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Marco Nolden,
Sascha Zelzer,
Alexander Seitel,
Diana Wald,
Michael Müller,
Alfred M Franz,
Daniel Maleike,
Markus Fangerau,
Matthias Baumhauer,
Lena Maier-Hein,
Klaus H Maier-Hein,
Hans -Peter Meinzer, Ivo Wolf
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ABSTRACT: PURPOSE: The Medical Imaging Interaction Toolkit (MITK) has been available as open-source software for almost 10 years now. In this period the requirements of software systems in the medical image processing domain have become increasingly complex. The aim of this paper is to show how MITK evolved into a software system that is able to cover all steps of a clinical workflow including data retrieval, image analysis, diagnosis, treatment planning, intervention support, and treatment control. METHODS: MITK provides modularization and extensibility on different levels. In addition to the original toolkit, a module system, micro services for small, system-wide features, a service-oriented architecture based on the Open Services Gateway initiative (OSGi) standard, and an extensible and configurable application framework allow MITK to be used, extended and deployed as needed. A refined software process was implemented to deliver high-quality software, ease the fulfillment of regulatory requirements, and enable teamwork in mixed-competence teams. RESULTS: MITK has been applied by a worldwide community and integrated into a variety of solutions, either at the toolkit level or as an application framework with custom extensions. The MITK Workbench has been released as a highly extensible and customizable end-user application. Optional support for tool tracking, image-guided therapy, diffusion imaging as well as various external packages (e.g. CTK, DCMTK, OpenCV, SOFA, Python) is available. MITK has also been used in several FDA/CE-certified applications, which demonstrates the high-quality software and rigorous development process. CONCLUSIONS: MITK provides a versatile platform with a high degree of modularization and interoperability and is well suited to meet the challenging tasks of today's and tomorrow's clinically motivated research.
International Journal of Computer Assisted Radiology and Surgery 04/2013; · 1.48 Impact Factor
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ABSTRACT: Right ventricular (RV) function is an important aspect of anesthesia management during orthotopic liver transplantation (OLT). Because of its geometrical complexity, assessment of RV dimensions with transesophageal echocardiography (TEE) is a difficult task. The aim of this prospective single-site study was to investigate the feasibility of intraoperative assessment of RV parameters based on reconstructive three-dimensional (3D) TEE and to compare the measurements to thermodilution-derived values acquired with a modified pulmonary artery catheter.
Measurements were performed at four different time points during 30 OLT with 3D-TEE. At the same time comparative values of RV parameters were acquired with a fast-response thermistor pulmonary artery catheter.
3D reconstruction was feasible in all patients. RV dimensions measured with 3D-TEE averaged 119.4 ml (± 38.5 ml) for enddiastolic and 68.9 ml (± 27.7 ml) for endsystolic volumes. The RV ejection fraction was 42.2% (± 9.3%). The volumes obtained by thermodilution were 263.7 ml (± 64.5 ml) enddiastolic and 159.3 ml (± 47.5 ml) endsystolic, both significantly greater than by 3D-TEE, and the ejection fraction was found to be 39.5% (± 8.4%). No correlation was found between the volumes or the function determined by either method.
Reconstructive 3D-TEE is a viable technique during OLT and leads to plausible RV parameters. However, no correlation was found with simultaneous measurements or parameters performed with thermodilution. However, based on our data cardiac output measurements by thermodilution appear reasonable. Due to both lack of agreement with 3D-TEE and extraordinary high RV volumes the question about the most valuable monitoring technique of RV dimensions and function during OLT can not finally be answered.
Annals of transplantation: quarterly of the Polish Transplantation Society 03/2012; 17(1):21-30. · 2.02 Impact Factor
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ABSTRACT: Glomerular number and size are important risk factors for chronic kidney disease (CKD) and cardiovascular disease and have traditionally been estimated using invasive techniques. Here, we report a novel technique to count and size every glomerulus in the rat kidney using magnetic resonance imaging (MRI).
The ferromagnetic nature of cationized ferritin allowed visualization of single glomeruli in high-resolution susceptibility-weighted MRI. A segmentation algorithm was used to identify and count all glomeruli within the whole kidney. To prove our concept, we estimated total glomerular number and mean glomerular volume of each kidney using design-based stereology.
The glomerular counts obtained with MRI agreed well with estimates obtained using traditional methods [MRI, 32 785 (3117); stereology, 35 132 (3123)]. For the first time, the glomerular volume distribution for the entire kidney is shown. Additionally, the method is substantially faster than the current methods.
MRI provides a new method for measuring these important microanatomical markers of disease risk and leads the way to in vivo analysis of these parameters, including longitudinal studies of animal models of CKD.
