Jens Schneider

Johannes Gutenberg-Universität Mainz, Mayence, Rheinland-Pfalz, Germany

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Publications (17)24.16 Total impact

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    ABSTRACT: PURPOSE Visceral arterial aneurysms (VAA) are a rare entity with a prevalence between 0.1 – 2% and have a high risk for rupture with mortality rates between 20-75%. We therefore reviewed and analyzed the institutional data base for diagnosis and management of VAA over a period of 10 years. METHOD AND MATERIALS An automatic analysis of the institutional database using the word “aneurysm” resulted in identification of 12.588 reports (CT, MRI, and Angiography). 239 of these patients could be identified suffering from VAA (mean age 65 years ± 12.5 years). VAA were analyzed with respect to location, size, true aneurysm or false aneurysms after surgery/intervention, rupture status, management, and clinical follow-up. RESULTS Diagnosis included VAA of the splenic artery (n=81), celiac trunk (n=46), renal artery (n=42), hepatic artery (n=37), superior mesenteric artery (n=15), gastroduodenal artery (n=10) and others (8). The overall size of the aneurysms was 17.8 ± 10.2mm; min. 4 mm, max. 112 mm). 44 VAA were rated as false aneurysms (18%), 25 of them after surgery and 11 after percutaneous interventions like biopsies or drainages. 58 of 239 cases were treated with transarterial intervention (n=47) or surgery (n=11). Interventions included embolization with coils (n=35) or glue (n=4), implantations of covered stents (n=4), and combinations of these (n=4). 40 patients were diagnosed at rupture and were treated on an emergency basis (hemoglobin 8.6±1.7mg/dl). There was no significant difference in size between ruptured and non-ruptured VAA (15.2 ± 8.4mm vs. 16.3 ± 10.1mm). The 30-day mortality in ruptured cases was 8.3% (12 of 36) after interventional treatment compared to 25% after surgery (1 of 4). No fatality occurred after interventional treatment of non-ruptured aneurysms (n=11). The conservatively treated patients presented a 30-day mortality of 6.1% (11 of 181). CONCLUSION The clinical impact of accidentally diagnosed VAA still remains unclear. However, symptomatic or ruptured VAA might me associated with a high mortality rate. There was no difference in size in ruptured and non-ruptured aneurysms. Interventional treatment seems to offer a beneficial approach in emergency cases compared to surgery. CLINICAL RELEVANCE/APPLICATION False aneuryms seem to have a considerably higher risk of rupture and should be promptly treated irrespective of the diameter.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction. We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series. Eighy-five percent of the total radiation dose was applied during the pre- and post-interventional CT series, leaving only 15% applied by the CT-guided intervention itself. Single slice acquisition was associated with lower doses than continuous CT-fluoroscopy (37mGycm vs. 153mGycm, p<0.001). The third quartile of radiation doses varied considerably for different interventions. The highest doses were observed in complex interventions like RFA/MWA of the liver, followed by vertebroplasty and RFA/MWA of the lung. This paper suggests preliminary reference levels for various intervention types and discusses strategies for dose reduction. A multicenter registry of radiation exposure including a broader spectrum of scanners and intervention types is needed to develop definitive reference levels.
    European journal of radiology 08/2013; · 2.65 Impact Factor
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    ABSTRACT: -Right heart catheterization (RHC) is the gold standard for assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH). So far, MRI has not been able to produce precise measurements of mPAP. The purpose of the study was to create a model for estimating mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with CTEPH by high temporal resolution phase-contrast MR imaging (PC-MRI) and to correlate the results with simultaneously acquired, invasive catheter-based measurements (mPAP_sim) and with RHC measurements. -19 patients with CTEPH underwent RHC and - after digital subtraction angiography of the pulmonary arteries - subsequent PC-MRI at 1.5 T with simultaneous recording of mPAP. Velocity- and flow-time curves of PC-MRI were used to calculate absolute acceleration time (Ata), maximum of mean velocities (MV), volume of acceleration (AV), and maximum flow acceleration (dQ/dt). Based on these parameters, multiple linear regression analysis revealed maximum achievable model fit (B = 0.902) for the following linear combination equation to calculate mPAP (mPAP_cal): mPAP_cal = 69.446 - (0.521 • Ata) - (0.570 • MV) + (1.507 • AV) + (0.002 • dQ/dt). There was a statistically significant equivalence of mPAP_cal and mPAP_sim with a goodness of fit of 0.892. PVR was overestimated by calculated PVR based on PC-MRI in comparison with RHC-based measurements by a median of -112 dyn•s•cm(-5), the pairwise regression formula revealed a goodness of fit of 0.792. -PC-MRI derived parameters enable non-invasive assessment of pulmonary hemodynamics in patients with CTEPH.
