title: Separate modal analysis for tumor detection with a digital image elasto tomography (DIET) breast cancer screening system.
abstract: OBJECTIVE
  It is estimated that every year, 1 × 10(6) women are diagnosed with breast cancer, and more than 410,000 die annually worldwide. Digital Image Elasto Tomography (DIET) is a new noninvasive breast cancer screening modality that induces mechanical vibrations in the breast and images its surface motion with digital cameras to detect changes in stiffness. This research develops a new automated approach for diagnosing breast cancer using DIET based on a modal analysis model.
  
  
  METHODS
  The first and second natural frequency of silicone phantom breasts is analyzed. Separate modal analysis is performed for each region of the phantom to estimate the modal parameters using imaged motion data over several input frequencies. Statistical methods are used to assess the likelihood of a frequency shift, which can indicate tumor location. Phantoms with 5, 10, and 20 mm stiff inclusions are tested, as well as a homogeneous (healthy) phantom. Inclusions are located at four locations with different depth.
  
  
  RESULTS
  The second natural frequency proves to be a reliable metric with the potential to clearly distinguish lesion like inclusions of different stiffness, as well as providing an approximate location for the tumor like inclusions. The 10 and 20 mm inclusions are always detected regardless of depth. The 5 mm inclusions are only detected near the surface. The homogeneous phantom always yields a negative result, as expected.
  
  
  CONCLUSIONS
  Detection is based on a statistical likelihood analysis to determine the presence of significantly different frequency response over the phantom, which is a novel approach to this problem. The overall results show promise and justify proof of concept trials with human subjects.
authors: Department of Mechanical Engineering, Centre for Bioengineering, University of Canterbury, Christchurch 8041, New Zealand.
authors: Amer S
authors: AS
authors: Kashif
authors: Thomas F
authors: TF
authors: Lotz
authors: Adrianus M W
authors: AM
authors: Heeren
authors: James G
authors: JG
authors: Chase
mesh_terms: D001331:Automation; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D002138:Calibration; D054459:Elasticity Imaging Techniques / Q000379:methods*; D004867:Equipment Design; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D016013:Likelihood Functions; D009038:Motion; D009369:Neoplasms / Q000473:pathology; D019047:Phantoms, Imaging; D012828:Silicones / Q000737:chemistry; D013314:Stress, Mechanical; D014054:Tomography / Q000379:methods*; D014732:Vibration
chemical_list: D012828:Silicones