Longitudinal, intermodality registration of quantitative breast PET and MRI data acquired before and during neoadjuvant chemotherapy: preliminary results.
OBJECTIVE
The authors propose a method whereby serially acquired DCE-MRI, DW-MRI, and FDG-PET breast data sets can be spatially and temporally coregistered to enable the comparison of changes in parameter maps at the voxel level.


METHODS
First, the authors aligned the PET and MR images at each time point rigidly and nonrigidly. To register the MR images longitudinally, the authors extended a nonrigid registration algorithm by including a tumor volume-preserving constraint in the cost function. After the PET images were aligned to the MR images at each time point, the authors then used the transformation obtained from the longitudinal registration of the MRI volumes to register the PET images longitudinally. The authors tested this approach on ten breast cancer patients by calculating a modified Dice similarity of tumor size between the PET and MR images as well as the bending energy and changes in the tumor volume after the application of the registration algorithm.


RESULTS
The median of the modified Dice in the registered PET and DCE-MRI data was 0.92. For the longitudinal registration, the median tumor volume change was -0.03% for the constrained algorithm, compared to -32.16% for the unconstrained registration algorithms (p = 8 × 10(-6)). The medians of the bending energy were 0.0092 and 0.0001 for the unconstrained and constrained algorithms, respectively (p = 2.84 × 10(-7)).


CONCLUSIONS
The results indicate that the proposed method can accurately spatially align DCE-MRI, DW-MRI, and FDG-PET breast images acquired at different time points during therapy while preventing the tumor from being substantially distorted or compressed.
Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 and Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675.
Nkiruka C
NC
Atuegwu
Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310.
Xia
X
Li
Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310.
Lori R
LR
Arlinghaus
Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675; and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838.
Richard G
RG
Abramson
Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310 and Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675.
Jason M
JM
Williams
Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-5671 and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838.
A Bapsi
AB
Chakravarthy
Department of Medical Oncology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6307 and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838.
Vandana G
VG
Abramson
Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2310; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675; Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37240-1807; Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838; Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1631; and Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6838.
Thomas E
TE
Yankeelov
D000328:Adult; D000465:Algorithms; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D016896:Treatment Outcome; D047368:Tumor Burden
D019788:Fluorodeoxyglucose F18