Time

Prog #

Xin Li¹, Wei Huang², Elizabeth A. Morris², Luminita A. Tudorica³, William D. Rooney¹, Ya Wang², Jingang Xu¹, Charles S. Springer, Jr. ¹

¹Oregon Health & Science University, Portland, USA; ²Memorial Sloan Kettering Cancer Center, USA; ³State University of New York at Stony Brook, USA

Dynamic-Contrast-Enhanced (DCE) MRI data were acquired from the lesions of 22 breast cancer patients, who had been screened positive by institutional protocols, but before biopsy and pathology analyses were performed.  The data were subjected to pharmacokinetic analyses by both the Standard Model (SM) and the Shutter Speed Model (SSM).  For ROIs circumscribing every one of the 15 lesions subsequently proven benign, the SM returned essentially the same value for K^trans (a measure of CR extravasation rate) as the SSM.  However, for every one of the 7 malignant tumors, the SM underestimated K^trans.  This allows complete separation of malignant from benign tumors.

Elizabeth Ramsay¹, Donald Plewes¹

¹Sunnybrook Health Sciences Centre, Toronto, Canada

In this work, the effect of reducing the spatial resolution of the a priori phase information on Single-Point Dixon (SPD) images is examined, considering both noise performance and the quality of the fat-water separation.  Decreasing the spatial resolution of the a priori images improves the noise properties of fat-water images, as well as reducing acquisition time.  Human and phantom studies show that is possible to reduce the size of the acquisition matrix for the phase mapping scans to about 64x64 (voxel size 3mm) without compromising the quality of fat-water separation.

Rebecca Rakow-Penner¹, Laura Pisani¹, Bruce Daniel¹, Stephanie Oberfoell¹, Christine Law¹, Gary H. Glover¹

¹Stanford University, Stanford, California , USA

BOLD contrast imaging applied to breast tumors may provide useful clinical information on tumor oxygenation.  Before studying tumors, we are developing a robust method for measuring BOLD contrast in healthy breast tissue at 3T.  The method includes heart saturation to diminish cardiac motion artifact, along with corrections for respiratory motion and cardiac pulsation.  A rapid multi-interleave spiral sequence is used to acquire the images.  Results indicate that in healthy breast tissue that there is an inverse correlation between BOLD contrast and oxygenation.

Kristin L. Granlund¹, ², Brian A. Hargreaves¹

¹Stanford University, Stanford, California , USA

Off-resonance is a problem in spiral imaging because it causes image blurring and water/fat separation to fail.  The problem may be severe when imaging over large volumes, such as in bilateral breast MRI.  This project simultaneously corrects for off-resonance and performs water/fat separation using a multi-frequency reconstruction for 3D stack-of-spiral breast images with multiple echo times.

Erez Eyal¹, Edna Furman-Haran¹, Hadassa Degani¹

¹Weizmann Institute of Science, Rehovot, Israel

Mammary malignancies typically develop from the ductal epithelial cells, and spread within the ducts. Consequently, the ductal structures are an important area of investigation of both normal breast development and malignant breast transformation. Our aim is to develop an MRI method for tracking the spatial anisotropic diffusion of the water in the breast ducts and thereby map the ductal tree. The preliminary results show that diffusion in the mammary tissue has an anisotropic nature and that the orientation of the primary diffusion direction indicates that the tube-like micro structure of the ductal system can be tracked by DT-MRI

Ka-Loh Li¹, Savannah C. Partridge², Bonnie N. Joe¹, Jessica Gibbs¹, Ying Lu¹, Evelyn Proctor¹, Laura Esserman¹, Nola M. Hylton¹

¹University of California, San Francisco, San Francisco, USA; ²University of Washington, Seattle, Washington, USA

This study aimed to evaluate the predictive value of high spatial resolution signal enhancement ratio (SER) MR imaging performed prior to neoadjuvant chemotherapy in patients with breast cancers. The major finding was that breast tumor volume calculated from the number of voxels with high SER value and the volume (in voxels) of cancerous breast tissue infiltrating into the parenchyma (Such infiltrating voxels were of low SER) were important predictors of recurrence. 6/10 of patients with early recurrence (within 1.6 years) and 6/9 of deceased patients were identified. This study demonstrated the potential of pre-neoadjuvant chemotherapy contrast-enhanced MRI in predicting disease recurrence.

Tone Frost Bathen¹, Beathe Sitter¹, Hans Fjøsne², David E. Axelson³, Steinar Lundgren¹, ⁴, Ingrid S. Gribbestad¹

¹NTNU, Trondheim, Norway; ²St Olav Univeristy Hospital, Trondheim, Norway; ³MRi_Consulting, Kingston, Canada; ⁴St Olav University Hospital, Trondheim, Norway

MR metabolomics is the systematic study of MR visible small-molecules. Metabolite profiles of breast cancer tissue have been found to correlate to lymph node and hormone receptor status. In this study, breast cancer tissue from patients with invasive ductal carcinomas were analysed by HR MAS MRS. The spectra were further analysed in a supervised manner with Support Vector Machine, relating selected variables from the spectra to the actual survival status 4 years after surgery. This preliminary investigation suggests that MR metabolomics can predict long term breast cancer survival. Early identification of patients with poor prognosis may be important for the administration of more aggressive treatment and closer follow-up of this patient group.

Thomas Yankeelov¹, E. Brian Welch², Anuradha Chakravarthy³, Robert Lee³, Darla Freehardt³, Ingrid Mayer³, Ingrid Meszoely³, Mark Kelley³, Julie Means-Powell³, John C. Gore³

¹Vanderbilt University, Nashville, USA; ²Philips Medical Systems, USA; ³Vanderbilt University, USA

We apply three statistical measures to determine when water exchange effects should be incorporated in DCE-MRI data analysis.  Simulations predict that after ti becomes above ~0.1 s, the FXR model will be preferred and this is what is seen in the breast cancer data.  We conclude that, at least in the case of human breast cancer, water exchange effects should be explicitly incorporated in the analysis of DCE-MRI data.

Scott Logan Lipnick¹, Xiaoyu Liu¹, Nanette DeBruhl¹, M. Albert Thomas¹

¹University of California, Los Angeles, Los Angeles, California , USA

The reported specificity of DCE-MRI has been variable, ranging from 37% to 97%, resulting in many unnecessary biopsies of benign lesion.  Studies of breast cancer cell lines and breast tumors have consistently shown that choline (Cho) is elevated in malignant lesions.  Magnetic Resonance Spectroscopy (MRS) allows noninvasive measurements of the concentrations of metabolites such as Cho in human breast. The purpose of this pilot study was to combine the DCE breast MRI analysis with localized two-dimensional MR correlated spectroscopy (2D L- COSY) in order to increase the specificity of breast cancer detection.

Robert E. Lenkinski¹, Mostafa Elian¹, Xiaoen Wang¹, S Nahum Goldberg¹

¹Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA

There is increasing interest in applying proton MRS to increase the specificity of characterizing breast lesions.  The most common approach is to employ DCEMRI to identify suspicious lesions followed by localized proton MRS to determine either the presence of choline containing compounds or their absolute concentrations. The implicit assumption is that that the administration of a Gadolinium based contrast agent has little or no effect on the choline resonance.  We report both in vitro and in vivo investigations of the effects of six commercially available contrast agents on the choline resonance. All of the negatively charged chelates showed significant effects.