title: DIfferential Subsampling with Cartesian Ordering (DISCO): a high spatio-temporal resolution Dixon imaging sequence for multiphasic contrast enhanced abdominal imaging.
abstract: OBJECTIVE
  To develop and evaluate a multiphasic contrast-enhanced MRI method called DIfferential Sub-sampling with Cartesian Ordering (DISCO) for abdominal imaging.
  
  
  METHODS
  A three-dimensional, variable density pseudo-random k-space segmentation scheme was developed and combined with a Dixon-based fat-water separation algorithm to generate high temporal resolution images with robust fat suppression and without compromise in spatial resolution or coverage. With institutional review board approval and informed consent, 11 consecutive patients referred for abdominal MRI at 3 Tesla (T) were imaged with both DISCO and a routine clinical three-dimensional SPGR-Dixon (LAVA FLEX) sequence. All images were graded by two radiologists using quality of fat suppression, severity of artifacts, and overall image quality as scoring criteria. For assessment of arterial phase capture efficiency, the number of temporal phases with angiographic phase and hepatic arterial phase was recorded.
  
  
  RESULTS
  There were no significant differences in quality of fat suppression, artifact severity or overall image quality between DISCO and LAVA FLEX images (P > 0.05, Wilcoxon signed rank test). The angiographic and arterial phases were captured in all 11 patients scanned using the DISCO acquisition (mean number of phases were two and three, respectively).
  
  
  CONCLUSIONS
  DISCO effectively captures the fast dynamics of abdominal pathology such as hyperenhancing hepatic lesions with a high spatio-temporal resolution. Typically, 1.1 × 1.5 × 3 mm spatial resolution over 60 slices was achieved with a temporal resolution of 4-5 s.
authors.affiliation: Department of Radiology, Stanford University, Stanford, California 94305, USA. manojsar@stanford.edu
authors.forename: Manojkumar
authors.initials: M
authors.lastname: Saranathan
authors.forename: Dan W
authors.initials: DW
authors.lastname: Rettmann
authors.forename: Brian A
authors.initials: BA
authors.lastname: Hargreaves
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Clarke
authors.forename: Shreyas S
authors.initials: SS
authors.lastname: Vasanawala
mesh_terms: D000005:Abdomen / Q000473:pathology*; D000008:Abdominal Neoplasms / Q000473:pathology*; D000328:Adult; D000465:Algorithms; D003287:Contrast Media; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D005682:Gadolinium