Nephrology Dialysis Transplantation 06/2011; 27(1):100-7. · 3.40 Impact Factor
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Bildverarbeitung für die Medizin 2009: Algorithmen - Systeme - Anwendungen, Proceedings des Workshops vom 20. bis 22. März 2011 in Lübeck; 01/2011
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Sascha A Müller,
Lena Maier-Hein,
Aysun Tekbas,
Alexander Seitel,
Stefanie Ramsauer,
Boris Radeleff,
Alfred M Franz,
Ralf Tetzlaff,
Arianeb Mehrabi, Ivo Wolf,
Hans-Ulrich Kauczor,
Hans-Peter Meinzer,
Bruno M Schmied
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ABSTRACT: The aim of this prospective, randomized animal study was to compare a new computer guided needle-based navigation system for liver biopsy with conventional computed tomography (CT)-guided liver biopsy. Computer-navigated interventions provide continuous needle tracking during motion and deformation from patient respiration and movement.
Twenty artificial tumors of about 5 mm in diameter were injected into the livers of five pigs, each at a different site. Each tumor was targeted by conventional CT-guided and computer navigated intervention. Intervention was considered complete after successful tumor biopsy. Data on procedure time, number of CT scans performed, accuracy, and success rate were recorded.
All tumors (100%) were biopsied successfully. Mean procedural time was comparable between the two techniques (20 ± 9 minutes conventional versus 20 ± 8 minutes navigation). Mean number of CT scans were 1.2 ± 0.4 with navigation and 6.1 ± 3.8 with the conventional technique (P < .01). The dose-length product in the conventional group was significantly higher (212 ± 116 mGy × cm) than in the navigated group (78 ± 22 mGy × cm; P < .001). Mean number of capsule penetrations was 4 ± 1 with navigation versus 2 ± 1 with the conventional technique (P < .001).
Computer-navigated liver biopsy may provide a promising and innovative device for easy, rapid, and successful liver biopsies with low morbidity. Further technical improvements and clinical studies in humans are required.
Academic radiology 10/2010; 17(10):1282-7. · 2.09 Impact Factor
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ABSTRACT: To evaluate the use of three-dimensional imaging of pancreatic carcinoma using multidetector computed tomography (CT) in a prospective study.
Ten patients with suspected pancreatic tumors were examined prospectively using multidetector CT (Somatom Sensation 16, Siemens, Erlangen, Germany). The images were evaluated for the presence of a pancreatic carcinoma and invasion of the peripancreatic vessels and surrounding organs. Using the isotropic CT data sets, a three-dimensional image was created with automatic vascular analysis and semi-automatic segmentation of the organs and pancreatic tumor by a radiologist. The CT examinations and the three-dimensional images were presented to the surgeon directly before and during the patient's operation using the Medical Imaging Interaction Toolkit-based software "ReLiver". Immediately after surgery, the value of the two images was judged by the surgeon. The operation and the histological results served as the gold standard.
Nine patients had a pancreatic carcinoma (all pT3), and one patient had a serous cystadenoma. One tumor infiltrated the superior mesenteric vein. The infiltration was correctly evaluated. All carcinomas were resectable. In comparison to the CT image with axial and coronal reconstructions, the three-dimensional image was judged by the surgeons as better for operation planning and consistently described as useful.
A 3D-image of the pancreas represents an invaluable aid to the surgeon. However, the 3D-software must be further developed in order to be integrated into daily clinical routine.
World Journal of Gastroenterology 12/2009; 15(46):5827-32. · 2.47 Impact Factor
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Eugénie Riesenkampff,
Urte Rietdorf, Ivo Wolf,
Bernhard Schnackenburg,
Peter Ewert,
Michael Huebler,
Vladimir Alexi-Meskishvili,
Robert H Anderson,
Nicole Engel,
Hans-Peter Meinzer,
Roland Hetzer,
Felix Berger,
Titus Kuehne
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ABSTRACT: Detailed 3-dimensional anatomic information is essential when planning strategies of surgical treatment for patients with complex congenitally malformed hearts. Current imaging techniques, however, do not always provide all the necessary anatomic information in a user-friendly fashion. We sought to assess the practical clinical value of realistic 3-dimensional models of complex congenitally malformed hearts.
In 11 patients, aged from 0.8 to 27 years, all with complex congenitally malformed hearts, an unequivocal decision regarding the optimum surgical strategy had not been reached when using standard diagnostic tools. Therefore, we constructed 3-dimensional virtual computer and printed cast models of the heart on the basis of high-resolution whole-heart or cine magnetic resonance imaging or computed tomography. Anatomic descriptions were compared with intraoperative findings when surgery was performed.
