Medical Imaging Interaction Toolkit Research Articles

Prognosis of Performing Split-Rib Bone Graft for Cranial Bone Defects.

Frontal sinus anterior wall defects occur because of various diseases, causing not only aesthetic problems, such as forehead bulging and upper eyelid ptosis, but also exerting physical pressure on the brain or optic nerve. Therefore, this study aimed to evaluate the prognosis of performing split-rib bone graft for frontal sinus anterior wall defects. This study included 30 patients who received a split-rib bone graft for a frontal sinus anterior wall defect. The sizes and volumes of the defects and grafts were measured using three-dimensional computed tomography before, after, and every 6 months for 2 years after the surgery. The Medical Imaging Interaction Toolkit was used for analysis. The average size and volume of the grafts were 27.29 cm 2 and 5.88 cm 3 , whereas they were 23.76 cm 2 and 4.80 cm 3 at 24 months after surgery, respectively. In a graft size and volume of less than 27 cm 2 and 6 cm 3 , respectively, the rate of graft take was greater than 80% during long-term observation. The younger the age, the higher the rate of graft take. No difference was found in the defect causes. Absorption occurred for up to 18 months. Frontal bone defect reconstruction revealed the stable results of the split-rib bone graft over a long period when the size and volume were less than 27 cm 2 and 6 cm 3 , respectively. Furthermore, bone resorption was seen in more than 20% to 30% of the patients, and the rate of resorption increased with age; thus, it is appropriate to consider overcorrection and other reconstruction methods. Therapeutic, IV.

Diffusion kurtosis imaging and MRI-detected extramural venous invasion in rectal cancer: correlation with clinicopathological prognostic factors.

To investigate the prognostic value of the diffusion kurtosis imaging (DKI)-derived parameters D value, K value, diffusion-weighted imaging (DWI) parameter apparent diffusion coefficient (ADC) value, and magnetic resonance imaging (MRI)-detected extramural venous invasion (EMVI) (mrEMVI) in rectal cancer patients. Forty patients who underwent MRI for rectal cancer were retrospectively evaluated. DKI-derived parameters D and K were measured using the Medical Imaging Interaction Toolkit. Conventional ADC values were measured from the corresponding DWI images. An experienced radiologist evaluated the mrEMVI status on MR images using the mrEMVI scoring system. An independent sample t-test or analysis of variance was used to analyze and compare the measurement data. The x2 test or Fisher exact test was used for categorical variables. Receiver operating characteristic curves were used to assess the diagnostic performance of these parameters. Among the 40 patients, MRI showed positive EMVI in 15 patients and negative EMVI in 25 patients. Positive mrEMVI status was associated with age, positive circumferential resection margin, pT-stage, lymphovascular invasion (LVI), distant metastasis, and serum carcinoembryonic antigen (CEA) level (P = 0.004-0.036). The dispersion coefficient (D) values and ADC values were significantly higher in the mucinous adenocarcinoma (MC) group than in the common adenocarcinoma (AC) group (P = 0.001), while kurtosis coefficient (K) values were lower in the MC group than in the AC group (P = 0.022). D values were significantly higher in the KRAS-mutated group than in the wild-type group (P < 0.05), whereas K values were lower in the KRAS-mutated group than in the wild-type group (P < 0.05). All three parameters (D, K, and ADC values) showed good diagnostic performance for discriminating MC from AC. Both the D and K values showed certain diagnostic performance for discriminating KRAS mutation. DKI-derived parameters, conventional ADC values, and mrEMVI are associated with different histopathological prognostic factors. All DKI-derived parameters and conventional ADC values may distinguish MC from AC. DKI-derived parameters may also be used to discriminate KRAS mutation.

Three-Dimensional Reconstruction of Pelvicalyceal System of the Kidney Based on Native CT Images Are 1-Step Away from the Use of Contrast Agent.

