European Journal of Radiology 81S1 (2012) S162–S164

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European Journal of Radiology

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Contrast enhanced spectral mammography: better than MRI?

Fabienne Thibaulta, *, Corinne Balleyguierb, Anne Tardivona, Clarisse Dromainb

aDepartment of Medical Imaging, Institut Curie, Paris, FrancebDepartment of Imaging, Institut de Cancerologie Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex, France

Contrast enhanced mammography is an advanced application of

digital mammography (DM) that combines a full field DM with

intravenous injection of contrast medium. CESM allows imaging

the effect of tumor angiogenesis. This technology thus holds the

potential for better depiction of malignant lesions within dense

breast tissue.

1. Technical background

The initial method developed for contrast enhanced mammography

used temporal acquisitions of high-energy images before and after

intravenous injection of iodinated contrast medium [1–4]. The

patient had to be primarily positioned for breast compression,

using minimal pressure not to alter diffusion of contrast agent.

A baseline image (mask) was obtained before injection. Following

contrast administration, serial images were acquired over several

minutes. Logarithmic subtraction of pre and post-contrast images

was applied. Initial experience with such dynamic imaging showed

the clinical feasibility of the technique. Further work investigated

the diagnostic benefits offered by this modality over conventional

mammography, showing a gain in sensitivity for the detection of

cancer particularly in dense breasts [4]. The technique, however,

proved sensitive to motion artifacts. It also posed the issue of the

additional radiation exposure applied for an examination limited to

one breast at a time in a single projection view.

The second method developed for contrast enhanced mammog-

raphy was based on dual energy acquisition. Physical and clinical

research currently focuses on this technology also referred to

as spectral imaging or contrast enhanced spectral mammography

(CESM). To allow visualization of low concentration of iodine with

only a modest increase in radiation exposure, the x-ray spectrum

delivers energies just above the K-edge of iodine (33.2 keV) while

using a high voltage range of 45–50kVp [5]. In that setting the

patient receives contrast administration first and then is positioned

for mammography with normal compression of the breast. A typical

protocol goes from obtaining the mediolateral oblique (MLO) view

on one breast – typically 2 min after the start of injection – to

the MLO view on the other breast, then from the craniocaudal (CC)

view on the first side – 4 min after the start of injection – to the

CC view on the other side. For each view, a pair of low and high-

energy images is acquired. The two images are combined so that

the areas of iodine enhancement are highlighted from background

parenchyma. Two views of both breasts can be obtained after a

single injection of contrast medium.

* Fabienne Thibault, Department of Medical Imaging, Institut Curie,

26 rue d’Ulm, 75248 Cedex 05 Paris, France.

E-mail address: fabienne.thibault@curie.net (F. Thibault).

2. Clinical performance of CESM

In the first series published in 26 patients [6], all of the

invasive cancers enhanced, most of them (11/13) with a strong

to moderate subjective score. One in situ carcinoma showed only

faint enhancement. In another malignancy, the in situ component

showed no enhancement but the lesion was recognizable by the

presence of microcalcifications. Two of the 12 benign lesions also

enhanced in the form of focal non-masslike areas, being potential

false positive cases. Lastly, diffuse enhancement of normal breast

tissue was noted in two other patients.

More recently, the relative performance of digital mammography

(DM), DM+CESM, and DM+breast ultrasound was evaluated in

120 patients using ROC analysis [7]. The diagnostic performance

was higher for DM+CESM than for DM alone (p < 0.01) and for

DM+ultrasound (p < 0.03). Using a confidence of presence criterion,

DM+CESM was found more specific than DM+ultrasound. Similarly,

in the subsequent multireader review of 148 breast lesions

(110 consenting women), the average per-lesion sensitivity across

readers was significantly increased and all readers improved their

clinical performance when using DM+ultrasound +CESM versus

DM+ultrasound [8].

The above results supported the view that the clinical

applications of CESM were similar to those of MR imaging in several

diagnostic situations such as problem solving issues after equivocal

conventional imaging, initial staging of malignancies (Figs. 1, 2),

preoperative medical treatment monitoring.

More data are currently being collected in a prospective

multicenter study assessing the respective accuracy of CESM and

MRI for breast cancer staging. Study was approved by ethics

committee and patients gave informed consent. Preliminary results

derived from data in 54 patients were communicated at the

2011 scientific assembly of the radiological society of North

America [Dromain C et al., unpublished results]. Lesions were

unifocal in 33 patients and multifocal and/or multicentric in

21 patients. A total of 82 malignant lesions (74 invasive cancers,

8 pure in situ lesions) were found. Due to inclusion criteria a

high percentage (29%) of the invasive lobular form was present.

There were 11 benign lesions. The sensitivity of CESM appeared

slightly inferior to that of MRI, e.g. 50/53 index tumor detected

with CESM versus 53/53 with MRI; 26/29 additional tumour foci

detected with CESM versus 27/29 with MRI. The specificity of

CESM appeared slightly superior to that of MRI, with 1 false

positive case found with CESM (cylindric metaplasia) versus 5 false

positive cases with MRI. CESM yielded 6 false negative cases, e.g. 2

invasive ductal tumours located outside the mammographic field

of view (suboptimal patient positioning) and 4 invasive lobular

0720-048X/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved.

F. Thibault et al. / European Journal of Radiology 81S1 (2012) S162–S164 S163

Fig. 1. Invasive ductal carcinoma in deep portion of the left breast in a 69-year-old patient. Preoperative contrast enhanced MR imaging, subtracted images, MIP axial and

3-dimentional views. 3.5-cm index lesion (open arrows) and distinct anterior enhancing focus (white arrow).

a c

b d

Fig. 2. Same patient as in Fig. 1. Preoperative bilateral contrast enhanced spectral mammography. Post-contrast low-energy (a-b) and combined images (c-d). Contrast uptake

is highlighted in both index lesion and anterior focus (arrows). No significant enhancement of breast tissue is seen otherwise. Note similar lesion visibility on CESM and

MRI.

cancers 10-mm in median size. MRI yielded 2 false negatives

cases, e.g. 1 ductal in situ and 1 invasive lobular carcinoma

9-mm in size.

If confirmed, these successive results indicate the potential for

an important role of CESM in routine practice with the benefit of

wider equipment access than for breast MRI and favorable economic

considerations. The validation of further contribution of CESM

information to clinical management is underway. In parallel, the

development of combined modalities such as contrast-enhanced

tomosynthesis promises further diagnostic performance based on

the digital mammography platform [9].

Competing interests: The authors declare that the clinical studies

were partly sponsored by GE healthcare.

S164 F. Thibault et al. / European Journal of Radiology 81S1 (2012) S162–S164

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