Modelos anatómicos personalizados impresos en 3D como herramientas para el aprendizaje y la preparación de intervenciones / Custom 3D printed anatomical models as tools for learning and preparation of Interventions / Modelos anatômicos personalizados impressos em 3D como ferramentas para aprendizagem e preparação de intervenções

Objetivo: presentar un método de desarrollo basado en dos casos de modelos anatómicos personalizados impresos en 3D, el\r\nprimero una arteria cerebral y el segundo una estructura ósea del húmero humano, a fin de ejemplificar el uso de herramientas\r\nde visualización tridimensionales para planificar intervenciones quirúrgicas. Método: se seleccionaron imágenes médicas de\r\ntomografías computarizadas o imágenes de resonancia magnética de pacientes anónimos y la sección específica del órgano se\r\nsegmentó con el software 3D Slicer. El modelo se convirtió en mallas poligonales en tres dimensiones, se optimizó y se imprimió\r\nen 3D. La morfología del órgano representada en el modelo anatómico se validó con especialistas para determinar si son oportunas\r\npara planificar procedimientos médicos. Resultados: diversos modelos anatómicos de los mismos casos se elaboraron en dos laboratorios de fabricación digital, uno en la Universidad El Bosque y otro en el FabLab Valencia, con diferentes variables en su\r\nproceso técnico y características, dada la dificultad de morfologías y delicadeza de las estructuras presentes en el cuerpo humano.\r\nConclusiones: con el método presentado sí es posible realizar modelos anatómicos personalizados en 3D para visualizar y simular\r\nestructuras anatómicas de pacientes útiles en la planeación de cirugías y la enseñanza de anatomía, que podrían mejorar el éxito\r\nen las intervenciones y el entrenamiento de profesionales en áreas de la salud.

Objective: To present a method of development based on\r\ntwo cases of custom anatomical models printed in 3D; the\r\nfirst one a cerebral artery and the second a bone structure\r\nof the human humerus, to exemplify the use of three-dimensional\r\nvisualization tools to perform planning of surgical\r\noperations. Method: It consisted of: a) Searching CT or MRI\r\nimages of anonymous patients, b) Segmenting with the 3D\r\nSlicer software the specific section of the organ, c) Converting\r\nthe model into polygonal meshes in three dimensions, d)\r\nOptimizing and printing in 3D, e) Validating with specialists\r\nthe organ morphology to determine if they are pertinent to\r\nplanning medical procedures. Results: Models were made in\r\ntwo different manufacturing laboratories; El Bosque University\r\nand FabLab in Valencia, with various anatomical models\r\nmanufactured of the same case with different variables in their\r\nprocess and characteristics given the difficulty of morphologies\r\nand delicacy of the structures present in the human body.\r\nConclusion: The method presented does provide useful results\r\nas an example for the planning of surgeries and anatomy\r\nteaching of anatomical structures in different scenarios that\r\ncould improve the success in interventions and the training of\r\nprofessionals in health areas.

Objetivo: apresentar um método de desenvolvimento de\r\nmodelos anatômicos personalizados em 3D para exemplificar\r\no uso de ferramentas de visualização para realizar planificação\r\nde operações cirúrgicas. Realizaram-se dois modelos como\r\nexemplo; o primeiro uma artéria cerebral e o segundo uma\r\nestrutura óssea do úmero humano. Método: o método de\r\ntrabalho consistiu em a) Buscar imagens médicas realizadas\r\ncom CT ou MRI de pacientes anônimos, b) Segmentar com o\r\nsoftware 3D Slicer a seção específica do órgão, c) Converter o\r\nmodelo em malhas poligonais em três dimensões, d) Otimizar\r\ne imprimir em 3D, e) Validar com especialistas a morfologia do\r\nórgão para determinar se são pertinentes para planejar procedimentos\r\nmédicos. Resultados: fabricou-se em dois laboratórios\r\nde fabricação diferentes, um na Universidad El Bosque e outro\r\nno FabLab Valencia, diversos modelos anatômicos do mesmo\r\ncaso com diferentes variáveis em seu processo e características\r\ndada a dificuldade de morfologias e delicadeza das estruturas\r\npresentes no corpo humano. Conclusão: o método apresentado\r\nproporciona resultados úteis para o planejamento de\r\ncirurgias e ensino de anatomia de estruturas anatômicas em\r\ndiferentes cenários que poderiam melhorar o êxito das intervenções\r\ne o treinamento de profissionais na área de saúde.

Application of MRI simulation in delineation of gross tumor volume in pre-operative radiotherapy for low rectal carcinoma / 中华放射医学与防护杂志

Objective To explore the value of MRI simulation in the pre-operative radiotherapy for locally advanced low rectal carcinoma.Methods A total of 40 patients diagnosed with locally advanced low rectal carcinoma by endoscopic biopsy and radiological staging examinations were included in this study.There were 22 male and 18 female with nedian age 58 years (range 31-80).Patients underwent CT and MRI simulation scanning in the same position and fixing device.GTV under CT images and MRI inages were delineated respectively by two experienced radiologists.Primary tumor length,tumor volume and distance of distal tumor from the anal verge were calculated by treatment planning system(TPS).The two groups of data were compared.Results The distance of distal tumor to the anal verge were all no more than 5 cm on digital examination.The mean length of GTVcT was remarkably longer than that of GTVMRI [(5.21 ±1.65) cm vs.(4.46 ± 1.51) cm,t =5.059,P ＜0.05].The mean volume of GTVcTWaS significantly larger than that of GTVMRI[(55.71 ±31.57) cm3vs.(44.02 ±25.11) cm3,t=6.977,P＜ 0.05)].The mean distance of distal tumor to the anal verge was (3.72 ± 0.93) cm,significantly longer than that of lower bounds of GTVCT to the anal verge,which had a high consistency with GTVMRI.The IMRT plan was based on CT-MRI fusion images.There were no 3-4 grade adverse effects of radiotherapy.The overall pCR rate was 32.5％.Conclusions MRI simulation could define smaller GTV and more precise lower bounds than CT.With improved accuracy of target volumes contours,the application of MRI simulation may promote the efficacy of radiotherapy and result in a reduction in the incidence of toxicities.