title: MRI versus bone scintigraphy. Evaluation for diagnosis and grading of stress injuries.
abstract: OBJECTIVE
  This study was set up to determine the value of magnetic resonance imaging (MRI) and bone scintigraphy (BS) for the diagnosis of stress injuries in athletes, and furthermore to assess reliability and prediction of healing time.
  
  
  METHODS
  Imaging data was analyzed retrospectively from 28 athletes who had received MRI and BS examinations for suspected stress injuries. MRI- and BS-data were rated by three specialists each in a blinded read, using a 5-point score (i.e. 0-4: inconspicuous to high-grade stress fracture). An interdisciplinary expert truth-panel set the reference standard. Standard statistical parameters, Fleiss' kappa (κ), and group comparisons were calculated.
  
  
  RESULTS
  The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for detection of stress injuries were 71.4%, 85.7%, 78.6%, 83.3% and, 75.0%, for MRI and 92.9%, 73.8%, 83.3%, 78.0% and, 91.2% for BS, respectively. Interobserver reliability for the diagnosis of a stress injury was κ = 0.9 for BS and κ = 0.85 for MRI. Mean healing times of mild (grades 1 and 2) and severe (grades 3 and 4) stress injuries were 88 days (d) versus 142d for BS and 57d versus 116d for MRI. No significant difference in healing time could be shown.
  
  
  CONCLUSIONS
  MRI and BS reliably detect stress injuries. MRI is to be recommended as the primary imaging modality due to its potential for assessment of differential diagnoses and the lack of radiation exposure, the value of BS lies in the exclusion of stress fractures after inconclusive MRI examinations.
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Leipziger Straße 44, 39120 Magdeburg, Germany. o.dobrindt@gmail.com
authors.forename: O
authors.initials: O
authors.lastname: Dobrindt
authors.forename: B
authors.initials: B
authors.lastname: Hoffmeyer
authors.forename: J
authors.initials: J
authors.lastname: Ruf
authors.forename: M
authors.initials: M
authors.lastname: Seidensticker
authors.forename: I G
authors.initials: IG
authors.lastname: Steffen
authors.forename: A
authors.initials: A
authors.lastname: Zarva
authors.forename: F
authors.initials: F
authors.lastname: Fischbach
authors.forename: G
authors.initials: G
authors.lastname: Wieners
authors.forename: C
authors.initials: C
authors.lastname: Furth
authors.forename: C H
authors.initials: CH
authors.lastname: Lohmann
authors.forename: H
authors.initials: H
authors.lastname: Amthauer
mesh_terms: D001265:Athletic Injuries / Q000175:diagnosis* / Q000628:therapy*; D004164:Diphosphonates; D005260:Female; D017102:Fracture Healing; D015775:Fractures, Stress / Q000175:diagnosis* / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D004164:Diphosphonates; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C033905:technetium Tc 99m 1,1-diphosphonopropane-2,3-dicarboxylic acid