Soenke Bartling

Publications

• 5.53

  Impact points

  In vivo monitoring of cystic fibrosis-like lung disease in mice by volumetric computed tomography.

  M O Wielpütz, M Eichinger, Z Zhou, K Leotta, S Hirtz, S H Bartling, W Semmler, H-U Kauczor, M Puderbach, M A Mall

  The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. 04/2011; 38(5):1060-70.

  The onset and spontaneous development of cystic fibrosis (CF) lung disease remain poorly understood. In the present study, we used volumetric computed tomography (VCT) as a new method for longitudinal in vivo monitoring of early lesions and disease progression in CF-like lung disease in β-epithelial... [more] The onset and spontaneous development of cystic fibrosis (CF) lung disease remain poorly understood. In the present study, we used volumetric computed tomography (VCT) as a new method for longitudinal in vivo monitoring of early lesions and disease progression in CF-like lung disease in β-epithelial Na(+) channel (ENaC)-transgenic (TG) mice. Using a VCT scanner prototype (80 kV, 50 mA·s, scan time 19 s and spatial resolution 200 μm), βENaC-TG mice and wild-type (WT) littermates were examined longitudinally at 10 time-points from neonatal to adult ages, and VCT images were assessed by qualitative and quantitative morphological parameters. We demonstrate that VCT detected early-onset airway mucus obstruction, diffuse infiltrates, atelectasis and air trapping as characteristic abnormalities in βENaC-TG mice. Furthermore, we show that early tracheal mucus obstruction predicted mortality in βENaC-TG mice and that the density of lung parenchyma was significantly reduced at all time-points in βENaC-TG compared with WT mice (median ± sem -558 ± 8 HU in WT versus -686 ± 16 HU in βENaC-TG at 6 weeks of age; p < 0.005). Our study demonstrates that VCT is a sensitive, noninvasive technique for early detection and longitudinal monitoring of morphological abnormalities of CF-like lung disease in mice, and may thus provide a useful tool for pre-clinical in vivo evaluation of novel treatment strategies for CF.
• 4.85

  Impact points

  First multimodal embolization particles visible on x-ray/computed tomography and magnetic resonance imaging.

  Soenke H Bartling, Johannes Budjan, Hagit Aviv, Stefan Haneder, Bettina Kraenzlin, Henrik Michaely, Shlomo Margel, Steffen Diehl, Wolfhard Semmler, Norbert Gretz, Stefan O Schönberg, Maliha Sadick

  Investigative radiology. 03/2011; 46(3):178-86.

  Embolization therapy is gaining importance in the treatment of malignant lesions, and even more in benign lesions. Current embolization materials are not visible in imaging modalities. However, it is assumed that directly visible embolization material may provide several advantages over current embo... [more] Embolization therapy is gaining importance in the treatment of malignant lesions, and even more in benign lesions. Current embolization materials are not visible in imaging modalities. However, it is assumed that directly visible embolization material may provide several advantages over current embolization agents, ranging from particle shunt and reflux prevention to improved therapy control and follow-up assessment. X-ray- as well as magnetic resonance imaging (MRI)-visible embolization materials have been demonstrated in experiments. In this study, we present an embolization material with the property of being visible in more than one imaging modality, namely MRI and x-ray/computed tomography (CT). Characterization and testing of the substance in animal models was performed. To reduce the chance of adverse reactions and to facilitate clinical approval, materials have been applied that are similar to those that are approved and being used on a routine basis in diagnostic imaging. Therefore, x-ray-visible Iodine was combined with MRI-visible Iron (Fe3O4) in a macroparticle (diameter, 40-200 μm). Its core, consisting of a copolymerized monomer MAOETIB (2-methacryloyloxyethyl [2,3,5-triiodobenzoate]), was coated with ultra-small paramagnetic iron oxide nanoparticles (150 nm). After in vitro testing, including signal to noise measurements in CT and MRI (n = 5), its ability to embolize tissue was tested in an established tumor embolization model in rabbits (n = 6). Digital subtraction angiography (DSA) (Integris, Philips), CT (Definition, Siemens Healthcare Section, Forchheim, Germany), and MRI (3 Tesla Magnetom Tim Trio MRI, Siemens Healthcare Section, Forchheim, Germany) were performed before, during, and after embolization. Imaging signal changes that could be attributed to embolization particles were assessed by visual inspection and rated on an ordinal scale by 3 radiologists, from 1 to 3. Histologic analysis of organs was performed. Particles provided a sufficient image contrast on DSA, CT (signal to noise [SNR], 13 ± 2.5), and MRI (SNR, 35 ± 1) in in vitro scans. Successful embolization of renal tissue was confirmed by catheter angiography, revealing at least partial perfusion stop in all kidneys. Signal changes that were attributed to particles residing within the kidney were found in all cases in all the 3 imaging modalities. Localization distribution of particles corresponded well in all imaging modalities. Dynamic imaging during embolization provided real-time monitoring of the inflow of embolization particles within DSA, CT, and MRI. Histologic visualization of the residing particles as well as associated thrombosis in renal arteries could be performed. Visual assessment of the likelihood of embolization particle presence received full rating scores (153/153) after embolization. Multimodal-visible embolization particles have been developed, characterized, and tested in vivo in an animal model. Their implementation in clinical radiology may provide optimization of embolization procedures with regard to prevention of particle misplacement and direct intraprocedural visualization, at the same time improving follow-up examinations by utilizing the complementary characteristics of CT and MRI. Radiation dose savings can also be considered. All these advantages could contribute to future refinements and improvements in embolization therapy. Additionally, new approaches in embolization research may open up.

