title: Diagnosis of recurrent meniscal tears: prospective evaluation of conventional MR imaging, indirect MR arthrography, and direct MR arthrography.
abstract: OBJECTIVE
  To prospectively investigate the accuracy of conventional magnetic resonance (MR) imaging, direct MR arthrography, and indirect MR arthrography in assessment of possible recurrent or residual meniscal tears.
  
  
  METHODS
  Three hundred sixty-four patients who had previously undergone meniscal preservation surgery were prospectively examined with conventional MR imaging, indirect MR arthrography, and direct MR arthrography. Ninety-four patients (104 postoperative menisci) underwent subsequent second-look arthroscopic surgery. Each case was evaluated for (a) surfacing intrameniscal intermediate- or T1-weighted signal intensity, (b) surfacing intrameniscal T2-weighted signal intensity, (c) morphologic changes beyond those expected postoperatively, (d) joint effusion on conventional MR or indirect MR arthrographic studies, and (e) overall presence or absence of recurrent meniscal tear.
  
  
  RESULTS
  Seventy-one arthroscopically proved recurrent meniscal tears were found. In the diagnosis of recurrent meniscal tears, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 86%, 67%, 83%, 71%, and 80%, respectively, for conventional MR imaging; 83%, 78%, 90%, 64%, and 81%, respectively, for indirect MR arthrography; and 90%, 78%, 90%, 78%, and 85%, respectively, for direct MR arthrography. No significant difference in the diagnostic accuracy of one method relative to another was observed (P >.54). Surfacing intrameniscal T2-weighted signal intensity was the most specific sign, with the highest positive predictive value of a recurrent tear.
  
  
  CONCLUSIONS
  Although a small incremental increase in accuracy is associated with the use of direct MR arthrography over conventional MR imaging and indirect MR arthrography, no significant difference in diagnostic accuracy among the three techniques was demonstrated for detection of recurrent or residual meniscal tear.
authors.affiliation: Dept of Medical Imaging, Mount Sinai Hosp and Univ Health Network, Univ of Toronto, Toronto, Ontario, Canada. lwhite@mtsinai.on.ca
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: White
authors.forename: Mark E
authors.initials: ME
authors.lastname: Schweitzer
authors.forename: Dominik
authors.initials: D
authors.lastname: Weishaupt
authors.forename: Josef
authors.initials: J
authors.lastname: Kramer
authors.forename: Aileen
authors.initials: A
authors.lastname: Davis
authors.forename: Paul H
authors.initials: PH
authors.lastname: Marks
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001175:Arthrography / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000070600:Tibial Meniscus Injuries