Respiratory motion-compensated radial dynamic contrast-enhanced (DCE)-MRI of chest and abdominal lesions

Wei Lin, Junyu Guo, Mark A. Rosen, Hee Kwon Song
2008 Magnetic Resonance in Medicine  
Dynamic contrast-enhanced (DCE)-MRI is becoming an increasingly important tool for evaluating tumor vascularity and assessing the effectiveness of emerging antiangiogenic and antivascular agents. In chest and abdominal regions, however, respiratory motion can seriously degrade the achievable image quality in DCE-MRI studies. The purpose of this work is to develop a respiratory motion-compensated DCE-MRI technique that combines the self-gating properties of radial imaging with the reconstruction
more » ... flexibility afforded by the golden-angle view-order strategy. Following radial data acquisition, the signal at k-space center is first used to determine the respiratory cycle, and consecutive views during the expiratory phase of each respiratory period (34-55 views, depending on the breathing rate) are grouped into individual segments. Residual intra-segment translation of lesion is subsequently compensated for by an autofocusing technique that optimizes image entropy, while intersegment translation (among different respiratory cycles) is corrected using 3D image correlation. The resulting motion-compensated, undersampled dynamic image series is then processed to reduce image streaking and to enhance the signal-tonoise ratio (SNR) prior to perfusion analysis, using either the k-space-weighted image contrast (KWIC) radial filtering technique or principal component analysis (PCA). The proposed data acquisition scheme also allows for high framerate arterial input function (AIF) sampling and freebreathing baseline T 1 mapping. The performance of the proposed radial DCE-MRI technique is evaluated in subjects with lung and liver lesions, and results demonstrate that excellent pixelwise perfusion maps can be obtained with the proposed methodology. Dynamic contrast-enhanced (DCE)-MRI has emerged as a prime method for evaluating tumor blood flow and capillary wall permeability, which is the target of many emerging antiangiogenic and antivascular agents (1-4). In DCE-MRI, dynamic T 1 -weighted image series following the intravenous bolus injection of contrast agents are acquired and subsequently analyzed to characterize tumor micro-vasculature. Accurate perfusion assessment with DCE-MRI requires high temporal resolution, particularly for the arterial
doi:10.1002/mrm.21740 pmid:18956465 pmcid:PMC4772667 fatcat:ewdgykbpujel3nkiumd3rruuby