Dual-energy contrast-enhanced digital breast tomosynthesis--a feasibility study

Abstract

Contrast-enhanced digital breast tomosynthesis (CE-DBT) is a novel modality for imaging breast lesion morphology and vascularity. The purpose of this study is to assess the feasibility of dual-energy subtraction as a technique for CE-DBT (a temporal subtraction CE-DBT technique has been described previously). As CE-DBT evolves, exploration of alternative image acquisition techniques will contribute to its optimisation. Evaluation of dual-energy CE-DBT was conducted with Institutional Review Board (IRB) approval from our institution and in compliance with federal Health Insurance Portability and Accountability Act (HIPAA) guidelines. A 55-year old patient with a known malignancy in the right breast underwent imaging with MRI and CE-DBT. CE-DBT was performed in the medial lateral oblique view with a DBT system, which was modified under IRB approval to allow high-energy image acquisition with a 0.25 mm Cu filter. Image acquisition occurred via both temporal and dual-energy subtraction CE-DBT. Between the pre- and post-contrast DBT image sets, a single bolus of iodinated contrast agent (1.0 ml kg(-1)) was administered, followed by a 60 ml saline flush. The contrast agent and saline were administrated manually at a rate of approximately 2 ml s(-1). Images were reconstructed using filtered-back projection and transmitted to a clinical PACS workstation. Dual-energy CE-DBT was shown to be clinically feasible. In our index case, the dual-energy technique was able to provide morphology and kinetic information about the known malignancy. This information was qualitatively concordant with that of CE-MRI. Compared with the temporal subtraction CE-DBT technique, dual-energy CE-DBT appears less susceptible to motion artefacts.

Figures

Figure 1

Illustration of the imaging sequence and timing of acquisition. The affected breast is compressed, after which a high-energy (HE) pre-contrast tomosynthesis image series is acquired. After injection, two HE/LE (low-energy) tomosynthesis image series are acquired. After image processing and tomographic reconstruction, temporal subtraction CE-DBT images at two time points (Temp 1 and Temp 2) and dual-energy (DE) contrast-enhanced digital breast tomosynthesis images at three time points (DE 1, DE 2 and DE 3) were available.

Figure 2

(a) Contrast-enhanced MRI subtraction slice and (b) second post-contrast low-energy digital breast tomosynthesis slice (illustrating breast morphology) at similar planes demonstrate comparable morphological information about the malignant lesion (arrow).

Figure 3

Dual-energy contrast-enhanced digital breast tomosynthesis image at (a) the first time point, which demonstrates the malignancy (arrow). The malignant lesion showing rim enhancement is highlighted in the zoomed images at each of the three dual-energy time points (b–d). Note that the images shown have been denoised using a TV noise reduction algorithm [22].

Figure 4

Temporal subtraction contrast-enhanced digital breast tomosynthesis (CE-DBT) image at (a) the first time point also demonstrates the malignancy (arrow). The malignant lesion showing rim enhancement is highlighted in the zoomed images at each of the two temporal subtraction time points (b,c) Note the motion artefacts in the temporal subtraction CE-DBT images; the clip in the lesion shows a displacement of approximately 2 mm.