Approximating the Ideal Observer for Joint Signal Detection and Localization Tasks by use of Supervised Learning Methods

Research output: Contribution to journalArticlepeer-review

Abstract

Medical imaging systems are commonly assessed and optimized by use of objective measures of image quality (IQ). The Ideal Observer (IO) performance has been advocated to provide a figure-of-merit for use in assessing and optimizing imaging systems because the IO sets an upper performance limit among all observers. When joint signal detection and localization tasks are considered, the IO that employs a modified generalized likelihood ratio test maximizes observer performance as characterized by the localization receiver operating characteristic (LROC) curve. Computations of likelihood ratios are analytically intractable in the majority of cases. Therefore, sampling-based methods that employ Markov-Chain Monte Carlo (MCMC) techniques have been developed to approximate the likelihood ratios. However, the applications of MCMC methods have been limited to relatively simple object models. Supervised learning-based methods that employ convolutional neural networks have been recently developed to approximate the IO for binary signal detection tasks. In this paper, the ability of supervised learning-based methods to approximate the IO for joint signal detection and localization tasks is explored. Both background-known-exactly and background-known-statistically signal detection and localization tasks are considered. The considered object models include a lumpy object model and a clustered lumpy model, and the considered measurement noise models include Laplacian noise, Gaussian noise, and mixed Poisson-Gaussian noise. The LROC curves produced by the supervised learning-based method are compared to those produced by the MCMC approach or analytical computation when feasible. The potential utility of the proposed method for computing objective measures of IQ for optimizing imaging system performance is explored.

Original languageEnglish (US)
Article number9139307
Pages (from-to)3992-4000
Number of pages9
JournalIEEE transactions on medical imaging
Volume39
Issue number12
DOIs
StatePublished - Dec 2020

Keywords

  • Numerical observers
  • deep learning
  • ideal observer
  • joint signal detection and localization tasks
  • localization receiver operating characteristic curve
  • task-based image quality

ASJC Scopus subject areas

  • Software
  • Radiological and Ultrasound Technology
  • Computer Science Applications
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Approximating the Ideal Observer for Joint Signal Detection and Localization Tasks by use of Supervised Learning Methods'. Together they form a unique fingerprint.

Cite this