title: Feasibility and safety of perfusion MRI for Legg-Calvé-Perthes disease.
abstract: BACKGROUND
  Recent studies have suggested that perfusion magnetic resonance imaging (pMRI) using gadolinium contrast and a subtraction technique can provide useful prognostic information in Legg-Calvé-Perthes disease (LCPD) and allow earlier stratification for outcome. There are, however, sparse data available regarding the feasibility and safety of these studies in children. The purpose of this study was to collect this information across multiple centers using pMRI for LCPD.
  
  
  METHODS
  We retrospectively reviewed a consecutive series of patients with confirmed or suspected LCPD who had undergone pMRI at 1 of 5 large tertiary-care children's hospitals in the United States, UK, and Mexico. Demographic information, type of contrast administered, and requirement for sedation or anesthesia were noted. Records were scrutinized for adverse events associated with the pMRI protocol.
  
  
  RESULTS
  Over the study period, 165 patients underwent 298 pMRI studies. The median age at the time of imaging was 8.6 years (range, 2.5to 16.9 y). A total of 252 scans (85%) were performed for a known diagnosis of LCPD, whereas 46 were performed for a suspected diagnosis. Ninety-two of the 298 (31%) pMRIs required sedation, 48 (16%) required general anesthesia, and 122 (41%) were facilitated by video goggles only. The remaining 36 patients (12%) had their studies performed without additional measures. The ages of patients requiring sedation (mean, 7.2±2.4 y) and anesthesia (mean, 7.7±2.3 y) were significantly younger than those patients requiring neither (mean, 10.2±2.3 y, P<0.001). Four patients (1.3%) reported nausea or vomiting as a result of sedation. Two patients (0.7%) had complications from intravenous cannulation (pull out, difficult access). One child (0.3%) had nausea/vomiting as a result of contrast administration. There were no serious adverse events as a result of the pMRI protocol; specifically none of nephrogenic systemic fibrosis, anaphylaxis, or death.
  
  
  CONCLUSIONS
  pMRI is a safe and feasible imaging technique for LCPD. Almost half of our patients required either sedation or general anesthesia to complete the study.
  
  
  METHODS
  IV (case series).
authors.affiliation: *Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA †Bristol Royal Hospital for Children, Bristol, UK ‡Shriners Hospitals for Children, Mexico City, Mexico §Texas Scottish Rite Hospital for Children, Dallas, TX ∥Boston Children's Hospital, Boston, MA.
authors.forename: Wudbhav N
authors.initials: WN
authors.lastname: Sankar
authors.forename: Simon
authors.initials: S
authors.lastname: Thomas
authors.forename: Pablo
authors.initials: P
authors.lastname: Castañeda
authors.forename: Tiffany
authors.initials: T
authors.lastname: Hong
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Shore
authors.forename: Harry K W
authors.initials: HK
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007873:Legg-Calve-Perthes Disease / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies