Sebastian N Nagel

Charité Universitätsmedizin Berlin | Charité · Institute of Radiology

18F-FDG-PET/CT is standard to assess response in Hodgkin lymphoma by quantifying metabolic activity with the Deauville score. PET/CT, however, is time-consuming, cost-extensive, linked to high radiation and has a low availability. As an alternative, we investigated radiomics from non-contrast-enhanced computed tomography (NECT) scans. 75 PET/CT exa...

Splenomegaly is a common cross-sectional imaging finding with a variety of differential diagnoses. This study aimed to evaluate whether a deep learning model could automatically segment the spleen and identify the cause of splenomegaly in patients with cirrhotic portal hypertension versus patients with lymphoma disease. This retrospective study inc...

Background Left bundle branch block (LBBB) is a ventricular conduction delay with high prevalence. Aim of our study is to identify possible recurring patterns of artefacts in late gadolinium enhancement (LGE) imaging in patients with LBBB who undergo cardiac magnetic resonance imaging (MRI) and to define parameters of mechanical dyssynchrony associ...

Background In radiomics studies, differences in the volume of interest (VOI) are often inevitable and may confound the extracted features. We aimed to correct this confounding effect of VOI variability by applying parametric maps with a fixed voxel size. Methods Ten scans of a cup filled with sodium chloride solution were scanned using a multislic...

Introduction Cardiac biomarkers, such as high-sensitivity cardiac troponin T (hs-cTnT), are frequently elevated in ischemic stroke patients but the mechanisms underlying this elevation are insufficiently understood. We determined the presence of cardiac damage, assessed using cardiac MRI (CMR), in stroke patients with elevated hs-cTnT and brain nat...

The aim of this study was to develop a deep learning-based algorithm for fully automated spleen segmentation using CT images and to evaluate the performance in conditions directly or indirectly affecting the spleen (e.g., splenomegaly, ascites). For this, a 3D U-Net was trained on an in-house dataset (n = 61) including diseases with and without spl...

We aimed to evaluate the stability of radiomic features in the liver of healthy individuals across different three-dimensional regions of interest (3D ROI) sizes in T1-weighted (T1w) and T2-weighted (T2w) images from different MR scanners. We retrospectively included 66 examinations of patients without known diseases or pathological imaging finding...

Aim was to develop a user-friendly method for creating parametric maps that would provide a comprehensible visualization and allow immediate quantification of radiomics features. For this, a self-explanatory graphical user interface was designed, and for the proof of concept, maps were created for CT and MR images and features were compared to thos...

Purpose: This study aimed to evaluate the diagnostic performance of texture analysis (TA), T1 mapping, and signal intensity quotients derived from fast T1-weighted gradient echo (T1w GRE) sequences for differentiating pulmonary lymphoma manifestations and nonlymphoma infiltrates in possible invasive fungal disease in immunocompromised hematologica...

We aimed to evaluate radiomic features’ stability across different region of interest (ROI) sizes in CT and MR images. We chose a phantom with a homogenous internal structure so no differences for a feature extracted from ROIs of different sizes would be expected. For this, we scanned a plastic cup filled with sodium chloride solution ten times in...

Objectives To evaluate texture analysis in nonenhanced 3-T MRI for differentiating pulmonary fungal infiltrates and lymphoma manifestations in hematological patients and to compare the diagnostic performance with that of signal intensity quotients (“nonenhanced imaging characterization quotients,” NICQs).MethodsMR scans were performed using a speed...

Aims Heart failure (HF) is frequent in patients with acute ischaemic stroke (AIS) and associated with higher morbidity and mortality. Assessment of cardiac function in AIS patients using cardiovascular MRI (CMR) may help to detect HF. We report the rate of systolic and diastolic dysfunction in a cohort of patients with AIS using CMR and compare cin...

Purpose To evaluate the diagnostic performance of diastolic function parameters derived from long-axis (LAX) planimetry compared with short-axis (SAX) volumetry in cardiac magnetic resonance imaging. Materials and Methods Cine steady-state free precession (SSFP) datasets of 15 healthy participants (8 young and 7 middle aged) and 25 patients with ec...

Background: Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique in order to clarify rare focal splenic lesions (FSL). CEUS is a safe and cost-effective modality for assessment of perfusion. Objective: To validate contrast enhancement pattern and evaluate the diagnostic accuracy of CEUS in unclear FSL. Methods:...

Purpose To evaluate the diagnostic performance and reliability of non-enhanced imaging characterization quotients (NICQs) derived from magnetic resonance imaging (MRI) in the differential diagnosis of pulmonary nodules in hematological patients. Materials and Methods A total of 83 lesions in 45 consecutive hematological patients were analyzed (10 b...

Objective The aim of this study was to compare the age-dependent diagnostic performance of clinical scores and D-dimer testing to identify patients with suspected pulmonary embolism (PE). Methods Consecutive patients with suspected PE referred from the emergency department for computed tomography pulmonary angiography (CTPA) were retrospectively e...

Purpose: To evaluate parameters that influence the amount of movement of peripherally inserted central catheter (PICC) tips regarding upper limb movement. Methods: In a prospective 12-month observational study, 200 PICCs were implanted in 162 patients (mean age 56.8 ± 15.2 years) by interventional radiologists into the basilic vein of the mid-as...

Objective: To investigate 3T pulmonary magnetic resonance imaging (MRI) for characterization of solid pulmonary lesions in immunocompromised patients and to differentiate infectious from malignant lesions. Materials and methods: Thirty-eight pulmonary lesions in 29 patients were evaluated. Seventeen patients were immunocompromised (11 infections...

Objective: To prospectively evaluate a short MRI examination protocol for the detection of nodular pulmonary infiltrates in immunocompromised patients with hematologic diseases and suspected invasive fungal infections. Methods: Patients with nodular infiltrates on CT scans were examined on a 3T MRI scanner. The standardized protocol included axi...

Purpose: To evaluate the extent of normal variation in implantable port devices between supine fluoroscopy and upright chest x-ray in relation to body mass index (BMI) based on three different measurement methods. Methods: Retrospectively, 80 patients with implanted central venous access port systems from 2012-01-01 until 2013-12-31 were analyze...

Purpose: Analysis, evaluation and classification of hepatic arterial supply variants and determination of their frequency distribution in CT-angiographies. Materials and Methods: CT-angiographies of 1,568 patients were evaluated retrospectively for the period between January 1, 2010 and August 30, 2012. The hepatic arterial anatomy was assessed and...

Purpose: Evaluation of correlations between underlying disease and port complications. Materials and methods: Retrospective analysis of a data set of 3160 port systems, which had been interventionally implanted over a period of 10 years. Of these, 1393 were included in the final evaluation. The 7 most common underlying diseases and port-induced...

Pneumomediastinum is known to occur during labor. Patients typically present with chest pain and symptoms may be suspicious, for example of pulmonary embolism or aortic dissection. The condition itself, however, is rather harmless and self-limiting.Takotsubo cardiomyopathy is associated with psychologically or physiologically stressful events and i...

Interdisziplinäre Tumorkonferenzen Regionale und überregionale telemedizinische und teleradiologische Anbindung von Tumorzentren In der Onkologie findet Telemedizin vorwiegend im Rahmen interdiszi-plinärer Tumorkonferenzen Anwen-dung. Der zeitnahe Wissenstransfer und die gemeinschaftliche Diagno-se-und Therapieempfehlung ermög-lichen eine verbesser...

Der Einsatz interaktiver Videokommunikation ist in der Onkologie die derzeit wichtigste telemedizinische Anwendung. Sie ermöglicht durch den zeitnahen Wissenstransfer die Erstellung effizienter, interdisziplinär abgestimmter Behandlungspläne. Die Teilnahme an einer interdisziplinären Videotumorkonferenz kann ortsunabhängig erfolgen, bedarf jedoch b...

NAGEL S.N., TEICHGRÄBER U.K.M., KAUSCHE S. & LEHMANN A. (2011) European Journal of Cancer Care21, 197–204 Satisfaction and quality of life: a survey-based assessment in patients with a totally implantable venous port system The purpose was to assess the satisfaction and quality of life in patients with a totally implantable central venous port syst...

In this retrospective study the success and complication rates after radiologically guided port catheter implantation were evaluated. Between 2000 and 2008, 3,160 port catheter systems were implanted in our interventional suite. All interventions were imaging guided. The puncture of the preferably right internal jugular vein (IJV) was ultrasound-as...

The aim of this study was to evaluate explantations of central venous port systems that were implanted by interventional radiologists in cases where complications demanded the removal of the port device. In this retrospective single-center study, explantation rates of central venous port catheter systems (CVPS) associated with complications were in...

To evaluate the impact of interventional radiological imaging and treatment of central venous port catheter complications. In this retrospective analysis 429 port catheter dysfunctions were evaluated in 393 port catheter systems for a total of 389 patients over a period of 10 years. The study included 193 (49.1 %) patients with radiologically impla...

To prospectively evaluate the clinical benefit of a central venous port system, which is approved for contrast media injection during contrast enhanced computed tomography. At a university teaching hospital, 98 patients (59 female, 39 male; median age 61.7 years; range 23-83) had a power-injectable central venous port catheter system implanted. All...

PURPOSE Retrospective analysis of success and complication rates after radiologically assisted catheter port implantation. METHOD AND MATERIALS Between 4/26/2000 and 11/3/2008, 3,160 port catheter systems were implanted in our interventional suite. The final follow-up deadline was 12/31/2009. The indication for port implantation was impending chem...

This study was designed to evaluate the clinical benefit of low-profile double-lumen port catheters in patients receiving simultaneous chemotherapy and parenteral nutrition (PN). Potential advantages, complications, and the durations of simultaneous and single use of the catheter were assessed. At a university teaching hospital, 10 patients receive...