Heinz-Otto Peitgen

• Dr. rer.nat.
• Managing Director at University of Bremen

Studies have demonstrated the feasibility of late Gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging for guiding the management of patients with sequelae to myocardial infarction, such as ventricular tachycardia and heart failure. Clinical implementation of these developments necessitates a reproducible and reliable segmen...

To investigate middle hepatic vein (MHV) management in adult living donor liver transplantation and safer remnant volumes (RV). There were 59 grafts with and 12 grafts without MHV (including 4 with MHV-5/8 reconstructions). All donors underwent our five-step protocol evaluation containing a preoperative protocol liver biopsy Congestive vs non-conge...

Accuracy of radiologic assessment may have a crucial impact on clinical studies and therapeutic decisions. We compared the variability of a central radiologic assessment (RECIST) and computer-aided volume-based assessment of lung lesions in patients with metastatic renal cell carcinoma (RCC). The investigation was prospectively planned as a substud...

Providing an intuitive and easy to operate interaction mechanism for use in medical augmented reality applications is one of the very crucial aspects for accept-ing these applications for use in the operating room. Currently, soft tissue (e.g. liver) navigation information is displayed on the monitor, requiring the operating surgeon to change focus...

Late Gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging can be used to visualise regions of fibrosis and scarring in the left atrium (LA) myocardium. This can be important for treatment stratification of patients with atrial fibrillation (AF) and for assessment of treatment after radio frequency catheter ablation (RFCA). In this...

The vascular anatomy of the liver can be described at three different levels of complexity according to the use that the description has to serve. The first -conventional- level corresponds to the traditional 8-segments scheme of Couinaud and serves as a common language between clinicians from different specialties to describe the location of focal...

Purpose Computed tomography (CT) imaging is the modality of choice for lung cancer diagnostics. With the increasing number of lung interventions on sublobar level in recent years, determining and visualizing pulmonary segments in CT images and, in oncological cases, reliable segment‐related information about the location of tumors has become increa...

Since its introduction to hepatobiliary surgery, three-dimensional (3D) imaging has assumed a growing importance for the visualization of abdominal diseases. The main clinical applications include preoperative simulation for oncologic liver resection [1, 2], and living-donor liver transplantation [3, 4]. The advantages of 3D imaging are the exact v...

In this paper we present a benchmarking framework for the validation of cardiac motion analysis algorithms. The reported methods are the response to an open challenge that was issued to the medical imaging community through a MICCAI workshop. The database included magnetic resonance (MR) and 3D ultrasound (3DUS) datasets from a dynamic phantom and...

The delineation and diagnosis of non-mass-like lesions, most notably DCIS (ductal carcinoma in situ), is among the most challenging tasks in breast MRI reading. Even for human observers, DCIS is not always easy to diferentiate from patterns of active parenchymal enhancement or from benign alterations of breast tissue. In this light, it is no surpri...

Purpose: To evaluate the significance of the hypertrophy concept in patients requiring extended liver resections for colorectal metastasis in the time of computer assisted surgery. Methods: Retrospective analysis of patient collective undergoing major liver surgery. 2D CT, 3D CAS with Fraunhofer MeVis Sofware. Portal vein embolisation (PVE) with...

Myocardial viability assessment is an important task in the diagnosis of coronary heart disease. The measurement of the delayed enhancement effect, the accumulation of contrast agent in defective tissue, has become the gold standard for detecting necrotic tissue with MRI. The purpose of the presented work was to provide a segmentation and quantific...

Background: Preoperative imaging and donor selection are cardinal components of adult-to-adult live donor liver transplantation (ALDLT). The purpose of this study was to evaluate our three-dimensional (3D) computed tomography image-derived computer-assisted surgical planning (3D CASP) in ALDLT. Methods: Eighty-three consecutive ALDLTs (71 right...

Analysis of echocardiograms is a valuable tool for assessing myocardial function and diseases. Processing of ultrasound data is challenging due to noise levels and depth-dependent quality of structure edges. We propose to adapt a method based on quadrature filters that is invariant to changes in intensity and has been successfully applied to MRI da...

