Erin B Adamson¹, Roberta M Strigel^1,2,3, David J Niles¹, Kai D Ludwig¹, Ben L Cox^1,4,5, Amy R Moser^2,6, and Sean B Fain^1,3,7
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ²Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States, ⁴Morgridge Institute for Research, Madison, WI, United States, ⁵Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI, United States, ⁶Human Oncology, University of Wisconsin-Madison, Madison, WI, United States, ⁷Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States

Hyperpolarized (HP) ¹³C MRSI, dynamic contrast-enhanced (DCE) MRI, and blood-oxygen-level dependent (BOLD) MRI have the potential to non-invasively characterize tumor metabolism, perfusion, and oxygenation, respectively, and aid in the development of individualized treatment plans for cancer patients. However, a regional comparison of these non-invasive techniques for probing the tumor microenvironment has not been explored. This work aims to test the feasibility of performing quantitative, spatial analysis and comparison of HP ¹³C MRSI and BOLD and DCE MRI in a murine breast cancer model. 

Yong Chen¹, Shivani Pahwa¹, Jesse Hamilton², Sara Dastmalchian¹, Donna Plecha³, Nicole Seiberlich², Mark Griswold¹, and Vikas Gulani^1
1Department of Radiology, Case Western Reserve University, Cleveland, OH, United States, ²Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ³Department of Radiology, University Hospitals Case Medical Center, Cleveland, OH, United States

In this study, a rapid relaxometry method was developed for breast imaging using the MRF technique, which allows simultaneous and volumetric quantification of T₁ and T₂ relaxation times for breast tissues.

Gorane Santamaria¹, Jessica Buck^2,3, Leah Best⁴, David Clark⁵, Judith Silcock⁵, Peter Lau⁴, Saadallah Ramadan⁶, Scott Quadrelli^3,7, Peter Malycha³, and Carolyn Mountford^3
1Hospital Clinic de Barcelona, Barcelona, Spain, ²Oxford University, Oxford, United Kingdom, ³Translational Research Institute, Brisbane, Australia, ⁴Hunter New England Area Health, Newcastle, Australia, ⁵The Breast and Endocrine Centre, Gateshead, Gateshead, Australia, ⁶University of Newcastle, Australia, Newcastle, Australia, ⁷Queensland University of Technology, Brisbane, Australia

Women carrying the BRCA1 and BRCA2 gene mutations exhibited lipid and metabolite profiles consistent with very early deregulation recorded earlier in cancer cell models. The deregulation was different for BRCA1 and BRCA2. Here we report a longitudinal study where these same women are monitored every six month using the L-COSY MRS method and every 12 month with contrast enhanced MRI.  For most women in the study the biomarkers remained relatively stable over time. Of the 6 BRCA1 and 10 BRCA2 patients examined, one BRCA1 patient and one BRCA2 patient showed further deregulation.

Subashini Srinivasan¹, Brian A Hargreaves¹, and Bruce L Daniel^1
1Radiology, Stanford University, Stanford, CA, United States

Three-dimensional breast dynamic contrast-enhanced imaging is susceptible to deformable motion and affects both semi-quantitative and pharmacokinetic parameters. B-Spline motion registration with a mutual information metric is often used to register DCE images but is sometimes susceptible to introduction of new motion. Here we have introduced a fat-based motion registration, using a mean-squared-difference signal metric, to register the water images without introducing new motion. The acquired images and both registration methods were qualitatively assessed in 16 breasts. Voxel-by-voxel pharmacokinetic mapping was also performed in 21 tumors. Our results show that fat-based registration can be used to register the water images with improved image quality and reduced errors in quantification.

Olgica Zaric¹, Katja Pinker-Domenig^2,3, Esau Poblador ¹, Vadimir Mlynarik¹, Thomas Helbich⁴, Siegfrid Trattnig^1,5, and Wolfgang Bogner^1
1High Field Magnetic Resonance Centre, Medical University of Vienna, Vienna, Austria, ²Department of Biomedical Imaging and Image-guided Therapy, Medical University Vienna, Vienna, Austria, ³Molecular Imaging and Therapy Service, Memorial Sloan Kettering Cancer Center, New York, NY, United States, ⁴Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria,⁵Christian Doppler Lab for Clinical Molecular MRI, Christian Doppler Forschungsgesellschaft, Vienna, Austria, Vienna, Austria

Proteoglycans content in malignant tumors may provide information regarding the altered metabolism and neoplastic cell behavior. The aim of this study was to investigate the feasibility of gagCEST imaging in patients with breast tumors at 7 Tesla. Eleven patients with 15 lesions were examined. gagCEST imaging was performed with 1.7mm in-plane resolution and nine minutes of measurement time. Results based on MTRasym showed excellent differentation between malignant and benign lesions (CI=95%, p=0.001) and insignificant difference between benign and healthy tissue (CI=95%, p=0.159). gagCEST has a great potential in breast tumors evaluations providing substantially different information obtained with standard MRI techniques.

