title: Recurrent inverted papilloma: diagnosis with pharmacokinetic dynamic gadolinium-enhanced MR imaging.
abstract: OBJECTIVE
  Dynamic gadolinium-enhanced MR imaging has been used successfully to identify post-treatment recurrence or postoperative changes in rectal and cervical carcinoma. Our purpose was to evaluate the usefulness of dynamic gadolinium-enhanced MR imaging for distinguishing recurrent inverted papilloma (IP) from postoperative changes.
  
  
  METHODS
  Fifteen patients with 20 pathologically proved lesions (recurrent IP, 12; fibrosis or granulation tissue, eight) were enrolled in the study. Three observers, blinded to pathologic results, independently evaluated conventional MR images, including T1-weighted (unenhanced and postcontrast), proton-density-weighted, and T2-weighted spin-echo images. Results then were determined by consensus. Dynamic images were obtained using fast spin-echo sequences at 5, 30, 60, 90, 120, 150, 180, and 300 seconds after the injection of gadolinium-diethylene-triamine penta-acetic acid. Time-signal intensity curves of suspected lesions were analyzed by a pharmacokinetic model. The calculated amplitude and tissue distribution time were used to characterize tissue, and their values were displayed as a color-coded overlay.
  
  
  RESULTS
  T2-weighted images yielded a sensitivity of 67%, a specificity of 75%, and an accuracy of 70% in the diagnosis of recurrent IP. Contrast-enhanced T1-weighted images yielded a sensitivity of 75%, a specificity of 50%, and an accuracy of 65%. Pharmacokinetic analysis showed that recurrent IP had faster (distribution time, 41 versus 88 seconds) and higher (amplitude, 2.4 versus 1.2 arbitrary units) enhancement than did fibrosis or granulation tissue. A cut-off of 65 seconds for distribution time and 1.6 units for amplitude yielded a sensitivity of 100% and a specificity of 100% for diagnosing recurrent IP.
  
  
  CONCLUSIONS
  Dynamic MR imaging can differentiate accurately recurrent IP from postoperative changes and seems to be a valuable diagnostic tool.
authors.affiliation: Department of Radiology, Veterans General Hospital-Kaohsiung, National Yang-Ming College, Taiwan, ROC, USA.
authors.forename: P H
authors.initials: PH
authors.lastname: Lai
authors.forename: C F
authors.initials: CF
authors.lastname: Yang
authors.forename: H B
authors.initials: HB
authors.lastname: Pan
authors.forename: M T
authors.initials: MT
authors.lastname: Wu
authors.forename: S T
authors.initials: ST
authors.lastname: Chu
authors.forename: L P
authors.initials: LP
authors.lastname: Ger
authors.forename: W C
authors.initials: WC
authors.lastname: Huang
authors.forename: C C
authors.initials: CC
authors.lastname: Hsu
authors.forename: C N
authors.initials: CN
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000493:pharmacokinetics*; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D009666:Nose / Q000473:pathology / Q000601:surgery; D009669:Nose Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D018308:Papilloma, Inverted / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D010255:Paranasal Sinus Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D010256:Paranasal Sinuses / Q000473:pathology / Q000601:surgery; D011183:Postoperative Complications / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA