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O.176 Digital Volume Tomography: Experience after 1081 examinations
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Journal of Cranio-Maxillofacial Surgery 34(2006) Suppl. S1
evaluation, 100 conventional orthopantomogram images obtained with a digital panoramic X-ray device were compared with the CB panoramic reconstruction. Additionally, 30 CT scans of the maxillofacial area were compared with images obtained with the CB device. The effective radiation dose of a CB study was about four times as large as in a digital panoramic X-ray scan. The spatial accuracy measurements revealed no significant differences between real distances and the distances measured on CB scans. The clinical investigation showed a superior diagnostic value of the CB panoramic image compared to the conventional panoramic X-ray examination using the possibilities of the integrated software. The comparison with CT scans showed that the CB device can be considered as equivalent for detection of bony lesions in the maxillofacial area. The results show that the newly developed CB device can be recommended for general use in maxillofacial radiology. The diagnostic value for detection of bony lesions can be compared to that of a CT examination with the benefit of better resolution and just a fraction of radiation exposure. O.175 Computer-assisted treatment of oral and maxillofacial tumours C. Eulzer, N.-C. Gellrich, A. Schramm. Department of Oral & Maxillofacial Surgery, Medical School Hanover, Germany Surgical treatment of patients with oral and oropharyngeal cancer needs detailed pre-operative planning using computed tomography or magnetic resonance imaging to show extension of the tumour, define intended safety resection margins and point out vital structures. Furthermore, hard tissue reconstruction following tumour resection needs reliable information also to choose correct type and volume of grafts and to predict the outcome. Recent advances in both computer hardware and software technology achieve three-dimensional analysis of anatomical position and extension of the neoplasm and virtual planning of surgical procedures. Based on CT or MRI data sets navigation systems can be used for pre-operative planning, intraoperative navigation and post-operative controlling of resection and reconstruction. Furthermore, computer-based virtual three-dimensional simulation methods for surgical procedures that are based on imaging data assist the necessary visual understanding of complex pathological situations and provide the ability to perform ‘virtual surgery’ preoperatively. We present our experience with computer-assisted treatment in oral and oropharyngeal cancer: Navigation systems offer better anatomical orientation in biopsies of orbital or skull base tumours. Furthermore, pre-operatively outlined safety margins can be exactly controlled during tumour resection. Computerassisted planning and surgery can also be very helpful in primary reconstruction after tumour resection. By mirroring and superimposing the unaffected over the affected side an ideal virtual template for navigation-controlled reconstruction can be achieved. Furthermore, image-fusion of CT-scans before and after radio-chemotherapy enables a better assessment of changes in tumour volume. O.176 Digital Volume Tomography: Experience after 1081 examinations A. Dini1 , N. Sakkas2 , N.-C. Gellrich1 , A. Schramm1 . 1 Klinik und Poliklinik f¨ur Mund-, Kiefer- und Gesichtschirurgie, Medizinische Hochschule Hannover, Germany; 2 Klinik und Poliklinik f¨ur
Abstracts, EACFMS XVIII Congress Mund-, Kiefer- und Gesichtschirurgie, Universit¨atsklinikum Freiburg, Germany Cone beam computer tomography or digital volume tomography (DVT) is a new imaging acquisition technique used in the maxillofacial area. The patients head is placed between an X-ray generator and an X-ray detector which rotate around the patients head. Three hundred and sixty bidimensional addition images are taken and processed with special software. Axial images are generated to allow reconstruction of multiplanar and 3D images. The radiation dose equals: 16 periapical X-rays, 4 panoramic X-rays, or 25% of a Dental CT. DVT is used for planning of implants insertion, sinus lift procedures and impacted wisdom teeth extractions, also used in trauma, for computer-assisted surgery, and in bone, maxillary sinus and TMJ pathology. We performed: 556 implant insertion planning, 146 trauma, 24 computer-assisted surgery, 154 wisdom teeth extraction planning, 101 bone pathology, 48 maxillary sinus and 52 TMJ examinations. The advantages of DVT compared to Dental CT are: similar image quality by lower radiation, less metallic artefacts, in Germany dentists are allowed to do this examination without special CT radiological qualification, and also the lower cost. The disadvantage compared to CT is that soft tissue cannot be demonstrated. A series of cases will be presented to demonstrate the value of the DVT usage in the maxillofacial area. O.177 Bone pathologies visualized by 3D flat-panel volume CT in a preclinical trial P.H. Streckbein1 , H. Schaaf1 , M. Obert2 , H.