TRADITIONAL POSTER - ismrm

Poster Sessions
Akaike model selection criterion applied to dynamic contrast-enhanced MR data of liver tumours. We demonstrate that the extended Kety model is preferred
within the tumour with a trend towards the Materne model within non-tumour liver tissue. This has implications for the identification of tumours in the liver
and for partial volume errors.
2729. A Semi-Automated Method for Obtaining the Arterial Input Function in Dynamic Breast Data
Xia Li 1,2 , E. Brian Welch 3 , A. Bapsi Chakravarthy 4 , Ingrid Mayer 5 , Mark Kelley 6 , Ingrid Meszoely 7 , Julie
Means-Powell 6 , John C. Gore, 28 , Thomas E. Yankeelov 1,2
1 Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 2 Institute of Imaging Science, Nashville,
TN, United States; 3 Philips Healthcare, Nashville, TN, United States; 4 Radiation Oncology, Vanderbilt University; 5 Medical
Oncology, Vanderbilt University; 6 Surgical Oncology, Vanderbilt University; 7 Radiology, Vanderbilt University; 8 Radiology and
Radiological Sciences , Vanderbilt University, Nashville, TN, United States
Quantitative analysis of dynamic contrast enhanced MRI (DCE-MRI) data requires the accurate determination of the time rate of change of the concentration
of contrast agent, Cp, in the blood pool; what is typically referred to as the arterial input function, or AIF. While there have been several methods suggested
for capturing AIF kinetics, many are difficult to apply in the particular case of breast cancer. Here, we propose a simple and effective approach to obtain the
AIF from breast DCE-MRI data. The method is based on tracking an initial seed point placed within the axillary artery.
2730. Tissue Estimated Vascular Input Functions Improve DCE-MRI Model Fitting
Michael Germuska 1 , Sophie Riches 1 , David Collins 1 , Geoffrey Payne 1 , Nandita deSouza 1 , Martin Leach 1 ,
Matthew Orton 1
1 CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, London, United
Kingdom
Dynamic contrast enhanced MRI requires an estimate or measurement of the arterial input function (AIF) to model pharmacokinetic behaviour. To reduce
the variability in a measured AIF, a population AIF is often used. Alternatively it is possible to obtain an AIF from local tissue. Pharmacokinetic models
driven by AIFs extracted from the prostate tissue were compared to a population AIF for 12 prostate cancer patients. Tissue estimated AIFs were found to
out performed the population AIF in terms of fitting residuals and variability in KTrans estimates. The results show tissue estimated AIFs can be used to
improve DCE-MRI model fitting.
2731. Identification of Hypoxic Regions In Vivo in the Prostate
Radka Stoyanova 1 , Ellen Ackerstaff 2 , HyungJoon Cho 2 , Jason A. Koutcher 2 , Alan Pollack 1
1 Radiation Oncology, University of Miami, Miami, FL, United States; 2 Medical Physics, Memorial Sloan-Kettering Cancer Center,
New York, United States
We present an application of Pattern Recognition techniques to identify the characteristic temporal pattern of hypoxia in Dynamic Contrast Enhanced
Magnetic Resonance Imaging (DCE-MRI). The approach is confirmed in DCE-MRI data from an animal model, acquired concurrently with several
complementary imaging modalities including pimonidazole staining. The technique is also applied to DCE-MRI data from the tumor of a prostate cancer
patient where a similar temporal pattern is uncovered in parts of the tumor. Our results suggest that by applying this approach we can potentially deconvolve
the hypoxic temporal pattern in in vivo data from patients with prostate cancer.
2732. Assessment of Tumor Hypoxia with DCE-MRI: A Preclinical Study on Human Melanoma Tumor
Lines
Tormod André Mjelde Egeland 1 , Jon-Vidar Gaustad 1 , Berit S. Mathiesen 1 , Einar Kåre Rofstad 1
1 Department of Radiation Biology, The Norwegian Radium Hospital, Oslo, Norway
Purpose: To study the potential usefulness of DCE-MRI for assessing the extent of tumor hypoxia. Methods: Gd-DTPA-based DCE-MRI was performed on
human melanoma xenografts from 8 different tumor lines grown orthotopically in mice. v e and K trans from Tofts model were obtained on a voxel-by-voxelbasis,
and compared with the radiobiologically hypoxic fraction (HF rad ). Results: A strong linear correlation between v e and HF rad (p