The lactating breast: Contrast-enhanced MR Imaging of normal tissue and cancer
ABSTRACT To retrospectively describe the magnetic resonance (MR) imaging characteristics of normal breast tissue and breast cancer in the setting of lactation.
The HIPAA-compliant study was exempt from institutional approval, and informed consent was not required. Unilateral MR imaging of 10 breasts was performed in seven lactating patients aged 27-42 years. For the three patients in whom both breasts were imaged, each breast was imaged on a separate day. Nonenhanced T1-weighted and fat-saturated T2-weighted images and contrast material-enhanced dynamic three-dimensional (3D) T1-weighted spiral gradient-echo images interleaved with T1-weighted high-spatial-resolution 3D gradient-echo images (2.0 x 1.0 x 0.4-mm voxels) were obtained. Three readers in consensus assessed the glandular density, T2-weighted signal intensity, milk duct appearance, and contrast enhancement in normal and tumor-containing breast regions. The pharmacokinetic contrast enhancement parameters of tumors were compared with those of normal tissue by using Student t and Mann-Whitney tests.
MR findings of normal breast tissue in the seven women included increased glandular density in six women, high T2-weighted signal intensity in six, dilated central ducts in seven, and rapid initial glandular contrast enhancement in seven. MR findings of invasive ductal carcinoma in five women, compared with findings of the normal glandular tissue, included lower T2-weighted signal intensity in five women, more avid and rapid contrast enhancement in five, and early contrast enhancement washout in four. One minute after contrast agent injection, tumor signal intensity increased significantly more than normal lactating tissue signal intensity (153% vs 60% from baseline, P = .016). The median two-compartment model K(21) exchange rate in the tumors, 0.078 sec(-1), was significantly faster than the K(21) exchange rate in normal tissue, 0.011 sec(-1) (P = .03).
Normal lactating glands have increased density, high T2-weighted signal intensity, and rapid moderate contrast enhancement. Breast cancers are visible during lactation owing to their lower signal intensity and more intense initial contrast enhancement with early washout compared with normal breast tissue.
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ABSTRACT: Purpose To investigate the parameters obtained with diffusion-tensor (DT) magnetic resonance (MR) imaging of the breast throughout the menstrual cycle phases, during lactation, and after menopause, with and without hormone replacement therapy (HRT). Materials and Methods All protocols were approved by the internal review board, and signed informed consent was obtained from all participants. Forty-five healthy volunteers underwent imaging by using T2-weighted and DT MR sequences at 3 T. Premenopausal volunteers (n = 16) underwent imaging weekly, four times during one menstrual cycle. Postmenopausal volunteers (n = 19) and lactating volunteers (n = 10) underwent imaging once. The principal diffusion coefficients (λ1, λ2, and λ3), apparent diffusion coefficient (ADC), fractional anisotropy (FA), and maximal anisotropy (λ1-λ3) were calculated pixel by pixel for the fibroglandular tissue in the entire breast. Results In all premenopausal volunteers, the DT parameters exhibited high repeatability, remaining almost equal along the menstrual cycle, with a low mean within-subject coefficient of variance of λ1, λ2, λ3, and ADC (1%-2% for all) and FA (5%), as well as a high intraclass correlation of 0.92-0.98. The diffusion coefficients were significantly lower (a) in the group without HRT use as compared with the group with HRT use (P < .01) and premenopausal volunteers (P < .01) and (b) in the lactating volunteers as compared with the premenopausal volunteers (P < .005). No significant differences in DT parameters were found between premenopausal volunteers free of oral contraceptives and those who used oral contraceptives (P = .28-0.82) and between premenopausal volunteers and postmenopausal volunteers who used HRT (P = .31-0.93). Conclusion DT imaging parameters are not sensitive to menstrual cycle changes, while menopause, long-term HRT, and presence of milk in lactating women affected the DT parameters. Therefore, the timing for performing breast DT imaging is not restricted throughout the menstrual cycle, whereas the modulations in diffusion parameters due to HRT and lactation should be taken into account in DT imaging evaluation. © RSNA, 2014 Online supplemental material is available for this article.Radiology 02/2014; 271(3):132084. DOI:10.1148/radiol.14132084 · 6.21 Impact Factor
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ABSTRACT: At magnetic resonance (MR) imaging, both normal and abnormal breast tissue enhances after contrast material administration. The morphology and temporal degree of enhancement of pathologic breast tissue relative to normal breast tissue form the basis of MR imaging's diagnostic accuracy in the detection and diagnosis of breast disease. Normal parenchymal enhancement at breast MR imaging is termed background parenchymal enhancement (BPE). BPE may vary in degree and distribution in different patients as well as in the same patient over time. Typically BPE is minimal or mild in overall degree, with a bilateral, symmetric, diffuse distribution and slow early and persistent delayed kinetic features. However, BPE may sometimes be moderate or marked in degree, with an asymmetric or nondiffuse distribution and rapid early and plateau or washout delayed kinetic features. These patterns cause diagnostic difficulty because these features can be seen with malignancy. This article reviews typical and atypical patterns of BPE seen at breast MR imaging. The anatomic and physiologic influences on BPE in women undergoing diagnostic and screening breast MR imaging are reviewed. The potential for false-positive and false-negative interpretations due to BPE are discussed. Radiologists can improve their interpretive accuracy by increasing their understanding of various BPE patterns, influences on BPE, and the potential effects of BPE on MR imaging interpretation. © RSNA, 2014.Radiographics 01/2014; 34(1):234-47. DOI:10.1148/rg.341135034 · 2.73 Impact Factor
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ABSTRACT: To investigate the potential of diffusion weighted imaging (DWI) and in vivo proton MR spectroscopy (MRS) in the differentiation of breast tissue of healthy lactating women volunteers and breast cancer patients. DWI and MRS were carried out at 1.5 Tesla on 12 breast cancer patients and 12 normal lactating women volunteers. Apparent diffusion coefficient (ADC) and total choline (tCho) concentration were determined. tCho was observed in all breast cancer patients and in 10/12 lactating women. Additionally a peak at 3.8 ppm corresponding to lactose was seen in 10/12 of lactating women. Concentration of tCho was similar in malignant breast tissue of patients (3.51 ± 1.72 mmol/kg) and in normal breast tissue of lactating women (3.52 ± 1.70 mmol/kg). However, ADC was significantly higher in the normal breast tissue of lactating women (1.62 ± 0.22 × 10(-3) mm(2) /s) compared with the malignant breast tissue of patients (1.01 ± 0.10 × 10(-3) mm(2) /s). Observation of lactose peak with higher ADC in the breast tissue of healthy lactating women volunteers may aid in differentiation of changes that occur in breast tissue due to normal physiological conditions like lactation compared with malignant transformation. J. Magn. Reson. Imaging 2013;. © 2013 Wiley Periodicals, Inc.Journal of Magnetic Resonance Imaging 01/2015; 41(1). DOI:10.1002/jmri.24507 · 2.79 Impact Factor