Prateek Prasanna¹, Nathaniel Braman¹, Salendra Singh¹, Donna Plecha², Hannah Gilmore², Lyndsay Harris², Tao Wan³, Vinay Varadan¹, and Anant Madabhushi^1
1Case Western Reserve University, Cleveland, OH, United States, ²University Hospitals, Cleveland, OH, United States, ³Beihang University, Beijing, China, People's Republic of

  We present the initial results of using a novel radiogenomic descriptor, CoLlAGe, on breast DCE-MRI to identify associations with HER2+ breast cancer subtypes. Current method involves using a PAM50 assay to analyze primary tumor tissues. CoLlAGe is a quantitative measurement of the degree of order/disorder of localized image gradient orientations. We extract CoLlAGe entropy from the regions of interest. Unsupervised hierarchical clustering of the entropy statistics show that we can segregate the cohort into three distinct subtypes (enriched, basal and luminal), as identified by PAM50 assay. CoLlAGe resulted in higher clustering accuracy as compared to pharmacokinetic parameters and signal intensities.

Glen Morrell¹, Josh Kaggie², Matthew Stein¹, Scott Parker¹, and Neal Bangerter^3
1Radiology, University of Utah, Salt Lake City, UT, United States, ²Radiology, University of Cambridge, Cambridge, United Kingdom, ³Electrical and Computer Engineering, Brigham Young University, Provo, UT, United States

We have performed rapid high-resolution breast sodium MRI relaxometry using a custom sodium breast phased array coil.  Clear delineation of short- and long-T2* components of the sodium signal is possible with a spatial resolution of 3.75 x 3.75 x 4mm over the entire breast with a total imaging time of under 10 min.  This method will allow the investigation of the potential of sodium relaxometry to improve the specificity of breast MRI for the detection of breast cancer.

Suzan Vreemann¹, Albert Gubern-Merida¹, Susanne Lardenoije¹, Nico Karssemeijer¹, and Ritse M. Mann^1
1Radiology and Nuclear Medicine, Radboudumc, Nijmegen, Netherlands

Women at increased risk for breast cancer require annual mammography and MRI. The purpose of this study is to evaluate cancers detected in MRI screening and assess the visibility on prior MRI-examinations. MRI-scans of breast cancers detected in our MRI screening program were re-evaluated and lesions on the diagnostic MRI and prior MRI were scored according to Breast Imaging Reporting and Data (BI-RADS) MR-lexicon. The visibility of the lesions on the prior MRI was rated as visible, minimal sign and invisible. Our results show that almost one third of the breast cancers should have been recalled based on consensus review. 

Laura Heacock¹, Yiming Gao¹, Samantha Heller¹, Amy Melsaether¹, Sungheon Kim^1,2, and Linda Moy^1
1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, ²Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States

GRASP DCE-MRI (Golden-angle Radial Sparse Parallel) DCE-MRI allows simultaneous high spatial and temporal resolution. The purpose of this study was to evaluate breast lesion conspicuity between GRASP and conventional Cartesian sampling DCE-MRI. Readers assessed conspicuity of 48 biopsy-proven lesions on conventional DCE-MRI and subsequent GRASP biopsy. No significant difference was found between the two techniques for all lesions (p=0.21, p=0.19, p=0.46), masses (p=1.0, p=0.48, p=0.7) or NME (p=0.18,p=0.08, p=0.64). There was strong reader agreement in evaluating conspicuity (ICC=0.735). GRASP DCE-MRI is comparable to conventional DCE-MRI imaging for masses and NME with diagnostic-quality high spatial resolution and flexibility of temporal resolution. 

Eugene Kim¹, Jana Cebulla¹, Astrid Jullumstrø Feuerherm², Berit Johansen², Olav Engebråten³, Gunhild Mari Mælandsmo³, Tone Frost Bathen¹, and Siver Andreas Moestue^1
1MR Cancer Group, Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, ²Avexxin AS, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway, ³Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway

This study investigated the relationship between tumor vascular function (DCE-MRI) and structure (ex vivo micro-CT). Control tumors did not exhibit any significant correlations between micro-CT and DCE-MRI parameters. Tumors treated with bevacizumab or a cPLA2 inhibitor (AVX235), both anti-angiogenic drugs, displayed reduced perfusion and vascularization. But interestingly, there was a significant positive correlation between vascular surface area and Ktrans in AVX235-treated tumors, whereas the corresponding correlation was negative in bevacizumab-treated tumors. This suggests that different therapies can differentially modulate the vascular structure-function relationship, which highlights the challenge in interpreting DCE-MRI measurements and adopting them as clinical biomarkers of therapeutic response.