Brain function has long been the realm of philosophy, psychology and psychiatry and since the mid 1800s, of histopathology. Through the advent of magnetic imaging in the end of the last century, an... Show moreBrain function has long been the realm of philosophy, psychology and psychiatry and since the mid 1800s, of histopathology. Through the advent of magnetic imaging in the end of the last century, an in vivo visualization of the human brain became available. This thesis describes the development of two unique techniques, imaging of diffusion of water protons and manganese enhanced imaging, that both allow for the depiction of white matter tracts. The reported studies show, that these techniques can be used for a three-dimensional depiction of fiber bundles and that quantitative measures reflecting fiber integrity and neuronal function can be extracted from such data. In clinical applications, the potential use of the developed methods is illustrated in human gliomas, as measure for fiber infiltration, and in spinal cord injury, to monitor potential neuroprotective and __regenerative medication. Show less
In this thesis, several strategies are presented that aim to facilitate the analysis and visualization of whole-body in vivo data of small animals. Based on the particular challenges for image... Show moreIn this thesis, several strategies are presented that aim to facilitate the analysis and visualization of whole-body in vivo data of small animals. Based on the particular challenges for image processing, when dealing with whole-body follow-up data, we addressed several aspects in this thesis. The developed methods are tailored to handle data of subjects with significantly varying posture and address the large tissue heterogeneity of entire animals. In addition, we aim to compensate for lacking tissue contrast by relying on approximation of organs based on an animal atlas. Beyond that, we provide a solution to automate the combination of multimodality, multidimensional data. Show less
In this research heavy chain antibody fragments (VHHs) are developed as potential tools for non-invasive in vivo imaging of Alzheimer__s disease (AD) and Cerebral Amyloid Angiopathy (CAA). First... Show moreIn this research heavy chain antibody fragments (VHHs) are developed as potential tools for non-invasive in vivo imaging of Alzheimer__s disease (AD) and Cerebral Amyloid Angiopathy (CAA). First the generation of antibody fragments, directed against A_ is described. VHHs that were selected from different libraries showed differential affinity for different A_ epitopes when used for immunohistochemistry. These observations indicate that the VHHs are the first immunologic probes with the capacity to differentiate between parenchymal and vascular beta amyloid aggregates. Next, in chapter three the VHH are assessed on their ability to cross the blood-brain barrier using an established in vitro blood brain barrier co-culture system. VHH ni3A showed the highest transmigration efficiency of all tested VHHs. This transport is, in part, facilitated by a 3 amino acid substitution in its N-terminal domain. Additional studies indicated that the mechanism of transcellular passage of ni3A is by active transport. The data described in chapter four provides preliminary proof that these VHHs have the capacity to target A_ depositions in vivo. Consequently, the VHHs are promising tools for further development as imaging agents for the differential diagnosis of A_-related neurodegenerative diseases like CAA and AD. Show less
Non-invasive imaging plays an increasingly important role in the diagnosis and risk stratification of coronary artery disease. Several techniques such as stress echocardiography and myocardial... Show moreNon-invasive imaging plays an increasingly important role in the diagnosis and risk stratification of coronary artery disease. Several techniques such as stress echocardiography and myocardial perfusion imaging have become available to assess cardiac function and myocardial perfusion. With the arrival of multi-slice computed tomography coronary angiography (CTA), non-invasive imaging of coronary anatomy has also become possible. CTA is a relatively new imaging technique; the objective of the thesis is therefore to explore the value of CTA for diagnosis and risk stratification of CAD in patients presenting with suspected and known CAD, in order to further define its role in clinical practice. The results of this thesis show that CTA provides important diagnostic information relative to existing non-invasive imaging strategies. In addition the detailed anatomic information obtained using CTA was shown to provide important prognostic information. CTA supplies complementary information to existing non-invasive imaging techniques, and has the potential to provide a more patient tailored approach to patient management. What remains to be determined is how CTA and non-invasive functional imaging should be integrated into clinical practice. Show less