To describe special algorithm for the semi-autonomous 3-dimensional reconstruction of the pelvicalyceal system based on native computed tomography images of patients with upper urinary tract obstruction. Fifty patients with renal colic fitting to inclusion criteria were enrolled. All patients underwent computed tomography urography to perform 3-dimensional reconstruction of the pelvicalyceal system on the affected size based on excretory phase representing "gold standard" and on native phase, which was performed via Medical Imaging Interaction Toolkit program updated with the described algorithm. Five urologists estimated their similarities and the potential use of non-contrast models for interventional planning. Contralateral non-distended pelvicalyceal system was reconstructed to evaluate the viability of the proposed technology in such cases. Surface areas of contrast and non-contrast models were compared. Distended pelvicalyceal system of 1 patient was used to reconstruct virtual endoscopic view. Obtained 3-dimensional noncontrast pelvicalyceal system models were analyzed by an engineer for suitability for 3-dimensional printing. The average surface area of contrast and non-contrast models was 3513 and 3371 mm2 , respectively (P=.0818). Non-contrast 3-dimensional reconstruction was possible with all distended pelvicalyceal systems and with 9 non-distended cases. Properties of non-contrast models were estimated as 4.3 out of 5. Obtained models were suitable for their intraluminal reconstruction and potential 3-dimensional printing. Described semi-autonomous approach allows for 3-dimensional reconstruction of dilated pelvicalyceal system based on non-contrast computed tomography images.

Prediction of Malignant Cell Infiltration Patterns with Texture Features of Biopsy-Correlated Positron Emission Tomography of Osteolytic Lesions in Multiple Myeloma

Prediction of Malignant Cell Infiltration Patterns with Texture Features of Biopsy-Correlated Positron Emission Tomography of Osteolytic Lesions in Multiple Myeloma

The three-dimensional reconstruction of the dilated renal pelvicalyceal system by non-enhanced computed tomography

Introduction. The three-dimensional reconstruction of the renal pelvicalyceal system (PCS) is possible when performing enhanced computed tomography (CT). However, the use of a contrast agent has its limitations associated with the presence of allergy and chronic kidney disease.Purpose of the study. To describe the method of semi-autonomous three-dimensional (3D) reconstruction of the PCS based on non-enhanced CT images of patients with upper urinary tract obstruction.Materials and methods. Five patients diagnosed with renal colic were recruited from April-May 2021. All patients underwent CT-urography after informed consent. Medical Imaging Interaction Toolkit program (MITK) expanded with explainable update were used for 3D-reconstruction of PCS via excretory and native phases. To assess the accuracy of the latter, both contrast and non-contrast models were compared regarding their surface area. Also, the PCS of one patient was used to reconstruct virtual endoscopic views based on enhanced and non-enhanced models. Five urologists estimated their similarity and potential use of non-enhanced models for the interventional planning via a Likert scale questionnaire. The resulting models were also analyzed by programmer-engineers to test their suitability for 3D-printing.Results. The average surface area of enhanced and non-enhanced models was 3291 mm2 and 2879 mm2, respectively. Obtained models were suitable for their intraluminal reconstruction and potential 3D-printing. Analyzed properties of non-enhanced models were estimated at 4.5 out of 5.0.Conclusion. The described semi-autonomous reconstruction of the renal PCS based on non-enhanced CT images allows for a short time to reconstruct its 3D-view in patients with the upper urinary tract obstruction.

Validation of Segmented Brain Tumor from MRI Images Using 3D Printingthe.

Background:Early diagnosis of a brain tumor is important for improving the treatment possibilities. Manually segmenting the tumor from the volumetric data is time-consuming, and the visualization of the tumor is rather challenging. Methods:This paper proposes a user-guided brain tumour segmentation from MRI (Magnetic Resonance Imaging) images developed using Medical Imaging Interaction Toolkit (MITK) and printing the segmented object using the 3D printer for tumour quantification. The proposed method includes segmenting the tumour interactively using connected threshold method, then printing the physical object from the segmented volume of interest. Then the distance between two voxels was measured using electronic callipers on the 3D volume in a specific direction. And next, the same distance was measured in the same direction on the 3D printed object. Results:The technique was tested with n=5 samples (20 readings) of brain MRI images from RIDER Neuro MRI dataset of National Cancer Institute. MITK provides various tools that enable image visualization, registration, and contouring. We were able to achieve the same measurements using both the approaches and this has been tested statistically with paired t-test method. Through this and the observer’s opinion, the accuracy of the segmentation was proved. Conclusion:When the difference in measurement of tumor volume through the electronic calipers and with 3D printed object equates to zero, proves that the segmentation technique is accurate. This helps to delineate the tumor more accurately during radio therapy.

Shear Stress Modulates Osteoblast Cell and Nucleus Morphology and Volume.

Mechanical loading preserves bone mass and function—yet, little is known about the cell biological basis behind this preservation. For example, cell and nucleus morphology are critically important for cell function, but how these morphological characteristics are affected by the physiological mechanical loading of bone cells is under-investigated. This study aims to determine the effects of fluid shear stress on cell and nucleus morphology and volume of osteoblasts, and how these effects relate to changes in actin cytoskeleton and focal adhesion formation. Mouse calvaria 3T3-E1 (MC3T3-E1) osteoblasts were treated with or without 1 h pulsating fluid flow (PFF). Live-cell imaging was performed every 10 min during PFF and immediately after PFF. Cytoskeletal organization and focal adhesions were visualized, and gene and protein expression quantified. Two-dimensional (2D) and three-dimensional (3D) morphometric analyses were made using MeasureStack and medical imaging interaction toolkit (MITK) software. 2D-images revealed that 1 h PFF changed cell morphology from polygonal to triangular, and nucleus morphology from round to ellipsoid. PFF also reduced cell surface area (0.3-fold), cell volume (0.3-fold), and nucleus volume (0.2-fold). During PFF, the live-cell volume gradually decreased from 6000 to 3000 µm3. After PFF, α-tubulin orientation was more disorganized, but F-actin fluorescence intensity was enhanced, particularly around the nucleus. 3D-images obtained from Z-stacks indicated that PFF increased F-actin fluorescence signal distribution around the nucleus in the XZ and YZ direction (2.3-fold). PFF increased protein expression of phospho-paxillin (2.0-fold) and integrin-α5 (2.8-fold), but did not increase mRNA expression of paxillin-a (PXNA), paxillin-b (PXNB), integrin-α5 (ITGA51), or α-tubulin protein expression. In conclusion, PFF induced substantial changes in osteoblast cytoskeleton, as well as cell and nucleus morphology and volume, which was accompanied by elevated gene and protein expression of adhesion and structural proteins. More insights into the mechanisms whereby mechanical cues drive morphological changes in bone cells, and thereby, possibly in bone cell behavior, will aid the guidance of clinical treatment, particularly in the field of orthodontics, (oral) implantology, and orthopedics.

Radiographic Response of Vessel Involvement and Resectability After Neoadjuvant Chemoradiation in Patients With Locally Advanced Pancreatic Cancer.

Survival of patients with locally advanced pancreatic cancer (LAPC) is improved when neoadjuvant chemoradiation enables subsequent surgical resection. Here, the authors assess changes in vessel involvement as a possible indicator of resectability. Pancreatic gross tumor and all major abdominal vessels were contoured for 49 patients with unresectable LAPC before and after neoadjuvant chemoradiation. Changes were compared by paired t tests. Tumor-vessel relationships were automatically quantified using Medical Imaging Interaction Toolkit and examined for correlation with resectability and outcome. Tumor volumes were significantly reduced by chemoradiation (41 to 33 mL, P<0.0001). Maximum circumferential vessel involvement decreased for most patients and was statistically significant for the superior mesenteric (P<0.003) and splenic veins (P<0.038). Resection was possible in some patients and correlated positively with survival (28 vs. 15 mo, r=0.40), a decrease in CA 19.9 levels (r=0.48), and reduced involvement of most vessels. Nevertheless, surgical resection with a successful detachment of tumor tissue from major vessels was also achieved in some patients who did not show improvement in radiographic vessel involvement, but rather a reduction in tumor volume and CA 19.9 levels. The present analysis demonstrates that neoadjuvant chemoradiation can enable subsequent surgical resection in patients with LAPC. Complete resection substantially prolongs survival. Therefore, surgical exploration should be offered if vessel involvement is improved by chemoradiation and considered in radiographic unchanged vessel involvement if size and CA 19.9 levels decrease, as these factors may indicate resectable disease, too.

