Diane M Renz

Humboldt-Universität zu Berlin, Berlín, Berlin, Germany

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Publications (89)190.01 Total impact

  • RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren; 04/2015
  • RöFo - Fortschritte auf dem Gebiet der R 04/2015; 187(S 01). DOI:10.1055/s-0035-1551134 · 1.96 Impact Factor
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    ABSTRACT: The first objective of this study was to determine normative digital X-ray radiogrammetry (DXR) values, based on original digital images, in a pediatric population (aged 6-18 years). The second aim was to compare these reference data with patients suffering from distal radius fractures, whereas both cohorts originated from the same geographical region and were evaluated using the same technical parameters as well as inclusion and exclusion criteria. DXR-BMD and DXR-MCI of the metacarpal bones II-IV were assessed on standardized digital hand radiographs, without printing or scanning procedures. DXR parameters were estimated separately by gender and among six age groups; values in the fracture group were compared to age- and gender-matched normative data using Student's t tests and Z scores. In the reference cohort (150 boys, 138 girls), gender differences were found in bone mineral density (DXR-BMD), with higher values for girls from 11 to 14 years and for boys from 15 to 18 years (p < 0.05). Girls had higher normative metacarpal index (DXR-MCI) values than boys, with significant differences at 11-14 years (p < 0.05). In the case-control investigation, the fracture group (95 boys, 69 girls) presented lower DXR-BMD at 15-18 years in boys and 13-16 years in girls vs. the reference cohort (p < 0.05); DXR-MCI was lower at 11-18 years in boys and 11-16 years in girls (p < 0.05). Mean Z scores in the fracture group for DXR-BMD were -0.42 (boys) and -0.46 (girls), and for DXR-MCI were -0.51 (boys) and -0.53 (girls). These findings indicate that the fully digital DXR technique can be accurately applied in pediatric populations ≥ 6 years of age. The lower DXR-BMD and DXR-MCI values in the fracture group suggest promising early identification of individuals with increased fracture risk, without the need for additional radiation exposure, enabling the initiation of prevention strategies to possibly reduce the incidence of osteoporosis later in life.
    Journal of Bone and Mineral Metabolism 02/2015; DOI:10.1007/s00774-014-0641-3 · 2.11 Impact Factor
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    ABSTRACT: The established scoring techniques based on radiographs present limitations in the evaluation of structural integrity due to high effectiveness of innovative therapeutic strategies. The aim of this study was to evaluate the periarticular mineralisation as detected by Digital X-ray Radiogrammetry (DXR) as surrogate marker for structural integrity during the course of rheumatoid arthritis (RA). 11 centers throughout Germany contributed data of 94 patients with verified RA. The patients were treated with leflunomide or methotrexate during a mean observation period of 22 months. All patients underwent complete computerized calculations of bone mineral density (BMD) and metacarpal index (MCI) by DXR using digitized hand radiographs. The radiological assessment of disease progression was estimated by the Sharp Score. The Sharp Score revealed no significant change during the study period. DXR-BMD revealed minimal decrease of -1.4 % (leflunomide group) versus a higher reduction of -4.3 % (methotrexate group). Regarding DXR-MCI, a reduction of -2.2 % (leflunomide group) and -4.9 % (methotrexate group) was observed. Quantitative data of hand bone mass estimated by the presented DXR-technique may be a complementary precise tool in the identification of RA-related radiographic changes and in the assessment of structural integrity.
    BMC Musculoskeletal Disorders 01/2015; 16:155. DOI:10.1186/s12891-015-0577-3 · 1.90 Impact Factor
  • Aktuelle Rheumatologie 12/2014; 39(06):393-398. DOI:10.1055/s-0034-1394423 · 0.06 Impact Factor
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    ABSTRACT: Objectives To compare intraindividually two macrocyclic contrast agents - gadobutrol and gadoterate meglumine (Gd-DOTA) - for dynamic and quantitative assessment of relative enhancement (RE) in benign and malignant breast lesions. Methods This was an ethically approved, prospective, single-centre, randomized, crossover study in 52 women with suspected breast lesions referred for magnetic resonance imaging (MRI). Each patient underwent one examination with gadobutrol and one with Gd-DOTA (0.1 mmol/kg BW) on a 1.5 T system 1 - 7 days apart. Dynamic, T1-weighted, 3D gradient echo sequences were acquired under identical conditions. Quantitative evaluation with at least three regions of interest (ROI) per lesion was performed. Primary endpoint was RE during the initial postcontrast phase after the first and second dynamic acquisition, and peak RE. All lesions were histologically proven; differences between the examinations were evaluated. Results Forty-five patients with a total of 11 benign and 34 malignant lesions were assessed. Mean RE was significantly higher for gadobutrol than Gd-DOTA (p p = 0.048) Conclusions Gadobutrol has higher RE values compared with Gd-DOTA, whereas Gd-DOTA shows more marked washout in malignant lesions. This might improve the detection of breast lesions and influence the specificity of breast MRI-imaging. Key Points • Contrast agents differ in terms of peak enhancement and postinitial contrast behaviour. • Gadobutrol results in greater peak RE in lesions, likely due to relaxivity. • Gd-DOTA shows more pronounced washout in postinitial contrast behaviour of malignant lesions. • Further investigations of the differences among GD-CM may improve sensitivity and specificity.
    European Radiology 09/2014; 25(3). DOI:10.1007/s00330-014-3426-0 · 4.34 Impact Factor
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    ABSTRACT: Objective Digital X-ray radiogrammetry (DXR) is a computer-assisted technique used to quantify cortical bone density of the metacarpals. The influence of metacarpal bone rotation and type of cast material on bone mineral density (BMD) measurements using the DXR technique was tested. Methods The bone mineral density of the hand was measured by DXR, and rotation error (DXR-RE) as coefficients of variation were calculated, to verify reliability and reproducibility of this radiogeometric technique to assess in particular minor disease-related changes in the metacarpal bone mass. The reproducibility of the DXR measurements was also investigated using different cast materials (mull, elastic, and plastic). Results There were no significant changes in absolute values of DXR-BMD observed between 0 to \(19^\circ \) angulation. The relative DXR-RE ranged between 0 % (degree 1) and 0.70 % (degrees 15 and 19) for DXR-BMD. Regarding the different cast materials, DXR-BMD revealed a coefficient of variation with 0.41 % (mull cast) and 0.21 % (elastic cast). For the plastic cast, the DXR technique was not able to perform an analysis of DXR-BMD. Conclusion The study revealed no significant influence of metacarpal rotation on the measurements of metacarpal bone mineral density as estimated by DXR. DXR measurements are not optimal when cast material is used. DXR can accurately quantify periarticular cortical bone mass. This is significant especially for rheumatoid arthritis and related conditions where X-ray imaging of arthritic hands with varying degrees of deformity is performed.
    International Journal of Computer Assisted Radiology and Surgery 07/2014; 10(5). DOI:10.1007/s11548-014-1076-y · 1.66 Impact Factor
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    ABSTRACT: The purpose of this study was to compare contrast-enhanced spectral mammography (CESM) with mammography (MG) and combined CESM + MG in terms of detection and size estimation of histologically proven breast cancers in order to assess the potential to reduce radiation exposure. A total of 118 patients underwent MG and CESM and had final histological results. CESM was performed as a bilateral examination starting 2 min after injection of iodinated contrast medium. Three independent blinded radiologists read the CESM, MG, and CESM + MG images with an interval of at least 4 weeks to avoid case memorization. Sensitivity and size measurement correlation and differences were calculated, average glandular dose (AGD) levels were compared, and breast densities were reported. Fisher's exact and Wilcoxon tests were performed. A total of 107 imaging pairs were available for analysis. Densities were ACR1: 2, ACR2: 45, ACR3: 42, and ACR4: 18. Mean AGD was 1.89 mGy for CESM alone, 1.78 mGy for MG, and 3.67 mGy for the combination. In very dense breasts, AGD of CESM was significantly lower than MG. Sensitivity across readers was 77.9 % for MG alone, 94.7 % for CESM, and 95 % for CESM + MG. Average tumor size measurement error compared to postsurgical pathology was -0.6 mm for MG, +0.6 mm for CESM, and +4.5 mm for CESM + MG (p < 0.001 for CESM + MG vs. both modalities). CESM alone has the same sensitivity and better size assessment as CESM + MG and was significantly better than MG with only 6.2 % increase in AGD. The combination of CESM + MG led to systematic size overestimation. When a CESM examination is planned, additional MG can be avoided, with the possibility of saving up to 61 % of radiation dose, especially in patients with dense breasts.
    Breast Cancer Research and Treatment 07/2014; 146(2). DOI:10.1007/s10549-014-3023-6 · 4.20 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 04/2014; 186(S 01). DOI:10.1055/s-0034-1372724 · 1.96 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 04/2014; 186(S 01). DOI:10.1055/s-0034-1373128 · 1.96 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 04/2014; 186(S 01). DOI:10.1055/s-0034-1373587 · 1.96 Impact Factor
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    ABSTRACT: In contrast to conventional breast imaging techniques, one major diagnostic benefit of breast magnetic resonance imaging (MRI) is the simultaneous acquisition of morphologic and dynamic enhancement characteristics, which are based on angiogenesis and therefore provide insights into tumor pathophysiology. The aim of this investigation was to intraindividually compare 2 macrocyclic MRI contrast agents, with low risk for nephrogenic systemic fibrosis, in the morphologic and dynamic characterization of histologically verified mass breast lesions, analyzed by blinded human evaluation and a fully automatic computer-assisted diagnosis (CAD) technique. Institutional review board approval and patient informed consent were obtained. In this prospective, single-center study, 45 women with 51 histopathologically verified (41 malignant, 10 benign) mass lesions underwent 2 identical examinations at 1.5 T (mean time interval, 2.1 days) with 0.1-mmol kg doses of gadoteric acid and gadobutrol. All magnetic resonance images were visually evaluated by 2 experienced, blinded breast radiologists in consensus and by an automatic CAD system, whereas the morphologic and dynamic characterization as well as the final human classification of lesions were performed based on the categories of the Breast imaging reporting and data system MRI atlas. Lesions were also classified by defining their probability of malignancy (morpho-dynamic index; 0%-100%) by the CAD system. Imaging results were correlated with histopathology as gold standard. The CAD system coded 49 of 51 lesions with gadoteric acid and gadobutrol (detection rate, 96.1%); initial signal increase was significantly higher for gadobutrol than for gadoteric acid for all and the malignant coded lesions (P < 0.05). Gadoteric acid resulted in more postinitial washout curves and fewer continuous increases of all and the malignant lesions compared with gadobutrol (CAD hot spot regions, P < 0.05). Morphologically, the margins of the malignancies were different between the 2 agents, whereas gadobutrol demonstrated more spiculated and fewer smooth margins (P < 0.05). Lesion classifications by the human observers and by the morpho-dynamic index compared with the histopathologic results did not significantly differ between gadoteric acid and gadobutrol. Macrocyclic contrast media can be reliably used for breast dynamic contrast-enhanced MRI. However, gadoteric acid and gadobutrol differed in some dynamic and morphologic characterization of histologically verified breast lesions in an intraindividual, comparison. Besides the standardization of technical parameters and imaging evaluation of breast MRI, the standardization of the applied contrast medium seems to be important to receive best comparable MRI interpretation.
    Investigative radiology 03/2014; DOI:10.1097/RLI.0000000000000039 · 4.45 Impact Factor
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    ABSTRACT: To evaluate postinterventional magnetic resonance imaging (MRI) characteristics following MRI-guided laser ablation of osteoid osteoma (OO). 35 patients treated with MRI-guided laser ablation underwent follow-up MRI immediately after the procedure, after 3, 6, 12, 24, 36, and up to 48 months. The imaging protocol included multiplanar fat-saturated T2w TSE, unenhanced and contrast-enhanced T1w SE, and subtraction images. MR images were reviewed regarding the appearance and size of treated areas, and presence of periablation bone and soft tissue changes. Imaging was correlated with clinical status. Mean follow-up time was 13.6 months. 28/35 patients (80%) showed a postinterventional "target-sign" appearance consisting of a fibrovascular rim zone and a necrotic core area. After an initial increase in total lesion diameter after 3 months, a subsequent progressive inward remodeling process of the zonal compartments was observed for up to 24 months. Periablation bone and soft tissue changes showed a constant decrease over time. MR findings correlated well with the clinical status. Clinical success was achieved in 32/35 (91%). Evaluation of long-term follow-up MRI after laser ablation of OO identified typical postinterventional changes and thus may contribute to the interpretation of therapeutic success and residual or recurrent OO in suspected cases.