• First Multimodal Embolization particles visible on X-ray/CT and MRI

  Bartling, Budjan, Biton, Haneder, Kraenzlin, Michaely, Margel, Diehl, Semmler, Gretz, Schoenberg, Sadick

  Investigative Radiology. 01/2011;

  Objectives: Embolization therapy is gaining importance in the treatment of malignant and even more in benign lesions. Current embolization materials are not visible in imaging modalities. However, it is assumed that directly visible embolization material may provide several advantages over current e... [more] Objectives: Embolization therapy is gaining importance in the treatment of malignant and even more in benign lesions. Current embolization materials are not visible in imaging modalities. However, it is assumed that directly visible embolization material may provide several advantages over current embolization agents, ranging from particle shunt and reflux prevention to improved therapy control and follow-up assessment. X-ray as well as MRI visible embolization materials have been demonstrated in experiments. In this study we present an embolization material with the property of being visible in more than one imaging modality, namely MRI and X- ray/CT. Characterization and testing of the substance in animal models was performed. Materials and Methods: In order to reduce the chance of adverse reactions and to facilitate clinical approval materials have been applied that are similar to those that are approved and being used on a routine-basis in diagnostic imaging. Herefore X- ray visible Iodine was combined with MRI visible Iron (Fe3+O4) in a macroparticle (diameter 40-200 μm). Its core, consisting of a copolymerized monomer MAOETIB [2-methacryloyloxyethyl(2,3,5-triiodobenzoate)], was coated with ultra-small paramagnetic iron oxide nanoparticles (USPIO, 150 nm). After in-vitro testing, including signal to noise measurements in CT and MRI (n=5), its ability to embolize tissue was tested in an established tumor embolization model in rabbits (n=6). Digital subtraction angiography (DSA) (Integris, Philipps), CT (Definition, Siemens Healthcare Section, Forchheim, Germany) and MRI (3 Tesla Magnetom Tim Trio MRI, Siemens Healthcare Section, Forchheim, Germany) were performed before, during and after embolization. Imaging signal changes that could be attributed to embolization particles were assessed by visual inspection and rated on an ordinal 2 scale by three radiologists from 1 to 3. Histological analysis of organs was performed. Results: Particles provided a sufficient image contrast on DSA, CT (signal to noise (SNR) 13 ±2.5) and MRI (SNR 35 ±1) in in-vitro scans. Successful embolization of renal tissue was confirmed by catheter angiography revealing at least partial perfusion stop in all kidneys. Signal changes that were attributed to particles residing within the kidney were found in all cases in all three imaging modalities. Localization distribution of particles corresponded well in all imaging modalities. Dynamic imaging during embolization provided real-time monitoring of the inflow of embolization particles within DSA, CT and MRI. Histological visualization of the residing particles as well as associated thrombosis in renal arteries could be performed. Visual assessment of the likelihood of embolization particle presence received full rating scores (153/153) after embolization. Conclusions: Multimodal visible embolization particles have been developed, characterized and tested in-vivo in an animal model. Their implementation in clinical radiology may provide optimization of embolization procedures with regard to prevention of particle misplacement and direct intraprocedural visualization, at the same time improving follow-up examinations by utilizing the complementary characteristics of CT and MRI. Radiation dose savings can also be considered. All these advantages could contribute to future refinements and improvements in embolization therapy. Additionally, new approaches in embolization research may open up.

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• 4.41

  Impact points

  Expansion of the Multi-Link Frontier™ coronary bifurcation stent: micro-computed tomographic assessment in human autopsy and porcine heart samples.

  Stefan Kralev, Benjamin Haag, Jens Spannenberger, Siegfried Lang, Marc A Brockmann, Soenke Bartling, Alexander Marx, Karl-Konstantin Haase, Martin Borggrefe, Tim Süselbeck

  PloS one. 01/2011; 6(7):e21778.

  Treatment of coronary bifurcation lesions remains challenging, beyond the introduction of drug eluting stents. Dedicated stent systems are available to improve the technical approach to the treatment of these lesions. However dedicated stent systems have so far not reduced the incidence of stent res... [more] Treatment of coronary bifurcation lesions remains challenging, beyond the introduction of drug eluting stents. Dedicated stent systems are available to improve the technical approach to the treatment of these lesions. However dedicated stent systems have so far not reduced the incidence of stent restenosis. The aim of this study was to assess the expansion of the Multi-Link (ML) Frontier™ stent in human and porcine coronary arteries to provide the cardiologist with useful in-vitro information for stent implantation and selection. Nine ML Frontier™ stents were implanted in seven human autopsy heart samples with known coronary artery disease and five ML Frontier™ stents were implanted in five porcine hearts. Proximal, distal and side branch diameters (PD, DD, SBD, respectively), corresponding opening areas (PA, DA, SBA) and the mean stent length (L) were assessed by micro-computed tomography (micro-CT). PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm(2) vs. 12.84±1.38 mm(2), p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014). L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015). Micro-CT is a feasible tool for exact surveying of dedicated stent systems and could make a contribution to the development of these devices. The proximal diameter and proximal area of the stent system were considerably smaller in human autopsy heart samples than in porcine heart samples and than those given by the manufacturer. Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated stent systems, considering final intravascular ultrasound or optical coherence tomography to visualize (and if necessary optimize) stent expansion.

• Method and system for 4D radiological intervention guidance

  Bartling, Kuntz, Kachelriess

  Ref. No: PCT/EP2011/073091

  Year: 12/2010

  A method is disclosed that provides 4D intervention guidance imaging without exceeding radiation dose levels of current intervention guidance methods

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• 1.44

  Impact points

  Cochlear osteoneogenesis after meningitis in cochlear implant patients: a retrospective analysis.

  Martin Durisin, Soenke Bartling, Christoph Arnoldner, Melanie Ende, Jana Prokein, Anke Lesinski-Schiedat, Heinrich Lanfermann, Thomas Lenarz, Timo Stöver

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 09/2010; 31(7):1072-8.

  Retrospective clinical study. Academic tertiary referral center at the Medical University of Hannover. Computed tomographic findings of 126 patients (95 children and 31 adults) profoundly deafened by meningitis during a period of 20 years were evaluated. Children were defined as up to 12 years old a... [more] Retrospective clinical study. Academic tertiary referral center at the Medical University of Hannover. Computed tomographic findings of 126 patients (95 children and 31 adults) profoundly deafened by meningitis during a period of 20 years were evaluated. Children were defined as up to 12 years old at the onset of meningitis. No patients showed any relevant bilateral auditory brainstem response thresholds at the time of admission to our clinic. Patient histories, surgical findings, and imaging results were analyzed by experienced surgeons/neuroradiologists. Of 95 children, 30 (32%) displayed symptoms of labyrinthitis ossificans, whereas 11 (36%) of 31 adults showed changes of the bony structure of the cochlea. High-resolution computed tomography (HRCT) evaluation indicated that the ossification was detected more frequently if there was a larger time interval between onset of meningitis and high-resolution computed tomographic scan. Bilateral ossification at various stages was observed in 67% of children and 55% of adults with obliteration. In the comparison of cochlear ossification found in computed tomographic scans and intraoperative obliteration, HRCT showed a specificity of 73% and a sensitivity of 88%. The intraoperative evaluation revealed various stages of cochlear obliteration in 44% of children and 39% of adults. In our study, the earliest onset of labyrinthitis ossificans was found in high-resolution computed tomographic scans as early as 4 weeks after the onset of meningitis. In most cases, ossification occurred bilaterally with predominantly asymmetric involvement of both ears. The rate of osteoneogenesis increases significantly over time after meningitis. This leads to the conclusion that cochlear ossification can start very early and increase over time with unpredictable speed. Cochlear ossification typically develops bilaterally. From these results, we conclude that cochlear implantation should be performed bilaterally as soon as possible after meningitis and deafness have been diagnosed. HRCT offers good specificity but only limited sensitivity. Preoperative diagnostics should include magnetic resonance imaging to optimize preparation for cochlear implantation.
• 4.50

  Impact points

  Synthesis and characterization of dual modality (CT/MRI) core-shell microparticles for embolization purposes.

  Aviv Hagit, Bartling Soenke, Budjan Johannes, Margel Shlomo

  Biomacromolecules. 06/2010; 11(6):1600-7.

  Core P(MAOETIB-GMA) microparticles of 40-200 microm were prepared by suspension copolymerization of the iodinated monomer 2-methacryloyloxyethyl (2,3,5-triiodobenzoate), MAOETIB, with a low concentration of the monomer glycidyl methacrylate, GMA, which formed hydrophilic surfaces on the particles. M... [more] Core P(MAOETIB-GMA) microparticles of 40-200 microm were prepared by suspension copolymerization of the iodinated monomer 2-methacryloyloxyethyl (2,3,5-triiodobenzoate), MAOETIB, with a low concentration of the monomer glycidyl methacrylate, GMA, which formed hydrophilic surfaces on the particles. Magnetic gamma-Fe(2)O(3)/P(MAOETIB-GMA) core-shell microparticles were prepared by coating the aforementioned core particles through nucleation of iron oxide nanoparticles on the surfaces of the P(MAOETIB-GMA) particles. This was followed by stepwise growth of thin iron oxide layers. The radiopacity and magnetism of these particles were demonstrated in vitro by CT and MRI. In vivo embolization capabilities of these first multimodal visible embolization particles were demonstrated in a rat's kidney tumor embolization model.
• 2.09

  Impact points

  Image findings of patients with H1N1 virus pneumonia and acute respiratory failure.

  Thomas Henzler, Mathias Meyer, Armin Kalenka, Markus Alb, Gerald Schmid-Bindert, Sönke Bartling, Joseph U Schoepf, Stefan O Schoenberg, Christian Fink

  Academic radiology. 06/2010; 17(6):681-5.

  The aim of this study was to assess the findings of chest radiography and high-resolution computed tomography in patients requiring intensive care unit treatment for severe H1N1 virus pneumonia. In 2009, 10 patients required treatment in an intensive care unit for confirmed H1N1 pneumonia. All patie... [more] The aim of this study was to assess the findings of chest radiography and high-resolution computed tomography in patients requiring intensive care unit treatment for severe H1N1 virus pneumonia. In 2009, 10 patients required treatment in an intensive care unit for confirmed H1N1 pneumonia. All patients underwent chest radiography and high-resolution computed tomography. All 10 patients required mechanical ventilation because of respiratory failure. Nine patients presented with severe acute respiratory distress syndrome, and one patient died. Four patients underwent extracorporeal membrane oxygenation (ECMO) therapy. The results of chest radiography and high-resolution computed tomographic scans of these patients were systematically analyzed. The mean age of all patients was 44.1 +/- 12.3 years. All 10 patients showed abnormal results on chest radiography. The radiographic abnormalities were bilateral and multifocal in 10 patients. The predominant radiographic findings were consolidations (n = 9), ground-glass opacities (n = 8), and reticular opacities (n = 2). The most frequent computed tomographic findings at presentation consisted of bilateral ground-glass opacities (n = 9), pleural effusion (n = 9), areas of consolidation (n = 8), interstitial marking (n = 8), and crazy paving (n = 4). All patients undergoing ECMO therapy showed extensive bilateral ground-glass opacities, multifocal areas of consolidation, and crazy paving. Pleural effusion was present in three of four patients undergoing ECMO therapy. Patients requiring treatment in an intensive care unit for severe H1N1 pneumonia are at high risk for developing acute respiratory distress syndrome and frequently require ECMO therapy.
• 9.99

  Impact points

  Anti-CD4-targeted gold nanoparticles induce specific contrast enhancement of peripheral lymph nodes in X-ray computed tomography of live mice.

  Wolfgang Eck, Anthony I Nicholson, Hanswalter Zentgraf, Wolfhard Semmler, Sönke Bartling

  Nano letters. 05/2010; 10(7):2318-22.

  Antibody-conjugated gold nanoparticles have been applied as a biologically targeted contrast agent in live mice for one of the most widely used medical imaging methods, X-ray computed tomography. Such nanoprobes directed toward the CD4 receptor lead to distinctly enhanced X-ray contrast of periphera... [more] Antibody-conjugated gold nanoparticles have been applied as a biologically targeted contrast agent in live mice for one of the most widely used medical imaging methods, X-ray computed tomography. Such nanoprobes directed toward the CD4 receptor lead to distinctly enhanced X-ray contrast of peripheral lymph nodes. This study demonstrates the general feasibility of biologically specific X-ray imaging in living animals and discusses basic requirements for the use of nanoparticles as a targeted X-ray contrast agent.
• 2.78

  Impact points

  Fully automated intrinsic respiratory and cardiac gating for small animal CT.

  J Kuntz, J Dinkel, S Zwick, T Bäuerle, M Grasruck, F Kiessling, R Gupta, W Semmler, S H Bartling

  Physics in medicine and biology. 04/2010; 55(7):2069-85.

  A fully automated, intrinsic gating algorithm for small animal cone-beam CT is described and evaluated. A parameter representing the organ motion, derived from the raw projection images, is used for both cardiac and respiratory gating. The proposed algorithm makes it possible to reconstruct motion-c... [more] A fully automated, intrinsic gating algorithm for small animal cone-beam CT is described and evaluated. A parameter representing the organ motion, derived from the raw projection images, is used for both cardiac and respiratory gating. The proposed algorithm makes it possible to reconstruct motion-corrected still images as well as to generate four-dimensional (4D) datasets representing the cardiac and pulmonary anatomy of free-breathing animals without the use of electrocardiogram (ECG) or respiratory sensors. Variation analysis of projections from several rotations is used to place a region of interest (ROI) on the diaphragm. The ROI is cranially extended to include the heart. The centre of mass (COM) variation within this ROI, the filtered frequency response and the local maxima are used to derive a binary motion-gating parameter for phase-sensitive gated reconstruction. This algorithm was implemented on a flat-panel-based cone-beam CT scanner and evaluated using a moving phantom and animal scans (seven rats and eight mice). Volumes were determined using a semiautomatic segmentation. In all cases robust gating signals could be obtained. The maximum volume error in phantom studies was less than 6%. By utilizing extrinsic gating via externally placed cardiac and respiratory sensors, the functional parameters (e.g. cardiac ejection fraction) and image quality were equivalent to this current gold standard. This algorithm obviates the necessity of both gating hardware and user interaction. The simplicity of the proposed algorithm enables adoption in a wide range of small animal cone-beam CT scanners.
• 14.51

  Impact points

  Resistance to antiangiogenic therapy is directed by vascular phenotype, vessel stabilization, and maturation in malignant melanoma.

  Iris Helfrich, Inka Scheffrahn, Sönke Bartling, Joachim Weis, Verena von Felbert, Mark Middleton, Masahi Kato, Süleyman Ergün, Dirk Schadendorf

  The Journal of experimental medicine. 03/2010; 207(3):491-503.

