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Background: Novel treatment strategies in Ewing sarcoma include targeted cellular therapies. Preclinical in vivo models are needed that reflect their activity against systemic (micro)metastatic disease. Methods: Whole-body magnetic resonance imaging (WB-MRI) was used to monitor the engraftment and dissemination of human Ewing sarcoma xenografts in mice. In this model, we evaluated the therapeutic efficacy of T cells redirected against the Ewing sarcoma-associated antigen GD2 by chimeric receptor engineering. Results: Of 18 mice receiving intravenous injections of VH-64 Ewing sarcoma cells, all developed disseminated tumour growth detectable by WB-MRI. All mice had lung tumours, and the majority had additional manifestations in the bone, soft tissues, and/or kidney. Sequential scans revealed in vivo growth of tumours. Diffusion-weighted whole-body imaging with background signal suppression effectively visualised Ewing sarcoma growth in extrapulmonary sites. Animals receiving GD2-targeted T-cell therapy had lower numbers of pulmonary tumours than controls, and the median volume of soft tissue tumours at first detection was lower, with a tumour growth delay over time. Conclusion: Magnetic resonance imaging reliably visualises disseminated Ewing sarcoma growth in mice. GD2-retargeted T cells can noticeably delay tumour growth and reduce pulmonary Ewing sarcoma manifestations in this aggressive disease model.

New pyridine-phosphine ligands of general structure 2-[2-(diarylphosphino)ethyl]pyridine were developed. The phosphorus substituents in these bidentates are 2-tolyl, 2-anisyl, and mesityl. The ligands could be conveniently synthesized in good yields. The nickel dichloride complexes of the ligands are paramagnetic. The metal centers have a distorted tetrahedral geometry, as was evident from the crystal structures and the magnetic moments in solution. The neutral methylpalladium chloride and the cationic methylpalladium complexes have a distorted square-planar geometry around the metal center. For the complexes of two of the ligands, an anagostic C−H···Pd interaction of a ligand-proton with the palladium atom was observed in the crystal structures and in solution. These interactions probably were related to hindered inversion of the six-membered metallocycle, which was observed in VT-NMR measurements. The complexes of the mesityl-substituted ligand show neither hindered inversion of the metal chelate ring nor a sign of Pd···H interactions. The nickel complexes form active catalysts for the oligomerization of ethene after MAO activation. The bulky 2-tolyl and mesityl groups suppress isomerization of the growing chain, reflected in a high 1-butene selectivity. For the complex made from the ligand with the most bulky (mesityl) substituents, this selectivity was 90%. The anisyl substituents induced a different catalytic behavior of the corresponding nickel complex. Selectivity for 1-butene was lower, but the productivity was higher, with a turnover frequency of 65 × 10(3) (mol C2H4)·(mol Ni·h)(−1). The cationic palladium complexes showed a very low activity in ethene oligomerization. Butenes were the major product, but significant amounts of higher olefins were formed as well.

Pyridine−phosphine ligands 1−5 have been used to prepare neutral nickel dichloride complexes, neutral methylpalladium chloride complexes, and cationic methylpalladium complexes. The ligands consist of a diphenylphosphine and a pyridine moiety and differ in the backbone connecting those donor groups. Nickel complexes 9−13 are paramagnetic complexes, and they were characterized by elemental analysis, high-resolution mass spectrometry, and, for 10 and 12, single-crystal X-ray diffraction. Neutral palladium complexes 14−18 were fully characterized. Single-crystal X-ray diffraction was performed on complexes 15 and 16, and variable-temperature NMR demonstrated that 16 exhibits slow inversion of the metallacycle. Cationic palladium species 19−23 were obtained from the neutral complexes after chloride abstraction. Like its neutral precursor, 21 showed slow ring inversion. The nickel species were evaluated as ethene oligomerization catalysts after activation with MAO. All complexes were highly active, with TOFs between 24 × 103 and 85 × 103 (mol C2H4)·(mol Ni·h)−1. Butenes were the major product in all cases, forming 76 to 96 mol % of the product. Selectivities for 1-butene were between 10% and 40%. The cationic palladium species showed a very low productivity for ethene oligomerization, with TOFs ≤16 (mol C2H4)·(mol Pd·h)−1 and 38 to 88 mol % butenes as the main product.

A prototype detection unit of the KM3NeT deep-sea neutrino telescope has been installed at 3500m depth 80 km offshore the Italian coast. KM3NeT in its final configuration will contain several hundreds of detection units. Each detection unit is a mechanical structure anchored to the sea floor, held vertical by a submerged buoy and supporting optical modules for the detection of Cherenkov light emitted by charged secondary particles emerging from neutrino interactions. This prototype string implements three optical modules with 31 photomultiplier tubes each. These optical modules were developed by the KM3NeT Collaboration to enhance the detection capability of neutrino interactions. The prototype detection unit was operated since its deployment in May 2014 until its decommissioning in July 2015. Reconstruction of the particle trajectories from the data requires a nanosecond accuracy in the time calibration. A procedure for relative time calibration of the photomultiplier tubes contained in each optical module is described. This procedure is based on the measured coincidences produced in the sea by the $$^{40}$$40K background light and can easily be expanded to a detector with several thousands of optical modules. The time offsets between the different optical modules are obtained using LED nanobeacons mounted inside them. A set of data corresponding to 600 h of livetime was analysed. The results show good agreement with Monte Carlo simulations of the expected optical background and the signal from atmospheric muons. An almost background-free sample of muons was selected by filtering the time correlated signals on all the three optical modules. The zenith angle of the selected muons was reconstructed with a precision of about 3$$^\circ $$∘. © 2016, The Author(s).

PURPOSE To compare three dimensional contrast enhanced MR angiography with parallel imaging technique (sensitivity encoding) to standard MR angiography technique. MATERIAL AND METHODS CE-3D MRA of renal arteries was performed in 22 patients (23 examinations) on a 1.5 T MR- scanner (Gyroscan Intera, Philips, Netherlands). For contrast enhanced MRA a single dose of Gd-DTPA (0.1 mmol/kg b.w.) was administered. Group I: The following standard 3D gradient echo (GE) sequence was performed in 9 of the 22 patients: TR: 4.3 ms, TE: 1.5 ms, flip angle: 40, 40 slices, scan duration: 19 seconds. A spatial resolution of 1.96 x 1.76 x 3.0 mm (3) (1.76 x 1.76 x 1.5 mm (3) interpolated) was obtained. Group II: 14 examinations were acquired in 13 patients: TR, TE and flip angle were equal compared to the first protocol. The k-space lines were acquired with CENTRA (contrast-enhanced time robust angiography) and parallel imaging technique (SENSE). 60 slices were acquired, scan duration was 24 seconds. The spatial resolution of this sequence was 1.19 x 1.08 x 2.0 mm (3) (0,84 x 0,84 x 1,0 mm (3) interpolated). Original images and calculated maximum intensity projection (MIP) images were analysed by two radiologists. Image quality and the visibility of renal arteries were rated on a four-point scale. RESULTS In the first group the image quality was rated "good" in 8/9 patients. The renal arteries were detected in all cases and rated "good". The anterior and posterior segments were rated "good" in only 5/9 and the lobar arteries were detectable only in 3 of 9 cases. The interlobar arteries could not be seen in these patients. In the second group the image quality was rated excellent in 5 examinations and good in 9 of 14 examinations. The rating for the renal arteries was excellent in all examinations (14/14). The results of the anterior and posterior segment were as followed: excellent 5/14, good 7/14, insufficient 2/14; the lobar arteries: good 6/14, insufficient 6/14 and not detectable 2/14. Interlobar arteries could be seen in 7/14 examinations, but the quality was insufficient. In 7/14 the interlobar arteries could not be detected. CONCLUSION The use of parallel imaging technique improves image quality and the delineation of small vessels in renal MRA.