For both visual analysis and Computer Aided (CADe/CADx) systems in breast MRI reading, the delineation and diagnosis of DCIS is among the most challenging tasks in spite of recent success in finding discriminative patterns1. For the human observer, DCIS is not always easy to differentiate from patterns of active parenchymal enhancement. CADe/CADx a...

Background: In adult live donor liver transplantation, postoperative venous congestion of graft and remnant livers can lead to life-threatening complications. The purpose of this study was to evaluate the safety and benefits of our 3-dimensional, computed tomographic, computer-assisted donor hepatectomy using the "carving" partitioning technique....

We propose a novel paradigm for clinical diagnostic software using a mobile multi-touch device for user interaction and dedicated monitors for image display. We show a demonstrator implementing a workflow-based breast MRI reading system tailored to multi-touch interaction. The demonstrator explores the feasibility of touch interaction for diagnosti...

Objectives: In chemotherapy monitoring, an estimation of the change in tumour size is an important criterion for the assessment of treatment success. This requires a comparison between corresponding lesions in the baseline and follow-up computed tomography (CT) examinations. We evaluate the clinical benefits of an automatic lesion tracking tool th...

Background: In an interdisciplinary approach, HepaVision (MEVIS, Bremen), a software tool specifically developed for 3D visualization of the liver, was employed for individual planning of extensive liver resections and evaluation of living-relative donations. So far there is experience with more than 50 biphasic spiral CT examinations. Results: The...

Local resection for hepatocellular carcinoma (HCC) has been traditionally performed non-anatomically. The purpose of this study is to evaluate the feasibility of precise local resection of HCC according to the anatomy of tumor-surrounding vessels revealed by three-dimensional (3D) analysis technique. The CT datasets of the livers of the patients wi...

The passage through the hilar plate during right graft live donor liver transplantation (LDLT) can have dangerous consequences for both donors and recipients. The purpose of our study was to delineate hilar transection and biliary reconstruction strategies in right graft LDLT, with special consideration of central and peripheral hilar anatomical va...

User interaction during navigated surgery is often a critical issue in the overall procedure, as several complex aspects must be considered, such as sterility, workflow, field of view, and cognitive load. This work introduces a new approach for intraoperative interaction that seamlessly fits the high surgical requirements. A navigation system, typi...

Image-guided radiofrequency ablation (RFA) is becoming a standard procedure for minimally invasive tumor treatment in clinical practice. To verify the treatment success of the therapy, reliable post-interventional assessment of the ablation zone (coagulation) is essential. Typically, pre- and post-interventional CT images have to be aligned to comp...

Breast surgery might benefit from image guidance, if position and extend of the disease could be visualized in the same breast deformation as the surgery is performed. Such visualizations, however, are challenging to obtain, since the positioning for image acquisition in MRI is prone, while the patient lies supine for surgical procedures, causing a...

Analysis of tagged MRI is a valuable tool for assessing regional myocardial function. One major obstacle for existing methods based on feature extraction and registration is the desaturation of the tagging grid over time. We propose a method based on quadrature filters that is invariant to changes in intensity, robust with respect to the grid geome...

In the present paper we consider the finite difference approximation for a specific nonlinear boundary value problem which generates spurious solutions. Several mechanisms for spurious solutions will be presented. The key connection is that of the homoclinic structure of an adjoint time discrete dynamical system.

Rescaled evolution sets of linear cellular automata on a lattice ℤ ⊕ G, where G is a finite Abelian group, with states in the finite field ${\mathbb F}_q$ are defined and investigated.

The scaling properties of the portal vein and the hepatic vein are examined, based on three-dimensional computed tomography images of casts of human livers. In particular, a quantitative analysis of the branching ratio based on the Strahler ordering scheme as well as the diameter and length ratios are performed. To quantify the segment anatomy of t...

Since the discovery of the X-ray radiation by Wilhelm Conrad Roentgen in 1895, the field of medical imaging has developed into a huge scientific discipline. The analysis of patient data acquired by current image modalities, such as computerized tomography (CT), magnetic resonance tomography (MRT), positron emission tomography (PET), or ultrasound (...

This paper presents image-guided therapies development and advantages using real time imaging modalities such as computed tomography, ultrasound imaging, and magnetic resonance imaging. The following are also highlighted: image-guided cancer interventions and image-guided cardiovascular interventions.