  Angiogenesis is not only dependent on endothelial cell invasion and proliferation, it also requires pericyte coverage of vascular sprouts for stabilization of vascular walls. Clinical efficacy of angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signaling pathway is sti... [more] Angiogenesis is not only dependent on endothelial cell invasion and proliferation, it also requires pericyte coverage of vascular sprouts for stabilization of vascular walls. Clinical efficacy of angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signaling pathway is still limited to date. We hypothesized that the level of vessel maturation is critically involved in the response to antiangiogenic therapies. To test this hypothesis, we evaluated the vascular network in spontaneously developing melanomas of MT/ret transgenic mice after using PTK787/ZK222584 for anti-VEGF therapy but also analyzed human melanoma metastases taken at clinical relapse in patients undergoing adjuvant treatment using bevacizumab. Both experimental settings showed that tumor vessels, which are resistant to anti-VEGF therapy, are characterized by enhanced vessel diameter and normalization of the vascular bed by coverage of mature pericytes and immunoreactivity for desmin, NG-2, platelet-derived growth factor receptor beta, and the late-stage maturity marker alpha smooth muscle actin. Our findings emphasize that the level of mural cell differentiation and stabilization of the vascular wall significantly contribute to the response toward antiangiogenic therapy in melanoma. This study may be useful in paving the way toward a more rational development of second generation antiangiogenic combination therapies and in providing, for the first time, a murine model to study this.

• First multimodal embolization particles being visible in MRI and CT

  S.H. Bartling, J. Budjan, H. Aviv, H.J. Michaely, W. Semmler, S.O. Schoenberg, S. Diehl, S. Margel, M. Sadick

  ECR 2010, Vienna; 03/2010

  Purpose: To develop and test the first multimodal embolization particles being visible within CT and MRI. Its usage might be beneficial within multimodality angiography setups, therapy control, long-term follow-up of embolization therapy, future transition to interventional MRI and research of novel... [more] Purpose: To develop and test the first multimodal embolization particles being visible within CT and MRI. Its usage might be beneficial within multimodality angiography setups, therapy control, long-term follow-up of embolization therapy, future transition to interventional MRI and research of novel embolization concepts. Methods and Materials: CT visible iodine was combined with MRI visible iron in a macroparticle (diameter 50-250 µm). Its core - consisting of copolymerized monomer MAOETIB [2-methacryloyloxyethyl(2,3,5-triiodobenzoate)] - was coated with paramagnetic iron oxide nanoparticles (USPIO). After ex-vivo testing, including SNR measurements (n=5), its ability to embolize tissue was tested in an established tumor embolization model in rats (2) and rabbits (5). X-ray angiography, CT and MR imaging was performed on clinical scanners (Dual-source Definition CT, 3 Tesla Magnetom Tim Trio MRI, Siemens) before, during and after application of particles to the catheterized renal artery. Histology was prepared. Results: The particles provided a sufficient image contrast in both CT (SNR: 14±4) and MRI (SNR: 14±1). Successful embolization of renal tissue was confirmed by particles residing within the kidney as seen in corresponding areas in MRI and CT. Histology allowed a direct visualization of the residing particles as well as associated thrombosis in kidney arteries. Successful embolization was confirmed by inflammation and necrosis in treated kidneys while the control kidneys were unaltered. Conclusion: A multimodality embolization material was successfully developed and tested in animal models. Its consistence of clinically used substances might ease approval.

• Verfahren für eine öffentliche, dynamische, wissenschaftliche Publikation

  Bartling

  Ref. No: German provisional application

  Year: 01/2010

  Not disclosed.

• SYSTEMS AND METHODS FOR 4D RADIOLOGICAL INTERVENTION GUIDANCE (4D-CATH)

  Bartling, Kachelriess, Kuntz

  Ref. No: US Provisional

  Year: 01/2010

  Will be disclosed, if appropiate.

• Data Documentation Systems

  Bartling, Semmler

  01/2010: pages 405;
• 4.02

  Impact points

  Intrarenal artery delineation with ultra high resolution, flat panel based, volume computerized tomography: outer limits of spatial resolution.

  Martin Neukamm, Moritz Palmowski, Soenke Bartling, Simone Schawo, Urte Rietdorf, Hans-Peter Meinzer, Markus Hohenfellner, Hans-Ulrich Kauczor, Peter Hallscheidt

  The Journal of urology. 12/2009; 182(6):2915-9.