    Circulation Cardiovascular Imaging 07/2013; · 5.80 Impact Factor
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    ABSTRACT: AIM: To determine local response, its predictors and survival and complication rates after DC-Bead™-TACE in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: DC-Beads™ are non-resorbable, polyvinyl-alcoholic hydrophilic microspheres. They release high amounts of chemotherapeutics directly into the tumour. Delivery is sustained over time, tumour feeders are embolised. We used beads from 100-300 to 500-700μm loaded with Doxorubicin (max. 150mg/4ml). Fifty patients (mean age: 68.5±8.8years) with HCC were analysed. DC-Bead™-TACE was performed once or repeated in two-month intervals. Imaging scans (CT or MRI) were done one-month following each procedure. To evaluate tumour response EASL and RECIST criteria was applied. If eligible, every patient received a non-selective TACE. RESULTS: 128 DC-Bead™ sessions were performed: 127 showed technical success, 120 successful stasis. Complications occurred in 7% (9/128): active bleeding into the tumour (n=1), liver failure (n=1), liver abscess (n=1) ascites (n=3), pleural effusion (n=1), false aneurysm (n=1) and hypoglycaemia (n=1). At imaging after the 1st, 2nd, 3rd and 4th-8th session, objective response (complete+partial) was 49%, 67%, 67% and 31%, progressive disease was seen in n=11/50. Baseline diameter and differentiation significantly impacted response. Median overall survival was 25.1months (95% [CI]: 18.3-31.9) with an estimated cumulative survival rate at one and two-to-four years of 66.7% and 45.7%, respectively. CONCLUSION: DC-Beads™ can be safely and effectively control HCC. Survival and response rates are encouraging, complications are low. Many factors are involved in response to treatment like liver function or child state.
    European journal of radiology 07/2012; · 2.65 Impact Factor
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    ABSTRACT: PURPOSE: To evaluate dose reduction in vascular angiographic procedures by using fluoroscopy capture instead of digital subtraction angiography frames for documentation. MATERIALS AND METHODS: A total of 764 consecutive vascular interventional procedures performed over a period of 1 year were retrospectively analyzed with respect to the fluoroscopy time and the resulting dose-area product (DAP), the DAP of the radiographic frames, and the overall DAP. RESULTS: A total of 70% of the total DAP was a result of the acquisition of radiographic frames, leaving only 30% being applied by fluoroscopy. CONCLUSIONS: Fluoroscopy capture should be used for documentation whenever possible. A registry of radiation exposure should not only comprise a sufficiently large number of interventions but also different intervention types to allow the development of interventional reference levels.
    Journal of vascular and interventional radiology: JVIR 07/2012; · 1.81 Impact Factor
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    ABSTRACT: To determine the most comprehensive imaging technique for the assessment of pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH). 24 patients with CTEPH were examined by ECG-gated multi-detector CT angiography (MD-CTA), contrast-enhanced MR angiography (ce-MRA) and selective digital subtraction angiography (DSA) within 3 days. Two readers in consensus separately evaluated each imaging technique (48 main, 144 lobar and 449 segmental arteries) for typical changes like complete obstructions, vessel cut-offs, intimal irregularities, incorporated thrombus formations, and bands and webs. A joint interpretation of all three techniques served as a reference standard. Based on image quality, there was no non-diagnostic examination by either imaging technique. DSA did not sufficiently display 1 main, 3 lobar and 4 segmental arteries. The pulmonary trunk was not assessable by DSA. One patient showed thrombotic material at this level only by MD-CTA and MRA. Sensitivity and specificity of MD-CTA regarding CTEPH-related changes at the main/lobar and at the segmental levels were 100%/100% and 100%/99%, of ce-MRA 83.1%/98.6% and 87.7%/98.1%, and of DSA 65.7%/100% and 75.8%/100%, respectively. ECG-gated MD-CTA proved the most adequate technique for assessment of the pulmonary arteries in the diagnostic work-up of CTEPH patients. • A prospective single-centre study evaluated ECG-gated MDCTA, ce-MRA and DSA in CTEPH patients. • ECG-gated MD-CT angiography outperformed DSA and ce-MRA. • Right heart catheterisation should be reserved only for assessment of pulmonary haemodynamics.