Holmium-loaded PLLA microspheres are useful systems in radioembolization therapy of liver metastases because of their low density, biodegradability and favourable radiation characteristics. Neutron activated Ho-loaded microspheres showed a surprisingly low release of the relatively small holmium complex. In this paper factors responsible for this behaviour are investigated, in particular by the use of differential scanning calorimetry, scanning electron microscopy, infrared spectroscopy and X-ray diffraction. The holmium complex is soluble in PLLA up to 8% in films and 17% in microspheres. Interactions between carbonyl groups of PLLA, and the Ho-ion in the HoAcAc complex, explain very satisfactorily the high stability of holmium-loaded microspheres.

Studies. Purpose: Measurement of the oscillating CSF flow in the spinal canal (SC) of healthy volunteers and in patients with post-traumatic syringomyelia (PTS) using an optimized MRI protocol as well as to determine whether stenosis induced velocity changes are detectable using MRI. Methods: In 68 healthy volunteers quantitative studies of CSF flow in the cervical, thoracic, and lumbar regions were performed. First, an optimized sequence was developed and tested in 19 volunteers using four different flow-encoding velocities (4, 8, 12, 16 cm/s). Secondly, the optimized sequence was employed in 49 volunteers to measure the different CSF patterns in the cervical, thoracic, and lumbar spinal canals (CSC, TSC, LSC). Part three of the study, in which patients with PTS are being examined is still underway. We measured the maximum velocity (cm/s). the pixel area (mm 2 ), and the stroke volume (ml/s). Using a flow model the velocities prior to and after compression with 5 different power levels were measured at the stenosis and at a distance of 70 cm. Results: A total of 226 dynamic measurements have been performed - so far 76 in the first part (62=81.5% evaluable) and 150 in the second part - using the optimized sequence and optimal flow velocities. A flow-encoding sequence of 12 cm/s was found best in the CSC and one of 6 cm/s in the TSC and LSC. The maximum velocity in the CSC was 0.95 cm/s with the flow being directed caudal and 0.38 cm/s with the flow being directed cranial. In the TSC the values were 4.7 cm/s and 1.65 cm/s and in the LSC 0.96 cm/s and 0.59 cm/s. The highest velocities were found at the TSC, which has the smallest diameter compared to the CSC and LSC. In the 4 patients with PTS, the maximum velocities were between 0.09 cm/s anal 0.97 cm/s with the flow being directed cranial and between 0.04 cm/s and 1.03 cm/s with the flow being directed caudal. The stroke volumina in the CSC were between 0.1 and 1.23 ml/s (mean: 0.48 ml/s) and 0.2 and 2.45 ml/s (mean: 0.66ml/s) in the TSC and in the LSC 0.08 ml/s and 0.67 ml/s (mean: 0.29 ml/s). The results of the flow model studies showed an increase of velocity between 2.06 and 4.94 cm/s (mean: 3.31 cm/s) at the stenosis and 1.1 and 1.33 cm/s (mean: 1.23 cm/s) at a distance of 70 cm. Conclusion: Quantitative measurement of the oscillating CSF flow in the entire spinal canal (SC) is possible using an optimized MRI protocol as well as to detect stenosis induced velocity changes. Due to the high interindividual variability in the data of spinal CSF dynamics, further studies are necessary to collect normal data. The detection of movement of CSF in a post-traumatic spinal cord lesion may alter the therapeutic management.