  PURPOSE: New methods of noninvasive high resolution imaging may improve the delineation of tumor microvessels and, thus, be of significant help in surgical planning and cost-effective monitoring of novel anti-angiogenic therapy. We determined the maximum delineation of intrarenal microvessels with a... [more] PURPOSE: New methods of noninvasive high resolution imaging may improve the delineation of tumor microvessels and, thus, be of significant help in surgical planning and cost-effective monitoring of novel anti-angiogenic therapy. We determined the maximum delineation of intrarenal microvessels with a novel flat panel based volume computerized tomography system in an experimental setting. MATERIALS AND METHODS: We prospectively evaluated 13 porcine renal specimens for intrarenal vessel delineation using a prototype gantry based, flat panel, cone beam computerized tomography system. The gantry incorporates an array of a 40 x 30 cm(2) CsI amorphous silicon flat panel detector consisting of a 2,048 x 1,536 matrix. After catheterizing the renal artery with a 5Fr end hole catheter a contrast enhanced scan was performed using BaS as contrast medium at a dilution of 200 mg/ml. The diameter of all definable arterial branches was determined using a software tool based on Medical Imaging and Interaction Toolkit, allowing semi-automatic segmentation of the vessel tree. In step 1 the vessel tree is segmented by a 3-dimensional region growing algorithm. Following its medial axis the vessel tree is extracted and converted to a representation, including the diameter of the vessels. RESULTS: In each kidney an average +/- SD of 47,454 +/- 22,382 arterial branches could be delineated. The diameter of the branches was 0.029 (mean 0.032 +/- 0.0025) to 3.444 mm (mean 1.813 +/- 0.6139) with a median of 0.263 mm. Of visible intrarenal arteries 2.7% had a vessel diameter of 0.029 mm. CONCLUSIONS: Flat panel based volume computerized tomography can visualize intrarenal microvessels down to a diameter of 0.03 mm. It may improve the assessment of renal microvessel architecture in healthy patients and in those with pathological conditions.

• A robot-guided minimally invasive approach for cochlear implant surgery: preliminary results of a temporal bone study.

  Omid Majdani, Thomas S Rau, Stephan Baron, Hubertus Eilers, Claas Baier, Bodo Heimann, Tobias Ortmaier, Sönke Bartling, Thomas Lenarz, Martin Leinung

  International journal of computer assisted radiology and surgery. 09/2009; 4(5):475-86.

  The aim of this study was to create an access canal to the inner ear, by drilling, and perform the cochleostomy for cochlear implant surgery using robot guidance. A robot, a surgical drill and an Image-Guided Surgery (IGS) system were combined in a closed-loop setup. Ten temporal bones were scanned ... [more] The aim of this study was to create an access canal to the inner ear, by drilling, and perform the cochleostomy for cochlear implant surgery using robot guidance. A robot, a surgical drill and an Image-Guided Surgery (IGS) system were combined in a closed-loop setup. Ten temporal bones were scanned at the planning stages of the procedure. The robot guided the drill along the preplanned trajectory and created the approach. Postoperative scans were obtained. The cochleostomy was performed completely in nine out of ten cases. This did not prove possible for one of the specimens, the target site selected being in too superficial a location in relation to the round window. No violation of the facial nerve took place, although the chorda tympani nerve was violated in one case and the stapes in two. It was obvious during preoperative planning that these structures would be violated, but this was accepted in order to maintain a safety margin from the facial nerve. No other unforeseen damage occurred. This preliminary study suggests that robot-guided drilling of a minimally invasive approach to the cochlea might be feasible, but further improvements are necessary before any clinical application becomes possible. Where the width of the facial recess is less than 2.5 mm, the chorda tympani nerve and the ossicles are at risk.
• 7.37

  Impact points

  Radiopaque iodinated copolymeric nanoparticles for X-ray imaging applications.

  Hagit Aviv, Sonke Bartling, Fabian Kieslling, Shlomo Margel

  Biomaterials. 08/2009;

