title: An anatomical study of normal meniscal roots with isotropic 3D MRI at 3T.
abstract: OBJECTIVE
  To clarify the morphological features of normal meniscal roots on magnetic resonance (MR) imaging with an isotropic 3D proton density-weighted (PDW) sequence.
  
  
  METHODS
  3D PDW MR was performed in sixty-two patients at 3T before knee arthroscopy. MR images of 34 normal medial menisci and 33 intact lateral menisci confirmed by arthroscopy were retrospectively evaluated. MR signals, insertion sites, dimensions and courses of four meniscal roots were recorded.
  
  
  RESULTS
  The anterior root of medial meniscus (ARMM) was typically hypointense, while the posterior root of medial meniscus (PRMM) and the anterior root of lateral meniscus (ARLM) were prone to be hyperintense or showing a comblike signal, and the posterior root of lateral meniscus (PRLM) was usually hypointense or comblike on PDW MR images. ARMM and PRLM had more complex and diverse insertion patterns than ARLM and PRMM. There were significant statistical differences of the lengths, widths, heights and course angles among four meniscal roots (all P<0.001).
  
  
  CONCLUSIONS
  The signal intensity of each meniscal root can be hypointense, hyperintense, or comblike on 3D PDW MR images. ARMM and PRLM have more complex and diverse insertion patterns than ARLM and PRMM. The dimensions and courses of four meniscal roots all differ.
authors.affiliation: Department of Radiology, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, PR China. renahong@126.com
authors.forename: A-Hong
authors.initials: AH
authors.lastname: Ren
authors.forename: Zhuo-Zhao
authors.initials: ZZ
authors.lastname: Zheng
authors.forename: Yao
authors.initials: Y
authors.lastname: Shang
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Tian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001182:Arthroscopy; D002648:Child; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008592:Menisci, Tibial / Q000033:anatomy & histology*; D008875:Middle Aged; D012189:Retrospective Studies