Dataset of voxelwise correlated signal values of ADC, rCBV and FAP-specific PET of 13 Glioblastoma patients.

This dataset is based on multimodal MRI and FAP-specific PET/CT Imaging applied to 13 patients with histologically proven glioblastomas. Imaging Data was processed using Medical Imaging Interaction Toolkit (MITK) software. MRI images (contrast enhanced T1w, T2w/FLAIR, ADC, rCBV) were co-registrated with FAP-specific PET images. T2w/FLAIR hyperintensities and contrast enhancing lesions were segmented manually. Necrotic areas were segmented manually and subtracted from T2w/FLAIR hyperintensities and contrast enhancing lesions. Voxelwise ADC/rCBV and PET signal intensities in projection on T2w/FLAIR hyperintensities and contrast enhancing lesions were extracted using the pixel dumper function of the MITK software and stored as excel-files. The data presented in this article has been analysed and described in the article FAP-specific “PET signaling shows a moderately positive correlation with relative CBV and no correlation with ADC in 13 IDH wildtype Glioblastomas” published in the European Journal of Radiology.

3D-Cell-Annotator: an open-source active surface tool for single-cell segmentation in 3D microscopy images.

SummarySegmentation of single cells in microscopy images is one of the major challenges in computational biology. It is the first step of most bioimage analysis tasks, and essential to create training sets for more advanced deep learning approaches. Here, we propose 3D-Cell-Annotator to solve this task using 3D active surfaces together with shape descriptors as prior information in a semi-automated fashion. The software uses the convenient 3D interface of the widely used Medical Imaging Interaction Toolkit (MITK). Results on 3D biological structures (e.g. spheroids, organoids and embryos) show that the precision of the segmentation reaches the level of a human expert.Availability and implementation3D-Cell-Annotator is implemented in CUDA/C++ as a patch for the segmentation module of MITK. The 3D-Cell-Annotator enabled MITK distribution can be downloaded at: www.3D-cell-annotator.org. It works under Windows 64-bit systems and recent Linux distributions even on a consumer level laptop with a CUDA-enabled video card using recent NVIDIA drivers.Supplementary information Supplementary data are available at Bioinformatics online.

Computer-aided pancreas segmentation based on 3D GRE Dixon MRI: a feasibility study.

BackgroundPancreas segmentation is of great significance for pancreatic cancer radiotherapy positioning, pancreatic structure, and function evaluation.PurposeTo investigate the feasibility of computer-aided pancreas segmentation based on optimized three-dimensional (3D) Dixon magnetic resonance imaging (MRI).Material and MethodsSeventeen healthy volunteers (13 men, 4 women; mean age = 53.4 ± 13.2 years; age range = 28–76 years) underwent routine and optimized 3D gradient echo (GRE) Dixon MRI at 3.0 T. The computer-aided segmentation of the pancreas was executed by the Medical Imaging Interaction ToolKit (MITK) with the traditional segmentation algorithm pipeline (a threshold method and a morphological method) on the opposed-phase and water images of Dixon. The performances of our proposed computer segmentation method were evaluated by Dice coefficients and two-dimensional (2D)/3D visualization figures, which were compared for the opposed-phase and water images of routine and optimized Dixon sequences.ResultsThe dice coefficients of the computer-aided pancreas segmentation were 0.633 ± 0.080 and 0.716 ± 0.033 for opposed-phase and water images of routine Dixon MRI, respectively, while they were 0.415 ± 0.143 and 0.779 ± 0.048 for the optimized Dixon MRI, respectively. The Dice index was significantly higher based on the water images of optimized Dixon than those in the other three groups (all P values < 0.001), including water images of routine Dixon MRI and both of the opposed-phase images of routine and optimized Dixon sequences.ConclusionComputer-aided pancreas segmentation based on Dixon MRI is feasible. The water images of optimized Dixon obtained the best similarity with a good stability.