    European Radiology 09/2011; 22(3):607-16. · 4.34 Impact Factor
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    ABSTRACT: To investigate the radiation exposure in non-vascular fluoroscopy guided interventions and to search strategies for dose reduction. Dose area product (DAP) of 638 consecutive non-vascular interventional procedures of one year were analyzed with respect to different types of interventions; gastrointestinal tract, biliary interventions, embolizations of tumors and hemorrhage. Data was analyzed with special focus on the fluoroscopy doses and frame doses. The third quartiles (Q3) of fluoroscopy dose values were defined in order to set a reference value for our in-hospital practice. Mean fluoroscopy times of gastrostomy, jejunostomy, right and left sided percutaneous biliary drainage, chemoembolization of the liver and embolization due to various hemorrhages were 5.9, 8.6, 13.5, 16.6, 17.4 and 25.2 min, respectively. The respective Q3 total DAP were 52.9, 73.3, 155.1, 308.4, 428.6 and 529.3 Gy*cm2. Overall, around 66% of the total DAP originated from the radiographic frames with only 34% of the total DAP applied by fluoroscopy (P<0.001). The investigators experience had no significant impact on the total DAP applied, most likely since there was no stratification to intervention-complexity. To establish Diagnostic Reference Levels (DRLs), there is a need to establish a registry of radiation dose data for the most commonly performed procedures. Documentation of interventional procedures by fluoroscopy "grabbing" has the potential to considerably reduce radiation dose applied and should be used instead of radiographic frames whenever possible.
    CardioVascular and Interventional Radiology 07/2011; 35(3):613-20. · 2.09 Impact Factor
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    ABSTRACT: PURPOSE To evaluate outcome after LifeStent-implantation of short and long distance stenoses or occlusions of the superficial femoral artery (SFA) and the proximal popliteal artery (APOP). METHOD AND MATERIALS In the last 2 years in 92 patients (69male, 23female, mean age 67.5±10.6, range 47-98 yrs) with short and long distance lesions (TASC-A – TASC-D) in SFA and proximal APOP secondary stenting was necessary. Decision for endovascular treatment was done interdisciplinary. Anti-platelet medication consisted of Clopidogrel (75mg) and ASS (100mg) for three months, and ASS-monotherapy thereafter. Patients were prospectively followed-up (FU) at 6 week, 6 moths, and every 6 months thereafter including standardized questionnaire, clinical examination, and Ankle brachial index (ABI). Mean follow-up was 176±145 days (max 713 days). Angiography was performed at 6 months or in any case of ABI reduction or clinical complaints. RESULTS A total of 122 Life-Stents were implanted, using one stent in 73 procedures (including 4 re-intervention), two stents in 16 procedures (2 re-intervention), and three stents in 7 procedures. The mean stent length (sum) was 163,0±102 mm (range 40-470). Stent diameters ranged from 6 to 8 mm. Technical success was 100%. ABI increased from 0.52±0.22 (pre-stent) to 0.98±0.12 (post-stent) and was 0.94±0.19, 0.90±0.23, and 0.86±0.26 at 6 week, 6months, and 12months, respectively. Until now 41 patients reached 12 month FU. At this point patency was 63%, n=26 (primary patency n=20; assisted primary patency (instent-stenoses) n=6; secondary patency (stent occlusion) n=0). By dividing into TASC-A and TASC-B lesions (group A) versus TASC-C and TASC-D lesions (group B) patency was 92% (group A, n=16) versus 37% (group B, n=25) after 12 months. CONCLUSION Secondary and primary stenting of lesions in the SFA has become a everyday practice. In our collective Life-Stents in femoropopliteal occlusive disease show very good patency rates in TASC-A and TASC-B lesions compared to historical data with PTA only. In TASC-C and TASC-D lesions patency is poor after 12 months. The decision for endovascular treatment in TASC-C or TASC-D lesions should be done interdisciplinary. CLINICAL RELEVANCE/APPLICATION long segment stenting SFA
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting; 11/2010