Independently of age-related factors, images acquired in all patients using magnetic resonance imaging and computed tomography proved to be of sufficient quality for producing the models without major differences in the postprocessing and revealing the anatomy in an unequivocal 3-dimensional context. Examination of the models provided invaluable additional information that supported the surgical decision-making. The anatomy as shown in the models was confirmed during surgery. Biventricular corrective surgery was achieved in 5 patients, palliative surgery was achieved in 3 patients, and lack of suitable surgical options was confirmed in the remaining 3 patients.
Realistic 3-dimensional modeling of the heart provides a new means for the assessment of complex intracardiac anatomy. We expect this method to change current diagnostic approaches and facilitate preoperative planning.
The Journal of thoracic and cardiovascular surgery 10/2009; 138(3):571-80. · 3.41 Impact Factor
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ABSTRACT: We present a system which co-registers physical anatomy models with virtual three-dimensional (3D) representations. Interactions performed on the physical model by means of a 3D pointing device are directly reflected on its virtual counterpart. Complex anatomical information integrated into the virtual model thus becomes accessible through the physical interface in a simple and intuitive manner.
Using an optical tracking system, we implemented and tested a reference application that includes several tools for the exploration and quantification of anatomical models. We theoretically evaluated the accuracy of the landmark-based registration for different landmark configurations.
Physicians and computer scientists found the system simple to learn and intuitive to use. By optimizing landmark configurations, the accuracy could be significantly increased, particularly for scenarios in which only selected regions required higher accuracy.
Physical anatomical models can benefit from the combination with a virtual counterpart in several ways. Applications include anatomical education and the study of patient-individual organ models. Optimizing the registration landmark configuration for specific applications can lower the accuracy requirements for the tracking system.
International Journal of Computer Assisted Radiology and Surgery 09/2009; 4(5):417-24. · 1.48 Impact Factor
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ABSTRACT: To introduce and evaluate a process for refinement of software quality that is suitable to research groups. In order to avoid constraining researchers too much, the quality improvement process has to be designed carefully. The scope of this paper is to present and evaluate a process to advance quality aspects of existing research prototypes in order to make them ready for initial clinical studies. The proposed process is tailored for research environments and therefore more lightweight than traditional quality management processes.
Focus on quality criteria that are important at the given stage of the software life cycle. Usage of tools that automate aspects of the process is emphasized. To evaluate the additional effort that comes along with the process, it was exemplarily applied for eight prototypical software modules for medical image processing.
The introduced process has been applied to improve the quality of all prototypes so that they could be successfully used in clinical studies. The quality refinement yielded an average of 13 person days of additional effort per project. Overall, 107 bugs were found and resolved by applying the process.
Careful selection of quality criteria and the usage of automated process tools lead to a lightweight quality refinement process suitable for scientific research groups that can be applied to ensure a successful transfer of technical software prototypes into clinical research workflows.
Methods of Information in Medicine 07/2009; 48(4):336-9. · 1.53 Impact Factor
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Bildverarbeitung für die Medizin 2009: Algorithmen - Systeme - Anwendungen, Proceedings des Workshops vom 22. bis 25. März 2009 in Heidelberg; 01/2009
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Jochen Neuhaus,
Ingmar Wegner,
Johannes Käst,
Matthias Baumhauer,
Alexander Seitel,
Ingmar Gergel,
Marco Nolden,
Daniel Maleike, Ivo Wolf,
Hans-Peter Meinzer,
Lena Maier-Hein
Bildverarbeitung für die Medizin 2009: Algorithmen - Systeme - Anwendungen, Proceedings des Workshops vom 22. bis 25. März 2009 in Heidelberg; 01/2009
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Int. J. Computer Assisted Radiology and Surgery. 01/2009; 4:203-213.
