Made available in DSpace on 2015-04-14T13:30:29Z (GMT). No. of bitstreams: 1
452798.pdf: 11258762 bytes, checksum: 1779e23c337cdf8d461b246e5a82e0c5 (MD5)
Previous issue date: 2013-03-07 / Introduction : this thesis aimed to evaluate the software accuracy for 3D analysis of craniofacial complex in cone beam computed tomography (CBCT). With this purpose, two studies were performed. The first study evaluated the precision and accuracy of 6 imaging software programs for measuring the upper airway volume in CBCT. The second study aimed to validate a fast method for 3D superimposition of CBCT. Methods : in study 1, the sample consisted of 33 growing patients and 1 oropharynx acrylic phantom (OAP), scanned with iCAT scanner. The known OAP volume was used as gold standard (GS). Semi-automatic segmentations of the patients? oropharynx (OP) and OAP was performed using Mimics, ITK-Snap, OsiriX, Dolphin3D, InVivo Dental and Ondemand3D software programs. In study 2, the sample consisted of CBCT scans of 18 patients. For 10 patients as a gold standard, the spatial position of the pretreatment CBCT volume was reoriented, saved as a reoriented volume, and then superimposed to the original image. For 8 patients, 4 non-growing and 4 growing patients, pre and post-treatment scans were superimposed. Superimposition accuracy was assessed by visual inspection and measured by using the CMF application and expressed via color maps. Results : in study 1, the OAP segmentations with Mimics, Dolphin3D, OsiriX and ITK-Snap showed less than 2% error in volume compared to the GS. Ondemand3D and InVivo Dental showed more than 5% error compared to the GS. In the OP segmentation, ITK-Snap, Mimics, OsiriX and Dolphin3D were statistically significantly different (P<.05) from InVivo Dental. No statistical difference (P>.05) was found between InVivo Dental and OnDemand3D. In study 2, Superimposition error of the spatial reorientation as measured by the color-coded surface distances was less than 0.5mm. Superimposition error of pre and post treatment scans for both growing and non-growing patients at the cranial base were smaller than 0.5 mm, which was considered acceptable and clinically insignificant. Conclusion : in study 1, all 6 imaging software programs were reliable but showed errors in the volume segmentation of OP. Mimics, Dolphin3D, ITK-Snap and OsiriX were similar and more accurate than InVivo Dental and Ondemand3D. In study 2, the voxel-based superimposition method evaluated was reproducible in different clinical conditions, time-efficient and potentially applicable for both research and clinical practice. / Introdu??o : o objetivo desta tese foi avaliar a acur?cia de programas para an?lises 3D do complexo maxilofacial em tomografia computadorizada cone beam (TCCB). Com esse prop?sito, dois estudos foram realizados. O primeiro estudo avaliou a precis?o e acur?cia de 6 programas para avalia??o do volume da via a?rea superior em TCCB. O segundo estudo objetivou validar um m?todo r?pido de superposi??o 3D de TCCB. M?todo : no estudo 1, a amostra consistiu de 33 pacientes e 1 Phantom de acr?lico da orofaringe (PAO), escaneados com o tom?grafo iCAT. O volume conhecido do PAO foi utilizado com padr?o ouro. Segmenta??o semiautom?tica da orofaringe dos pacientes (OP) e do PAO foi realizada com os programas Mimics, ITK-Snap, OsiriX, Dolphin3D, InVivo Dental e Ondemand3D. No estudo 2, a amostra consistiu de TCCB de 18 pacientes. Em 10 pacientes, como padr?o de compara??o, a TCCB pr?-tratamento foi reorientada espacialmente, salva como TCCB reorientada, e ent?o superposta na imagem original. Em 8 pacientes, sendo 4 sem crescimento e 4 em crescimento, foram superpostas as TCCB e p?s-tratamento. A acur?cia da superposi??o foi avaliada atrav?s de inspe??o visual e mensurada atrav?s do programa CFM com mapas coloridos. Resultados : no estudo 1, as segmenta??es com o Mimics, Dolphin3D, OsiriX e ITK-Snap mostraram menos de 2% de erro no volume do PAO em compara??o ao padr?o ouro. O Ondemand3D e o InVivo Dental apresentaram mais de 5% de erro no volume do PAO em compara??o ao padr?o ouro. As segmenta??es da OP com o ITK-Snap, Mimics, OsiriX e Dolphin3D foram estatisticamente diferentes (P<.05) em compara??o ao InVivo Dental. N?o houve diferen?a estatisticamente significante (P>.05) entre os programas InVivo Dental e o OnDemand3D. No estudo 2, o erro da superposi??o das TCCB reorientadas, medidas atrav?s dos mapas coloridos foi menor que 0,5mm. O erro da superposi??o das TCCB pr?-tratamento e p?s-tratamento para pacientes com e sem crescimento, na regi?o da base do cr?nio, foi menor que 0,5 mm e considerado aceit?vel e clinicamente insignificante. Conclus?o : no estudo 1, todos os 6 programas foram precisos, mas apresentaram erros no volume da segmenta??o da OP. Mimics, Dolphin3D, ITK-Snap e OsiriX foram considerados similares e mais acurados em compara??o ao InVivo Dental e Ondemand3D. No estudo 2, o m?todo de superposi??o baseado em voxel avaliado foi reproduz?vel em diferentes condi??es cl?nicas, r?pido e potencialmente aplic?vel para pesquisa e pr?tica cl?nica.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/1229 |
| Date | 07 March 2013 |
| Creators | Weissheimer, Andr? |
| Contributors | Menezes, Luciane Macedo de |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Odontologia, PUCRS, BR, Faculdade de Odontologia |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -8096554818733665164, 500, 600, 4673435736271820140 |
Page generated in 0.0022 seconds