  Recently we described iodinated homopolymeric radiopaque nanoparticles of 28.9+/-6.3nm dry diameter synthesized by emulsion polymerization of 2-methacryloyloxyethyl(2,3,5-triiodobenzoate) (MAOETIB). The nanoparticle aqueous dispersion, however, was not stable and tended to agglomerate, particularly ... [more] Recently we described iodinated homopolymeric radiopaque nanoparticles of 28.9+/-6.3nm dry diameter synthesized by emulsion polymerization of 2-methacryloyloxyethyl(2,3,5-triiodobenzoate) (MAOETIB). The nanoparticle aqueous dispersion, however, was not stable and tended to agglomerate, particularly at weight concentration of dispersed nanoparticles above approximately 0.3%. The agglomeration rate increases as the concentration of nanoparticles in aqueous phase rises and prevents the potential in vivo use as contrast agent for medical X-ray imaging. Here we describe efforts to overcome this limitation by synthesis of iodinated copolymeric nanoparticles of 25.5+/-4.2nm dry diameter, by emulsion copolymerization of the monomer, MAOETIB, with a low concentration of glycidyl methacrylate (GMA). The surface of resulting copolymeric nanoparticles is far more hydrophilic than that of polyMAOETIB (PMAOETIB) nanoparticles. Therefore, P(MAOETIB-GMA) nanoparticles are significantly more stable against agglomeration in aqueous continuous phase. After intravenous injection of P(MAOETIB-GMA) nanoparticles in rats and mice (including those with a liver cancer model) CT-imaging revealed a significant enhanced visibility of the blood pool for 30min after injection. Later, lymph nodes, liver and spleen strongly enhanced due to nanoparticle uptake by the reticuloendothelial system. This favorably enabled the differentiation of cancerous from healthy liver tissue and suggests our particles for tumor imaging in liver and lymph nodes.
• 3.76

  Impact points

  Gating in small-animal cardio-thoracic CT.

  Soenke H Bartling, Jan Kuntz, Wolfhard Semmler

  Methods (San Diego, Calif.). 08/2009;

  Gating is necessary in cardio-thoracic small-animal imaging because of the physiological motions that are present during scanning. In small-animal computed tomography (CT), gating is mainly performed on a projection base because full scans take much longer than the motion cycle. This paper presents ... [more] Gating is necessary in cardio-thoracic small-animal imaging because of the physiological motions that are present during scanning. In small-animal computed tomography (CT), gating is mainly performed on a projection base because full scans take much longer than the motion cycle. This paper presents and discusses various gating concepts of small-animal CT, and provides examples of concrete implementation. Since a wide variety of small-animal CT scanner systems exist, scanner systems are discussed with respect to the most suitable gating methods. Furthermore, an overview is given of cardio-thoracic imaging and gating applications. The necessary contrast media are discussed as well as gating limitations. Gating in small-animal imaging requires the acquisition of a gating signal during scanning. This can be done extrinsically (additional hardware, e.g. electrocardiogram) or intrinsically from the projection data itself. The gating signal is used retrospectively during CT reconstruction, or prospectively to trigger parts of the scan. Gating can be performed with respect to the phase or the amplitude of the gating signal, providing different advantages and challenges. Gating methods should be optimized with respect to the diagnostic question, scanner system, animal model, type of narcosis and actual setup. The software-based intrinsic gating approaches increasingly employed give the researcher independence from difficult and expensive hardware changes.

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• 3.30

  Impact points

  Temporal Bone Imaging: Comparison of Flat Panel Volume CT and Multisection CT.

  O Majdani, K Thews, S Bartling, M Leinung, C Dalchow, R Labadie, T Lenarz, G Heidrich

  AJNR. American journal of neuroradiology. 05/2009;

  BACKGROUND AND PURPOSE: A recent development in radiology is the use of flat panel detectors in CT to obtain higher-resolution images. This technique is known as flat panel volume CT (fpVCT). We sought to compare the image quality and diagnostic value of 2 different flat panel detector-equipped scan... [more] BACKGROUND AND PURPOSE: A recent development in radiology is the use of flat panel detectors in CT to obtain higher-resolution images. This technique is known as flat panel volume CT (fpVCT). We sought to compare the image quality and diagnostic value of 2 different flat panel detector-equipped scanners: one is a prototype fpVCT scanner, and the other is a so-called flat panel digital volume tomography (fpDVT) scanner, which is routinely used in clinical setup with current state-of-the-art multisection CT (MSCT) scanners. MATERIALS AND METHODS: Five explanted temporal bones and 2 whole-head cadaveric specimens were scanned with fpVCT, fpDVT, and MSCT scanners. The image series were blindly evaluated by 3 trained observers who rated 38 anatomic structures with regard to their delineation/appearance. RESULTS: Although the image quality obtained with fpVCT and fpDVT was rated significantly better compared with MSCT on isolated temporal bones, the differences were not significant when whole cadaveric heads were scanned. CONCLUSIONS: Theoretic and practical advantages exist for flat panel detector-equipped scanners, including improved image quality. However, when imaging whole cadaveric heads, no significant difference could be demonstrated between them and standard-of-care MSCT.