Breast MRI Gets Better!
Thursday 23 April 2009
Room 312 10:30-12:30


Eva C. Gombos and Ingrid S. Gribbestad

10:30 579. Fat Suppression with Independent Shims for Bilateral Breast MRI
    Misung Han1,2, Sandra Rodriguez1, Anne M. Sawyer1, Bruce L. Daniel1, Charles Cunningham3, John M. Pauly2, Brian A. Hargreaves1
Radiology, Stanford University, Stanford, CA, USA; 2Electrical Engineering, Stanford University, Stanford, CA, USA; 3Medical Biophysics, University of Toronto, Toronoto, ON, Canada
    There exists a significant static field inhomogeneity for breast MRI related to the shape of the breast and the susceptibility difference at air/tissue interfaces. Field inhomogeneity can cause imaging artifacts or failure in fat suppression, especially when spectral-selective fat suppression methods are used. For bilateral breast MRI, the large field variation over the two breast volumes makes robust fat suppression more difficult. We compared fat suppression by using standard shims and independent shims of each breast, incorporated with a dual-band spectral-spatial pulse. Our experiments show that independent shims provide improved fat suppression compared to standard shims.
10:42 580. Preoperative Breast MRI in Patients with Invasive Lobular Carcinoma Reduces the Rate of Surgical Re-Excision
    Ritse Maarten Mann1, Claudette E. Loo2, Jelle O. Barentsz1, Kenneth G.A. Gilhuijs2, Theo Wobbes3, Carla Boetes1,4
Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2Radiology, The Netherlands Cancer Institute \ Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands; 3Surgery, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 4Radiology, Maastricht University Medical Centre, Maastricht, Netherlands

In invasive lobular carcinoma of the breast (ILC), conventional imaging is unable to assess tumor size. Though preoperative MRI has been shown more reliable, the use of preoperative MRI is disputed. We assessed the need for surgical re-excision and the rate of mastectomies in patients treated for ILC with or without preoperative breast MRI. Our results clearly show that preoperative MRI reduces the rate of re-excisions without increasing the rate of mastectomies and should thus be performed in all patients.



10:54 581. MRI Characterization of Ex Vivo Healthy Human Lymph Nodes at 7T

Mies Andrea Korteweg1, Jaco J.M. Zwanenburg1, Paul van Diest2, I. H. Borel Rinkes3, Willem P. Mali1, Peter R. Luijten1, Wouter B. Veldhuis1
Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Pathology, University Medical Center Utrecht, Utrecht, Netherlands; 3Surgery, University Medical Center Utrecht, Utrecht, Netherlands

