Carolin Brockmann

Universität Mannheim, Mannheim, Baden-Württemberg, Germany

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Publications (25)23.45 Total impact

  • 10/2012; 23(3). DOI:10.1007/s00062-012-0176-8
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    ABSTRACT: INTRODUCTION: Central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) are rare neurological disorders characterized by demyelination in and/or outside the pons. Whether diffusion-weighted imaging (DWI) might facilitate an earlier diagnosis has not yet been studied systematically. METHODS: We describe demographics, clinical presentation, and early magnetic resonance imaging (MRI) findings with special emphasis on the relevance for diagnosis of CPM and/or EPM in eight patients. RESULTS: Of the analysed eight patients (aged 37-70 years; two men, six women), CPM was diagnosed in three, EPM in one, and a combination of CPM and EPM in four patients. Aetiology was rapid correction of sodium in two patients; a combination of hyponatremia, alcoholism and alcohol withdrawal in five patients and unclear in one patient. Seven patients suffered from chronic alcoholism and four from malnutrition. Demyelinating lesions were found in the pons, thalamus, caudate nucleus, putamen and midbrain. While the lesions could be clearly delineated on T2- and T1-weighted images, DWI demonstrated a strong signal in only six patients. Furthermore, DWI demonstrated lesions only to some extent in two patients and was completely negative in two patients on initial MRI. In none of the patients did the demonstration of hyperintense lesions on DWI precede detection on conventional MRI sequences. Apparent diffusion coefficient (ADC) values were heterogenous with a decrease in two cases and an increase in the remainder. CONCLUSIONS: We conclude that early DWI changes are a common finding in CPM/EPM but do not regularly precede tissue changes detectable on conventional MRI sequences. Heterogenous ADC values possibly represent different stages of disease.
    Neuroradiology 08/2012; 55(1). DOI:10.1007/s00234-012-1083-z · 2.37 Impact Factor
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    ABSTRACT: INTRODUCTION: Cerebral vasospasm is a severe complication of subarachnoid hemorrhage (SAH). The calcium channel inhibitor nimodipine has been used for treatment of cerebral vasospasm. No evidence-based recommendations for local nimodipine administration at the site of vasospasm exist. The purpose of this study was to quantify nimodipine's local vasodilatory effect in an ex vivo model of SAH-induced vasospasm. METHODS: SAH-induced vasospasm was modeled by contracting isolated segments of rat superior cerebellar arteries with a combination of serotonin and a synthetic analog of prostaglandin A(2). A pressure myograph system was used to determine vessel reactivity of spastic as well as non-spastic arteries. RESULTS: Compared to the initial vessel diameter, a combination of serotonin and prostaglandin induced considerable vasospasm (55 ± 2.5 % contraction; n = 12; p < 0.001). Locally applied nimodipine dilated the arteries in a concentration-dependent manner starting at concentrations as low as 1 nM (n = 12; p < 0.05). Concentrations higher than 100 nM did not relevantly increase the vasodilatory effect. Nimodipine's vasodilatory effect was smaller in spastic than in non-spastic vessels (n = 12; p < 0.05), which we assume to be due to structural changes in the vessel wall. CONCLUSION: The described ex vivo model allows to investigate the dose-dependent efficacy of spasmolytic drugs prior to in vivo experiments. Low concentrations of locally applied nimodipine have a strong vasodilatory effect, which is of relevance when considering the local application of nimodipine in cerebral vasospasm.
    Neuroradiology 08/2012; 55(1). DOI:10.1007/s00234-012-1079-8 · 2.37 Impact Factor
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    ABSTRACT: The aim of the present study was to examine the superior sagittal sinus (SSS) and bridging veins (BVs) from an anatomical, neurosurgical and radiological perspective. Computed tomography venographies (CTVs) of 30 patients and 9 cadaveric dissections of human SSS were analyzed. CTV and cadavers showed most BVs emptying into the SSS close by (±3 cm) and distal to the coronary suture (74% in CTV, 62% in cadavers). Important anatomical information can be drawn from cerebral CTV for neurosurgical preoperative planning.
    Clinical imaging 03/2012; 36(2):85-9. DOI:10.1016/j.clinimag.2011.05.003 · 0.60 Impact Factor
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    ABSTRACT: The patency of a bypass plays an important role in the postoperative recovery of patients especially when dealing with complicated intracranial aneurysms. In this study two-dimensional phase contrast magnetic resonance angiography (PC-MRA) was used to measure cerebral blood flow in 23 patients before extracranial-intracranial high-flow bypass surgery using the excimer laser-assisted non-occlusive anastomosis (ELANA) technique and in 15 patients following surgery. The results showed that PC-MRA is a suitable technique for assessing bypass patency and that with the ELANA technique the bypass has the capability of compensating the blood flow of an occluded internal carotid artery (ACI) in cases of complex aneurysms.
    12/2011; 22(1):39-45. DOI:10.1007/s00062-011-0116-z
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    ABSTRACT: PURPOSE To evaluate the clinical feasability of a newly developed fully automatic vessel segmentation software (Angioscope, Cathi GmbH, Germany) with bone and calcification removal based on dual energy CT data against a commercially available vessel segmentation and bone removal tool (Leonardo, Siemens Medical Solutions, Erlangen, Germany). METHOD AND MATERIALS Angioscope is a fully automated vessel segmentation software. It uses a graph-based matching technique as well as subvoxel analysis of high contrast structures for segmentation. For data acquisition dual energy CTA was used at 140kV and 80kV. The CTA protocol was specifically designed to improve the imaging quality of the lower legs. 108 vessel segments of 9 patients with peripheral arterial occlusive disease (PAOD) who underwent dual energy CTA and DSA of the pelvis and lower extremities with intention to treat were analysed. CTA data were evaluated by two readers using the newly developed Angioscope (ASBE, automatic structured bone elimination) software and a standard software (Leonardo, Siemens AG, Erlangen, Germany) against the DSA goldstandard. RESULTS Using the Angioscope software sensitivity increased from 96,3% to 100% and data concordance with DSA increased from 64,5% to 88,6%, whereas specificity slightly decreased (79% vs 87%) compared to the standard software. Data concordance between the Angioscope software and DSA was especially high in severely calcified blood vessels. CONCLUSION Angioscope showed good concordance with the DSA goldstandard and non-inferiority compared to standard segmentation software. Segmentation problems occurred in severly calcified vessels with a calcification grade of more than half the vessel perimeter. The main advantage of Angioscope lies in its full automation and thus lower susceptibility to user prone errors. CLINICAL RELEVANCE/APPLICATION PAOD is associated with high morbidity. A fully automated tool for vascular status evaluation may proof beneficial in clinical practice in terms of cost, effectiveness and patient benefit.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011
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    ABSTRACT: Mice are often used as small animal models of brain ischemia, venous thrombosis, or vasospasm. This article aimed at providing an overview of the currently available methodologies for in vivo imaging of the murine cerebrovasculature and comparing the capabilities and limitations of the different methods. Micro-computed tomography angiography (CTA) was performed during intra-arterial and intravenous administration of a contrast agent bolus. Digital subtraction angiography (DSA) was performed during intra-arterial administration of contrast agent using the micro-CT scanner. Time-of-flight (ToF) magnetic resonance (MR) angiography was performed using a small animal scanner (9.4 T) equipped with a cryogenic transceive quadrature coil. Datasets were compared for scan time, contrast-to-noise ratio (CNR), temporal and spatial resolution, radiation dose, contrast agent dose and detailed recognition of cerebrovascular structures. Highest spatial resolution was achieved using micro-CTA (16 x 16 x 16 µm) and DSA (14 x 14 µm). Compared to micro-CTA (20-40 s) and ToF-MRA (57 min), DSA provided highest temporal resolutions (30 fps) allowing analyses of the cerebrovascular blood flow. Highest mean CNR was reached using ToF-MRA (50.7 ± 15.0), while CNR of micro-CTA depended on the intra-arterial (19.0 ± 1.0) and intravenous (1.3 ± 0.4) use of agents. The CNR of DSA was 10.0 ± 1.8. The use of dedicated small animal scanners allows cerebrovascular imaging in live animals as small as mice. As each of the methods analyzed has its advantages and limitations, choosing the best suited imaging modality for a defined question is of great importance. By this means the aforementioned methods offer a great potential for future projects in preclinical cerebrovascular research including ischemic stroke or vasospasm.
