Task-based strategy for optimized contrast enhanced breast imaging: Analysis of six imaging techniques for mammography and tomosynthesis

Authors

  • Ikejimba Lynda C.,

    1. Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705
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    • Author to whom correspondence should be addressed. Electronic mail: lci@duke.edu

  • Kiarashi Nooshin,

    1. Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705
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  • Ghate Sujata V.,

    1. Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705
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  • Samei Ehsan,

    1. Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705; Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705; Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705; Department of Physics, Duke University, Durham, North Carolina 27705; and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27705
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  • Lo Joseph Y.

    1. Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705; Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705; Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705; and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27705
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Abstract

Purpose:

The use of contrast agents in breast imaging has the capability of enhancing nodule detectability and providing physiological information. Accordingly, there has been a growing trend toward using iodine as a contrast medium in digital mammography (DM) and digital breast tomosynthesis (DBT). Widespread use raises concerns about the best way to use iodine in DM and DBT, and thus a comparison is necessary to evaluate typical iodine-enhanced imaging methods. This study used a task-based observer model to determine the optimal imaging approach by analyzing six imaging paradigms in terms of their ability to resolve iodine at a given dose: unsubtracted mammography and tomosynthesis, temporal subtraction mammography and tomosynthesis, and dual energy subtraction mammography and tomosynthesis.

Methods:

Imaging performance was characterized using a detectability index d, derived from the system task transfer function (TTF), an imaging task, iodine signal difference, and the noise power spectrum (NPS). The task modeled a 10 mm diameter lesion containing iodine concentrations between 2.1 mg/cc and 8.6 mg/cc. TTF was obtained using an edge phantom, and the NPS was measured over several exposure levels, energies, and target-filter combinations. Using a structured CIRS phantom, d was generated as a function of dose and iodine concentration.

Results:

For all iodine concentrations and dose, temporal subtraction techniques for mammography and tomosynthesis yielded the highest d, while dual energy techniques for both modalities demonstrated the next best performance. Unsubtracted imaging resulted in the lowest d values for both modalities, with unsubtracted mammography performing the worst out of all six paradigms.

Conclusions:

At any dose, temporal subtraction imaging provides the greatest detectability, with temporally subtracted DBT performing the highest. The authors attribute the successful performance to excellent cancellation of inplane structures and improved signal difference in the lesion.

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