MRI and (1)H MRS of the breast: presence of a choline peak as malignancy marker is related to K21 value of the tumor in patients with invasive ductal carcinoma.

To assess which specific morphologic features, enhancement patterns, or pharmacokinetic parameters on breast Magnetic Resonance Imaging (MRI) could predict a false-negative outcome of Proton MR Spectroscopy ((1)H MRS) exam in patients with invasive breast cancer. Sixteen patients with invasive ductal carcinoma of the breast were prospectively included and underwent both, contrast-enhanced breast MRI and (1)H MRS examination of the breast. The MR images were reviewed and the lesions morphologic features, enhancement patterns and pharmacokinetic parameters (k21-value) were scored according to the ACR BI-RADS-MRI lexicon criteria. For the in vivo MRS studies, each spectrum was evaluated for the presence of choline based on consensus reading. Breast MRI and (1)H MRS data were compared to histopathologic findings. In vivo (1)H MRS detected a choline peak in 14/16 (88%) cancers. A false-negative (1)H MRS study occurred in 2/16 (14%) cancer patients. K21 values differed between both groups: the 14 choline positive cancers had k21 values ranging from 0.01 to 0.20/second (mean 0.083/second), whereas the two choline-negative cancers showed k21 values of 0.03 and 0.05/second, respectively (mean 0.040/second). Also enhancement kinetics did differ between both groups; typically both cancers that were choline-negative showed a late phase plateau (100%), whereas this was only shown in 5/14 (36%) of the choline positive cases. There was no difference between both groups with regard to morphologic features on MRI. This study showed that false-negative (1)H MRS examinations do occur in breast cancer patients, and that the presence of a choline peak on (1)H MRS as malignancy marker is related to the k21 value of the invasive tumor being imaged.

Magnetic resonance imaging characteristics of fibrocystic change of the breast.

OBJECTIVE: The objective of this study was to identify magnetic resonance imaging (MRI) characteristics of fibrocystic change (FCC) of the breast. MATERIALS AND METHODS: Fourteen patients with a histopathologic diagnosis of solitary FCC of the breast underwent x-ray mammography and MRI of the breast. Three experienced breast imaging radiologists retrospectively reviewed the MRI findings and categorized the lesions on morphologic and kinetic criteria according to the ACR BI-RADS-MRI Lexicon. RESULTS: The most striking morphologic feature of fibrocystic change was nonmass-like regional enhancement found in 6 of 14 (43%) FCC lesions. Based on morphologic criteria alone, 12 of 14 (86%) lesions were correctly classified as benign. According to analysis of the time-intensity curves, 10 of 14 (71%) FCC lesions were correctly classified as benign. CONCLUSION: Although FCC has a wide spectrum of morphologic and kinetic features on MRI, it most often presents as a mass or a nonmass-like regional enhancing lesion with benign enhancement kinetics.

The lactating breast: contrast-enhanced MR imaging of normal tissue and cancer.

PURPOSE: To retrospectively describe the magnetic resonance (MR) imaging characteristics of normal breast tissue and breast cancer in the setting of lactation. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Contrast-enhanced MRI of ductal carcinoma in situ: characteristics of a new intensity-modulated parametric mapping technique correlated with histopathologic findings.

PURPOSE: To identify morphologic and dynamic enhancement magnetic resonance imaging (MRI) features of pure ductal carcinoma in situ (DCIS) by using a new intensity-modulated parametric mapping technique, and to correlate the MRI features with histopathologic findings. MATERIALS AND METHODS: Fourteen patients with pure DCIS on pathology underwent conventional mammography and contrast-enhanced (CE) MRI using the intensity-modulated parametric mapping technique. The MR images were reviewed and the lesions were categorized according to morphologic and kinetic criteria from the ACR BI-RADS-MRI Lexicon, with BI-RADS 4 and 5 lesions classified as suspicious. RESULTS: With the use of a kinetic curve shape analysis, MRI classified seven of 14 lesions (50%) as suspicious, including four with initial-rapid/late-washout and three with initial-rapid/late-plateau. Using morphologic criteria, MRI classified 10/14 (71%) as suspicious, with the most prominent morphologic feature being a regional enhancement pattern. Using the intensity modulated parametric mapping technique, MRI classified 12/14 cases (86%) as suspicious. Parametric mapping identified all intermediate- and high-grade DCIS lesions. CONCLUSION: The intensity-modulated parametric mapping technique for breast MRI resulted in the highest detection rate for the DCIS cases. Furthermore, the parametric mapping technique identified all intermediate- and high-grade DCIS lesions, suggesting that a negative MRI using the parametric mapping technique may exclude intermediate- and high-grade DCIS. This finding has potential clinical implications.