    11/2011; 22(1):21-8. DOI:10.1007/s00062-011-0113-2
  • C Brockmann, F Seker, C Weiss, C Groden, J Scharf
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    ABSTRACT: Assuming thromboembolic events to be the origin of silent strokes during cerebral digital subtraction angiography (DSA), antiplatelet therapy with acetylsalicylic acid (ASA) should significantly reduce the risk for DSA-related silent stroke. The aim of this retrospective analysis was to assess whether ASA does prevent DSA-related silent stroke in terms of high signal intensity lesions in diffusion-weighted magnetic resonance imaging (DW-MRI). All patients underwent a baseline DW-MRI 24 h before DSA and a follow-up DW-MRI 3-24 h after DSA. Patients were considered to have an acute (silent) infarction caused by DSA if there was at least one hyperintense lesion of at least 1 mm in diameter and no neurological deficits. Out of 52 patients in the ASA group 11 (21.2%) had high signal lesions on DW-MRI and 20 out of 123 (16.3%) in the non-ASA group. No significant relationship between the ASA and non-ASA group and the post-angiographic appearance of high signal intensity lesions in DW-MRI could be found (Wilcoxon 2-sample test: p-value 0.9). The use of oral antiplatelet therapy by ASA (100 mg/day) in cerebrovascular patients did not prevent DSA-related high signal intensity lesions in DW-MRI in this study. Despite a potential bias of this retrospective analysis the findings challenge the current theory of thromboembolisms being the predominant origin of silent stroke. The findings therefore support alternative hypotheseses of the etiology of silent strokes, such as air embolism and mobilized embolic material by the catheter at the vessel wall.
    05/2011; 22(1):15-20. DOI:10.1007/s00062-011-0076-3
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    ABSTRACT: The aim of this study was to evaluate the optimal preanalytical conditions prior to nucleic acid amplification technology (NAT) for human immunodeficiency virus-1 (HIV-1) or Hepatitis C virus (HCV) RNA in pools of 96 plasma specimens with regard to storage temperature, time and plasma separation in a blood donation environment. Changes in viral nucleic acid concentration of HIV-1 and HCV were observed for 5 days according to the Paul-Ehrlich-Institute's (PEI) guidelines that demand 95%-detection limit of at least 10 000 IU mL(-1) for HIV-1 RNA and 5000 IU mL(-1) for HCV RNA within a single donor blood specimen. Ninety-five per cent detection limits of HIV-1 RNA over 3 days after storage at either 5 or 21 °C were evaluated by using standardised HIV-1 RNA-positive plasma. HCV RNA in whole blood samples proved to be more stable than HIV-1 RNA. Whole blood storage at 21 °C was shown to decrease the detectability of HIV-1 RNA even after only 18 h. Plasma samples once used for NAT at time 18 h did not alter viral stability up to 48 h after donation. Ninety-five per cent detection limits of HIV-1 RNA were securely below 10 000 IU mL(-1) for 24 h after whole blood storage at 5 °C. These results may lead to a discussion around the most suitable preanalytical conditions in blood donation environments. Contrary to the current PEI guidelines that allow storage of whole blood specimens up to 18 h at 21 °C, these results suggest that immediate storage in a 5 °C container after blood donation is more suitable and would permit storage of whole blood up to 24 h prior to the separation of plasma from cells.
