Ultrafast DCE-MRI for discriminating pregnancy-associated breast cancer lesions from lactation related background parenchymal enhancement.

OBJECTIVE: To investigate the utility of ultrafast dynamic-contrast-enhanced (DCE) MRI in visualization and quantitative characterization of pregnancy-associated breast cancer (PABC) and its differentiation from background-parenchymal-enhancement (BPE) among lactating patients. MATERIALS AND METHODS: Twenty-nine lactating participants, including 10 PABC patients and 19 healthy controls, were scanned on 3-T MRI using a conventional DCE protocol interleaved with a golden-angle radial sparse parallel (GRASP) ultrafast sequence for the initial phase. The timing of the visualization of PABC lesions was compared to lactational BPE. Contrast-noise ratio (CNR) was compared between the ultrafast and conventional DCE sequences. The differences in each group's ultrafast-derived kinetic parameters including maximal slope (MS), time to enhancement (TTE), and area under the curve (AUC) were statistically examined using the Mann-Whitney test and receiver operator characteristic (ROC) curve analysis. RESULTS: On ultrafast MRI, breast cancer lesions enhanced earlier than BPE (p < 0.0001), enabling breast cancer visualization freed from lactation BPE. A higher CNR was found for ultrafast acquisitions vs. conventional DCE (p < 0.05). Significant differences in AUC, MS, and TTE values were found between the tumor and BPE (p < 0.05), with ROC-derived AUC of 0.86 ± 0.06, 0.82 ± 0.07, and 0.68 ± 0.08, respectively. The BPE grades of the lactating PABC patients were reduced as compared with the healthy lactating controls (p < 0.005). CONCLUSION: Ultrafast DCE MRI allows BPE-free visualization of lesions, improved tumor conspicuity, and kinetic quantification of breast cancer during lactation. Implementation of this method may assist in the utilization of breast MRI for lactating patients. CLINICAL RELEVANCE: The ultrafast sequence appears to be superior to conventional DCE MRI in the challenging evaluation of the lactating breast. Thus, supporting its possible utilization in the setting of high-risk screening during lactation and the diagnostic workup of PABC. KEY POINTS: • Differences in the enhancement slope of cancer relative to BPE allowed the optimal visualization of PABC lesions on mid-acquisitions of ultrafast DCE, in which the tumor enhanced prior to the background parenchyma. • The conspicuity of PABC lesions on top of the lactation-related BPE was increased using an ultrafast sequence as compared with conventional DCE MRI. • Ultrafast-derived maps provided further characterization and parametric contrast between PABC lesions and lactation-related BPE.

Breast MRI during lactation: effects on tumor conspicuity using dynamic contrast-enhanced (DCE) in comparison with diffusion tensor imaging (DTI) parametric maps.

PURPOSE: To investigate the effect of lactation on breast cancer conspicuity on dynamic contrast-enhanced (DCE) MRI in comparison with diffusion tensor imaging (DTI) parametric maps. MATERIALS AND METHODS: Eleven lactating patients with 16 biopsy-confirmed pregnancy-associated breast cancer (PABC) lesions were prospectively evaluated by DCE and DTI on a 1.5-T MRI for pre-treatment evaluation. Additionally, DCE datasets of 16 non-lactating age-matched breast cancer patients were retrospectively reviewed, as control. Contrast-to-noise ratio (CNR) comprising two regions of interests of the normal parenchyma was used to assess the differences in the tumor conspicuity on DCE subtraction images between lactating and non-lactating patients, as well as in comparison against DTI parametric maps of λ1, λ2, λ3, mean diffusivity (MD), fractional anisotropy (FA), and maximal anisotropy index, λ1-λ3. RESULTS: CNR values of breast cancer on DCE MRI among lactating patients were reduced by 62% and 58% (p < 0.001) in comparison with those in non-lactating patients, when taking into account the normal contralateral parenchyma and an area of marked background parenchymal enhancement (BPE), respectively. Among the lactating patients, DTI parameters of λ1, λ2, λ3, MD, and λ1-λ3 were significantly decreased, and FA was significantly increased in PABC, relative to the normal lactating parenchyma ROIs. When compared against DCE in the lactating cohort, the CNR on λ1, λ2, λ3, and MD was significantly superior, providing up to 138% more tumor conspicuity, on average. CONCLUSION: Breast cancer conspicuity on DCE MRI is markedly reduced during lactation owing to the marked BPE. However, the additional application of DTI can improve the visualization and quantitative characterization of PABC, therefore possibly suggesting an additive value in the diagnostic workup of PABC. KEY POINTS: • Breast cancer conspicuity on DCE MRI has decreased by approximately 60% among lactating patients compared with non-lactating controls. • DTI-derived diffusion coefficients and the anisotropy indices of PABC lesions were significantly different than those of the normal lactating fibroglandular tissue. • Among lactating patients, breast cancer conspicuity on DTI-derived parametric maps provided up to 138% increase in contrast-to-noise ratio compared with DCE imaging.

What Is the Color of Your Lymph Node?

We describe a case of tattoo ink in an axillary lymph node, which was observed during an axillary dissection and mastectomy surgery. It is important to be aware of this phenomenon and correctly identify it at the time of surgery, as a misdiagnosis can have serious consequences.