5 research outputs found
Assessment of the distraction regenerate using three-dimensional quantitative computer tomography
No full textThis study presents a new method for objective assessment of the distraction regenerate using three-dimensional quantitative computer tomography (3D-QCT). The distraction specimens of 16 sheep that underwent bifocal cranial distraction osteogenesis to reconstruct a critical size defect were used to evaluate this method. To analyse the validity of this method the results were compared to conventional quantitative computer tomography (QCT). Squared correlation coefficients (r(2)) according to Sackett showed a high reliability (r(2) > 70% for the total DO regenerate, DO Regions 2-4). Method comparison according to Bland-Altman (less than or equal to 6.25% of measurements out of 95% limits of agreement) showed that three-dimensional computer tomography based bone densitometry is valid for future DO research
Effect of platelet-rich-plasma on cranial distraction osteogenesis in sheep: preliminary clinical and radiographic results
No full textThe purpose of this study was to investigate the effect of platelet-rich-plasma (PRP) on cranial distraction osteogenesis. Standardized calvaria critical size defects (6 cm x 5 cm) were created in 16 adult female sheep. Bifocal cranial transport distraction osteogenesis with autogenous free calvaria bone grafts (2 cm x 4 cm) was performed at a rate of I mm once daily to a total of 30 mm. The 16 sheep involved in the experiment were randomly divided into four groups, four animals in each: Group 1 (no PRP, latency 5 days); Group 2 (no PRP, latency 0 day), Group 3 (PRP, latency 5 days) and Group 4 (PRP, latency 0 day). After a consolidation phase of 6 weeks, the animals were sacrificed and specimens harvested for conventional radiological and 3D quantitative computer tomographic (3D-QCT) assessment. New bone was generated in the distraction zone in all groups. There were significantly (P < 0.05) higher densities in the proximal region of the distraction regenerate in Group 4 (PRP, latency 0 day) compared to Group 2. However, no significant differences in mean density of the total distraction regenerate were found, neither in volume of the bony regenerate between the experimental groups. This study showed that PRP only had an effect on bone regeneration if active distraction was started immediately after application of PRP in the distraction gap
A Dataset of Reconstructed Carotid Bifurcation Lumen and Plaque Models with Centerline Tree and Simulated Hemodynamics
No full text<p><code>carotid_bifurcation_database.zip</code> contains 79 cases of left and right-side carotid bifurcations (152 inner wall models). For each case, inner wall (lumen) and plaque models were extracted from computed tomography angiography (CTA) scans. The models were segmented, reconstructed, and a centerline tree was created for each geometry using the <a href="https://github.com/PepeEulzer/CarotidAnalyzer">CarotidAnalyzer</a> pipeline. The geometries include varying degrees of internal carotid stenosis. Bifurcations with 100% stenosis were omitted, as the vessel is not discernible in the scan.</p>
<p><code>carotid_flow_database.zip</code> contains hemodynamic flow simulations of the above models. Fluid data (velocity, pressure) and surface data (wall shear stress) are given in seperate files for each case. For each field, a systolic and diastolic time step are provided.</p>
<p><strong>Further information regarding the extraction pipeline and flow simulations can be obtained from the following publications:<br></strong>P. Eulzer, F. von Deylen, W.-C. Hsu, R. Wickenhöfer, C. M. Klingner, and K. Lawonn (2023), A Fully Integrated Pipeline for Visual Carotid Morphology Analysis. Computer Graphics Forum, 42(3): 25-37. <a href="https://doi.org/10.1111/cgf.14808">https://doi.org/10.1111/cgf.14808</a></p>
<p>Kevin Richter, Tristan Probst, Anna Hundertmark, Pepe Eulzer, and Kai Lawonn (2024), Longitudinal wall shear stress evaluation using centerline projection approach in the numerical simulations of the patient-based carotid artery. Computer Methods in Biomechanics and Biomedical Engineering, 27(3): 347-364. <a href="https://doi.org/10.1080/10255842.2023.2185478">https://doi.org/10.1080/10255842.2023.2185478</a></p>
<p>P. Eulzer, K. Richter, A. Hundertmark, R. Wickenhöfer, C. M. Klingner, and K. Lawonn (2024), Instantaneous Visual Analysis of Blood Flow in Stenoses Using Morphological Similarity. Computer Graphics Forum 43(3): in print. <a href="https://doi.org/10.1111/cgf.15081">https://doi.org/10.1111/cgf.15081</a></p>
The use of a new 3D splint and double CT scan procedure to obtain an accurate anatomic virtual augmented model of the skull.
No full textItem does not contain fulltextThree-dimensional (3D) virtual planning of orthognathic surgery requires detailed visualization of the interocclusal relationship. The purpose of this study was to introduce the modification of the double computed tomography (CT) scan procedure using a newly designed 3D splint in order to obtain a detailed anatomic 3D virtual augmented model of the skull. A total of 10 dry adult human cadaver skulls were used to evaluate the accuracy of the automatic rigid registration method for fusion of both CT datasets (Maxilim, version 1.3.0). The overall mean registration error was 0.1355+/-0.0323 mm (range 0.0760-0.1782 mm). Analysis of variance showed a registration method error of 0.0564 mm (P < 0.001; 95% confidence interval = 0.0491-0.0622). The combination of the newly designed 3D splint with the double CT scan procedure allowed accurate registration and the set-up of an accurate anatomic 3D virtual augmented model of the skull with detailed dental surface
