To test 3T proton magnetic resonance spectroscopy (1H-MRS) for breast mass lesions.

Poster: ECR 2017 / C-2795 / Multi-parametric MRI evaluation of breast lesions: may texture analysis have a role? by: Rossi, C. Cavedon, G. Meliado, L. Camera, I. Baglio, F. Caumo, S. Montemezzi ; Verona/IT

INTRODUCTION:The aim of this work was to assess the role of 3T-MR spectroscopy (MRS) in the multi-parametric MRI evaluation of breast lesions, using a pattern-recognition based classification method. METHODS:291 patients (301 lesions, median 2.3cm3) were enrolled in the study (age 18-85y, mean 54.2y). T1-TSE (TR/TE=400/10ms) and T2-STIR imaging (TR/TE=5000/60ms), dynamic-contrast-enhanced MRI (DCE-MRI), apparent diffusion coefficient (ADC) (b=0-800s/mm2), and single-voxel MRS (10×10×10mm3, PRESS, TR/TE=3000ms/135ms) were performed by means of a 3T scanner. MRS results were accepted if the FWHM of the water peak was ⩽45Hz. Total choline (tCho) was considered detected if the signal-to-noise ratio (SNR) of the 3.2ppmpeak was ⩾2. A classifier-based analysis (support-vector-machines, SVM) was performed with 4-dimensional vectors including type of margin, DCE-MRI kinetic curve type, ADC mean value, and tCho SNR. A comparison with 3-dimensional vectors (without tCho SNR) was used to assess MRS impact on sensitivity, specificity, and positive-negative predictive values (PPV-NPV) for malignancy. RESULTS:228 lesions (180 malignant/48 benign) showed acceptable spectral quality. Comparison of classification results with histopathological examination of surgical specimens showed sensitivity=93.7%, specificity=84.9%, PPV=95.2%, NPV=81.5% without the inclusion of MRS in the SVM analysis. When MRS was included, the figures increased to 95.1%, 90.7%, 97.2%, and 85.0%, respectively. CONCLUSIONS:Inclusion of 3T-MRS in the multi-parametric MRI evaluation of breast lesions improved the performance of the SVM-based classifier, showing a possible role of high-field MR spectroscopy in the differential diagnosis between benign and malignant breast lesions. Further research is however needed to confirm this initial evidence.

Introduction: In MR spectroscopy, it is crucial to recognize the reasons of inconsistent quantification of metabolite concentration due to inhomogeneities in the vicinity of the volume of interest (VOI) or to suboptimal coil geometry. The purpose of this work was to assess the relative response of a breast coil as a function of the position within the coil volume.

Poster: "ECR 2016 / B-1254 / 3T MR spectroscopy in the multi-parametric MRI evaluation of breast lesions: a pattern recognition approach" by: "C. Cavedon, L. Camera, I. Baglio, G. Meliado, F. Caumo, S. Montemezzi; Verona/IT"

The purpose of this study was to assess the performance of delayed second reading of screening mammograms when added to real-time reading plus immediate assessment.

PURPOSE:This study was done to verify the usefulness of preoperative breast magnetic resonance (MR) imaging in patients with newly diagnosed breast cancer. MATERIALS AND METHODS:A retrospective analysis of 291 patients with invasive breast cancer newly diagnosed with conventional breast imaging (mammography and ultrasound) was performed. All patients underwent MR imaging prior to surgery. The MR imaging detection rate of additional malignant cancers occult to mammography and ultrasound was calculated. Data were analysed with Fisher's exact test (p<0.05) according to the following parameters: histopathological features of the index tumour (histological type and size) and mammographic density [according to the Breast Imaging Reporting and Data System (BI-RADS) classification from 1 fatty to 4 dense). The gold standard was the histological examination on the surgical specimen. RESULTS:MR imaging identified 40 mammographically and sonographically occult malignant lesions other than the index cancer in 27/291 patients (9%). These additional cancers were located in the same quadrant as the index cancer in 13 women (4%), in a different quadrant in 12 (4%) and in the contralateral breast in the remaining two (1%). The cancer detection rate in the subgroup of index cancers with lobular histological type was 25%, significantly higher (p=0.03) than the detection rate of 11% recorded in the subgroup of ductal cancers. The cancer detection rate in the subgroup of index cancers >2 cm was 27%, significantly higher (p=0.001) than the rate of 8% found in the subgroup of index cancers <2 cm. Mammographic density was not correlated (p=0.48) with MR detection of additional cancer, with 14% of additional malignancies being detected in both dense and fatty breasts. CONCLUSIONS:In patients with newly diagnosed invasive breast cancer, preoperative MR imaging is useful for detecting additional synchronous malignancies that are not detected on conventional breast imaging. The cancer detection rate is 9%. The use of preoperative MR imaging as an adjunct to conventional breast imaging in women with an infiltrating lobular index cancer and an index cancer >2 cm is especially beneficial.

PURPOSE:The objective of this study was to determine the clinical value and accuracy of magnetic resonance (MR)-guided vacuum-assisted breast biopsy (VAB).MATERIALS AND METHODS:We retrospectively analysed 106 incidental breast lesions detected on MR imaging in 98 patients. Patients with nonpalpable suspicious lesions that were only MR visible were referred for MR-VAB performed with a 10-gauge needle. All patients with a VAB diagnosis of infiltrating carcinoma, carcinoma in situ or atypical epithelial hyperplasia were referred for surgery. Histopathology of the surgical specimen was considered the reference standard.RESULTS:MR-guided VAB was attempted in 29/106 lesions (27%); in 2/29 patients, the procedure could not be performed owing to failure to visualise the lesion. Lesions with clearly malignant features and borderline lesions (atypical ductal hyperplasias) were identified in 12 cases (44%) and benign entities in 15 (56%). Seven of 12 (58%) malignant lesions were <10 mm. Among the 27 successful MR-VAB procedures, VAB yielded one false-negative diagnosis (4%) and underestimation (4%). MR-guided VAB sensitivity and specificity were 92% and 100%, respectively, with a positive predictive value of 100% and a negative predictive value of 93%.CONCLUSIONS:The results of this study indicate that MR-guided VAB offers good accuracy in characterising nonpalpable breast lesions visible on MR imaging alone. Small lesion size (<1 cm) did not prove to be a limitation for the success of the procedure.