    Transfusion Medicine 04/2011; 21(2):99-106. DOI:10.1111/j.1365-3148.2010.01051.x · 1.31 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 04/2011; 183(S 01). DOI:10.1055/s-0031-1279477 · 1.96 Impact Factor
  • Carolin Brockmann, Sandra Kunze, Johann Scharf
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    ABSTRACT: The primary aim of our paper was to describe typical anatomical patterns of the superior sagittal sinus (SSS) and bridging veins (BV) using cerebral venous computed tomographic angiography (CTA) with a focus on the direction of the BV entering the SSS. We retrospectively analyzed venous CTA of 30 patients to estimate the total number and direction of the BV entering the SSS. Maximum intensive projections were analyzed for length, diameter and cross-sectional area of the SSS. Thee hundred and fifty-four BV were assessed. The mean total length of the SSS was 25.6 ± 1.6 cm (mean ± 1 SD). The mean horizontal diameter at the level of the coronary suture was 6.7 ± 2.0 mm, and the mean vertical diameter at the coronary suture measured 5.3 ± 1.8 mm. Most BV emptied into the SSS, at the level of or distal to the coronary suture (74%). The BV draining into the SSS at the level of the coronary suture typically joined into a lacunar formation (43%). Veins draining into the sinus more than 3 cm distal from the coronary suture presented a predominantly retrograde inflow direction (77%). Despite large variations in the location and course of BV, typical anatomical patterns were noted especially in relation to the direction of BV entering the SSS. The present anatomical analysis of the cerebral convexity veins by cerebral venous CTA provides an overview of the configuration of these veins which is useful information in neurosurgical preoperative planning.
    Anatomia Clinica 03/2011; 33(2):129-34. DOI:10.1007/s00276-010-0714-5 · 1.33 Impact Factor
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    ABSTRACT: To assess the efficiency of IIb/IIIa platelet receptor inhibition by abciximab in the prevention of silent embolism during digital subtraction angiography. In this randomized, double-blind, prospective study, pre- and postangiographic diffusion-weighted magnetic resonance imaging (DWI) of 184 participants was evaluated for the occurrence of silent embolism. No significant relationship was found between the patients receiving abciximab before digital subtraction angiography (15 of 90; 16.7%) and patients in the placebo group (16 of 94; 17.0%) regarding postangiographic appearance of silent emboli (p = 0.9). IIb/IIIa receptor inhibition by abciximab does not diminish the occurrence of silent embolism during digital subtraction angiography. Our findings indicate that solid blood clots are not the origin of hyperintense lesions observed on DWI and enhance the role of alternative mechanisms.
    Cerebrovascular Diseases 01/2011; 31(4):353-7. DOI:10.1159/000323219 · 3.70 Impact Factor
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    ABSTRACT: The aim was to assess the feasibility of dual-energy computed tomography (DE-CT) for detection of peri-interventional re-bleeding in patients with aneurysmal subarachnoid hemorrhage (re-SAH). For in vitro-analyses DE-CT of partially clotted blood intermixed with fresh blood containing contrast agent was performed. In a clinical setting, 4 patients routinely underwent DE-CT after suspected peri-interventional re-SAH. DE-CT source data images, iodine maps and virtual non-contrast images (VNC) were analyzed and regions-of-interest (ROI) measurements of density values were performed. In vitro experiments demonstrated the feasibility of DE-CT to discriminate between blood with and without contrast agent. In all patients peri-interventional re-SAH was confirmed by detection of extravasated iodine within the subarachnoid spaces in post-interventional DE-CT. Dual-energy CT allowed the discrimination of old blood clots of the initial SAH and blood originating from peri-interventional re-SAH. After subtraction of the iodine-related high density signal, VNC images optimized the estimation of the true amount of subarachnoid blood. Dual-energy CT allows the discrimination and subtraction of blood and iodine mixed within the subarachnoid spaces in patients with peri-interventional re-SAH. It helps to avoid overestimation of SAH after peri-interventional re-bleeding and therefore is a potentially valuable tool in the assessment of peri-interventional re-SAH.
