To honour W C Röntgen and review the entire area of X-ray development in the various fields of natural, technical, and life sciences, his successors at the Physikalisches Institut of the Universität Würzburg organized a conference, named “Röntgen Centennial”. It took place at the new “Physikalisches Institut” not far from the historical site shortly before the actual 100th anniversary of the discovery. Over forty renowned scientists were invited as representative speakers in the various subfields of X-ray activities. They reviewed the development, gave examples, and described the present status. Most of them provided survey articles, which are gathered in this book. Since most X-ray-related activities are somehow represented, an almost complete overview of the entire field is provided. This book thus represents the enormous breadth of X-ray activities and allows one to recognize the potential and quality of today's X-ray research.

Abstract: Modern oncology aims at patient-specific therapy approaches, which triggered the development of biomedical imaging techniques to synergistically address tumor biology at the cellular and molecular level. PET/MR is a new hybrid modality that allows acquisition of high-resolution anatomic images and quantification of functional and metabolic information at the same time. Key steps of the Warburg effect-one of the hallmarks of tumors-can be measured non-invasively with this emerging technique. The aim of this study was to quantify and compare simultaneously imaged augmented glucose uptake and LDH activity in a subcutaneous breast cancer model in rats (MAT-B-III) and to study the effect of varying tumor cellularity on image-derived metabolic information. Methods: For this purpose, we established and validated a multimodal imaging workflow for a clinical PET/MR system including proton magnetic resonance (MR) imaging to acquire accurate morphologic information and diffusion-weighted imaging (DWI) to address tumor cellularity. Metabolic data were measured with dynamic [18F]FDG-PET and hyperpolarized (HP) 13C-pyruvate MR spectroscopic imaging (MRSI). We applied our workflow in a longitudinal study and analyzed the effect of growth dependent variations of cellular density on glycolytic parameters. Results: Tumors of similar cellularity with similar apparent diffusion coefficients (ADC) showed a significant positive correlation of FDG uptake and pyruvate-to-lactate exchange. Longitudinal DWI data indicated a decreasing tumor cellularity with tumor growth, while ADCs exhibited a significant inverse correlation with PET standard uptake values (SUV). Similar but not significant trends were observed with HP-13C-MRSI, but we found that partial volume effects and point spread function artifacts are major confounders for the quantification of 13C-data when the spatial resolution is limited and major blood vessels are close to the tumor. Nevertheless, analysis of longitudinal data with varying tumor cellularity further detected a positive correlation between quantitative PET and 13C-data. Conclusions: Our workflow allows the quantification of simultaneously acquired PET, MRSI and DWI data in rodents on a clinical PET/MR scanner. The correlations and findings suggest that a major portion of consumed glucose is metabolized by aerobic glycolysis in the investigated tumor model. Furthermore, we conclude that variations in cell density affect PET and 13C-data in a similar manner and correlations of longitudinal metabolic data appear to reflect both biochemical processes and tumor cellularity

Abstract: pH is a tightly regulated physiological parameter that is often altered in diseased states like cancer. The development of biosensors that can be used to non-invasively image pH with hyperpolarized (HP) magnetic resonance spectroscopic imaging has therefore recently gained tremendous interest. However, most of the known HP-sensors have only individually and not comprehensively been analyzed for their biocompatibility, their pH sensitivity under physiological conditions, and the effects of chemical derivatization on their logarithmic acid dissociation constant (pKa). Proteinogenic amino acids are biocompatible, can be hyperpolarized and have at least two pH sensitive moieties. However, they do not exhibit a pH sensitivity in the physiologically relevant pH range. Here, we developed a systematic approach to tailor the pKa of molecules using modifications of carbon chain length and derivatization rendering these molecules interesting for pH biosensing. Notably, we identified several derivatives such as [1-13C]serine amide and [1-13C]-2,3-diaminopropionic acid as novel pH sensors. They bear several spin-1/2 nuclei (13C, 15N, 31P) with high sensitivity up to 4.8 ppm/pH and we show that 13C spins can be hyperpolarized with dissolution dynamic polarization (DNP). Our findings elucidate the molecular mechanisms of chemical shift pH sensors that might help to design tailored probes for specific pH in vivo imaging applications

The present Syllabus provides an integrated view of the set-up, processing and interpretation of magnetic resonance imaging and magnetic resonance spectroscopy experiments. There are specialized sections on spectroscopy, methodology and clinical MRI. Several chapters in each section provide authoritative descriptions, ranging from the physical basis to the most recent developments. The volume offers both a useful introduction to MR methods for the non-experienced reader and can be an advanced reference book for physicists, biologists and physicians actively working in MR.

In this Syllabus, the reader will find crutial information on MR methodology, clinical aspects of MR imaging, and MR spectroscopy. In particular, the relevant MR equipment specifications, efficacy and cost-effectiveness considerations, set-up and potentials of various imaging contrasts and spectroscopy applications will be covered. A special section will focus on the effects of patient ageing.

Im Laufe der Bearbeitung wurde gezeigt, dass es zu erheblichen gesundheitlichen Auswirkungen durch Einsamkeit im Alter kommen kann. Es wurde gezeigt, dass sich Einsamkeit im Alter auf die funktionale Gesundheit, die subjektive Gesundheit sowie auf chronische Krankheiten auswirkt und dadurch die Mortalität beeinflusst. Einsamkeit gilt als ein wichtiger Risikofaktor für Depressionen, wodurch es zu einem beschleunigten funktionellen Verfall kommt und somit die Sterblichkeit erhöht wird. Es wurde ein erhöhtes Risiko für eine Erkrankung an Alzheimer Demenz mit Einsamkeit in Verbindung gebracht.ger