title: Comparison of dynamic contrast-enhanced MRI parameters of breast lesions at 1.5 and 3.0 T: a pilot study.
abstract: OBJECTIVE
  To compare dynamic contrast-enhanced (DCE) MRI parameters from scans of breast lesions at 1.5 and 3.0 T.
  
  
  METHODS
  11 patients underwent paired MRI examinations in both Philips 1.5 and 3.0 T systems (Best, Netherlands) using a standard clinical fat-suppressed, T1 weighted DCE-MRI protocol, with 70-76 s temporal resolution. Signal intensity vs time curves were fit with an empirical mathematical model to obtain semi-quantitative measures of uptake and washout rates as well as time-to-peak enhancement (TTP). Maximum percent enhancement and signal enhancement ratio (SER) were also measured for each lesion. Percent differences between parameters measured at the two field strengths were compared.
  
  
  RESULTS
  TTP and SER parameters measured at 1.5 and 3.0 T were similar; with mean absolute differences of 19% and 22%, respectively. Maximum percent signal enhancement was significantly higher at 3 T than at 1.5 T (p = 0.006). Qualitative assessment showed that image quality was significantly higher at 3 T (p = 0.005).
  
  
  CONCLUSIONS
  Our results suggest that TTP and SER are more robust to field strength change than other measured kinetic parameters, and therefore measurements of these parameters can be more easily standardized than measurements of other parameters derived from DCE-MRI. Semi-quantitative measures of overall kinetic curve shape showed higher reproducibility than do discrete classification of kinetic curve early and delayed phases in a majority of the cases studied.
  
  
  CONCLUSIONS
  Qualitative measures of curve shape are not consistent across field strength even when acquisition parameters are standardized. Quantitative measures of overall kinetic curve shape, by contrast, have higher reproducibility.
authors.affiliation: 1 Department of Radiology, University of Chicago, Chicago, IL, USA.
authors.forename: F D
authors.initials: FD
authors.lastname: Pineda
authors.forename: M
authors.initials: M
authors.lastname: Medved
authors.forename: X
authors.initials: X
authors.lastname: Fan
authors.forename: M K
authors.initials: MK
authors.lastname: Ivancevic
authors.forename: H
authors.initials: H
authors.lastname: Abe
authors.forename: A
authors.initials: A
authors.lastname: Shimauchi
authors.forename: G M
authors.initials: GM
authors.lastname: Newstead
authors.forename: G S
authors.initials: GS
authors.lastname: Karczmar
mesh_terms: D000328:Adult; D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D010865:Pilot Projects; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA