Three-dimensional analysis of reconstructed skulls using three different open-source software versus commercial software.

This study aimed to compare the 3D skull models reconstructed from computed tomography (CT) images using three different open-source software with a commercial software as a reference. The commercial Mimics v17.0 software was used to reconstruct the 3D skull models from 58 subjects. Next, two open-source software, MITK Workbench 2016.11, 3D Slicer 4.8.1 and InVesalius 3.1 were used to reconstruct the 3D skull models from the same subjects. All four software went through similar steps in 3D reconstruction process. The 3D skull models from the commercial and open-source software were exported in standard tessellation language (STL) format into CloudCompare v2.8 software and superimposed for geometric analyses. Hausdorff distance (HD) analysis demonstrated the average points distance of Mimics versus MITK was 0.25 mm. Meanwhile, for Mimics versus 3D Slicer and Mimics versus InVesalius, there was almost no differences between the two superimposed 3D skull models with average points distance of 0.01 mm. Based on Dice similarity coefficient (DSC) analysis, the similarity between Mimics versus MITK, Mimics versus 3D Slicer and Mimics versus InVesalius were 94.1, 98.8 and 98.3%, respectively. In conclusion, this study confirmed that the alternative open-source software, MITK, 3D Slicer and InVesalius gave comparable results in 3D reconstruction of skull models compared to the commercial gold standard Mimics software. This open-source software could possibly be used for pre-operative planning in cranio-maxillofacial cases and for patient management in the hospitals or institutions with limited budget.

Shape-based interpolation method in measuring intracranial volume for pre- and post-operative decompressive craniectomy using open source software / Método de interpolación basado en formas para medir el volumen intracraneal en craneotomía descompresiva pre y postoperatoria utilizando un software de código abierto

Introduction: Intracranial volume (ICV) is an important tool in the management of patients undergoing decompressive craniectomy (DC) surgery. The aim of this study was to validate ICV measurement applying the shape-based interpolation (SBI) method using open source software on computed tomography (CT) images. Methods: The pre- and post-operative CT images of 55 patients undergoing DC surgery were analyzed. The ICV was measured by segmenting every slice of the CT images, and compared with estimated ICV calculated using the 1-in-10 sampling strategy and processed using the SBI method. An independent t test was conducted to compare the ICV measurements between the two different methods. The calculation using this method was repeated three times for reliability analysis using the intraclass correlations coefficient (ICC). The Bland-Altman plot was used to measure agreement between the methods for both pre- and post-operative ICV measurements. Results: The mean ICV (±SD) were 1341.1±122.1ml (manual) and 1344.11±122.6ml (SBI) for the preoperative CT data. The mean ICV (±SD) were 1396.4±132.4ml (manual) and 1400.53±132.1ml (SBI) for the post-operative CT data. No significant difference was found in ICV measurements using the manual and the SBI methods (p=.983 for pre-op, and p=.960 for post-op). The intrarater ICC showed a significant correlation; ICC=1.00. The Bland-Altman plot showed good agreement between the manual and the SBI method. Conclusion: The shape-based interpolation method with 1-in-10 sampling strategy gave comparable results in estimating ICV compared to manual segmentation. Thus, this method could be used in clinical settings for rapid, reliable and repeatable ICV estimations

Introducción: El volumen intracraneal (ICV) constituye una importante herramienta para el tratamiento de los pacientes sometidos a craneotomía descompresiva (CD). El objetivo de este estudio fue validar la medición del ICV aplicando el método de interpolación basado en formas (SBI), utilizando software de código abierto en las imágenes de tomografía computarizada (TC). Métodos: Se analizaron las imágenes pre- y postoperatorias de TC de 55 pacientes sometidos a CD. Se midió el ICV segmentando cada corte de las imágenes de TC, comparándose con el ICV estimado calculado utilizando la estrategia de muestreo 1 de 10, y procesándose mediante el método SBI. Se realizó una prueba t independiente para comparar las mediciones de ICV entre los 2 métodos. Se repitió 3 veces el cálculo con este método, para realizar el análisis de fiabilidad, utilizando el coeficiente de correlación intra-clase (ICC). Se utilizó el gráfico de Bland-Altman para medir el acuerdo entre ambos métodos, para las mediciones de ICV pre- y postoperatorias. Resultados: El ICV medio (±DE) fue de 1.341,1ml±122,1 (manual) y 1.344,11ml±122,6 (SBI) para los datos de la TC preoperatoria. El ICV medio (±DE) fue de 1.396,4ml±132,4 (manual) y 1.400,53ml±132,1 (SBI) para los datos de la TC postoperatoria. No se encontró diferencia significativa en cuanto a las mediciones de ICV utilizando los métodos manual y SBI (p=0,983 para preoperatoria, p=0,960 para postoperatoria). El ICC intra-evaluador reflejó una correlación significativa; ICC=1. El gráfico de Bland-Altman reflejó un buen acuerdo entre el método manual y el método SBI. Conclusión: El método de interpolación basado en formas con estrategia de muestreo 1 de 10 proporcionó resultados comparables a la hora de calcular el ICV, en comparación con la segmentación manual. Por tanto, este método podría utilizarse en el entorno clínico para realizar estimaciones del ICV rápidas, fidedignas y repetibles

Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology.

Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO2) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO2 sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO2-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO2 exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.

3D CT Imaging for Craniofacial Analysis Based on Anatomical Regions.

The development of a craniofacial database is a multidisciplinary initiative that will provide an important reference for community, security, social and medical applications. A method of landmark identifications and measurements in 3d on craniofacial patients is described. anatomical regions such as mandible, orbits, zygoma and maxilla are located, created and stored as templates of 3D CAD files for subsequent analysis. Data from these images were tested for accuracy and repeatability by comparing with direct measurements using caliper and CMM. The landmark points are reproducible in CAD system for further analysis. it was found that the approach provides a fast, accurate and efficient method for landmarks identification of the craniofacial areas in database development.