title: Initial study on in vivo conductivity mapping of breast cancer using MRI.
abstract: OBJECTIVE
  To develop and apply a method to measure in vivo electrical conductivity values using magnetic resonance imaging (MRI) in subjects with breast cancer.
  
  
  METHODS
  A recently developed technique named MREPT (MR electrical properties tomography) together with a novel coil combination process was used to quantify the conductivity values. The overall technique was validated using a phantom study. In addition, 90 subjects were imaged (50 subjects with previously biopsy-confirmed breast tumor and 40 normal subjects), which was approved by our institutional review board (IRB). A routine clinical protocol, specifically a T2 -weighted FSE (fast spin echo) imaging data, was used for reconstruction of conductivity.
  
  
  RESULTS
  By employing the coil combination, the relative error in the conductivity map was reduced from ~70% to 10%. The average conductivity values in breast cancers regions (0.89 ± 0.33S/m) was higher compared to parenchymal tissue (0.43 S/m, P < 0.0001) and fat (0.07 S/m, P < 0.00005) regions. Malignant cases (0.89 S/m, n = 30) showed increased conductivity compared to benign cases (0.56 S/m, n = 5) (P < 0.05). In addition, invasive cancers (0.96 S/m) showed higher mean conductivity compared to in situ cancers (0.57 S/m) (P < 0.0005).
  
  
  CONCLUSIONS
  This study shows that conductivity mapping of breast cancers is feasible using a noninvasive in vivo MREPT technique combined with a coil combination process. The method may provide a tool in the MR diagnosis of breast cancer.
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Republic of Korea.
authors.forename: Jaewook
authors.initials: J
authors.lastname: Shin
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Biomedical Science, College of Medicine, Yonsei University, Seoul, Republic of Korea.
authors.forename: Joonsung
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Republic of Korea.
authors.forename: Yoonho
authors.initials: Y
authors.lastname: Nam
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Republic of Korea.
authors.forename: Min-Oh
authors.initials: MO
authors.lastname: Kim
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Republic of Korea.
authors.forename: Narae
authors.initials: N
authors.lastname: Choi
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sooyeon
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Republic of Korea.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001943:Breast Neoplasms / Q000473:pathology* / Q000503:physiopathology*; D004553:Electric Conductivity; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010865:Pilot Projects; D010992:Plethysmography, Impedance / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: breast cancer; electrical conductivity mapping; electrical properties; magnetic resonance; tomography