title: The use of axial reconstructed images from three-dimensional MRI datasets for morphological diagnosis of meniscal tears of the knee.
abstract: BACKGROUND
  In recent years, three-dimensional (3D) MRI has been utilized to detect meniscal tears and has displayed several advantages over 2D MRI. The diagnostic performance to discriminate the type of meniscal tears by 2D MRI (sagittal and coronal images) and axial images from 3D MRI datasets has not been reported yet. The aim of the present study is to evaluate the efficacy of the axial reconstructed images from 3D MRI datasets for the morphological diagnosis of meniscal tears of the knee.
  
  
  METHODS
  Seventy-four menisci in 37 patients who underwent arthroscopic surgery of the knee were studied. All patients were examined by 2D sagittal and coronal MRI and by axial images from 3D MRI datasets prior to surgery. First, we compared the diagnostic performance for meniscal tears by 2D sagittal and coronal MRI to that by axial images from 3D MRI datasets as judged by arthroscopic findings. Second, we compared the correlation of tear types presumed from 2D sagittal and coronal MRI to arthroscopy with those presumed from axial images from 3D MRI datasets to arthroscopy.
  
  
  RESULTS
  For the diagnostic performance of meniscal tears on 2D MRI, the sensitivity, specificity and accuracy were 93.5%, 88.4% and 90.5%, respectively. On axial images from 3D MRI, the sensitivity, specificity and accuracy were 96.8%, 79.1% and 86.5%, respectively. Nine cases were false-positive on axial images, while 5 cases were false-positive on 2D images. Correlations to arthroscopy were 100% by both scans for longitudinal tears and discoid meniscus tears. Only 29% were correctly diagnosed by 2D sagittal and coronal images for radial tears, however, all radial tears could be correctly diagnosed by axial images. All horizontal tears were correctly diagnosed on 2D sagittal and coronal images, while none of the horizontal tears could be correctly diagnosed from axial images.
  
  
  CONCLUSIONS
  Axial images from 3D MRI datasets were useful in the diagnosis of radial tears, but two limitations are noted concerning the use of axial images. First, medial menisci should be carefully read on axial slices because of the relatively high rate of false-positives on medial menisci. Second, axial images cannot discriminate horizontal tears from other types of meniscus tears.
authors.affiliation: Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan. t-ohishi@ken.ja-shizuoka.or.jp
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ohishi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Masashi
authors.initials: M
authors.lastname: Abe
authors.forename: Takuya
authors.initials: T
authors.lastname: Tsuchikawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Mori
authors.forename: Akira
authors.initials: A
authors.lastname: Nagano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001182:Arthroscopy; D002648:Child; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007718:Knee Injuries / Q000175:diagnosis* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019651:Plastic Surgery Procedures; D012421:Rupture; D012680:Sensitivity and Specificity; D000070600:Tibial Meniscus Injuries