title: Is dynamic contrast-enhanced MRI useful for assessing proximal fragment vascularity in scaphoid fracture delayed and non-union?
abstract: OBJECTIVE
  To assess dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) as a measure of vascularity in scaphoid delayed-union or non-union.
  
  
  METHODS
  Thirty-five patients (34 male, one female; mean age, 27.4 ± 9.4 years; range, 16-51 years) with scaphoid delayed-union and non-union who underwent DCE MRI of the scaphoid between September 2002 and October 2012 were retrospectively reviewed. Proximal fragment vascularity was classified as good, fair, or poor on unenhanced MRI, contrast-enhanced MRI, and DCE MRI. For DCE MRI, enhancement slope, Eslope comparison of proximal and distal fragments was used to classify the proximal fragment as good, fair, or poor vascularity. Proximal fragment vascularity was similarly graded at surgery in all patients. Paired t test and McNemar test were used for data comparison. Kappa value was used to assess level of agreement between MRI findings and surgical findings.
  
  
  RESULTS
  Twenty-five (71 %) of 35 patients had good vascularity, four (11 %) had fair vascularity, and six (17 %) had poor vascularity of the proximal scaphoid fragment at surgery. DCE MRI parameters had the highest correlation with surgical findings (kappa = 0.57). Proximal scaphoid fragments with surgical poor vascularity had a significantly lower Emax and Eslope than those with good vascularity (p = 0.0043 and 0.027). The sensitivity, specificity, positive and negative predictive value and accuracy of DCE MRI in predicting impaired vascularity was 67, 86, 67, 86, and 80 %, respectively, which was better than that seen with unenhanced and post-contrast MRI. Flattened time intensity curves in both proximal and distal fragments were a feature of protracted non-union with a mean time interval of 101.6 ± 95.5 months between injury and MRI.
  
  
  CONCLUSIONS
  DCE MRI has a higher diagnostic accuracy than either non-enhanced MRI or contrast enhanced MRI for assessing proximal fragment vascularity in scaphoid delayed-union and non-union. For proper interpretation of contrast-enhanced studies in scaphoid vascularity, one needs to incorporate the time frame between injury and MRI.
authors: Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong, SAR, People's Republic of China. alex@sunghim.com
authors: Alex W H
authors: AW
authors: Ng
authors: James F
authors: JF
authors: Griffith
authors: Mihra S
authors: MS
authors: Taljanovic
authors: Alvin
authors: A
authors: Li
authors: W L
authors: WL
authors: Tse
authors: P C
authors: PC
authors: Ho
mesh_terms: D000293:Adolescent; D000328:Adult; D003287:Contrast Media; D005260:Female; D050723:Fractures, Bone / Q000473:pathology*; D017759:Fractures, Malunited / Q000473:pathology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D021361:Scaphoid Bone / Q000098:blood supply* / Q000293:injuries* / Q000473:pathology; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine
references: Radiology. 1992 Feb;182(2):445-50
references: 1732963
references: J Hand Surg Br. 1995 Dec;20(6):726-35
references: 8770730
references: Acta Orthop Scand. 1992 Apr;63(2):216-8
references: 1590062
references: J Bone Joint Surg Am. 1989 Dec;71(10):1560-5
references: 2687282
references: Hand Clin. 2010 Feb;26(1):105-17
references: 20006249
references: Eur J Radiol. 2004 Jun;50(3):217-24
references: 15145480
references: J Bone Joint Surg Am. 1966 Sep;48(6):1125-37
references: 5917699
references: Radiology. 2005 Apr;235(1):168-75
references: 15703312
references: Eur J Radiol. 2011 Feb;77(2):222-7
references: 20965679
references: Skeletal Radiol. 2005 Jun;34(6):314-20
references: 15834565
references: Radiology. 1991 May;179(2):535-9
references: 2014306
references: Scand J Plast Reconstr Surg Hand Surg. 1999 Dec;33(4):423-6
references: 10614752
references: J Hand Surg Am. 1991 May;16(3):479-84
references: 1861031
references: J Orthop Sci. 2006 Jul;11(4):424-31
references: 16897211
references: J Hand Surg Am. 1985 Sep;10(5):597-605
references: 3900189
references: J Bone Joint Surg Br. 1999 Jul;81(4):596-9
references: 10463727
references: AJR Am J Roentgenol. 2000 Jan;174(1):141-9
references: 10628470
references: Magn Reson Imaging. 1990;8(4):357-61
references: 2392023
references: AJR Am J Roentgenol. 2010 Oct;195(4):W281-6
references: 20858790
references: Clin Orthop Relat Res. 2010 Apr;468(4):1066-71
references: 19669847
references: J Hand Surg Am. 1995 Sep;20(5):818-31
references: 8522751
references: J Bone Joint Surg Br. 2001 Aug;83(6):809-14
references: 11521919
references: Skeletal Radiol. 2011 May;40(5):517-21
references: 21359689
references: Hand Clin. 2011 Aug;27(3):291-307
references: 21871352
references: Radiology. 1986 Sep;160(3):689-93
references: 3737907
references: J Hand Surg Br. 1995 Apr;20(2):201-5
references: 7797970
references: J Bone Joint Surg Am. 1995 Jun;77(6):883-93
references: 7782361
references: Radiology. 2011 Sep;260(3):808-16
references: 21712471
references: J Hand Surg Br. 2004 Oct;29(5):444-8
references: 15336746
references: J Hand Surg Eur Vol. 2011 Jan;36(1):23-8
references: 20621936
references: Radiology. 1989 Jun;171(3):767-73
references: 2717749
references: J Hand Surg Am. 2000 Sep;25(5):849-59
references: 11040300
references: Tech Hand Up Extrem Surg. 2008 Jun;12(2):107-13
references: 18528238
references: J Hand Surg Am. 1993 Jul;18(4):669-74
references: 8349979
references: Acta Orthop Scand. 1997 Apr;68(2):124-7
references: 9174447
references: J Radiol. 2004 Oct;85(10 Pt 1):1699-706
references: 15669563
references: Skeletal Radiol. 2000 Mar;29(3):133-41
references: 10794550