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Portrait of Predrag Bakic. Photo

Predrag Bakic

Associate Professor

Portrait of Predrag Bakic. Photo

Computer simulations of case difficulty in digital breast tomosynthesis using virtual clinical trials

Author

  • Bruno Barufaldi
  • Trevor Lewis Vent
  • Predrag Radomir Bakic
  • Andrew Douglas Arnould Maidment

Summary, in English

Purpose: Virtual clinical trials (VCTs) require computer simulations of representative patients and images to evaluate and compare changes in performance of imaging technologies. The simulated images are usually interpreted by model observers whose performance depends upon the selection of imaging cases used in training evaluation models. This work proposes an efficient method to simulate and calibrate soft tissue lesions, which matches the detectability threshold of virtual and human readings. Methods: Anthropomorphic breast phantoms were used to evaluate the simulation of four mass models (I–IV) that vary in shape and composition of soft tissue. Ellipsoidal (I) and spiculated (II–IV) masses were simulated using composite voxels with partial volumes. Digital breast tomosynthesis projections and reconstructions of a clinical system were simulated. Channelized Hotelling observers (CHOs) were evaluated using reconstructed slices of masses that varied in shape, composition, and density of surrounded tissue. The detectability threshold of each mass model was evaluated using receiver operating characteristic (ROC) curves calculated with the CHO's scores. Results: The area under the curve (AUC) of each calibrated mass model were within the 95% confidence interval (mean AUC [95% CI]) reported in a previous reader study (0.93 [0.89, 0.97]). The mean AUC [95% CI] obtained were 0.94 [0.93, 0.96], 0.92 [0.90, 0.93], 0.92 [0.90, 0.94], 0.93 [0.92, 0.95] for models I to IV, respectively. The mean AUC results varied substantially as a function of shape, composition, and density of surrounded tissue. Conclusions: For successful VCTs, lesions composed of soft tissue should be calibrated to simulate imaging cases that match the case difficulty predicted by human readers. Lesion composition, shape, and size are parameters that should be carefully selected to calibrate VCTs.

Department/s

  • Radiology Diagnostics, Malmö
  • LUCC: Lund University Cancer Centre

Publishing year

2022-04

Language

English

Pages

2220-2232

Publication/Series

Medical Physics

Volume

49

Issue

4

Document type

Journal article

Publisher

American Association of Physicists in Medicine

Topic

  • Radiology, Nuclear Medicine and Medical Imaging

Keywords

  • anthropomorphic breast phantom
  • digital breast tomosynthesis
  • virtual clinical trials

Status

Published

Research group

  • Radiology Diagnostics, Malmö

ISBN/ISSN/Other

  • ISSN: 0094-2405