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History:
30 year old female presented with a palpable abnormality in the right
breast. Ultrasound showed an area of heterogeneous echogenicity
(figure 1). The mammogram showed dense breasts with a small area of
microcalcifications (figure 2). Biopsy showed carcinoma. The patient
was then referred to Main Street Radiology for Breast MRI to
determine the extent of cancer for surgical planning.
Findings:
Post contrast axial and sagittal images (figures 3 and 4) demonstrate
an area of intense early arterial phase enhancement (arrows) which
corresponds to the sonographic finding. Although the mass is very
posterior in location, there is preservation of the fat plane between
the mass and the chest wall indicating the absence of chest wall
invasion.
The patient underwent lumpectomy and
was found to have a 2.5 cm invasive ductal carcinoma.
Discussion:
A meta-analysis of 16 studies demonstrated the sensitivity of
95% and a specificity of 67% for Breast MRI (Hrung JM, et.al Acad
Radiol 1999:6:387-397), significantly higher than mammography or
ultrasound.
At Main Street Radiology, the routine
Breast MRI includes images of both breast acquired simultaneously both
before and at multiple time-points after the administration of IV
contrast. Both the morphology as well as the dynamic enhancement
characteristics of lesions are evaluated.
Rapid enhancement and de-enhancement is
typical for malignancy (Type III curve on Figure 5). The rapid initial
enhancement rate of malignancies is likely due to tumor angiogenesis.
Malignant lesions are known to require the recruitment of a large
concentration of tumor neo-vessels to permit their continued growth
beyond a few millimeters.
