title: Cross-sectional area measurements versus volumetric assessment of the quadriceps femoris muscle in patients with anterior cruciate ligament reconstructions.
abstract: OBJECTIVE
  Our aim was to validate the use of cross-sectional area (CSA) measurements at multiple quadriceps muscle levels for estimating the total muscle volume (TMV), and to define the best correlating measurement level.
  
  
  METHODS
  Prospective institutional review board (IRB)-approved study with written informed patient consent. Thighs of thirty-four consecutive patients with ACL-reconstructions (men, 22; women, 12) were imaged at 1.5-T using three-dimensional (3D) spoiled dual gradient-echo sequences. CSA was measured at three levels: 15, 20, and 25 cm above the knee joint line. TMV was determined using dedicated volumetry software with semiautomatic segmentation. Pearson's correlation and regression analysis (including standard error of the estimate, SEE) was used to compare CSA and TMV.
  
  
  RESULTS
  The mean ± standard deviation (SD) for the CSA was 60.6 ± 12.8 cm(2) (range, 35.6-93.4 cm(2)), 71.1 ± 15.1 cm(2) (range, 42.5-108.9 cm(2)) and 74.2 ± 17.1 cm(2) (range, 40.9-115.9 cm(2)) for CSA-15, CSA-20 and CSA-25, respectively. The mean ± SD quadriceps' TMV was 1949 ± 533.7 cm(3) (range, 964.0-3283.0 cm(3)). Pearson correlation coefficient was r = 0.835 (p < 0.01), r = 0.906 (p < 0.01), and r = 0.956 (p < 0.01) for CSA-15, CSA-20 and CSA-25, respectively. Corresponding SEE, expressed as percentage of the TMV, were 15.2%, 11.6% and 8.1%, respectively.
  
  
  CONCLUSIONS
  The best correlation coefficient between quadriceps CSA and TMV was found for CSA-25, but its clinical application to estimate the TMV is limited by a relatively large SEE.
  
  
  CONCLUSIONS
  • Cross-sectional area was used to estimate QFM size in patients with ACL-reconstruction • A high correlation coefficient exists between quadriceps CSA and volume • Best correlation was seen 25 cm above the knee joint line • A relatively large standard error of the estimate limits CSA application.
authors.affiliation: Department of Radiology, University Hospital Zurich, Ramistrasse 100, 8091, Zurich, Switzerland, magda.marcon@gmail.com.
authors.forename: Magda
authors.initials: M
authors.lastname: Marcon
authors.forename: Bernhard
authors.initials: B
authors.lastname: Ciritsis
authors.forename: Christoph
authors.initials: C
authors.lastname: Laux
authors.forename: Daniel
authors.initials: D
authors.lastname: Nanz
authors.forename: Thi Dan Linh
authors.initials: TD
authors.lastname: Nguyen-Kim
authors.forename: Michael A
authors.initials: MA
authors.lastname: Fischer
authors.forename: Gustav
authors.initials: G
authors.lastname: Andreisek
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Ulbrich
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007718:Knee Injuries / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009929:Organ Size / Q000502:physiology; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000033:anatomy & histology*; D013848:Thigh; D055815:Young Adult