-P. Howaldt1 . 1 Department of Cranio-Maxillo-Facial Surgery, 2 Department of Neuroradiology, University of Giessen, Germany Introduction: The new experimental flat panel volume computed tomography (fpvCT) facilitates three-dimensional imaging with highest resolution. X-rays are thereby being detected by dual flat panels. So far there are only three prototypes of the fpvCT (General Electric) in experimental use worldwide which have demonstrated the possibility to visualize bonegrowth in mice. The progress in growth and vascularization of squamous cell carcinomas was visualized by micro-angiographic techniques. The image resolution is much higher compared to the CTs commonly used in clinical settings and reaches up to 60–100 mm in the bone window. The scope of this trial is to use this high-definition method to visualize and analyse craniofacial bone pathologies. Material and Methods: In this study 21 osseous resection specimen of different bone pathologies were scanned by the fpvCT. Included were osteomas, ameloblastomas, ossificated fibromas, osteomyelitis, adenoidcystic carcinomas, squamous cell carcinomas and craniosynostosis. Results: Growth pattern and infiltrative structures of the most frequent bone pathologies are visualized three-dimentionally in high-resolution quality which significantly exceeds all other imaging techniques like CT or MRI. Conclusion: The fpvCT has a definite potential in future preoperative tumor diagnostics and allows reliable valuation of the osseous resection border instead of using histological instantaneous section which is known to be technically impossible. Once this technique is approved for the use in humans there will be additional applications which one day will possibly replace bone biopsies of difficult access regions such as the skullbase.
Journal of Cranio-Maxillofacial Surgery 34(2006) Suppl. S1
evaluation, 100 conventional orthopantomogram images obtained with a digital panoramic X-ray device were compared with the CB panoramic reconstruction. Additionally, 30 CT scans of the maxillofacial area were compared with images obtained with the CB device. The effective radiation dose of a CB study was about four times as large as in a digital panoramic X-ray scan. The spatial accuracy measurements revealed no significant differences between real distances and the distances measured on CB scans. The clinical investigation showed a superior diagnostic value of the CB panoramic image compared to the conventional panoramic X-ray examination using the possibilities of the integrated software. The comparison with CT scans showed that the CB device can be considered as equivalent for detection of bony lesions in the maxillofacial area. The results show that the newly developed CB device can be recommended for general use in maxillofacial radiology. The diagnostic value for detection of bony lesions can be compared to that of a CT examination with the benefit of better resolution and just a fraction of radiation exposure. O.175 Computer-assisted treatment of oral and maxillofacial tumours C. Eulzer, N.-C. Gellrich, A. Schramm. Department of Oral & Maxillofacial Surgery, Medical School Hanover, Germany Surgical treatment of patients with oral and oropharyngeal cancer needs detailed pre-operative planning using computed tomography or magnetic resonance imaging to show extension of the tumour, define intended safety resection margins and point out vital structures. Furthermore, hard tissue reconstruction following tumour resection needs reliable information also to choose correct type and volume of grafts and to predict the outcome. Recent advances in both computer hardware and software technology achieve three-dimensional analysis of anatomical position and extension of the neoplasm and virtual planning of surgical procedures. Based on CT or MRI data sets navigation systems can be used for pre-operative planning, intraoperative navigation and post-operative controlling of resection and reconstruction. Furthermore, computer-based