    Nodal status strongly determines prognosis in breast cancer patients. We analyzed morphology and relaxation times of healthy human axillary nodes at 7T, with pathologic examination as the gold standard. Of two axillary lymph node dissection specimens the mean nodal T1, T2*, and T2 relaxation times, as well as the apparent diffusion coefficients (ADC) were determined. Results: Mean T1; 1387.22±114.81ms, mean T2*; 18.38±7.33ms, mean T2; 72.05±14.55ms, mean ADC; 0.40±0.11•10-3 s/mm2. MRI allowed detailed identification of B-cell follicles as well as blood- and lymph vessels. MRI correlated well with pathology.
11:06 582. Quantitative DWI for Differentiation of Benign and Malignant Breast Lesions: The Influence of the Choice of B-Values
    Nicky HGM Peters1, Koen L. Vincken2, Maurice A.A.J. van den Bosch1, Peter R. Luijten2, Willem PThM Mali1, Lambertum W. Bartels2
Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands
    The ADC varies with the choice of different b-values. However, the diagnostic performance is not affected by the choice of b-values. The results imply that to differentiate benign from malignant breast lesions, the choice of b-values is not important. However, when the ADC value is compared to reported ADC threshold values in literature, the b-values should be taken into account.
11:18 583. Comparison of Different Diffusion Parameters in DWI for Differentiation of Breast Lesions at 3.0 Tesla – Effects of Perfusion and Diffusion Compartments on ADC
    Wolfgang Bogner1,2, Stephan Gruber1,2, Katja Pinker1,2, Günther Grabner1,2, Andreas Stadlbauer3, Ewald Moser2, Thomas Helbich1, Siegfried Trattnig1,2
Department of Radiology, Medical University Vienna, Vienna, Austria; 2MR Center of Excellence, Medical University Vienna, Vienna, Austria; 3Landesklinikum St.Pölten, St.Pölten, Austria
    Seventy-four patients suspect for breast cancer were examined on a 3T MR system with an additional DWI protocol. The impact of different diffusion schemes on diagnostically relevant parameters such as CNR and ADC precision/accuracy was investigated. The influence of perfusion and compartment effects on the ADC were studied in the breast. The diagnostic accuracy of an optimized diffusion scheme were determined. The application of such an optimized DWI protocol at 3T provided a diagnostic sensitivity of 96% and specificity of 94% in our patient group of 69 women.
11:30 584. Statistical Modeling of Longitudinal Total Choline Measurements During Chemotherapy
    Ann M. Brearley1, Lynn E. Eberly1, Naomi R. Mraz2, Michael T. Nelson2, Douglas Yee3, Michael Garwood4, Patrick J. Bolan5
Biostatistics, University of Minnesota, Minneapolis, MN, USA; 2Radiology, University of Minnesota, Minneapolis, MN, USA; 3Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA; 4Center for MR Research / Radiology, University of Minnesota, Minneapolis, MN, USA; 5Center for MR Research / Radiology, University of Minnesota, Minneapolis, MN, USA
    In this work we describe a retrospective analysis of choline measurements acquired in breast cancer subjects undergoing neoadjuvant chemotherapy. We proposed a series of models to describe the time-course of the choline response during therapy, and selected an optimal model based on Akaike and Bayesian information criteria. The model fits, and the relative suitability of the various models, were then used to infer important characteristics of the total choline response that are useful for designing future clinical trials.
11:42 585. The Association Between Choline Concentration Measured by 1H MR Spectroscopy with Clinical Characteristics and Biomarkers of Breast Cancer
    Hui Liu1, Jeon-Hor Chen1,2, Hyeon-Man Baek1, Ke Nie1, Hon J. Yu1, Orhan Nalcioglu1, Min-Ying Lydia Su1
Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, USA; 2Department of Radiology, China Medical University, Taichung, Taiwan
    We investigated the association between tCho measured by single-voxel MRS (using the internal reference method) and other clinical characteristics in different breast lesions. A total of 63 patients were included. A higher choline concentration was significantly correlated with younger age (p<0.05), and was associated with DCE washout pattern (higher angiogenesis), higher tumor grade, and in patients with triple negative breast cancer, but not reaching significance level (p<0.1). We also found other well-known relationships such as a high correlation between ER and PR (p < 0.001), and that mass lesions are more likely to show washout DCE pattern (p<0.017).
11:54 586. Diagnostic Value of Breast Proton Magnetic Resonance Spectroscopy at 1.5T in Different Histological Types
    Hyeon-Man Baek1,2, Jeon-Hor Chen3,4, Orhan Nalcioglu3, Min-Ying Su3
Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA; 2Center for Function Onco-Imaging , University of California-Irvine, Irvine, CA, USA; 3Center for Function Onco-Imaging, University of California-Irvine, Irvine, CA, USA; 4Department of Radiology, China Medical University Hospital, Taichung 404, Taiwan
    The impact of tumor size and histological types on the diagnostic performance of in vivo 1H MR spectroscopy was investigated in 105 biopsy-confirmed breast tumors. The sensitivity was only 46% in tumors of 1.0-1.9 cm, then increased to 70% in 2.0-2.9 cm group, and 82% in 3.0 cm & above group. The detection sensitivity was higher for invasive cancer (71%) than for DCIS (27%), and higher for invasive ductal cancer (74%) or mixed type (67%) than for invasive lobular cancer (50%). Further improvement in the signal-to-noise ratio (SNR) may enhance the detection of tCho and improve the diagnostic sensitivity. One approach is to use the scanner at higher magnetic fields (3.0T and 7.0T).
12:06 587. Dynamic Imaging of Dual Contrast-Enhancement Using a Combined MR-Optical Imaging System
    Mehmet Burcin Unlu1, Yuting Lin1, Orhan Nalcioglu1, Gultekin Gulsen1
John Tu & Thomas Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, USA
    We measure the enhancement kinetics of an optical and an MR contrast agent in a small animal breast tumor model (R3230 ac) simultaneously using a combined magnetic resonance-diffuse optical tomographic imaging system. A mixture of a small molecular-weight MR contrast agent Gd-DTPA and a large molecular-weight optical contrast agent indocyanine green was administered intravenously for multimodal dynamic imaging.
12:18 588. Image-Guided Combined SiRNA and Enzyme/Prodrug Cancer Therapy
    Cong Li1, Marie-France Penet1, Flonné Wildes1, Tomoyo Takagi1, Paul Winnard Jr. 1, Dmitri Artemov1, Zaver M. Bhujwalla1
Radiology, Medical School of Johns Hopkins Univ., Baltimore, MD, USA
    The ability to downregulate specific pathways that are overexpressed and critically important in cancer using small interfering RNA (siRNA) technology provides unprecedented opportunities to develop novel cancer-cell specific treatments. The ability to detect the delivery of the siRNA and combine it with the delivery of a chemotherapeutic agent primarily localized within the tumor would be of significant advantage in this quest. Here we have developed a prototype agent to image the delivery of a prodrug enzyme, bacterial cytosine deaminase, that converts a nontoxic prodrug 5-fluorocytosine to 5-fluorouracil, in combination with siRNA targeting of choline kinase, an enzyme critically important in breast cancer.