    11/2010; 20(4):231-5. DOI:10.1007/s00062-010-0036-3
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    ABSTRACT: The objective of this study is to compare a graph-matching-based software and a conventional tool for postprocessing of computed tomography angiography (CTA) in correlation with the gold standard digital subtraction angiography. Sensitivity, specificity, accuracy, and interobserver agreement increased from 80.3% to 92.9%, from 69.1% to 92.4%, from 73.5% to 92.8%, and from 0.45 to 0.96, respectively, using the graph-matching-based technique. Graph-matching-based CTA increases sensitivity, specificity, accuracy, and interobserver agreement in comparison to a conventional bone elimination tool in the assessment of peripheral arterial occlusive disease.
    Clinical imaging 09/2010; 34(5):367-74. DOI:10.1016/j.clinimag.2009.10.034 · 0.60 Impact Factor
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    ABSTRACT: PURPOSE: Injuries of the craniocervical vessels in multi-traumatized patients are rare but devastating and can lead to stroke and death; nevertheless the diagnostic assessment of these injuries is often not part of the CT trauma examination protocol. MATERIALS AND METHODS: A total of 44 out of 315 multi-traumatized patients were defined to be at high risk for vessel injuries. Two readers analyzed the CT angiography (CTA) with respect to 1.) type and extent of fractures and 2.) trauma-associated pathologies of the vessels from the aortic arch to the cerebrum. The CTs were presented as original scans with the possibility to view the multiplanar reconstructions. RESULTS: The two readers could detect 12 out of 14 and 14 out of 14 cervical fractures, respectively. Both readers could demonstrate 28 out of 28 fractures of the skull, skull base and extended facial fractures. The diagnostic evaluation of vessel diseases showed correct classification of the type of pathology in 8 out of 12 and 7 out of 12 cases for the two readers, respectively. CONCLUSIONS: CTA of the craniocervical vessels is an important tool for rapid detection of vessel injuries and diseases in trauma patients. Different types of fractures may indicate the need for focused attention to vessel injuries, but even if there are no fractures present dissection of internal carotid and vertebral arteries can occur.
    Der Unfallchirurg 04/2010; 114(6). DOI:10.1007/s00113-010-1780-1 · 0.61 Impact Factor
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    ABSTRACT: PURPOSE As is known one of the limitations of CT angiography (CTA) of the craniocervical vessels is the visualization of the vessels at the level of the scull base and the cervical spine. With the different voltages (80 and 140kV) of the dual energy CT (DE-CT) technique a differentiation of tissues like contrast enhanced vessels and bony structures is possible. This can be used to eliminate the bones leading to a better delineation of the vessels. METHOD AND MATERIALS Three different bone elimination methods were used in 20 patients: Dual Energy bone removal (DE), Neuro-DSA (NDSA) and InSpace-Bone-removal (BR). Two readers analyzed the axial source data and the post processed VRT regarding the bone removal in 18 vessel segments (C1-6, V2-4, A1-3, M1-3, P1-3). The quality of bone removal at each segment was graduated from 0 (not analyzable) and 1-4 (1= excellent, 2 =good, 3= moderate and 4= bad). RESULTS 2160 vascular segments were analyzed by two radiologists. Concordant findings of the two readers were found as follows: DE 81.3%, NDSA 80.2% and BR 76.7%. The quality of bone removal in DE was excellent or good in 77.9%, moderate in 16.7%, bad in 1.5% and not analyzable in 3.9%. Bone removal using NDSA was rated with 1 or 2 in 92.1%, 3 in 6.2%, 4 in 0.4% and 0 in 1.3%. In BR the bone removal was excellent or good in 63.5%, moderate in 15.0%, bad in 13.5% and not analyzable in 8.1%. CONCLUSION The subtraction based Neuro-DSA post processing tool shows the best results followed by the dual-energy based DE bone removal. The InSpace bone elimination is often incomplete at the scull and not really helpful in the region of the scull base and the cervical spine. Although the NDSA is an older, not dual-energy based method, the results of bone removal are very conclusive. CLINICAL RELEVANCE/APPLICATION To reach a sufficient bone removal in the CTA of the craniocervical vessels the NeuroDSA tool is a reliable method and leads to better results compared to the Dual Energy based method.
