title: Comparing an accelerated 3D fast spin-echo sequence (CS-SPACE) for knee 3-T magnetic resonance imaging with traditional 3D fast spin-echo (SPACE) and routine 2D sequences.
abstract: OBJECTIVE
  To compare a faster, new, high-resolution accelerated 3D-fast-spin-echo (3D-FSE) acquisition sequence (CS-SPACE) to traditional 2D and high-resolution 3D sequences for knee 3-T magnetic resonance imaging (MRI).
  
  
  METHODS
  Twenty patients received knee MRIs that included routine 2D (T1, PD ± FS, T2-FS; 0.5 × 0.5 × 3 mm3; ∼10 min), traditional 3D FSE (SPACE-PD-FS; 0.5 × 0.5 × 0.5 mm3; ∼7.5 min), and accelerated 3D-FSE prototype (CS-SPACE-PD-FS; 0.5 × 0.5 × 0.5 mm3; ∼5 min) acquisitions on a 3-T MRI system (Siemens MAGNETOM Skyra). Three musculoskeletal radiologists (MSKRs) prospectively and independently reviewed the studies with graded surveys comparing image and diagnostic quality. Tissue-specific signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were also compared.
  
  
  RESULTS
  MSKR-perceived diagnostic quality of cartilage was significantly higher for CS-SPACE than for SPACE and 2D sequences (p < 0.001). Assessment of diagnostic quality of menisci and synovial fluid was higher for CS-SPACE than for SPACE (p < 0.001). CS-SPACE was not significantly different from SPACE but had lower assessments than 2D sequences for evaluation of bones, ligaments, muscles, and fat (p ≤ 0.004). 3D sequences had higher spatial resolution, but lower overall assessed contrast (p < 0.001). Overall image quality from CS-SPACE was assessed as higher than SPACE (p = 0.007), but lower than 2D sequences (p < 0.001). Compared to SPACE, CS-SPACE had higher fluid SNR and CNR against all other tissues (all p < 0.001).
  
  
  CONCLUSIONS
  The CS-SPACE prototype allows for faster isotropic acquisitions of knee MRIs over currently used protocols. High fluid-to-cartilage CNR and higher spatial resolution over routine 2D sequences may present a valuable role for CS-SPACE in the evaluation of cartilage and menisci.
authors.affiliation: Department of Radiology, Northwestern University Feinberg School of Medicine, 676 N Saint Clair St Suite 800, Chicago, IL, 60611, USA. faysalaltahawi@gmail.com.
authors.forename: Faysal F
authors.initials: FF
authors.lastname: Altahawi
authors.affiliation: Department of Radiology, Northwestern University Feinberg School of Medicine, 676 N Saint Clair St Suite 800, Chicago, IL, 60611, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Blount
authors.affiliation: Department of Radiology, Marshfield Clinic, Marshfield, WI, USA.
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Morley
authors.affiliation: Siemens Healthcare GmbH, Erlangen, Germany.
authors.forename: Esther
authors.initials: E
authors.lastname: Raithel
authors.affiliation: Department of Radiology, Northwestern University Feinberg School of Medicine, 676 N Saint Clair St Suite 800, Chicago, IL, 60611, USA.
authors.forename: Imran M
authors.initials: IM
authors.lastname: Omar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
keywords: 2D vs. 3D MRI; 3-T knee MRI; 3D MRI; Accelerated MRI; Compressed sensing; Incoherent k-space undersampling; Knee MRI; Multiplanar reconstruction; Nonlinear SENSE-type reconstruction