MITK-ModelFit: A generic open-source framework for model fits and their exploration in medical imaging \u2013 design, implementation and application on the example of DCE-MRI

BackgroundMany medical imaging techniques utilize fitting approaches for quantitative parameter estimation and analysis. Common examples are pharmacokinetic modeling in dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI)/computed tomography (CT), apparent diffusion coefficient calculations and intravoxel incoherent motion modeling in diffusion-weighted MRI and Z-spectra analysis in chemical exchange saturation transfer MRI. Most available software tools are limited to a special purpose and do not allow for own developments and extensions. Furthermore, they are mostly designed as stand-alone solutions using external frameworks and thus cannot be easily incorporated natively in the analysis workflow.ResultsWe present a framework for medical image fitting tasks that is included in the Medical Imaging Interaction Toolkit MITK, following a rigorous open-source, well-integrated and operating system independent policy. Software engineering-wise, the local models, the fitting infrastructure and the results representation are abstracted and thus can be easily adapted to any model fitting task on image data, independent of image modality or model. Several ready-to-use libraries for model fitting and use-cases, including fit evaluation and visualization, were implemented. Their embedding into MITK allows for easy data loading, pre- and post-processing and thus a natural inclusion of model fitting into an overarching workflow. As an example, we present a comprehensive set of plug-ins for the analysis of DCE MRI data, which we validated on existing and novel digital phantoms, yielding competitive deviations between fit and ground truth.ConclusionsProviding a very flexible environment, our software mainly addresses developers of medical imaging software that includes model fitting algorithms and tools. Additionally, the framework is of high interest to users in the domain of perfusion MRI, as it offers feature-rich, freely available, validated tools to perform pharmacokinetic analysis on DCE MRI data, with both interactive and automatized batch processing workflows.

Feasibility of using Medical Imaging Interaction Toolkit in volumetric studies to accurate diagnosing of vascular emboli by Extended NURBS-based Cardiac-Torso phantom

Introduction: Important complications of venous thromboembolism (VTE) are a longer hospital stay, readmission, recurrence of the emboli, complications of anticoagulant therapy and death in a sever condition. In present study, the volume measurement accuracy of the medical imaging interaction toolkit (MITK) software on determining VTE in computed tomography images was evaluated. Methods: Several VTEs, ranged from 0.1 to 20 mm, were simulated in the arteries of a XCAT Phantom. Then, the MITK software was used for localization and volume measurement of the produced VTEs on the images of the simulated phantom. Results: The scatter plot and correlation coefficient were showed a high correlation between the calculated emboli volume measures by MITK software with those designed in the XCAT Phantom (r=0.98; p<0.001), The differences of the calculated measures and the simulated clots were mostly related to the clot volumes less than 0.1 ml (mainly due to the inability of the software to measure the range), which may be clinically ignored. However, a difference of about 0.01 ml for the clot volumes greater than 0.1 ml was in acceptable range. Conclusion: MITK software may be used for volume measurement studies in medical diagnosis, also for VTE accurate measurement to achieve a more accurate diagnosis and to eliminate the need to onsite diagnosis by the imaging system due to MITK capability on running in a personal computer.

Signed Real-Time Delay Multiply and Sum Beamforming for Multispectral Photoacoustic Imaging

Reconstruction of photoacoustic (PA) images acquired with clinical ultrasound transducers is usually performed using the Delay and Sum (DAS) beamforming algorithm. Recently, a variant of DAS, referred to as Delay Multiply and Sum (DMAS) beamforming has been shown to provide increased contrast, signal-to-noise ratio (SNR) and resolution in PA imaging. The main reasons for the use of DAS beamforming in photoacoustics are its simple implementation, real-time capability, and the linearity of the beamformed image to the PA signal. This is crucial for the identification of different chromophores in multispectral PA applications. In contrast, current DMAS implementations are not responsive to the full spectrum of sound frequencies from a photoacoustic source and have not been shown to provide a reconstruction linear to the PA signal. Furthermore, due to its increased computational complexity, DMAS has not been shown yet to work in real-time. Here, we present an open-source real-time variant of the DMAS algorithm, signed DMAS (sDMAS), that ensures linearity in the original PA signal response while providing the increased image quality of DMAS. We show the applicability of sDMAS for multispectral PA applications, in vitro and in vivo. The sDMAS and reference DAS algorithms were integrated in the open-source Medical Imaging Interaction Toolkit (MITK) and are available as real-time capable implementations.