Percutaneous image-guided interventions, such as radiofrequency ablation or biopsy, are using needle-shaped instruments which have to be inserted into a target area without penetrating any vital structure. The established planning workflow is based on viewing 2D slices of a pre-interventional CT or MR scan. However, access paths not parallel to the...

Phase-Contrast (PC) MRI utilizes signal phase shifts resulting from moving spins to measure tissue motion and blood flow. Time-resolved 4D vector fields representing the motion or flow can be derived from the acquired PC MRI images. In cardiovascular PC MRI applications, visualization techniques such as vector glyphs, streamlines, and particle trac...

Development and integration of image registration methods become increasingly important for clinical workstations. Due to the complexity of such methods, prototyping, evaluation and workflow integration require in-depth knowledge foremostly available to registration developers. Rapid development and deployment is therefore often difficult, particul...

Hypodense liver lesions are commonly detected in CT, so their segmentation and characterization are essential for diagnosis and treatment. Methods for automatic detection and segmentation of liver lesions were developed to support this task. The detection algorithm uses an object-based image analysis approach, allowing for effectively integrating d...

We present an interactive segmentation method for 3D medical images that reconstructs the surface of an object using energy-minimizing, smooth, implicit functions. This reconstruction problem is called variational interpolation. For an intuitive segmentation of medical images, variational interpolation can be based on a set of user-drawn, planar co...

Lobe-based quantification of tomographic images is of increasing interest for diagnosis and monitoring lung pathology. With modern tomography scanners providing data sets with hundreds of slices, manual segmentation is time-consuming and not feasible in the clinical routine. Especially for patients with severe lung pathology that are of particular...

Manual delineations by experts are often used as reference standards for validating segmentation algorithms, although it is well known that they always show some degree of variability. Our goal is to estimate the effects of using a limited number of expert segmentations. Given ten manual delineations of 13 liver tumors, we analyzed the volume error...

1- or 2-directional MRI blood flow mapping sequences are an integral part of standard MR protocols for diagnosis and therapy control in heart diseases. Recent progress in rapid MRI has made it possible to acquire volumetric, 3-directional cine images in reasonable scan time. In addition to flow and velocity measurements relative to arbitrarily orie...

The development of segmentation algorithms for different anatomical structures and imaging protocols is an important task in medical image processing. The validation of these methods, however, is often treated as a subordinate task. Since manual delineations, which are widely used as a surrogate for the ground truth, exhibit an inherent uncertainty...

In situ ablation is increasingly being used for the treatment of liver malignancies. The application of these techniques is limited by the lack of a precise prediction of the destruction volume. This holds especially true in anatomically difficult situations, such as metastases in the vicinity of larger liver vessels. We developed a three-dimension...

This work presents an automatic and robust approach to detect the heart region in MRI perfusion images. Intensity variance is used to identify high variability regions, which are in turn filtered with features based on their shape and position. The approach is validated using 44 clinical data sets against a ground truth generated by experts.

Dynamic breast magnetic resonance imaging (MRI) com-monly acquires T1-and T2-weighted images. Joint inspection of both sequences in particular allows to distinguish between benign cyst-type and malignant lesions. However, in routine diagnostics both images are regarded independently, and immediate correlation is prevented by pa-tient motion and tis...

To investigate the feasibility of image fusion of MR-coronary angiography (MRCA) and delayed gadolinium enhancement imaging (LGE) and to assign areas of myocardial infarction to the corresponding supplying coronary arteries. An interactive segmentation of the coronary arteries was performed in MRCA data sets (n=25). The LGE slices were matched onto...

BACKGROUND The determination of causal relation between coronary lesions and myocardial perfusion defects can yield valuable information for diagnosis and treatment planning of coronary artery disease. The purpose of this work is an estimation of the accuracy and robustness achievable by a landmark-based fusion of corresponding CTCA and MR datasets...

The purpose of this study was (1) to compare 2-dimensional computed tomographic (2D-CT) and 3D-CT computer-assisted preoperative surgical planning, and (2) to define the indications for the latter method. The determination of functional residual liver volumes and the imaging of intrahepatic anatomy are critical when planning complex liver resection...