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    ABSTRACT: PURPOSE Purpose of this study was to evaluate the integration of the radiologic teaching database MIRC into the university wide Learning Management System ILIAS. METHOD AND MATERIALS At our institution an integrated web application using the learning management system ILIAS and the teaching file database MIRC is in use for about one year. Using this system, learning modules have been created to accompany different radiological lectures and courses at the university e.g. practical teaching course for final year students. Quality, usage and potential of the integrated web application were evaluated in two different groups such as final year students and third year students using an electronic survey. RESULTS The evaluation of this system revealed a very high overall acceptance of the system. 100% of the final year students (n=21) and 80% of the 3rd year students (n=124) rated the availability of the system as important or very important. The usability of the system was judged as easy by 95% of the final year students and 77% of the 3rd year students. Concerning frequency of use, 86% of the final year students and 44 % of the 3rd year students stated to use the system more than once a week. 24% of the final year students used the system more than four times a week. Concerning further development, final year students requested most frequently, that interdisciplinary content may gain more weight. 3rd year students most frequently wished that learning modules be created focused on guided image analysis in further development. CONCLUSION The integrated solution of the case database MIRC and the learning management system ILIAS proved to be easy to use and well accepted by students. More experienced learners desire multidisciplinary learning content. Less advanced students like to get detailed guidance for image analysis. By integrating MIRC and ILIAS we created a web application for efficient, well structured presentation of medical and radiological eLearning content. CLINICAL RELEVANCE/APPLICATION The integrated MIRC-ILIAS platform is easy to use, well accepted by students for blended learning and self study in radiology and has potential for further development.
    Radiological Society of North America 2008 Scientific Assembly and Annual Meeting; 12/2008
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    ABSTRACT: These case reports demonstrate a radiologic interventional technique for removal of pull-type gastrostomy tubes. This approach proved to be a safe and efficient procedure in two patients. The procedure may be applicable in situations where endoscopic attempts fail.
    CardioVascular and Interventional Radiology 05/2008; 31(6):1252-4. · 2.09 Impact Factor
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    ABSTRACT: OBJECTIVE: The purpose of this study was to evaluate the effectiveness of transarterial chemoembolization in the care of patients not eligible for liver transplantation. CONCLUSIONS: Prognosis depends on local response, Okuda score, alpha-fetoprotein level, and tumor size and is independent of the presence of portal venous thrombosis.
    American Journal of Roentgenology 05/2008; 190(4):1035-42. · 2.74 Impact Factor
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    ABSTRACT: PURPOSE To develop a software tool for vendor independent integration of PACS workstations with the teaching database MIRC and to evaluate the feasibility in routinely clinical work. METHOD AND MATERIALS A software tool with following functionality has been implemented: • Acceptance and storage of DICOM Instances via a local send process from the PACS workstation as well as the basic functionality as described in the IHE TCE profile for the Selector role. • Graphical user interface to enter keywords at time of reading and reporting using an implementation of the RadLex categorization system. • Generation and sending of DICOM instances, TCE manifests and ATFI to a MIRC teaching file system. Practicability and acceptance of the system in the daily clinical work of Radiologists were evaluated. RESULTS Based on the IHE specifications and the required integration of MIRC and different PACS software we developed an open source software tool with the functionality described above. The IHE conformance of the tool was successfully tested at the Europe Connectathon 2007. During the testing phase of 1 month three radiologists have been able to create about 250 significant teaching cases from within their daily routinely work. The additional time consumption for creation of a teaching file averaged out at well under five minutes. In daily routine between 30 – 50 cases / week are registered currently. CONCLUSION Integrating our tool with the PACS software proved to be robust, easy to set up and vendor independent. The process of image selection, categorization and file export is seamlessly compatible with the clinical workflow. Mandatory fields in categorization and entering of keywords ensure a determined level of quality and efficient retrieval by search processes. Implementation of RadLex provides a uniform, widely accepted categorization system based on a variety of established lexicons. The MIRC authoring tool offers extensive possibilities for authors to modify the automatically generated teaching files. CLINICAL RELEVANCE/APPLICATION Integration of MIRC with PACS clients using our TCE ExportSelector enables Radiologists to create significant teaching documents from within their clinical workflow at minimal effort.
