscle region linked to a supplying artery (traditional angiosome), the foot oximetric angiosome model assesses oxygen extraction fraction by its different levels in all foot muscle regions and thus may be more appropriate for assessing local ischemia in ulcerated diabetic feet. J. Magn. Reson. Imaging 2016. J. MAGN. RESON. IMAGING 2016;44:940-946.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA. zhengj@mir.wustl.edu.
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: David
authors.initials: D
authors.lastname: Muccigrosso
authors.affiliation: Department of Radiology, Peking University First Hospital, Beijing, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Hongyu
authors.initials: H
authors.lastname: An
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Coggan
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Bashir
authors.initials: B
authors.lastname: Adil
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Hildebolt
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Chandu
authors.initials: C
authors.lastname: Vemuri
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Geraghty
authors.affiliation: Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Hastings
authors.affiliation: Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mueller
mesh_terms: D000368:Aged; D017719:Diabetic Foot / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000378:metabolism*; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
chemical_list: D010100:Oxygen
keywords: angiosome; diabetic foot; magnetic resonance imaging; oxygen extraction fraction; skeletal muscle; susceptibility