Purpose. To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction in the piglet. Materials and methods. In 20 piglets unilateral ureteric stenosis was created operatively. Post-surgery repeated comparative examinations were obtained with MRU, diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US). MRU was performed as a combination study with a static 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA with frusemide administration. Results. MRU allowed complete depiction of the prestenotic urinary tract and of the stenosis in all cases. In 43 comparative studies MRU was superior to EU in 36, EU to MRU in 2. When single kidney function was calculated with both MRU and DRS, results were highly correlated (r = 0.92). When urinary excretion was compared, significant agreement was achieved with concordant findings in 86 % and slightly discordant results in 12%. Conclusions. Static-dynamic MR urography permits excellent depiction of experimentally induced urinary tract obstruction in piglets and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out - it does not require radiation and it permits functional-morphological correlation.

To demonstrate the technical feasibility and precision of a navigated diffusion-weighted (DW) MR imaging method with interleaved echo-planar imaging and test its diagnostic sensitivity for detection of ischemic stroke.Apparent diffusion coefficient (ADC) measurements were performed in phantoms, and six healthy adult volunteers were examined to determine intrasubject (precision) and intersubject (reference range) variations in absolute ADC and relative ADC (rADC) measurements. DW imaging maps and lesion rADC values were also obtained in 34 consecutive stroke patients to evaluate the sensitivity and reliability of DW-interleaved echo-planar imaging for detection of ischemic brain damage.Phantom and volunteer ADC values were in excellent agreement with published data. The intrasubject variation of rADC was 6.2%. The ADC precision ranged from 6.5% in the subcortical white matter in the frontal lobe to 12.9% in the head of the caudate nucleus. Interleaved echo-planar imaging enabled rapid acquisition of high-quality images of the entire brain without substantial artifacts. Within the 1st week, the sensitivity of DW-interleaved echo-planar imaging for detection of acute infarction was 90% (18 of 20 true-positive studies) and independent of lesion location.DW-interleaved echo-planar imaging with phase navigation and cardiac triggering is robust, reliable, and fast. With high sensitivity for detection of early ischemic infarction, it is useful for examining stroke patients by using MR systems with conventional gradient hardware.

The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deep waters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same40 K decay and the localisation of bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions. © 2014, The Author(s).

We report the crystal structure of (phenyldiazenido-N)[phenylhydrazido(2-)-N][3-(trimethylsilyl)-2-pyridinethiolato-S,N]bis­(triphenylphosphine-P)rhenium tetraphenylborate, [Re(C6H5N2)(C6H6N2)(C8H12NSSi)(C18H15P)2](C24H20B), prepared by the reaction of [ReCl(C6H6N2)2(C18H15P)2] with 3-(trimethylsilyl)-2-pyridinethiol in ethanol. The mixed diazenide/hydrazido(2-) complex represents a relatively rare class of complex.

Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average for angles up to 45° with respect to the perpendicular. Ray-tracing calculations could reproduce the measurements, allowing to estimate an increase in the overall photocathode sensitivity, integrated over all angles of incidence, by 27% (for a single PMT). Prototype DOMs, being built by the KM3NeT consortium, will be equipped with these expansion cones.© 2013 IOP Publishing Ltd and Sissa Medialab srl.

A recent analysis of the Fermi Large Area Telescope data provided evidence for a high-intensity emission of high-energy gamma rays with a E-2 spectrum from two large areas, spanning 50° above and below the Galactic centre (the "Fermi bubbles"). A hadronic mechanism was proposed for this gamma-ray emission making the Fermi bubbles promising source candidates of high-energy neutrino emission. In this work Monte Carlo simulations regarding the detectability of high-energy neutrinos from the Fermi bubbles with the future multi-km3 neutrino telescope KM3NeT in the Mediterranean Sea are presented. Under the hypothesis that the gamma-ray emission is completely due to hadronic processes, the results indicate that neutrinos from the bubbles could be discovered in about one year of operation, for a neutrino spectrum with a cutoff at 100 TeV and a detector with about 6 km3 of instrumented volume. The effect of a possible lower cutoff is also considered. © 2012 Elsevier B.V. All rights reserved.