    Radiological Society of North America 2007 Scientific Assembly and Annual Meeting; 11/2007
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    ABSTRACT: PURPOSE/AIM To understand how the IHE TCE profile(Teaching File and Clinical Study Export)can help to integrate a teaching file solution (like MIRC) in the regular radiology reporting workflow and how this imaging resource could be used by an eLearning-platform for medical students CONTENT ORGANIZATION A. Integration of the TCE Selector role into reporting workflow with a newly developed general software tool that can be used by any workstation software, which supports DICOM send. TCE relevant manifests will be generated including predefined categories and codings (also providing RadLax terms)by this tool B. Using MIRCs permission rights authored files could be accessed by students using their eLearning platform C. Results of acceptance testing by radiologists and students will be reported SUMMARY 1. A general teaching file solution is an essential requirement in academic hospitals 2. Registration of new files can be integrated with IHE TCE very effectively 3. Medical students have a vital interest to use real images for learning radiology, this could be fulfilled by linking the eLearning platform (ILIAS) with MIRC 4. RadLex Terms are used to have standardized content descriptions
    Radiological Society of North America 2007 Scientific Assembly and Annual Meeting; 11/2007
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    ABSTRACT: PURPOSE To investigate the diagnostic accuracy of MRI and spiral CT for endoleak detection. METHOD AND MATERIALS m52 patients, 48 men and 4 women (age 71.1 � 6.9, range 55 to 82 years) underwent endovascular aneurysm repair. Follow-up data sets included spiral CT (slice thickness of 3mm, reconstruction interval 2 mm, unenhanced and biphasic contrast enhanced) and MRI (1.5 Tesla MR scanner, transverse T2w-TSE, T1w-Flash 2D unenhanced, Flash 3D angio and T1w-Flash 2D contrast enhanced) within 48 hours postinterventionally, at 3, 6, and 12 months and every year. The endoleak size was categorized as A < 3%; B > 3%�10%; C > 10%�30%, D > 30% of the maximum cross sectional aneurysm area. Consensus reading of CT and MRI was defined as the standard of reference. RESULTS 141 of 252 data sets demonstrated evidence for endoleaks. The incidence of Type I, II, III, IV endoleaks, and combined endoleaks was 3.2%, 40.1%, 6.7%, 2.0%, and 4.0% respectively. Sensitivity for endoleak detection was 92.9%, 43.3%, 34.0%, and 37.6% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT respectively. The corresponding negative predictive values were 91.7%, 58.1%, 54.4%, and 55.8% respectively. The overall accuracy of endoleak sizing was 95.2%, 57.5%, 55.2%, and 56.8% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT respectively. CONCLUSIONS cMRI is significantly superior to biphasic CT for endoleak detection and rating of endoleak size, followed by uniphasic late and uniphasic arterial CT scans. Endoleak rates reported after endovascular aneurysm repair substantially depend on the imaging modalities used. Reporting standards for endoleak detection should be defined.
    Radiological Society of North America 2004 Scientific Assembly and Annual Meeting; 12/2004
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    ABSTRACT: PURPOSE/AIM Students request online access to teaching-files more often - this can be provided with MIRC -integrated in a LMS (learning management system) or not- in an excellent way Cooperative creation of teaching files from different departments should improve quality and number of cases Provide a concept and pilot implementation CONTENT ORGANIZATION p Implementation of a MIRC instance accessible from different universities Implementation of a PACS-integrated teaching-file generation according to the IHE TCE profile Establishing of harmonized coding schemes for the participating departments using a TCE selector with access to RadLex coding and additional fields Integration in LMS (ILIAS) for access by students SUMMARY PACS-integrated tools for creation of teaching files according to IHE TCE reduce the workload for individual physicians Cooperative creation fo teaching-files in a MIRC instance is feasible and extends the spectrum of cases Managed access to MIRC can be realized by a LMS
    Radiological Society of North America 2008 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM Students request very often teaching files with content from different disciplines, e.g. Radiology and Surgery and Pathology. Therefore an extension to a teaching-file solution based on MIRC for inclusion other departments in our hospital was developed. The workflow should be similar to Radiology and respect the IHE TCE profile. CONTENT ORGANIZATION an established teaching-file solution in Radiology should be extended with informations from other disciplines therefore special image aquisition solutions were adapted for digital photography, pathology, endoscopy and other modalities to aquire DICOM SC objects these objects can be completed with clinical informations and codes with a software tool, which provides the IHE TCE selector actor before sending to MIRC special coding schemes can be applied for different disciplines SUMMARY MIRC can be used for integrated presentation of radiological teaching-files enhanced with informations from other disciplines like Surgery or Pathology the workflow of the IHE TCE profile could be applied to other disciplines too the integrated presentation of teaching files meets the leading expectations of our students
    Radiological Society of North America 2008 Scientific Assembly and Annual Meeting;