Arne Hengerer

Assessment of vascular remodeling under antiangiogenic therapy using DCE-MRI and vessel size imaging†

To assess vascular remodeling in tumors during two different antiangiogenic therapies with dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) and vessel size imaging and to evaluate the vessel size index (VSI) as a novel biomarker of therapy response.

Affinity Measurements of Antibody Fragments on Phage by Quartz Crystal Microbalance (QCM)

U The screening of large combinatorial phage display gene libraries usually leads to a set of diverse recombinant antibody fragment clones specifically binding to the antigen which have to be characterised further and ranked for their usefulness. Beside specificity, the key parameter to be determined is the affinity to the antigen. The dissociation rate is of particular significance for diagnostic and therapeutic applications. For the affinity determination, the most convenient method would be one which directly utilises phage bound antibody fragments from the culture supernatants of isolated E. coli clones. However, affinity determinations of phage particles carrying recombinant antibodies are not easy with established methods like equilibrium ELISA or surface plasmon resonance due to a lack of sensitivity and unspecific effects caused by the large size and filamentous shape of the phage particles. QCM (Quartz Crystal Microbalance), however, provides a method to directly monitor association and dissociation of phage antibodies to their antigen, thus allowing to determine an apparent binding constant. The QCM is an acoustic sensor based on a piezoelectric crystal which can be used for the measurement of specific interactions between immobilized molecules and analytes in solution. Binding of a soluble analyte causes a frequency shift in the resonance frequency wich can be recorded by a frequency counter with high resolution.

Measurement of R1 dynamics using sliding window‐DESPOT

To measure longitudinal relaxation rate (R1) changes during contrast agent studies using a driven equilibrium single pulse observation of T1 (DESPOT) method with a sliding window (sw) acquisition.

Glossary of molecular imaging terminology1

The term “molecular imaging” can be broadly defined as the in vivo characterization and measurement of biologic processes at the cellular and molecular levels. In contradistinction to “conventional” diagnostic imaging, it sets forth to probe the specific molecular abnormalities that are the basis of disease, rather than imaging the end effects of these molecular alterations. While the underlying biology represents a new arena for many radiologists, concomitant efforts such as developing novel agents, signal amplification strategies, and imaging technologies clearly dovetail into prior research efforts of our specialty. Radiologists will play a leading role in directing developments within this growing field. To understand better the impact of the molecular revolution on medicine in general, it is helpful to look at the astonishing developments in other specialties. The most striking examples have been the continuous introduction of more specific drugs and inhibitors, the ability to engineer and repair cells and tissues genetically, and the commercialization of a multitude of diagnostic tools and kits (eg, DNA chips and protein assays). On the research side, an entire industry has been developed to speed up molecular research and drug discovery. These tools have led, in part, to dramatic advances in understanding the molecular pathways of disease. This knowledge of new targets and pathways can now be efficiently translated into new drugs. We expect that these self-feeding development loops will ultimately allow the earlier detection of disease and more efficient treatments, resulting in improved pa

Medical imaging beyond the Human Genome Project

Abstract Technological improvements in radiological imaging hardware and data visualization techniques will continue to be made at the rate we have experienced during the past two decades. Although this is an encouraging expectation, perhaps the most exciting predictions for the field of radiology are in the application of molecular biology techniques.