For carbohydrates the GROMOS force field has been extended to a more realistic all-atom model, with the use of parameters from the force field proposed by Ha, Giammona, Field & Brady [Carbohydr. Res. (1988), 180, 207-221]. This extended and modified GROMOS force field has been used to simulate the crystal structures of seven monosaccharides. The results, compared with the experimental data, are satisfactory, and an overall improvement over those obtained with the comparable Ha force field. The experimentally determined positions of the H atoms should be used with caution in this comparison, and the thermal parameters can only be used as indicators for the preservation of the symmetry during the simulation. The simulations gave rise to suspicion about the hydroxyl H-atom positions in two of the sugars. These two structures were redetermined by X-ray diffraction at low temperature. For β-D-glucose essentially the same structure was found as in the original publication. In the case of α-D-galactose, the new structure confirmed the results from the simulation, in contrast to earlier experimental determinations

The crystal structures of two aminosteroids, pancuronium and its analogue Org9616HBr, were simulated with molecular dynamics calculations at constant pressure, in order to assess the applicability of non-neutral charge groups combined with a longer cut-off radius to a system of charged molecules. The results of these simulations and of simulations without atomic point charges were compared with the observed crystal structure. The applied point charges were able to reproduce the crystal packing and unit-cell dimensions. The rms deviation of the simulated atomic coordinates from the crystal structure coordinates was 0.22 A and 0.33 A for Org9616HBr and pancuronium bromide (disordered atoms excluded) respectively. The temperature factors of pancuronium and Org9616HBr were found to be either too large or too small, respectively, although relative differences and anisotropy were reproduced reasonably well.

Ziele: Evaluation des Stellenwertes der diffusionsgewichteten echoplanaren (DW-EPI) Bildgebung zur Differenzierung unterschiedlicher histologischer Subtypen des Bronchialkarzinoms mittels ADC-Messung (apparent-diffusion-coefficient) bei 1.5 Tesla. Methode: Es wurden 15 Patienten mit histologisch gesichertem Bronchialkarzinom (Adenokarzinom: n=6; Plattenepithelkarzinom: n=5; kleinzelliges Bronchialkarzinom: n=4) unter Verwendung einer DW-EPI Sequenz (TR/TE: 2000/66ms; FOV: 425×298mm; Matrix: 256; Schichtdicke: 8mm; b-Faktor: 0 und 500s/mm2) untersucht. Alle Messungen erfolgten vor Einleitung einer Chemotherapie oder Radiatio. Mithilfe des Software-tools „MRIcro“ (Chris Rorden, University of Nottingham, Grosbritannien) erfolgte die Berechnung der mittleren ADC-Werte basierend auf einer den gesamten Tumor einschliesenden Region-of-interest (ROI). Zusatzlich wurde der mittlere ADC-Wert des Liquor cerebrospinalis berechnet. Die statistische Analyse beinhaltete den zweiseitigen Student's-t-Test, hierbei wurde ein p-Wert