Fractal geometry was created by Benoit B. Mandelbrot nearly 40 years ago, and with the 1982 publication of his seminal book, “The Fractal Geometry of Nature,” its application took off, opening our eyes to patterns in nature on all scales and across diverse disciplines. On 14 October, he died of cancer in Cambridge, Massachusetts. He fundamentally a...

An increasing number of surgical and radiological observations call Couinaud's concept of eight liver segments into question and such inconsistencies are commonly explained with anatomical variations. This paper was intended to demonstrate that, beyond variability, another anatomical principle may allow to understand supposedly differing concepts o...

Blood flow and tissue velocity can be measured using phase-contrast MRI. In this work, the statistical properties of 4D phase-contrast images are derived, and a novel probabilistic blood flow mapping method based on sequential Monte Carlo sampling is presented. The resulting flow maps visualize and quantify the uncertainty in conventional flow visu...

The radio frequency (RF) ablation is a promising minimally invasive form of treatment for hepatic metastases and primary tumors. Thereby a needle like applicator, which is interstitially placed into the lesion, induces an electric current that causes heating and consequent destruction of the tissue due to its Ohmic resistance. In order to be a true...

Automatic CT dataset classification is important to efficiently create reliable database annotations, especially when large collections of scans must be analyzed. An automated segmentation and labeling algorithm was developed based on a fast patient segmentation and extraction of statistical density class features from the CT data. The method also...

The development of segmentation algorithms for liver tumors in CT scans has found growing attention in recent years. The validation of these methods, however, is often treated as a subordinate task. In this article, we review existing approaches and present rst steps towards a new methodology that evaluates the quality of an algorithm in relation t...

The simulation of radiofrequency ablations (RFA) can predict the achievable coagulation area and thus provide useful information for treatment planning, especially in cases in which the heat distribution can be limited by vascular cooling effects. A strong reliability of the numerical simulation results is essential for clinical use. In this paper...

The purpose of this work is to integrate concepts from the field of auditory display to enhance an electronic surgical navigation assistant for image-guided liver surgery. Although alarms and other auditory notification and monitoring devices are commonplace in operating rooms, audio has been a neglected modality in interaction with tools for intra...

Percutaneous radiofrequency (RF) ablation is a minimally invasive, image-guided therapy for the treatment of liver tumors. The assessment of the ablation area (coagulation) is performed to verify the treatment success as an essential part of the therapy. Traditionally, pre- and post-interventional CT images are used to visually compare the shape, s...

Durch moderne Bildgebung steht eine ständig wachsende Vielfalt an Bildinformationen zur Verfügung, mit denen eine sehr differenzierte Analyse spezifischer Krankheitsverläufe ermöglicht werden kann. Im Mittelpunkt des Vorhabens steht die Entwicklung einer integrierten Softwareplattform, um neue molekulare und funktionelle Bildgebung mit etablie...

Lobewise analysis of the pulmonary parenchyma is of clinical relevance for diagnosing and monitoring pathologies. In this work, a fully automatic lobe segmentation approach is presented, which is based on a previously proposed watershed transformation approach. The proposed extension explicitly considers the pulmonary fissures by including them in...

According to the state of the art a breast disease treatment may be subdivided into the sections of detection, which usually happens via a screening examination or a self referral, the diagnosis using other adjunct imaging modalities such as ultrasound or MR (magnetic resonance) imaging, evaluation of clinical features, and perhaps some more advanc...

A multiple hypothesis tracking approach to the segmentation of small 3D vessel structures is presented. By simultaneously tracking multiple hypothetical vessel trajectories, low contrast passages can be traversed, leading to an improved tracking performance in areas of low contrast. This work also contributes a novel mathematical vessel template mo...

The implementation of intraoperative navigation in liver surgery is handicapped by intraoperative organ shift, tissue deformation, the absence of external landmarks, and anatomical differences in the vascular tree. To investigate the impact of surgical manipulation on the liver surface and intrahepatic structures, we conducted a prospective clinica...

In oncological therapy monitoring, the estimation of tumor growth from consecutive CT scans is an important aspect in deciding whether the given treatment is adequate for the patient. This can be done by measuring and comparing the volume of a lesion in the scans based on a segmentation. However, simply counting the voxels within the segmentation m...

