title: Evaluation of axillary lymph nodes by diffusion-weighted MRI using ultrasmall superparamagnetic iron oxide in patients with breast cancer: initial clinical experience.
abstract: OBJECTIVE
  To investigate the diagnostic performance and clinical feasibility of diffusion-weighted magnetic resonance imaging (MRI) using ultrasmall superparamagnetic iron oxide (USPIO) in the evaluation of axillary lymph nodes (ALNs) in patients with breast cancer.
  
  
  METHODS
  Sixteen patients with known breast cancer underwent 1.5 T MRI. Axial diffusion-weighted images (DWIs) and conventional T1- and T2*-weighted images (CIs) were acquired before and 24-36 hours after intravenous administration of USPIO. Detection of ALNs was evaluated on DWIs in comparison with CIs. The apparent diffusion coefficient values (ADCvs) of the nonmetastatic and metastatic nodes in precontrast DWIs were determined. The diagnostic performance of DWI using USPIO was compared with that of CIs using USPIO with pathological correlation.
  
  
  RESULTS
  Out of a total of 286 ALNs, 216/286 (76%) nodes were detected on DWIs and 238/286 (83%) on CIs. The differences in the ADCvs between metastatic and nonmetastatic nodes were not significant (P = 0.06). Sensitivity of CIs and DWIs using USPIO were respectively 70% and 83%, specificity 98% and 98%, and overall accuracy 93% and 95%.
  
  
  CONCLUSIONS
  Although the detection on DWIs of ALNs in patients with breast cancer was inferior compared to CIs, the sensitivity and accuracy of DWIs using USPIO were superior in the diagnosis of ALNs metastasis.
authors.affiliation: Department of Radiology, Osaka Medical College, Takatsuki City, Osaka, Japan. rad091@poh.osaka-med.ac.jp
authors.forename: Go
authors.initials: G
authors.lastname: Nakai
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Matsuki
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Harada
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Tanigawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.forename: Jelle
authors.initials: J
authors.lastname: Barentsz
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Narumi
mesh_terms: D000328:Adult; D001365:Axilla / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology* / Q000556:secondary*; D002277:Carcinoma; D003287:Contrast Media; D003911:Dextrans; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D058185:Magnetite Nanoparticles; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C097921:ferumoxtran-10