Ziele: Erfassung der Bedeutung der diffusionsgewichteten Bildgebung mit Unterdruckung des Hintergrundsignals (DWIBS) in der Detektion pulmonaler Noduli bei 1.5 Tesla. Methode: Es wurden 18 konsekutive Patienten mit disseminierter Tumorerkrankung (Bronchialkarzinom: 8 Patienten; Pulmonale Metastasen: 10 Patienten), bei denen computertomographisch Lungenrundherde nachgewiesen wurden, mittels einer diffusionsgewichteten Sequenz mit Unterdruckung des Hintergrundsignals (DWIBS) (TR/TE: 2700/65ms; TI: 180ms; FOV: 425×278mm; b-Faktor: 0 und 500s/mm2; Messzeit: 119s) unter Verwendung eines Atemtriggers bei 1,5 Tesla untersucht. Aus allen Datensatzen wurden Maximum-Intensitats-Projektionen in 5° Intervall entlang der Korperlangsachse rekonstruiert. Die Auswertung der anonymisierten Bilder erfolgte durch zwei Radiologen im Konsensus. Lage und Grose der detektierten Noduli wurden notiert. Als Goldstandard dienten die axialen CT-Bilder. Ergebnis: Die Analyse der CT-Datensatze der 18 Patienten zeigte insgesamt 62 pulmonale Herde mit einem Diameter von 3mm bis 9,2cm (Diameter 3–5mm: n=16; 6–10mm: n=19; >10mm: n=27). Fur die DWIBS-MRT fanden sich Sensitivitaten von 84,2% fur Noduli von 6–10mm und 96,3% fur Herde >10mm. Kleinere Lasionen 6mm mit einer der MDCT vergleichbaren Sensitivitat (>90%). Korrespondierender Autor: Schreiter D Universitatsklinikum Hamburg-Eppendorf, Diagnostikzentrum; Klinik und Poliklinik fur Diagnostische und Interventionelle Radiologie, Martinistr. 52, 20246 Hamburg E-Mail: d.schreiter@uke.uni-hamburg.de

BACKGROUND AND PURPOSE: Our aim was to compare different field strengths monitoring physiologic changes due to oral stimulation of parotid glands by using diffusion-weighted (DW) echo-planar imaging (EPI). MATERIALS AND METHODS: Twenty-seven healthy volunteers were examined with a DW-EPI sequence at 1.5T and 3T before and after oral stimulation with commercially available lemon juice. The b factors used were 0, 500, and 1000 s/mm(2). Apparent diffusion coefficient (ADC) maps were evaluated with a manually placed region of interest including the entire parotid gland. For comparison of results, a Student t test was used on the basis of the mean of the volunteer median values. To compare both field strengths, we calculated the Pearson correlation coefficient (r). RESULTS: DW-EPI MR imaging visualized the parotid glands of all volunteers. With 1.5T, the mean ADC before stimulation was 1.12 × 10(−3) mm(2)/s ± 0.08 × 10(−3) mm(2)/s. After stimulation with lemon juice, the ADC increased to 1.18 × 10(−3) mm(2)/s ± 0.09 × 10(−3) mm(2)/s. For 3T, the ADC before stimulation was 1.14 × 10(−3) mm(2)/s ± 0.04 × 10(−3) mm(2)/s, with an increase to 1.17 × 10(−3) mm(2)/s ± 0.05 × 10(−3) mm(2)/s after stimulation. For both field strengths, the increase in ADC after stimulation was significant (P < .001). High correlations between both field strengths were found pre- and poststimulation (r = 0.955, and 0.936, respectively). CONCLUSION: DW-EPI MR imaging allows monitoring of physiologic changes due to oral stimulation of parotid glands by using DW imaging with high correlation between 1.5T and 3T.

We designed a study to estimate the economic impact of CoSeal Surgical Sealant for the prevention of anastomotic bleeding in cardiac and vascular surgery. We also explored the potential economic value of CoSeal as a means of inhibiting the formation of pericardial tissue adhesions.A Delphi panel of 6 expert vascular and cardiac surgeons provided the assumptions and estimates needed to develop a decision analysis model to assess the impact of sealant on the costs associated with low- and high-risk forms of cardiac (valve replacement/reconstruction) and vascular (abdominal aortic aneurysm [AAA] repair, femoral bypass grafting) surgery. The primary outcome was incremental cost per patient.For valve repair/replacement surgery, sealant was expected to confer cost-savings in high-risk but not low-risk procedures. Predicted cost savings for high-risk AAA repairs were substantial, but minimal in the overall AAA group. Cost-savings were predicted for sealant use in all femoral-popliteal ePTFE bypass grafts, but in high-risk femoral-femoral ePTFE bypass grafts only.According to our decision analysis model, routine use of surgical sealant in select subgroups may confer considerable economic benefits to health service budgets. Future research should aim at testing this model in a real-world hospital setting. Assessment of the value of CoSeal in the prevention of postsurgical adhesions showed that expert surgeons see a need for effective prophylaxis. Further research into the clinical and economic benefit of this intervention is required.

