title: Quantitative assessment of patellar cartilage volume and thickness at 3.0 tesla comparing a 3D-fast low angle shot versus a 3D-true fast imaging with steady-state precession sequence for reproducibility.
abstract: OBJECTIVE
  We sought to compare patellar cartilage volume and thickness measurement between 3D-FLASH and 3D-True fast imaging with steady-state precession (FISP) image data at 3.0 T.
  
  
  METHODS
  One knee each of 6 healthy adults was examined by axial magnetic resonance imaging (MRI) performed with a 3D-fast flow angle shot (FLASH) water-excitation sequence and a 3D-TrueFISP water-excitation sequence (spatial resolution 0.31 x 0.31 x 1.5 mm3). Patellar cartilage volume and mean/maximum thickness were calculated. Intraindividual/average reproducibility and interindividual variability were determined from 3 consecutive data sets acquired for each volunteer and sequence.
  
  
  RESULTS
  Patellar cartilage volume and thickness as well as reproducibility was slightly but not significantly lower for the 3D-TrueFISP data than for the 3D-FLASH data (volume: 3.4-6.3 mL (3D-FLASH)/3.1-6.0 mL (3D-TrueFISP), average reproducibility 1.8% (3D-FLASH)/4.4% (3D-TrueFISP); mean thickness: 2.1-2.8 mm (3D-FLASH)/1.9-2.6 mm (3D-TrueFISP), average reproducibility 2.8% (3D-FLASH)/3.8% (3D-TrueFISP); maximum thickness: 4.7-6.6 mm (3D-FLASH)/4.5-6.2 mm (3D-TrueFISP), average reproducibility 2.6% (3D-FLASH)/4.1% (3D-TrueFISP)). Interindividual variability was comparable for both sequence techniques.
  
  
  CONCLUSIONS
  At 3.0 T, the 3D-FLASH sequence showed tendency to be slightly superior to the 3D-TrueFISP sequence considering robust and valid assessment of quantitative cartilage parameters in young healthy adults, although there was found no significant statistical difference between both imaging techniques. However, in patients suffering from osteoarthritis (OA), the 3D-TrueFISP sequence might prove advantageous for monitoring of disease progression and evaluation of therapy success, particularly because the substantially higher signal to noise ratio/contrast to noise ratio values might allow for higher spatial resolution and hence for improvement of the accuracy of segmentation process especially at the articular surface.
authors.affiliation: Department of Clinical Radiology, Ludwig-Maximilians-University of Munich-Grosshadern, Germany. sabine.wechbach@med.uni-muenchen.de
authors.forename: Sabine
authors.initials: S
authors.lastname: Weckbach
authors.forename: Thomas
authors.initials: T
authors.lastname: Mendlik
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Horger
authors.forename: Susi
authors.initials: S
authors.lastname: Wagner
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Christian
authors.initials: C
authors.lastname: Glaser
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015588:Observer Variation; D010329:Patella / Q000033:anatomy & histology*; D015203:Reproducibility of Results