MITK-OpenIGTLink for combining open-source toolkits in real-time computer-assisted interventions.

Due to rapid developments in the research areas of medical imaging, medical image processing and robotics, computer-assisted interventions (CAI) are becoming an integral part of modern patient care. From a software engineering point of view, these systems are highly complex and research can benefit greatly from reusing software components. This is supported by a number of open-source toolkits for medical imaging and CAI such as the medical imaging interaction toolkit (MITK), the public software library for ultrasound imaging research (PLUS) and 3D Slicer. An independent inter-toolkit communication such as the open image-guided therapy link (OpenIGTLink) can be used to combine the advantages of these toolkits and enable an easier realization of a clinical CAI workflow. MITK-OpenIGTLink is presented as a network interface within MITK that allows easy to use, asynchronous two-way messaging between MITK and clinical devices or other toolkits. Performance and interoperability tests with MITK-OpenIGTLink were carried out considering the whole CAI workflow from data acquisition over processing to visualization. We present how MITK-OpenIGTLink can be applied in different usage scenarios. In performance tests, tracking data were transmitted with a frame rate of up to 1000Hz and a latency of 2.81ms. Transmission of images with typical ultrasound (US) and greyscale high-definition (HD) resolutions of [Formula: see text] and [Formula: see text] is possible at up to 512 and 128Hz, respectively. With the integration of OpenIGTLink into MITK, this protocol is now supported by all established open-source toolkits in the field. This eases interoperability between MITK and toolkits such as PLUS or 3D Slicer and facilitates cross-toolkit research collaborations. MITK and its submodule MITK-OpenIGTLink are provided open source under a BSD-style licence ( http://mitk.org ).

Volumetry may predict early renal function after nephron sparing surgery in solitary kidney patients.

We investigate the impact of the residual kidney volume measured by tumor volumetry on preoperative imaging in predicting post-operative renal function. Nephron sparing surgery (NSS) in renal cell carcinoma (RCC) is the standard treatment for T1 kidney tumors. Resection of kidney tumors in solidary kidneys needs precise preoperative counseling of patients regarding post-operative renal function.Patients planned for renal tumor surgery who underwent prior nephrectomy on the contralateral side were included. We identified 35 patients in our database that underwent NSS in solitary kidneys and met the inclusion criteria. Tumor volumetry was performed on computer tomography (CT) or magnetic resonance imaging (MRI) with the Medical Imaging Interaction Toolkit (MITK). Clinical and pathological data were assessed. Follow-up data included renal function over 3 years.Mean age was 64 ± 8.1 years. Mean tumor volume on imaging was 27.5 ± 48.6 cc. Mean kidney volume was 195.2 ± 62.8 cc and mean residual kidney volume was 173.4 ± 65.3 cc. We found a correlation between renal function (MDRD) and residual kidney volume on imaging 1-week post-surgery (p = 0.038). Mid- and long-term renal function was not associated with residual kidney volume.In conclusion, renal volumetry may predict early renal function after NSS.

Estimation of ultrasound strain indices in carotid plaque and correlation to cognitive dysfunction.

Carotid plaque prone to release emboli may be predicted by increased strain variations within plaque due to arterial pulsation over a cardiac cycle. Non-invasive ultrasound strain imaging may therefore be a viable surrogate to determine the risk of embolic stroke and possible cognitive impairment. Ultrasound strain imaging was performed on 24 human subjects with significant plaque, who also underwent standardized cognitive assessment (Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)) prior to a carotid endarterectomy (CEA) procedure. Radiofrequency signals were acquired using a Siemens Antares with a VFX 13-5 linear array transducer. Plaque regions were segmented by a radiologist at end-diastole using the Medical Imaging Interaction Toolkit. A hierarchical block-matching motion tracking algorithm was utilized to estimate the cumulated axial, lateral, and shear strains within the imaging plane. The maximum strain indices of the plaque, defined as mean accumulated strain over a small region of interest in the plaque with large deformations, were obtained. All the strain indices were then correlated with RBANS Total score. Overall cognitive performance was negatively associated with maximum axial and lateral strains respectively. The results demonstrate a direct relationship between the maximum axial and lateral strain indices in carotid plaque and cognitive impairment.