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Bildverarbeitung für die Medizin 2009: Algorithmen - Systeme - Anwendungen, Proceedings des Workshops vom 22. bis 25. März 2009 in Heidelberg; 01/2009
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Bildverarbeitung für die Medizin 2009: Algorithmen - Systeme - Anwendungen, Proceedings des Workshops vom 22. bis 25. März 2009 in Heidelberg; 01/2009
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Journal of Cardiovascular Magnetic Resonance. 01/2009;
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Lena Maier-Hein,
Aysun Tekbas,
Alexander Seitel,
Alfred M Franz,
Boris Radeleff,
Frank Pianka,
Sascha A Mller,
Stefanie Satzl,
Ralf Tetzlaff, Ivo Wolf,
Hans-Ulrich Kauczor,
Bruno M Schmied,
Hans-Peter Meinzer
World Congress on Medical Physics and Biomedical Engineering; 01/2009
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Jochen Neuhaus,
Johannes Kast,
Ingmar Wegner,
Matthias Baumhauer,
Alexander Seitel,
Ingmar Gergel,
Marco Nolden,
Daniel Maleike, Ivo Wolf,
Hans-Peter Meinzer,
Lena Maier-Hein
Int. J. CARS; 01/2009
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ABSTRACT: This paper presents an in-vivo accuracy study on combining skin markers (external fiducials) and fiducial needles (internal fiducials) for motion compensation during liver interventions. We compared the target registration error (TRE) for different numbers of skin markers n(s) and fiducial needles n(f), as well as for different transformation types, in two swine using the tip of an additional tracked needle as the target. During continuous breathing, n(f) had the greatest effect on the accuracy, yielding mean root mean square (RMS) errors of 4.8 +/- 1.1 mm (n(f) = 0), 2.0 +/- 0.9 mm (n(f) = 1) and 1.7 +/- 0.8 mm (n(f) = 2) when averaged over multiple tool arrangements (n = 18, 36, 18) with n(s) = 4. These values correspond to error reductions of 11%, 64% and 70%, respectively, compared to the case when no motion compensation is performed, i.e., when the target position is assumed to be constant. At expiration, the mean RMS error ranged from 1.1 mm (n(f) = 0) to 0.8 mm (n(f) = 2), which is of the order of magnitude of the target displacement. Our study further indicates that the fiducial registration error (FRE) of a rigid transformation reflecting tissue motion generally correlates strongly with the TRE. Our findings could be used in practice to (1) decide on a suitable combination of fiducials for a given intervention, considering the trade-off between high accuracy and low invasiveness, and (2) provide an intra-interventional measure of confidence for the accuracy of the system based on the FRE.
Computer Aided Surgery 12/2008; 13(6):369-76. · 0.30 Impact Factor
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Beat P Müller-Stich,
Arianeb Mehrabi,
Hannes G Kenngott,
Hamidreza Fonouni,
Michael A Reiter,
Gani Kuttymoratov,
Felix Nickel,
Georg R Linke, Ivo Wolf,
Jörg Köninger,
Carsten N Gutt
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ABSTRACT: Mesh reinforcement in hiatal hernia surgery is debated. Randomized controlled trials have shown that recurrences may be reduced, but there is also the fear of mesh-related complications. Experimental studies on the characteristics of specific mesh types with regard to the risk of such complications are rare. The current study aimed to investigate the properties of a circular heavy-weight polypropylene mesh in terms of stenosis, migration, erosions, and adhesions in a porcine model.
A 55 x 55-mm heavy-weight polypropylene mesh with a 16.5-mm eccentric hole for the esophagus corresponding to a calculated mesh area of 2811 mm(2) and a hole area of 214 mm(2) were implanted in nine German Landrace pigs. Six weeks later, the meshes were explanted and investigated for size, shrinkage, migration and adhesions.
The total mesh area shrank to a mean of 2,040 +/- 178 mm(2) (p < 0.001), and the hole for the esophagus showed a trend toward an increase to 239 +/- 38 mm(2) (p = 0.108). In not a single location did the mesh overhang the hiatal margin. The mean distance of retraction from the hiatal margin was 4.3 +/- 2.8 mm. Therefore, no stenoses, migrations, or erosions occurred.
A circular heavy-weight polypropylene mesh seems to be appropriate for the application at the esophageal hiatus in terms of safety and stability. This means that it is characterized by a position-stable centered fixation around the esophagus without a tendency toward stenosis, migration, or erosion.
Surgical Endoscopy 10/2008; 23(6):1372-8. · 4.01 Impact Factor
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Sibylle Mottl-Link,
Michael Hübler,
Titus Kühne,
Urte Rietdorf,
Julia J Krueger,
Bernhard Schnackenburg,
Raffaele De Simone,
Felix Berger,
Amy Juraszek,
Hans-Peter Meinzer,
Matthias Karck,
Roland Hetzer, Ivo Wolf
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ABSTRACT: Our aim was to improve spatial imagination of complex congenital cardiac abnormalities for subsequent surgical intervention.
Magnetic resonance imaging data of a patient with complex congenital heart malformations was post-processed with software developed at our institution. The resulting virtual surface data sets were printed out three-dimensionally by rapid prototyping techniques.
We present the first patient operated on with intraoperative use of physical models representing the intracardiac volumes (RepliCast) or muscle and vessel walls (RepliCardio). The courses of the coronary arteries were visible on the RepliCast, whereas the RepliCardio showed intracardiac views a surgeon could never obtain intraoperatively in the relaxed heart. Other than on virtual reconstructions presented on computer screens, physical models vastly improve the spatial imagination and give precise information regarding localization and actual size of abnormal structures. The self-explanatory utility of these models shortened preparation and expedited orientation on the open heart.
The additional spatial information provided by RepliCast and RepliCardio models may enable even high-risk correction procedures in patients with complex congenital heart disease.
The Annals of thoracic surgery 08/2008; 86(1):273-7. · 3.74 Impact Factor