    European journal of radiology 01/2014; 83(4). DOI:10.1016/j.ejrad.2013.12.018 · 2.16 Impact Factor
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    ABSTRACT: PURPOSE To compare contrast-enhanced digital mammography (CESM) to mammography (MG) and MRI on diagnostic accuracy of histologically proven breast lesions. METHOD AND MATERIALS The study was approved by Health Authorities and Ethics Committee. 90 consenting patients diagnosed with breast cancer were imaged with MG, CESM and MRI and underwent surgery. CESM was performed as a bi-lateral mammography starting 2 minutes after injection of 1.5ml/kg of an iodinated contrast agent (300 mg/ml) with a flow of 3ml/s. CESM images alone and MG images were interpreted by two blinded independent radiologists with an interval of minimum 4 weeks for memory wash-out. MRI was analyzed by another set of two independent readers. Per lesion sensitivity and specificity were evaluated across readers. BI-RADS 4 was defined as threshold for true positives. Gold standard was post-surgical histology. RESULTS 105 malignant and 10 benign histologically proven lesions were assessed in this dataset. Average sensitivity were 84.1% (reader1) and 67% (reader 2) for MG, 90.2% and 88.8% for CESM and 91.1% and 90% for MRI, respectively. Specificity was 100% (reader 1) and 80% (reader 2) for MG, 81.8% and 90% for CESM and 71.4% and 50% for MRI. CONCLUSION CESM and MRI showed similar sensitivity for index cancer and multiple foci, both superior to MG. MG and CESM outperformed MRI in specificity. CLINICAL RELEVANCE/APPLICATION CESM is a reliable imaging technique, which may replace MRI in cases with contraindications and may replace MG due to superior diagnostic accuracy in symptomatic patients.
    Mammography and MRI – Clinical Performance in a Multi-reader Evaluation. Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: Background. The aim of this study was to evaluate imaging-based response to standardized neoadjuvant chemotherapy (NACT) regimen by dynamic contrast-enhanced magnetic resonance mammography (DCE-MRM), whereas MR images were analyzed by an automatic computer-assisted diagnosis (CAD) system in comparison to visual evaluation. MRI findings were correlated with histopathologic response to NACT and also with the occurrence of metastases in a follow-up analysis. Patients and methods. Fifty-four patients with invasive ductal breast carcinomas received two identical MRI examinations (before and after NACT; 1.5T, contrast medium gadoteric acid). Pre-therapeutic images were compared with post-therapeutic examinations by CAD and two blinded human observers, considering morphologic and dynamic MRI parameters as well as tumor size measurements. Imaging-assessed response to NACT was compared with histopathologically verified response. All clinical, histopathologic, and DCE-MRM parameters were correlated with the occurrence of distant metastases. Results. Initial and post-initial dynamic parameters significantly changed between pre- and post-therapeutic DCE-MRM. Visually evaluated DCE-MRM revealed sensitivity of 85.7%, specificity of 91.7%, and diagnostic accuracy of 87.0% in evaluating the response to NACT compared to histopathology. CAD analysis led to more false-negative findings (37.0%) compared to visual evaluation (11.1%), resulting in sensitivity of 52.4%, specificity of 100.0%, and diagnostic accuracy of 63.0%. The following dynamic MRI parameters showed significant associations to occurring metastases: Post-initial curve type before NACT (entire lesions, calculated by CAD) and post-initial curve type of the most enhancing tumor parts after NACT (calculated by CAD and manually). Conclusions. In the accurate evaluation of response to neoadjuvant treatment, CAD systems can provide useful additional information due to the high specificity; however, they cannot replace visual imaging evaluation. Besides traditional prognostic factors, contrast medium-induced dynamic MRI parameters reveal significant associations to patient outcome, i.e. occurrence of distant metastases.
