Trimboli RM, Carbonaro LA, Cartia F, Di Leo G, Sardanelli F. MRI of fat necrosis of the breast: the "black hole" sign at short tau inversion recovery.
Eur J Radiol 2011;
81:e573-9. [PMID:
21742453 DOI:
10.1016/j.ejrad.2011.06.048]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Revised: 06/06/2011] [Accepted: 06/09/2011] [Indexed: 11/29/2022]
Abstract
OBJECTIVE
To describe MRI features of fat necrosis of the breast.
MATERIALS AND METHODS
Twenty-five lesions in 16 patients were retrospectively analyzed. MRI was performed due to equivocal findings at conventional imaging after surgical treatment of cancer (n=14) or during anticoagulant therapy (n=1), after focal mastitis treated with ductal resection (n=1). In the 15 patients with previous surgery MRI was performed after a median interval of 24 months, using short tau inversion recovery (STIR) and contrast-enhanced dynamic T1-weighted sequences. Signal-to-noise ratio (SNR) inside the lesion and surrounding healthy fat was calculated on both STIR and unenhanced T1-weighted images. Maximal lesion diameter was measured on STIR images. All lesions had final clinical and imaging assessment in favor of fat necrosis and negative clinical and imaging follow-up (21-40 months; median 24 months).
RESULTS
At STIR sequence, fat necrosis appeared as a "black hole", being markedly hypointense (median SNR=29) compared with surrounding fat (median SNR=95) (P<0.001), while no significant difference was found at unenhanced T1-weighted sequence. No significant correlation with time from treatment was found. Of 25 lesions, 15 showed ring enhancement, with continuous increase (n=10), plateau (n=2), or wash-out curve (n=3). The 11 enhancing lesions in the 8 patients with previous radiation therapy showed an initial enhancement higher than that of the 4 enhancing lesions in the 2 patients who did not, although the difference was not significant (P=0.104).
CONCLUSION
Fat necrosis of the breast exhibits a "black hole" sign on STIR images, allowing for an easier diagnosis in clinical practice.
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