Magnetic resonance macromolecular agents for monitoring tumor microvessels and angiogenesis inhibition.

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using macromolecular contrast media enables assessments of the tumor vasculature based on the differential distribution of the contrast agent within normal and pathologic tissues. Quantitative assays of both morphologic and functional properties can provide useful diagnostic insight into tissue angiogenesis. The use of MRI enhanced with macromolecular agents for the characterization of tumor microvessels has been experimentally demonstrated in a range of malignant tumor types.

MR angiography of tumor-related vasculature: from the clinic to the micro-environment.

Angiogenesis is a very important process for tumor growth and proliferation. Given its high temporal and spatial resolution, magnetic resonance (MR) imaging is well suited for use in the assessment of angiogenesis. MR angiography can be used clinically and experimentally for identification of tumor feeding and draining vessels, for tumor characterization, and for treatment planning.

Magnetic resonance characterization of tumor microvessels in experimental breast tumors using a slow clearance blood pool contrast agent (carboxymethyldextran-A2-Gd-DOTA) with histopathological correlation.

Carboxymethyldextran (CMD)-A2-Gd-DOTA, a slow clearance blood pool contrast agent with a molecular weight of 52.1 kDa, designed to have intravascular residence for more than 1 h, was evaluated for its potential to characterize and differentiate the microvessels of malignant and benign breast tumors. Precontrast single-slice inversion-recovery snapshot FLASH and dynamic contrast-enhanced MRI using an axial T1-weighted three-dimensional spoiled gradient recalled sequence was performed in 30 Sprague-Dawley rats with chemically induced breast tumors.

The choice of region of interest measures in contrast-enhanced magnetic resonance image characterization of experimental breast tumors.

Objectives: The objectives of this study were to determine if magnetic resonance (MR) estimates of quantitative tissue microvascular characteristics from regions of interest (ROI) limited to the tumor periphery provided a better correlation with tumor histologic grade than ROI defined for the whole tumor in cross-section.

Methods: A metaanalysis was based on 98 quantitative MR image breast tumor characterizations acquired in 3 separate experimental studies using identical methods for tumor induction and contrast enhancement.

Results: The endothelial transfer coefficient (K) of albumin (Gd-DTPA)30 from the tumor periphery correlated (r = 0.

MRI monitoring of Avastin antiangiogenesis therapy using B22956/1, a new blood pool contrast agent, in an experimental model of human cancer.

Purpose: To evaluate the diagnostic and prognostic potential of a new protein-binding contrast medium, B22956/1, for quantitatively characterizing tumor microvessels by MRI and monitoring response to antiangiogenic therapy.

Materials And Methods: Dynamic contrast-enhanced MRI (DCE-MRI) was performed in an experimental cancer model with the use of the novel protein-binding agent B22956/1, a low molecular contrast agent (ProHance), and a macromolecular contrast medium, albumin-(Gd-DTPA). MDA-MB-435, a human cancer cell line, was implanted in 22 athymic rats.

Tumor microvascular changes in antiangiogenic treatment: assessment by magnetic resonance contrast media of different molecular weights.

Purpose: To test magnetic resonance (MR) contrast media of different molecular weights (MWs) for their potential to characterize noninvasively microvascular changes in an experimental tumor treatment model.

Materials And Methods: MD-MBA-435, a poorly differentiated human breast cancer cell line, was implanted into 31 female homozygous athymic rats. Animals were assigned randomly to a control (saline) or drug treatment (monoclonal antibody vascular endothelial growth factor (Mab-VEGF) antibody) group.

MRI monitoring of tumor response following angiogenesis inhibition in an experimental human breast cancer model.

The aim of this study was to evaluate the potential of dynamic magnetic resonance imaging (MRI) enhanced by macromolecular contrast agents to monitor noninvasively the therapeutic effect of an anti-angiogenesis VEGF receptor kinase inhibitor in an experimental cancer model. MDA-MB-435, a poorly differentiated human breast cancer cell line, was implanted into the mammary fat pad in 20 female homozygous athymic rats. Animals were assigned randomly to a control (n=10) or drug treatment group (n=10).

Complication rate and diagnostic yield of 515 consecutive ultrasound-guided biopsies of renal allografts and native kidneys using a 14-gauge Biopty gun.

Our objective was to evaluate the safety and diagnostic efficacy of the ultrasound-guided renal biopsy procedure using an automated biopsy device (Biopty gun) with a 14-gauge needle. Five hundred fifteen consecutive ultrasound-guided renal biopsies performed in two large university hospitals were retrospectively reviewed. Three hundred forty-five biopsies were performed on renal allografts and 170 on native kidneys.