title: Dynamic gadolinium-enhanced MRI of the proximal femur: preliminary experience in healthy children.
abstract: OBJECTIVE
  The purpose of this study is to use dynamic contrast-enhanced MRI to evaluate the perfusion characteristics of the proximal femur in the growing skeleton.
  
  
  METHODS
  We evaluated 159 subjects (mean age, 5.67 years) who underwent a well-controlled protocol of contrast-enhanced MRI of the abdomen and hips. Perfusion and permeability parameters (enhancement ratio peak, AUC, time to peak, and rate of extraction) for six regions of the proximal femur were calculated.
  
  
  RESULTS
  A decrease with age was found for all contrast kinetics parameters in all regions (p < 0.001). Perfusion parameters differed between the regions (p < 0.001). The highest perfusion and permeability parameters were found in the metaphyseal spongiosa, metaphyseal marrow, and periosteum. The metaphyseal spongiosa had a highly vascular pattern of enhancement and showed the highest enhancement ratio peak, AUC, and rate of extraction and the lowest time to peak. The metaphyseal marrow showed a vascular pattern of enhancement with a lower peak compared with the metaphyseal spongiosa. The periosteum showed prompt nonvascular contrast enhancement that reached a plateau that remained elevated.
  
  
  CONCLUSIONS
  The highest enhancement was seen in areas involved with growth: the metaphyseal spongiosa, which is related to endochondral ossification, and the periosteal cambium, which is related to membranous ossification. The enhancement characteristics are radically different: in the spongiosa; enhancement is brisk and declines, with a vascular pattern, whereas contrast uptake increases with time in the periosteum. Recognition of normal enhancement patterns of the proximal femur is important for distinguishing normal development from pathologic processes.
authors.affiliation: 1 Department of Radiology, The Children's Hospital of Philadelphia, 34th St and Civic Center Blvd, Philadelphia, PA 19104.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Bedoya
authors.forename: Camilo
authors.initials: C
authors.lastname: Jaimes
authors.forename: D'mitry
authors.initials: D
authors.lastname: Khrichenko
authors.forename: Jorge
authors.initials: J
authors.lastname: Delgado
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Dardzinski
authors.forename: Diego
authors.initials: D
authors.lastname: Jaramillo
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D002675:Child, Preschool; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology* / Q000502:physiology*; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006621:Hip Joint / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008954:Models, Biological; D010865:Pilot Projects; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: MRI; femur; growth plate; perfusion imaging; periosteum