title: SWIFT MRI enhances detection of breast cancer metastasis to the lung.
abstract: OBJECTIVE
  To evaluate the capability of longitudinal MR scans using sweep imaging with Fourier transformation (SWIFT) to detect breast cancer metastasis to the lung in mice.
  
  
  METHODS
  Mice with breast cancer metastatic to the lung were generated by tail vein injection of MDA-MB-231-LM2 cells. Thereafter, MR imaging was performed every week using three different pulse sequences: SWIFT [echo time (TE) ∼3 μs], concurrent dephasing and excitation (CODE; TE ∼300 μs), and three-dimensional (3D) gradient echo (GRE; TE = 2.2 ms). Motion during the long SWIFT MR scans was compensated for by rigid-body motion correction. Maximum intensity projection (MIP) images were generated to visualize changes in lung vascular structures during the development and growth of metastases.
  
  
  RESULTS
  SWIFT MRI was more sensitive to signals from the lung parenchyma than CODE or 3D GRE MRI. Metastatic tumor growth in the lungs induced a progressive increase in intensity of parenchymal signals in SWIFT images. MIP images from SWIFT clearly visualized lung vascular structures and their disruption due to progression of breast cancer metastases in the lung.
  
  
  CONCLUSIONS
  SWIFT MRI's sensitivity to fast-decaying signals and tolerance of magnetic susceptibility enhances its effectiveness at detecting structural changes in lung parenchyma and vasculature due to breast cancer metastases in the lung.
authors.affiliation: Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Naoharu
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Djaudat
authors.initials: D
authors.lastname: Idiyatullin
authors.forename: Curt
authors.initials: C
authors.lastname: Corum
authors.forename: Joseph
authors.initials: J
authors.lastname: Weber
authors.forename: Michael
authors.initials: M
authors.lastname: Garwood
authors.forename: Deepali
authors.initials: D
authors.lastname: Sachdev
mesh_terms: D000818:Animals; D016477:Artifacts; D045744:Cell Line, Tumor; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008137:Longitudinal Studies; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008325:Mammary Neoplasms, Experimental / Q000175:diagnosis*; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation
keywords: breast cancer metastasis; concurrent dephasing and excitation (CODE); lung MRI; rigid body motion correction; sweep imaging with Fourier transformation (SWIFT); ultrashort TE