title: Automated stratification of liver disease in ultrasound: An online accurate feature classification paradigm.
abstract: OBJECTIVE
  Fatty liver disease (FLD) is one of the most common diseases in liver. Early detection can improve the prognosis considerably. Using ultrasound for FLD detection is highly desirable due to its non-radiation nature, low cost and easy use. However, the results can be slow and ambiguous due to manual detection. The lack of computer trained systems leads to low image quality and inefficient disease classification. Thus, the current study proposes novel, accurate and reliable detection system for the FLD using computer-based training system.
  
  
  METHODS
  One hundred twenty-four ultrasound sample images were selected retrospectively from a database of 62 patients consisting of normal and cancerous. The proposed training system was generated offline parameters using training liver image database. The classifier applied transformation parameters to an online system in order to facilitate real-time detection during the ultrasound scan. The system utilized six sets of features (a total of 128 features), namely Haralick, basic geometric, Fourier transform, discrete cosine transform, Gupta transform and Gabor transform. These features were extracted for both offline training and online testing. Levenberg-Marquardt back propagation network (BPN) classifier was used to classify the liver disease into normal and abnormal categories.
  
  
  RESULTS
  Random partitioning approach was adapted to evaluate the classifier performance and compute its accuracy. Utilizing all the six sets of 128 features, the computer aided diagnosis (CAD) system achieved classification accuracy of 97.58%. Furthermore, the four performance metrics consisting of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) realized 98.08%, 97.22%, 96.23%, and 98.59%, respectively.
  
  
  CONCLUSIONS
  The proposed system was successfully able to detect and classify the FLD. Furthermore, the proposed system was benchmarked against previous methods. The comparison established an advanced set of features in the Levenberg-Marquardt back propagation network reports a significant improvement compared to the existing techniques.
authors.affiliation: Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.) di Cagliari - Polo di Monserrato, Università di Cagliari, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Saba
authors.affiliation: Point-of-Care Devices, Global Biomedical Technologies, Inc., Roseville, CA, USA.
authors.forename: Nilanjan
authors.initials: N
authors.lastname: Dey
authors.affiliation: Department of Electronics and Electrical Communications Engineering, Faculty of Engineering, Tanta University, Egypt.
authors.forename: Amira S
authors.initials: AS
authors.lastname: Ashour
authors.affiliation: Point-of-Care Devices, Global Biomedical Technologies, Inc., Roseville, CA, USA.
authors.forename: Sourav
authors.initials: S
authors.lastname: Samanta
authors.affiliation: Point-of-Care Devices, Global Biomedical Technologies, Inc., Roseville, CA, USA.
authors.forename: Siddhartha Sankar
authors.initials: SS
authors.lastname: Nath
authors.affiliation: Point-of-Care Devices, Global Biomedical Technologies, Inc., Roseville, CA, USA.
authors.forename: Sayan
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: Institute for Systems and Robotics (ISR), Instituto Superior Técnico (IST), Lisbon, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Sanches
authors.affiliation: Point-of-Care Devices, Global Biomedical Technologies, Inc., Roseville, CA, USA.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Liver Unit, Department of Gastroenterology and Hepatology, Hospital de Santa Maria, Medical School of Lisbon, Portugal.
authors.forename: RuiTato
authors.initials: R
authors.lastname: Marinho
authors.affiliation: Point-of-Care Devices, Global Biomedical Technologies, Inc., Roseville, CA, USA; Electrical Engineering Department (Affl.), Idaho State University, ID, USA. Electronic address: jsuri@comcast.net.
authors.forename: Jasjit S
authors.initials: JS
authors.lastname: Suri
mesh_terms: D001331:Automation; D005583:Fourier Analysis; D006801:Humans; D008107:Liver Diseases / Q000145:classification / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*
keywords: Accuracy; Back propagation network; Fatty liver disease; Gabor transform; Gupta transform; Haralick features