    Acta oncologica (Stockholm, Sweden) 12/2013; 53(6). DOI:10.3109/0284186X.2013.852688 · 3.71 Impact Factor
  • Annals of the rheumatic diseases 11/2013; DOI:10.1136/annrheumdis-2013-204786 · 9.27 Impact Factor
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    ABSTRACT: /st>Positioning central venous catheters (CVCs) in the proper part of the superior vena cava (SVC) is difficult. The aim of this exploratory study was to analyse topographic relationships of the extrapericardial SVC using chest X-ray (CXR) and computed tomography (CT). This included an appraisal of rules for optimal CVC tip placement. /st>We retrospectively evaluated 100 patients with CVCs who underwent bedside CXR and CT on the same day. Distances between the sternoclavicular joint (SCJ), tracheal carina, SVC origin, pericardial reflection, and CVC tip were analysed on CT and, if visible, on CXR. These measurements served to locate the extrapericardial SVC in relation to anatomical landmarks. Different strategies for CVC tip positioning were evaluated. /st>The mean (standard deviation) extrapericardial length of the SVC was 26 (12) mm. The average position of the pericardial reflection was 5 mm below the carina (range, 29 mm below to 25 mm above). In our patient population, the best results in terms of tip positions in the extrapericardial SVC would have been achieved by using 85% of the SCJ-to-carina distance (in 86%) or by positioning the CVC tip 9 mm above the carina (in 84% of patients). /st>The extrapericardial part of the SVC varies considerably in length and position, and rules of thumb based on anatomical landmarks should be used cautiously. In our series, using 85% of the SCJ-to-carina distance or placing the CVC tip 9 mm above the carina would have resulted in a high percentage of positions in the extrapericardial SVC.
    BJA British Journal of Anaesthesia 10/2013; 112(2). DOI:10.1093/bja/aet341 · 4.35 Impact Factor
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    ABSTRACT: Objectif L’analyse de l’interligne articulaire assistée par ordinateur (CAJSA) est une technique nouvellement développée, afin de mesurer la largeur de l’interligne articulaire radiogéométriquement des métacarpo-phalangiennes (JSD-MCP) et des interphalangiennes proximales (JSD-PIP). Le but de cette étude était de vérifier la sensibilité et la spécificité des mesures CAJSA dans l’évaluation des polyarthrites rhumatoïdes (PR) établies. Méthodes Quatre cent cinquante-huit participants (248 sujets sains et 210 patients présentant une PR) ont subi une mesure semi-automatique des JSD-MCP et JSD-PIP en utilisant un kit de radiogrammétrie CAJSA, version 1.3.6, en se basant sur des radiographies numérisées. Une évaluation du score de Sharp a été effectuée afin de déterminer un éventuel pincement de l’interligne articulaire. Résultats La réduction dépendant de la sévérité de la maladie était de –44,0 % pour le score JSD-MCP et de –26,5 % pour le score JSD-PIP entre les scores Sharp 0 et 3. La sensibilité et la spécificité du JSC-MCP (total) étaient respectivement de 88,1 % versus 77,8 % (aire sous la courbe [AUC] = 0,920 ; p < 0,001). Le JSD-PIP (total) avait révélé une sensibilité et spécificité plus basses avec des valeurs respectives de 61,4 % et de 88,7 % (AUC = 0,878 ; p < 0,001). Conclusion La méthode CAJSA est fiable pour l’évaluation du pincement radiographique chez les patients souffrant de PR, avec une excellente sensibilité/spécificité. En fournissant des données quantitatives, d’autres méthodes de cotation pourraient être significativement améliorées, permettant une meilleure précision diagnostique et une meilleure évaluation thérapeutique.
