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BACKGROUND The objective of this study was to prospectively evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as an early imaging indicator of tumor histologic response to preoperative chemotherapy and as a possible prognostic factor for event-free survival (EFS) and overall survival in pediatric patients with newly diagnosed,(More)
Diffusion tensor MRI (DTI), using single-shot 2D diffusion weighted-EPI (2D ss-DWEPI), is limited to intracranial (i.c.) applications far from the sinuses and bony structures, due to the severe geometric distortions caused by significant magnetic field inhomogeneities at or near the tissue-air or tissue-bone interfaces. Reducing these distortions in(More)
OBJECTIVE The purpose of this study was to investigate contrast-enhanced ultrasound assessment of tumor response to antiangiogenic therapy in children and adolescents with solid malignancies. SUBJECTS AND METHODS Children with recurrent solid tumors who were enrolled in an institutional phase 1 study of antiangiogenic therapy underwent contrast-enhanced(More)
OBJECTIVES We sought to develop a simple and robust algorithm capable of automatically detecting centerlines and bifurcations of a three-dimensional (3D) vascular bed. MATERIALS AND METHODS After necessary preprocessing, an appropriate cost function is computed for all vessel voxels and Dijkstra's minimum-cost-path algorithm is implemented. By back(More)
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(More)
The purpose of this study is to investigate how the structures of polydisulfide Gd(III) complexes affect their pharmacokinetics and in vivo contrast enhancement as biodegradable macromolecular MRI contrast agents. A negatively charged polydisulfide Gd(III) complex, (Gd-DTPA)-cystine copolymers (GDCP), and a neutral agent, (Gd-DTPA)-cystine diethyl ester(More)
Biodegradable macromolecular Gd(III) complexes, Gd-DTPA cystine copolymers (GDCP), were grafted with PEG of different sizes to modify the physicochemical properties and in vivo MRI contrast enhancement of the agents and to study the effect of PEG chain length on these properties. Three new PEG-grafted biodegradable macromolecular gadolinium(III) complexes(More)
Poly(L-glutamic acid) (PGA)-cystamine-[gadolinium (Gd)-DO3A] was prepared in high yield with a high Gd-DO3A conjugation efficiency. Approximately 55% of the carboxylic groups in PGA were loaded with Gd-DO3A via cystamine as the spacer. Cystamine can be readily cleaved by endogenous thiols to release the Gd(III) chelates from the conjugate facilitating(More)
The experimental validation of a model-based, thermal therapy control system which automatically and simultaneously achieves the specified efficacy and safety objectives of the treatment is reported. MR-thermometry measurements are used in real-time to control the power of a stationary, focused ultrasound transducer in order to achieve the desired treatment(More)