Assessing Treatment Response of Osteolytic Lesions by Manual Volumetry, Automatic Segmentation, and RECIST in Experimental Bone Metastases

Aim of the study was to compare between volumetric and unidimensional approaches for treatment response monitoring in a nude rat model of experimental bone metastases. For the volumetric approach, an automated segmentation algorithm of osteolytic lesions was introduced and compared to manual volumetry. Nude rats bearing osteolytic metastases were treated with zoledronate and sunitinib and compared to controls. Treatment response was assessed longitudinally invivo using flat-panel volumetric computed tomography at days 30, 35, 45, and 55 after tumor cell inoculation. The mean sizes and volumes of osteolytic lesions were determined according to response evaluation criteria in solid tumors (RECIST) and by automated and manual volumetry (software: MITK [The Medical Imaging Interaction Toolkit, Heidelberg, Germany] and VIRTUOS, Heidelberg, Germany). In contrary to RECIST, the manual volumetric approach indicated a significant decrease in osteolytic lesion volume in response to treatment. The presented automatic segmentation algorithm for treatment monitoring identified bone metastases adequately and assessed changes in the osteolytic lesion volume over time according to manual volumetry. In an animal model, volumetric treatment response assessment of osteolytic bone metastases is superior to unidimensional measurements, and automated volumetric segmentation may be a valuable alternative to manual volume determination.

MITK-US: real-time ultrasound support within MITK

Intra-procedural acquisition of the patient anatomy is a key technique in the context of computer-assisted interventions (CAI). Ultrasound (US) offers major advantages as an interventional imaging modality because it is real time and low cost and does not expose the patient or physician to harmful radiation. To advance US-related research, the purpose of this paper was to develop and evaluate an open-source framework for US-based CAI applications. We developed the open-source software module MITK-US for acquiring and processing US data as part of the well-known medical imaging interaction toolkit (MITK). To demonstrate its utility, we applied the module to implement a new concept for US-guided needle insertion. Performance of the US module was assessed by determining frame rate and latency for both a simple sample application and a more complex needle guidance system. MITK-US has successfully been used to implement both sample applications. Modern laptops achieve frame rates above 24 frames per second. Latency is measured to be approximately 250 ms or less. MITK-US can be considered a viable rapid prototyping environment for US-based CAI applications.

Stent graft visualization and planning tool for endovascular surgery using finite element analysis

A new approach to optimize stent graft selection for endovascular aortic repair is the use of finite element analysis. Once the finite element model is created and solved, a software module is needed to view the simulation results in the clinical work environment. A new tool for interpretation of simulation results, named Medical Postprocessor, that enables comparison of different stent graft configurations and products was designed, implemented and tested. Aortic endovascular stent graft ring forces and sealing states in the vessel landing zone of three different configurations were provided in a surgical planning software using the Medical Imaging Interaction Tool Kit (MITK) software system. For data interpretation, software modules for 2D and 3D presentations were implemented. Ten surgeons evaluated the software features of the Medical Postprocessor. These surgeons performed usability tests and answered questionnaires based on their experience with the system. The Medical Postprocessor visualization system enabled vascular surgeons to determine the configuration with the highest overall fixation force in 16+/-6 s, best proximal sealing in 56+/-24s and highest proximal fixation force in 38+/- s. The majority considered the multiformat data provided helpful and found the Medical Postprocessor to be an efficient decision support system for stent graft selection. The evaluation of the user interface results in an ISONORM-conform user interface (113.5 points). The Medical Postprocessor visualization software tool for analyzing stent graft properties was evaluated by vascular surgeons. The results show that the software can assist the interpretation of simulation results to optimize stent graft configuration and sizing.