virtual three-dimensional simulation methods for surgical procedures that are based on imaging data assist the necessary visual understanding of complex pathological situations and provide the ability to perform ‘virtual surgery’ preoperatively. We present our experience with computer-assisted treatment in oral and oropharyngeal cancer: Navigation systems offer better anatomical orientation in biopsies of orbital or skull base tumours. Furthermore, pre-operatively outlined safety margins can be exactly controlled during tumour resection. Computerassisted planning and surgery can also be very helpful in primary reconstruction after tumour resection. By mirroring and superimposing the unaffected over the affected side an ideal virtual template for navigation-controlled reconstruction can be achieved. Furthermore, image-fusion of CT-scans before and after radio-chemotherapy enables a better assessment of changes in tumour volume. O.176 Digital Volume Tomography: Experience after 1081 examinations A. Dini1 , N. Sakkas2 , N.-C. Gellrich1 , A. Schramm1 . 1 Klinik und Poliklinik f¨ur Mund-, Kiefer- und Gesichtschirurgie, Medizinische Hochschule Hannover, Germany; 2 Klinik und Poliklinik f¨ur
Abstracts, EACFMS XVIII Congress Mund-, Kiefer- und Gesichtschirurgie, Universit¨atsklinikum Freiburg, Germany Cone beam computer tomography or digital volume tomography (DVT) is a new imaging acquisition technique used in the maxillofacial area. The patients head is placed between an X-ray generator and an X-ray detector which rotate around the patients head. Three hundred and sixty bidimensional addition images are taken and processed with special software. Axial images are generated to allow reconstruction of multiplanar and 3D images. The radiation dose equals: 16 periapical X-rays, 4 panoramic X-rays, or 25% of a Dental CT. DVT is used for planning of implants insertion, sinus lift procedures and impacted wisdom teeth extractions, also used in trauma, for computer-assisted surgery, and in bone, maxillary sinus and TMJ pathology. We performed: 556 implant insertion planning, 146 trauma, 24 computer-assisted surgery, 154 wisdom teeth extraction planning, 101 bone pathology, 48 maxillary sinus and 52 TMJ examinations. The advantages of DVT compared to Dental CT are: similar image quality by lower radiation, less metallic artefacts, in Germany dentists are allowed to do this examination without special CT radiological qualification, and also the lower cost. The disadvantage compared to CT is that soft tissue cannot be demonstrated. A series of cases will be presented to demonstrate the value of the DVT usage in the maxillofacial area. O.177 Bone pathologies visualized by 3D flat-panel volume CT in a preclinical trial P.H. Streckbein1 , H. Schaaf1 , M. Obert2 , H.-P. Howaldt1 . 1 Department of Cranio-Maxillo-Facial Surgery, 2 Department of Neuroradiology, University of Giessen, Germany Introduction: The new experimental flat panel volume computed tomography (fpvCT) facilitates three-dimensional imaging with highest resolution. X-rays are thereby being detected by dual flat panels. So far there are only three prototypes of the fpvCT (General Electric) in experimental use worldwide which have demonstrated the possibility to visualize bonegrowth in mice. The progress in growth and vascularization of squamous cell carcinomas was visualized by micro-angiographic techniques. The image resolution is much higher compared to the CTs commonly used in clinical settings and reaches up to 60–100 mm in the bone window. The scope of this trial is to use this high-definition method to visualize and analyse craniofacial bone pathologies. Material and Methods: In this study 21 osseous resection specimen of different bone pathologies were scanned by the fpvCT. Included were osteomas, ameloblastomas, ossificated fibromas, osteomyelitis, adenoidcystic carcinomas, squamous cell carcinomas and craniosynostosis. Results: Growth pattern and infiltrative structures of the most frequent bone pathologies are visualized three-dimentionally in high-resolution quality which significantly exceeds all other imaging techniques like CT or MRI. Conclusion: The fpvCT has a definite potential in future preoperative tumor diagnostics and allows reliable valuation of the osseous resection border instead of using histological instantaneous section which is known to be technically impossible. Once this technique is approved for the use in humans there will be additional applications which one day will possibly replace bone biopsies of difficult access regions such as the skullbase.