    Revue du Rhumatisme 10/2013; 80(5):473–478. DOI:10.1016/j.rhum.2012.12.003
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    ABSTRACT: To compare mammography (MG), contrast-enhanced spectral mammography (CESM), and magnetic resonance imaging (MRI) in the detection and size estimation of histologically proven breast cancers using postoperative histology as the gold standard. After ethical approval, 80 women with newly diagnosed breast cancer underwent MG, CESM, and MRI examinations. CESM was reviewed by an independent experienced radiologist, and the maximum dimension of suspicious lesions was measured. For MG and MRI, routine clinical reports of breast specialists, with judgment based on the BI-RADS lexicon, were used. Results of each imaging technique were correlated to define the index cancer. Fifty-nine cases could be compared to postoperative histology for size estimation. Breast cancer was visible in 66/80 MG, 80/80 CESM, and 77/79 MRI examinations. Average lesion largest dimension was 27.31 mm (SD 22.18) in MG, 31.62 mm (SD 24.41) in CESM, and 27.72 mm (SD 21.51) in MRI versus 32.51 mm (SD 29.03) in postoperative histology. No significant difference was found between lesion size measurement on MRI and CESM compared with histopathology. Our initial results show a better sensitivity of CESM and MRI in breast cancer detection than MG and a good correlation with postoperative histology in size assessment. • Contrast-enhanced spectral mammography (CESM) is slowly being introduced into clinical practice. • Access to breast MRI is limited by availability and lack of reimbursement. • Initial results show a better sensitivity of CESM and MRI than conventional mammography. • CESM showed a good correlation with postoperative histology in size assessment. • Contrast-enhanced spectral mammography offers promise, seemingly providing information comparable to MRI.
    European Radiology 09/2013; 24(1). DOI:10.1007/s00330-013-3007-7 · 4.34 Impact Factor
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    ABSTRACT: To evaluate the accuracy, safety, and efficacy of cervical nerve root injection therapy using magnetic resonance guidance in an open 1.0 T MRI system. Between September 2009 and April 2012, a total of 21 patients (9 men, 12 women; mean age 47.1 ± 11.1 years) underwent MR-guided cervical periradicular injection for cervical radicular pain in an open 1.0 T system. An interactive proton density-weighted turbo spin echo (PDw TSE) sequence was used for real-time guidance of the MR-compatible 20-gauge injection needle. Clinical outcome was evaluated on a verbal numeric rating scale (VNRS) before injection therapy (baseline) and at 1 week and 1, 3, and 6 months during follow-up. All procedures were technically successful and there were no major complications. The mean preinterventional VNRS score was 7.42 and exhibited a statistically significant decrease (P < 0.001) at all follow-up time points: 3.86 ± 1.53 at 1 week, 3.21 ± 2.19 at 1 month, 2.58 ± 2.54 at 3 months, and 2.76 ± 2.63 at 6 months. At 6 months, 14.3 % of the patients reported complete resolution of radicular pain and 38.1 % each had either significant (4-8 VNRS score points) or mild (1-3 VNRS score points) relief of pain; 9.5 % experienced no pain relief. Magnetic resonance fluoroscopy-guided periradicular cervical spine injection is an accurate, safe, and efficacious treatment option for patients with cervical radicular pain. The technique may be a promising alternative to fluoroscopy- or CT-guided injections of the cervical spine, especially in young patients and in patients requiring repeat injections.
    CardioVascular and Interventional Radiology 09/2013; 37(3). DOI:10.1007/s00270-013-0738-4 · 1.97 Impact Factor

Publication Stats

295 Citations
190.01 Total Impact Points


  • 2014
    • Humboldt-Universität zu Berlin
      Berlín, Berlin, Germany
  • 2010–2014
    • Charité Universitätsmedizin Berlin
      Berlín, Berlin, Germany
  • 2012
    • Freie Universität Berlin
      • Division of Physical and Theoretical Chemistry
      Berlín, Berlin, Germany
  • 2007–2010
    • Friedrich-Schiller-University Jena
      • Institute of Diagnostic and Interventional Radiology
      Jena, Thuringia, Germany
  • 2009
    • Universitätsklinikum Jena
      Jena, Thuringia, Germany