title: Subtraction of in-phase and opposed-phase images in dynamic MR mammography.
abstract: OBJECTIVE
  To develop and to evaluate an advanced image acquisition and analysis method for collecting T(1)-weighted dynamic 3D MR mammography data sets by using a combined in-phase (IP) and opposed-phase (OP) imaging procedure.
  
  
  METHODS
  3D MR mammography data sets were acquired by applying an interleaved gradient-echo OP and IP imaging sequence during administration of contrast agent. A phantom data set, two volunteer breast data sets, and six patient breast data sets were recorded. Subtraction of dynamic in-phase magnitude images was performed for clinical assessment. In addition, the magnitude subtraction (SIPOP) as well as the complex subtraction (cSIPOP) of the IP and OP magnitude and phase images were considered.
  
  
  RESULTS
  The detection of small lesions, lesion boundaries, and tumor offshoots in fatty tissue was improved by the subtraction of IP and OP images without the risk of signal cancellation due to partial volume effects.
  
  
  CONCLUSIONS
  Dynamic MR mammography acquisition of IP and OP images in combination with appropriate data processing yields important supplementary information that can support routinely applied diagnostics of breast lesions that are fully embedded in fatty tissue by only marginally increasing acquisition time.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University, D-07743 Jena, Germany. juergen.reichenbach@med.uni-jena.de
authors.forename: Jürgen R
authors.initials: JR
authors.lastname: Reichenbach
authors.forename: Jens
authors.initials: J
authors.lastname: Hopfe
authors.forename: Alexander
authors.initials: A
authors.lastname: Rauscher
authors.forename: Susanne
authors.initials: S
authors.lastname: Wurdinger
authors.forename: Werner A
authors.initials: WA
authors.lastname: Kaiser
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D019047:Phantoms, Imaging; D013382:Subtraction Technique