Current applications and future direction of MR mammography

Abstract

Compared with triple assessment for symptomatic and occult breast disease, magnetic resonance mammography (MRM) offers higher sensitivity for the detection of multifocal cancer, which is important in selecting patients appropriately for breast-conserving surgery. It is an ideal tool for the screening of patients with a high risk of breast cancer or where there is axillary disease or nipple discharge and conventional imaging has not revealed the primary focus. Techniques are now available to biopsy lesions only apparent on MRM. MRM can differentiate scar tissue from tumour; therefore, it is useful in patients in which there is possible recurrent disease. Clinical and X-ray mammographic assessment of response to neoadjuvant chemotherapy may be unreliable because of replacement of the tumour with scar tissue. MRM can identify responders and nonresponders with more accuracy. It is the modality of choice for the assessment of breast implants for rupture with accuracy higher than X-ray mammography and ultrasound. Advances in both spatial and temporal resolutions, the imaging sequences employed, pharmacokinetic modelling of contrast uptake, the use of dedicated and now phased-array breast coils, and gadolinium-based contrast agents have all played their part in the advancement of this imaging technique. Despite the limitations of patient compliance, scan-time and cost, this review describes how MRM has become a valuable tool in breast disease, especially in cases of diagnostic uncertainty. However, MRM must make the transition from research institutions into routine clinical practice.

Figure 1

A T1-weighted image of an invasive breast cancer (A) fat-saturated image after gadolinium contrast (B).

Figure 2

Shapes of signal-intensity curves and likely histology (Kuhl et al, 1999).

Figure 3

Typical malignant and benign lesion signal-intensity curves (data points) and two-compartment pharmacokinetic modelling (lines).

Figure 4

Monitoring the response to neo-adjuvant chemotherapy. Before treatment (A) and response after 3 months (B).

Figure 5

T1-weighted image of DCIS (A) and fat-saturated image after gadolinium contrast (B) with malignant signal-intensity curve of enclosed area.

Figure 6

Silicone-specific series showing an extracapsular tear with silicone globules in soft tissues.

Figure 7

T1-weighted postcontrast fat-suppressed image of a breast showing signal voids from surgical instrument metal fragments.