    Radiological Society of North America 2009 Scientific Assembly and Annual Meeting; 12/2009
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    ABSTRACT: Separating bone, calcification, and vessels in computer tomography angiography (CTA) allows for a detailed diagnosis of vessel stenosis. This paper presents a new, graph-based technique that solves this difficult problem with high accuracy. The approach requires one native data set and one that is contrast enhanced. On each data set, an attributed level-graph is derived and both graphs are matched by dynamic programming to differentiate between bone, on one hand side, and vessel/calcification on the other hand side. Lumen and calcified regions are then separated by a profile technique. Evaluation is based on data from vessels of pelvis and lower extremities of elderly patients. Due to substantial calcification and motion of patients between and during the acquisitions, the underlying approach is tested on a class of difficult cases. Analysis requires 3-5 min on a Pentium IV 3 GHz for a 700 MByte data set. Among 37 patients, our approach correctly identifies all three components in 80% of cases correctly compared to visual control. Critical inconsistencies with visual inspection were found in 6% of all cases; 70% of these inconsistencies are due to small vessels that have 1) a diameter near the resolution of the CT and 2) are passing next to bony structures. All other remaining deviations are found in an incorrect handling of the iliac artery since the slice thickness is near the diameter of this vessel and since the orientation is not in cranio-caudal direction. Increasing resolution is thus expected to solve many the aforementioned difficulties.
    07/2009; 28(12):1940-54. DOI:10.1109/TMI.2009.2026370
  • RöFo - Fortschritte auf dem Gebiet der R 04/2009; 181. DOI:10.1055/s-0029-1221442 · 1.96 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 04/2009; 181. DOI:10.1055/s-0029-1221386 · 1.96 Impact Factor
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    ABSTRACT: We sought to study the accuracy of dual-energy computed tomographic angiography (DE-CTA) for the assessment of symptomatic peripheral arterial occlusive disease of the lower extremity by using the dual-energy bone removal technique compared with a commercially available conventional bone removal tool. Twenty patients underwent selective digital subtraction angiography and DE-CTA of the pelvis and lower extremities. CTA data were postprocessed with two different applications: conventional bone removal and dual-energy bone removal. All data were reconstructed and evaluated as 3D maximum-intensity projections. Time requirements for reconstruction were documented. Sensitivity, specificity, accuracy, and concordance of DE-CTA regarding degree of stenosis and vessel wall calcification were calculated. A total of 359 vascular segments were analyzed. Compared with digital subtraction angiography, sensitivity, specificity, and accuracy, respectively, of CTA was 97.2%, 94.1%, and 94.7% by the dual-energy bone removal technique. The conventional bone removal tool delivered a sensitivity of 77.1%, a specificity of 70.7%, and an accuracy of 72.0%. Best results for both postprocessing methods were achieved in the vascular segments of the upper leg. In severely calcified segments, sensitivity, specificity, and accuracy stayed above 90% by the dual-energy bone removal technique, whereas the conventional bone removal technique showed a substantial decrease of sensitivity, specificity, and accuracy. DE-CTA is a feasible and accurate diagnostic method in the assessment of symptomatic peripheral arterial occlusive disease. Results obtained by DE-CTA are superior to the conventional bone removal technique and less dependent on vessel wall calcifications.
    CardioVascular and Interventional Radiology 02/2009; 32(4):630-7. DOI:10.1007/s00270-008-9491-5 · 1.97 Impact Factor

Publication Stats

68 Citations
23.45 Total Impact Points


  • 2012
    • Universität Mannheim
      Mannheim, Baden-Württemberg, Germany
  • 1970–2012
    • Heidelberg University
      • • Neuroradiology
      • • Faculty of Medicine Mannheim and Clinic Mannheim
      • • Institute of Clinical Radiology
      Heidelburg, Baden-Württemberg, Germany
  • 2011
    • University Medical Center Schleswig-Holstein
      Kiel, Schleswig-Holstein, Germany
  • 2008
    • Universität zu Lübeck
      Lübeck Hansestadt, Schleswig-Holstein, Germany