Traditional Posters: Body Imaging

Sung Hun Kim¹, Jae Young Byun¹, Eun Suk Cha¹, Hyun Sook Kim¹, Jae Jeong Choi<sup>1

1</sup>Radiology, College of Medicine, the Catholic University of Korea, Seocho gu, Seoul, Korea, Republic of

Invasive lobular carcinoma (ILC) is the second most common breast cancer after invasive ductal carcinoma (IDC). The incidence of ILC has continuously increased probably due to hormone replacement therapy. There were little studies to compare the imaging findings of ILC and IDC according to BI-RADS. The purposes of our study were to characterize the mammographic and MR imaing features of ILC and to compare these imaging features with those of IDC. Furthermore, the multiplicity and MRI diagnostic accuracy to detect the multiplicity apart from the index mass were determined.

2495. BOLD Imaging of Compressed Breast Hemodynamics

Stefan Alexandru Carp¹, Azma Mareyam¹, Lawrence Wald¹, David Alan Boas<sup>1

1</sup>Radiology, Massachusetts General Hospital, Charlestown, MA, United States

External compression induced hemodynamic changes in the breast have recently been investigated as potential biomarkers of breast cancer. Using fast diffuse NIR spectroscopy our group has demonstrated the non-invasive estimation of breast tissue blood flow and oxygen consumption. Consequently, we have designed an integrated MRI-optical breast compression platform for simultaneous acquisition of MR and optical images. MR scans provide structural prior information for optical reconstructions, as well as hemodynamic (BOLD) images for cross-validation against optically measured deoxy-hemoglobin. We describe the MRI breast compression platform and present initial results demonstrating contrast between the BOLD signal evolution in fibro-glandular vs. adipose tissue.

2496. Development of Tissue Susceptibility Matched Pyrolytic Graphite Foam for Improved Frequency Selective Fat Suppression and Motion Suppression in Breast MRI

Gary Lee¹, Patrick Goodwill¹, Kevin Phuong², Ben Inglis³, Brian Hargreaves⁴, Steven Conolly<sup>1,2

1</sup>Berkeley/UCSF Bioengineering Joint Graduate Group, Berkeley, CA, United States; ²Bioengineering, University of California - Berkeley, Berkeley, CA, United States; ³Henry J Wheeler, Jr. Brain Imaging Center, Berkeley, CA, United States; ⁴Radiology, Stanford University, Palo Alto, CA, United States

DCE breast MRI is emerging as the second most common diagnostic imaging modality for breast cancer, which has ~200,000 new cases and ~40,000 deaths annually. However, breast MRI still lacks adequate specificity. Magnetic susceptibility mismatches near the breast/air interface contribute to field inhomogeneities which make frequency selective fat suppression techniques more difficult. We have developed tissue susceptibility matched pyrolytic graphite foam that is lightweight, safe for patients, and compatible with embedded RF coils. PG foams may improve frequency selective fat suppression for breast MRI and provide more robust motion suppression, which may lead to improved specificity in breast cancer diagnosis.

2497. Cactus Spines as Fiducials for MRI and Pathology Correlation of Ex-Vivo Human Lymph Nodes

Mies A. Korteweg¹, Jaco J.M. Zwanenburg¹, Cristian Koolstra, Paul J. van Diest², Arjen J. Witkamp³, Willem P.Th.M. Mali¹, Peter R. Luijten¹, Wouter B. Veldhuis<sup>1

1</sup>Radiology, University Medical Center Utrecht, Utrecht, Netherlands; ²Pathology, University Medical Center Utrecht, Utrecht, Netherlands; ³Surgery, University Medical Center Utrecht, Netherlands

We describe the properties and suitability of cactus spines used as fiducial markers in ex-vivo human lymph nodes for the correlation of MRI to histopathology. In 42 nodes cactus spines were inserted before scanning at 7T. Afterwards the nodes were pathologically examined. Geometric distortions, susceptibility- or pathologic examination artifacts and identification on MRI were scored. Cactus spines were readily identified both on MRI and at histopathology. No interference was noted for either analysis. It was concluded that cactus spines are suitable fiducials which aid in the accurate correlation of intranodal imaging features to histopathology.

2498. Local Excitation Important for Breast MR: Signal Energy from Outside the FOV Decreases Contrast Using Non-Cartesian Acquisitions