title: Diagnostic Performance of Fused Diffusion-Weighted Imaging Using T1-Weighted Imaging for Axillary Nodal Staging in Patients With Early Breast Cancer.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of fused diffusion-weighted imaging (DWI) using T1-weighted imaging (T1WI) for axillary nodal staging in patients with early breast cancer (stage I or II).
  
  
  METHODS
  We enrolled 149 axillae in 147 consecutive patients who performed preoperative breast magnetic resonance imaging (MRI) and definitive surgery. All patients underwent T2-weighted imaging (T2WI), fused DWI using T1WI, and non-fat-suppressed (non-FS) T1WI. Two radiologists scored each axillary nodal status by using a 5-point scale and independently measured the apparent diffusion coefficient (ADC) values of the most suspicious lymph node and an index tumor. Diagnostic performance was calculated on a patient-by-patient basis.
  
  
  RESULTS
  Macrometastasis was present in 26.2%, micrometastasis in 7.4%, and benign lymph nodes in 66.4%. Area under the receiver operating characteristic curves (AUCs) of both readers for predicting axillary lymph node metastasis were 0.676 and 0.603 for non-FS T1WI, 0.749 and 0.727 for T2WI, 0.838 and 0.790 for fused DWI, and 0.868 and 0.837 for the combined reading using ADC. AUCs of tumor ADC were 0.709 and 0.737, whereas those of lymph node ADC were 0.818 and 0.781 for both readers. With stepwise addition of tumor ADC, lymph node ADC, and lymphovascular invasion status to the fused DWI, the AUCs gradually increased from 0.838, 0.892, and 0.908 to 0.924 for reader 1 and from 0.790, 0.863, and 0.901 to 0.908 for reader 2.
  
  
  CONCLUSIONS
  Fused DWI using T1WI showed better diagnostic performance than conventional T2WI and non-FS T1WI for the prediction of lymph node metastasis.
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: So Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea. Electronic address: docshin@amc.seoul.kr.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Shin
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Ki Chang
authors.initials: KC
authors.lastname: Shin
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Chae
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Woo Jung
authors.initials: WJ
authors.lastname: Choi
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Cha
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Hak Hee
authors.initials: HH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D061206:Neoplasm Micrometastasis / Q000000981:diagnostic imaging; D009367:Neoplasm Staging / Q000379:methods*; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D012372:ROC Curve; D012189:Retrospective Studies
keywords: Axillary lymph node metastasis; Breast MRI; Breast neoplasm; Diffusion-weighted imaging; Fused MRI