title: Blinded-read of bone scintigraphy: the impact on diagnosis and healing time for stress injuries with emphasis on the foot.
abstract: OBJECTIVE
  This study evaluated the use of bone scintigraphy (BS) for the diagnosis of stress fractures in athletes and its validity for the prediction of healing time, with a focus on foot injuries.
  
  
  METHODS
  In our retrospective study, 84 athletes with a total of 93 suspected stress fractures (foot, n = 66; others, n = 27) were included. A blinded-read of BS was performed by 3 observers. The standard of reference was established by an interdisciplinary truth-panel using all imaging data (scintigraphic, radiographic, and magnetic resonance imaging) and follow-up data (>12 month). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosing stress fractures were calculated. Stress injuries were rated according to a 5-point grading score (0-4) and associated to the healing time.
  
  
  RESULTS
  For the diagnosis of stress injuries (n = 50/93), mean sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 97.3%, 67.4%, 77.7%, 95.6%, and 83.5%, respectively. Interobserver analysis showed a high agreement between all 3 readers (mean κ = 0.83). In univariate analysis healing time of grade 3 to 4 stress injuries was significantly higher (median, 87 days; interquartile range, 69-132 days) compared with grade 1 to 2 lesions (median, 63 days; interquartile range, 43-95 days; P = 0.0067). Moreover, healing time of scintigraphic high grade stress injuries was significantly longer in a general linear model with adjustment for cofactors (grade, 3-4 vs. 1-2; P = 0.033).
  
  
  CONCLUSIONS
  BS is a sensitive and reliable method for the diagnosis of stress injuries. In addition, the simplified classification for mild and severe stress injuries allows an estimation of healing time.
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Otto-von-Guericke Universität, Magdeburg, Germany. o.dobrindt@gmail.com
authors.forename: Oliver
authors.initials: O
authors.lastname: Dobrindt
authors.forename: Birgit
authors.initials: B
authors.lastname: Hoffmeyer
authors.forename: Juri
authors.initials: J
authors.lastname: Ruf
authors.forename: Ingo G
authors.initials: IG
authors.lastname: Steffen
authors.forename: Alina
authors.initials: A
authors.lastname: Zarva
authors.forename: Wolf S
authors.initials: WS
authors.lastname: Richter
authors.forename: Christian
authors.initials: C
authors.lastname: Furth
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ulrich
authors.forename: Oliver S
authors.initials: OS
authors.lastname: Grosser
authors.forename: Wolfram
authors.initials: W
authors.lastname: Neumann
authors.forename: Holger
authors.initials: H
authors.lastname: Amthauer
mesh_terms: D000293:Adolescent; D000328:Adult; D001265:Athletic Injuries / Q000000981:diagnostic imaging / Q000453:epidemiology; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D005260:Female; D005528:Foot / Q000000981:diagnostic imaging*; D018409:Foot Injuries / Q000000981:diagnostic imaging* / Q000453:epidemiology; D015775:Fractures, Stress / Q000000981:diagnostic imaging* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D011877:Radionuclide Imaging; D013997:Time Factors; D014945:Wound Healing; D055815:Young Adult