Das Lungenemphysem und der Umbau der kleinen Atemwege sind zwei wesentliche Auspragungen der COPD. Mittlerweile existieren sowohl zur regionalen Quantifizierung des Lungenparenchyms als auch zur Vermessung der Bronchialbaumgeometrie in CT Aufnahmen leistungsfahige, hochautomatische Algorithmen. In diversen Evaluationsstudien wurde die klinische Rel...

Ziele: Ermittlung der Genauigkeit eines Planungssystems zur Berechnung hepatischer RF-Ablationszonen unter Berucksichtigung von Kuhleffekten benachbarter Gefase in einem ex-vivo Schweinelebermodell. Methode: In 9 frisch entnommenen Schweinelebern wurden 38 RF-Ablationen mit einem bipolaren RF-System (30mm aktive Spitze, interne Kuhlung, Startleistu...

The optimal transfer of preoperative planning data and risk evaluations to the operative site is challenging. A common practice is to use preoperative 3D planning models as a printout or as a presentation on a display. One important aspect is that these models were not developed to provide information in complex workspaces like the operating room....

Augmented reality (AR) obtains increasing acceptance in the operating room. However, a meaningful augmentation of the surgical view with a 3D visualization of planning data which allows reliable comparisons of distances and spatial relations is still an open request. We introduce methods for intraoperative visualization of 3D planning models which...

Percutaneous image-guided interventions, such as radiofrequency ablation (RFA), biopsy, seed implantation, and several types of drainage, employ needle shaped instruments which have to be inserted into the patient's body. Precise planning of needle placement is a key to a successful intervention. The planning of the access path has to be carried ou...

Airway remodeling and accompanying changes in wall thickness are known to be a major symptom of chronic obstructive pulmonary disease (COPD), associated with reduced lung function in diseased individuals. Further investigation of this disease as well as monitoring of disease progression and treatment effect demand for accurate and reproducible asse...

We present a novel technique to predict the outcome of an RF ablation, including the vascular cooling effect. The main idea is to separate the problem into a patient independent part, which has to be performed only once for every applicator model and generator setting, and a patient dependent part, which can be performed very fast. The patient inde...

Computational support in intervention planning promises to support the subjective interpretation of data with reproducible measurements. Moreover, it is possible to develop and apply models that provide additional information which is not directly visible in the data. Based on computer-tomography multi-slice images of the liver, the planning softwa...

We present a fast and interactive segmentation method for medical images that allows a smooth reconstruction of an object's surface from a set of user drawn, three-dimensional, planar contours that can be arbitrarily oriented. Our algorithm uses an interpolation based on variational implicit functions. Because variational interpolation is computati...

Thoracic surgery would benefit from CT based risk analysis and preoperative planning based on patient individual models. This includes the decision support regarding resection strategies (general operability, lobectomy, sublobar resection, etc.) and the planning and supporting of the surgery - open surgery as well as video assisted thoracoscopic su...

In this work, we present a three-dimensional (3D) model for the optimization of the probe placement in radio-frequency ablation (RFA). The model is based on a system of partial differential equations (PDEs) that describe the electric potential of the tissue and the steady state of the heat which is induced into the tissue. The PDE system is solved...

The education of teachers in mathematics consists of two parts: enhancing the math-skills of the students and education in didactics. Mainly the math is taught in lessons for 50 to 100 students or even more. This has wrong influence to the teaching style and the attitude towards mathematics. This paper reports about a project, where active schoolte...

Modern software for surgery planning allows for definition of virtual resections within the liver. Thus, surgeons can simulate different resection strategies and assess the associated surgical risk preoperatively. Until now, it was impossi-ble to measure the quality of different resection plans objectively. The choice for the optimal resection stra...

The treatment of hepatic lesions with radio-frequency (RF) abla-tion has become a promising minimally invasive alternative to surgical resec-tion during the last decade. In order to achieve treatment qualities similar to surgical R0 resections, patient specific mathematical modeling and simulation of the biophysical processes during RF ablation are...

We present methods for intraoperative visualization of vascular structures in liver surgery. The underlying concept combines conventional augmented reality approaches with illustrative rendering techniques. Our methods reduce the visual complexity of vascular structures, and accentuate spatial relations. The proposed visualization techniques are em...