To compare three dimensional contrast enhanced MR angiography with parallel imaging technique (sensitivity encoding) to standard MR angiography technique.CE-3D MRA of renal arteries was performed in 22 patients (23 examinations) on a 1.5 T MR- scanner (Gyroscan Intera, Philips, Netherlands). For contrast enhanced MRA a single dose of Gd-DTPA (0.1 mmol/kg b.w.) was administered. Group I: The following standard 3D gradient echo (GE) sequence was performed in 9 of the 22 patients: TR: 4.3 ms, TE: 1.5 ms, flip angle: 40, 40 slices, scan duration: 19 seconds. A spatial resolution of 1.96 x 1.76 x 3.0 mm (3) (1.76 x 1.76 x 1.5 mm (3) interpolated) was obtained. Group II: 14 examinations were acquired in 13 patients: TR, TE and flip angle were equal compared to the first protocol. The k-space lines were acquired with CENTRA (contrast-enhanced time robust angiography) and parallel imaging technique (SENSE). 60 slices were acquired, scan duration was 24 seconds. The spatial resolution of this sequence was 1.19 x 1.08 x 2.0 mm (3) (0,84 x 0,84 x 1,0 mm (3) interpolated). Original images and calculated maximum intensity projection (MIP) images were analysed by two radiologists. Image quality and the visibility of renal arteries were rated on a four-point scale.In the first group the image quality was rated "good" in 8/9 patients. The renal arteries were detected in all cases and rated "good". The anterior and posterior segments were rated "good" in only 5/9 and the lobar arteries were detectable only in 3 of 9 cases. The interlobar arteries could not be seen in these patients. In the second group the image quality was rated excellent in 5 examinations and good in 9 of 14 examinations. The rating for the renal arteries was excellent in all examinations (14/14). The results of the anterior and posterior segment were as followed: excellent 5/14, good 7/14, insufficient 2/14; the lobar arteries: good 6/14, insufficient 6/14 and not detectable 2/14. Interlobar arteries could be seen in 7/14 examinations, but the quality was insufficient. In 7/14 the interlobar arteries could not be detected.The use of parallel imaging technique improves image quality and the delineation of small vessels in renal MRA.

Verglichen mit anderen Bereichen des taglichen Alltags ist die diagnostische Anwendung von Rontgenstrahlung eine verhaltnismasig stark von physikalischen Aspekten gepragte Technik. Um beispielsweise die Gesetzmasigkeiten der Bildgebung mittels Rontgenstrahlung zu verstehen, wird man um ein Mindestmas an Verstandnis fur die strahlenphysikalischen Zusammenhange kaum herumkommen. Dasselbe gilt, wenn optimale Losungen zwischen den konkurrierenden Anforderungen Bildqualitat und Strahlenexposition gefunden werden sollen. Erschwert wird das erforderliche Verstandnis jedoch durch den Umstand, dass die meisten Zusammenhange nichtlinearer Natur sind, d.h. der mathematische Dreisatz gilt nur in wenigen Ausnahmefallen.

Several small, lipophilic rhenium complexes form inclusion complexes with native beta-cyclodextrin (beta-CD) and beta-CD dimers. Association constants larger than 10(9)M(-1) were obtained using dimers. The use of beta-CD also enabled the synthesis of these rhenium complexes in water, in excellent yields, through complexation of the otherwise insoluble corresponding ligands. The influence of the reaction time and temperature on the configuration of the reaction products has been investigated in depth for one of these complexes. Using a beta-CD dimer, it proved possible to specifically template the formation of one configuration. The strength of the complexes of the rhenium complexes in cyclodextrin dimers may allow radiolabeling of biomolecules.