Contrast-enhanced mammography: past, present, and future

Abstract

Contrast-enhanced mammography (CEM) combines conventional mammography with iodinated contrast material to improve cancer detection. CEM has comparable performance to breast MRI without the added cost or time of conventional MRI protocols. Thus, this technique may be useful for indications previously reserved for MRI, such as problem-solving, determining disease extent in patients with newly diagnosed cancer, monitoring response to neoadjuvant therapy, evaluating the posttreatment breast for residual or recurrent disease, and potentially screening in women at intermediate- or high-risk for breast cancer. This article will provide a comprehensive overview on the past, present, and future of CEM, including its evolving role in the diagnostic and screening settings.

Keywords: Breast imaging; Contrast-enhanced digital mammography; Contrast-enhanced mammography; Contrast-enhanced spectral mammography.

Fig. 1.

Steps of a contrast-enhanced mammography examination. Approximately two minutes after completion of contrast injection, the breast is placed in compression. Low-energy (LE) and high-energy (HE) images are sequentially acquired in the four standard mammographic views within the next six minutes.

Fig. 2.

Paired low-energy (A) and high-energy (B) craniocaudal images are acquired after intravenous contrast agent administration. Post-processing generates a recombined (C) image, which highlights areas of iodine uptake. No suspicious findings are present on the recombined image shown here; scattered areas of enhancement are consistent with mild background parenchymal enhancement.

Fig. 3.

Background parenchymal enhancement (BPE) on CEM. Categories include minimal (A), mild (B), moderate (C), and marked (D).

Fig. 4.

Common artifacts seen on CEM. Rim artifact (A) and skin line artifact (B) from non-uniform scatter radiation in the breast and skin. Ripple artifact (C) from motion. Skin contamination artifact (D) from contrast spillage.

Fig. 5.

49-year-old with remote history of phyllodes tumor with new palpable left breast mass. MLO low-energy image (A) demonstrates an obscured mass underlying a triangular palpable skin marker. The full extent of the mass is not well delineated due to overlapping dense tissue. MLO recombined image (B) clearly shows a large avidly enhancing retroareolar mass. Targeted US image (C) demonstrates a solid vascular mass, which correlates to the CEM enhancement and palpable finding. US-guided biopsy yielded recurrent phyllodes tumor. CEM is beneficial in delineating the extent of suspicious abnormalities in areas of dense parenchymal breast tissue.

Fig. 6.

59-year-old women with history of LCIS with suspicious left breast calcifications on screening CEM. MLO low-energy image (A) and 2D ML magnification view (B) shows segmental fine pleomorphic calcifications in the lower breast (circle). MLO recombined image (C) demonstrates two enhancing masses (arrows) in the region of the calcifications and a superiorly located third mass (dashed arrow). Targeted US images (D) confirm three suspicious masses, two of which underwent US-guided biopsy yielding multicentric invasive ductal carcinoma. CEM may show greater extent of disease than conventional mammography, rendering more accurate staging.

Fig. 7.

54-year-old with palpable right breast mass status post ultrasound-guided biopsy yielding invasive ductal carcinoma and subsequently treated with neoadjuvant chemotherapy. Pre-treatment digital mammogram (A) demonstrates a high density irregular mass in the posterior breast corresponding to the palpable finding and known cancer. Post-treatment low-energy image (B) performed six months later shows decreased mass surrounding the biopsy marker suggestive of residual disease. Post-treatment recombined image (C) shows no abnormal enhancement. Surgical pathology specimen from lumpectomy confirmed no residual carcinoma concordant with the lack of enhancement on CEM.

Fig. 8.

70-year-old with remote history of left breast conservation therapy for invasive lobular carcinoma presenting for screening. Postsurgical changes are present in the upper posterior breast. MLO low-energy image (A) demonstrates no suspicious finding. MLO recombined image (B) shows an enhancing mass anterior to the lumpectomy site (arrow). Targeted ultrasound was negative (not shown). Sagittal MRI postcontrast subtraction image (C) shows an enhancing mass, which correlates to the CEM finding. MRI-guided biopsy yielded invasive lobular carcinoma recurrence.

Fig. 9.

47-year-old woman with family history of breast cancer presents for screening with incidentally found false-positive finding in the right breast on CEM. MLO low-energy image (A) demonstrates no suspicious finding. MLO recombined image (B) reveals a subtle enhancing mass in the upper breast (arrow). Targeted US image (C) shows an oval mass with slightly indistinct margins. US-guided biopsy yielded benign fibroadenoma

Fig. 10.

47-year-old woman with left breast palpable mass with false-negative finding on CEM. MLO low-energy (A) and recombined (B) images demonstrate no suspicious finding. Ultrasound targeted to site of palpable concern was also negative (not shown). Given persistent palpable concern, MRI was performed. Sagittal MRI postcontrast subtraction image (C) shows an enhancing focus at the site of palpable concern in the retroareolar region. MRI-guided biopsy yielded ductal carcinoma in situ. CEM may not detect all cancers, particularly if they are small or low-grade.