CONCLUSION We present a prototypical software assistant that integrates state-of-the-art segmentation, quantification, and visualization techniques for the examination of parenchyma and airways into a single, streamlined application that allows for a more comprehensive assessment of COPD. BACKGROUND Pulmonary emphysema and airway disease are prima...

CT scanning of the lungs is the standard procedure for preoperative evaluation of central lung tumors. The extent of the tumor and infiltration of central lung structures or lung segments are decisive parameters to clarify whether surgery is possible and the extent of resection. With computer-assisted methods for the segmentation of anatomical stru...

Virtual imaging procedures have only rarely been analyzed in pediatric populations. We evaluated the role of CT-based virtual surgery planning in pediatric patients experiencing hepatic vascular malformations (HVM). We analyzed 12 children with complex hepatic vascular malformations. All of the children received multislice CT scans with contrast me...

Background CT scanning of the lungs is the standard procedure for preoperative evaluation of central lung tumors. The extent of the tumor and infiltration of central lung structures or lung segments are decisive parameters to clarify whether surgery is possible and the extent of resection. With computer-assisted methods for the segmentation of anat...

Complex oncologic interventions in the liver require an extensive and careful preoperative analysis. Particularly the achievement of an optimal safety margin around tumors remains a difficult task for surgeons. We present new methods for evaluating different safety margins and their effect on the associated interruption of vascular supply or draina...

Although the consequences of partial venous outflow interruption have attracted only limited attention in liver surgery, maximal preservation of liver function after hepatic resection requires preservation of circulation in the remnant liver, especially hepatic vein drainage. Data from 30 patients undergoing 3-dimensional imaging were analyzed to c...

We sought was to quantify and visualize the regeneration of the remnant liver after living donor liver transplantation using computed tomographic (CT) data. For the evaluation of preoperative and follow-up data, we developed a software assistant that was able to compute the volume growth of the remnant liver and liver territories as well as visuali...

In follow-up CT examinations of cancer patients, therapy success is evaluated by estimating the change in tumor size from diameter or volume comparison between corresponding lesions. We present an algorithm that automatizes the detection of matching lesions, given a baseline segmentation mask. It is generally applicable and does not need an organ m...

As recent chemotherapy regimens for metastatic colorectal cancer become more and more effective in a neoadjuvant setting before liver surgery, a "complete" clinical response is sometimes documented on imaging. Without operation though, metastatic recurrence is likely to commence within 12 months. Surgeons now face the problem to resect non-visualiz...

To quantify the cooling effect of hepatic vessels on liver radiofrequency (RF) ablation ex situ. Bipolar RF applicators (diameter = 1.8 mm, electrode length = 30 mm) were inserted parallel to perfused glass tubes (diameter = 5 and 10 mm; flow = 250-1,800 ml/min) at distances of 5 and 10 mm in porcine livers ex vivo. RF ablation was performed at 30...

This article presents advanced algorithms for segmenting lung nodules, liver metastases, and enlarged lymph nodes in CT scans. Segmentation and volumetry are essential tasks of a software assistant for oncological therapy monitoring. Our methods are based on a hybrid algorithm originally developed for lung nodules that combines a threshold-based ap...

Zusammenfassung Zur Unterstützung komplexer chirurgischer Eingriffe stehen seit einiger Zeit computergestützte Planungssysteme bereit. Für den direkten Zugriff im OP sind diese Systeme jedoch nur sehr eingeschränkt einsetzbar, da sie für die präoperative Planung entworfen wurden und die besonderen Bedingungen im Operationssaal nicht berücksichtigen...

Image guided radiofrequency ablation (RFA) is becoming a standard procedure as a minimally invasive method for tumor treatment in the clinical routine. The visualization of pathological tissue and potential risk structures like vessels or important organs gives essential support in image guided pre-interventional RFA planning. In this work our aim...

Breast cancer diagnosis based on magnetic resonance images (breast MRI) is increasingly being accepted as an additional diagnostic tool to mammography and ultrasound, with distinct clinical indications.1 Its capability to detect and differentiate lesion types with high sensitivity and specificity is countered by the fact that visual human assessmen...

Segmentation is an essential task in medical image analysis. For example measuring tumor growth in consecutive CT scans based on the volume of the tumor requires a good segmentation. Since manual segmentation takes too much time in clinical routine automatic segmentation algorithms are typically used. However there are always cases where an automat...