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Ossama Almefty - One of the best experts on this subject based on the ideXlab platform.
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multimodal navigated Skull Base Tumor resection using image Based vascular and cranial nerve segmentation a prospective pilot study
Surgical Neurology International, 2015Co-Authors: Parviz Dolati, Abdulkerim Gokoglu, Daniel Eichberg, Amir A Zamani, Alexandra J Golby, Ossama AlmeftyAbstract:Skull Base Tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal Tumor resection with incomplete knowledge of patient anatomy remains a challenge.To determine the accuracy and utility of image-Based preoperative segmentation in Skull Base Tumor resections, we performed a prospective study. Ten patients with Skull Base Tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured.Strong correspondence between image-Based segmentation and microscopic view was found at the surface of the Tumor and Tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases.Image-Based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during Skull Base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.
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ni 17multimodal navigated Skull Base Tumor resection using image Based vascular and cranial nerve segmentation a prospective validation study
Neuro-oncology, 2014Co-Authors: Parviz Dolati, Abdulkerim Gokoglu, Alexandra J Golby, Ossama AlmeftyAbstract:INTRODUCTION: Skull Base Tumors frequently encase or invade adjacent normal neural and vascular structures. Preoperative segmentation and planning to identify these anatomical landmarks are essentially important in complex Skull Base Tumor resection for minimizing surgical morbidities. METHODS: Ten patients with Skull Base Tumors underwent preoperative 3TMRI, which included thin sectioned 3D space T2, 3D Time of Flight and MPRAGE sequences. Images were reviewed by an expert independent neuroradiologist. Imaging sequences were loaded in BrainLab iPlanNet (8/10) and Stryker (2/10) for segmentation and pre-operative planning. After patient registration to the intra-op neuronavigation system and surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe. RESULTS: Perfect correspondence between image-Based segmentation and microscopic view was found at the surface of the Tumor and Tumor-normal brain interfaces in all cases. Pre-operative segmentation of the major arteries, veins, and venous sinuses matched with the intra-operative microscopic findings in all cases (Dice-coefficient =1). This information reassured the surgeon and prevented vascular tearing during different stages of Tumor resection. This also helped in preventing major intra-operative arterial or venous bleeding. Preoperative segmentation of the related cranial nerves was technically possible in only 80% of cases. However, Image-guidance helped the surgeon to localize the involved cranial nerves in all cases. CONCLUSION: Image-Based pre-operative vascular and neural element segmentation, especially with 3D reconstruction, is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing vascular and neural injury during Skull Base surgeries. This novel preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients.
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Skull Base Tumor model
Journal of Neurosurgery, 2010Co-Authors: Cristian Gragnaniello, Remi Nader, Tristan P C Van Doormaal, Mahmoud Kamel, Eduard H J Voormolen, Giovanni Lasio, Emad Aboud, Luca Regli, C A F Tulleken, Ossama AlmeftyAbstract:Object Resident duty-hours restrictions have now been instituted in many countries worldwide. Shortened training times and increased public scrutiny of surgical competency have led to a move away from the traditional apprenticeship model of training. The development of educational models for brain anatomy is a fascinating innovation allowing neurosurgeons to train without the need to practice on real patients and it may be a solution to achieve competency within a shortened training period. The authors describe the use of Stratathane resin ST-504 polymer (SRSP), which is inserted at different intracranial locations to closely mimic meningiomas and other pathological entities of the Skull Base, in a cadaveric model, for use in neurosurgical training. Methods Silicone-injected and pressurized cadaveric heads were used for studying the SRSP model. The SRSP presents unique intrinsic metamorphic characteristics: liquid at first, it expands and foams when injected into the desired area of the brain, forming a s...
Parviz Dolati - One of the best experts on this subject based on the ideXlab platform.
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multimodal navigated Skull Base Tumor resection using image Based vascular and cranial nerve segmentation a prospective pilot study
Surgical Neurology International, 2015Co-Authors: Parviz Dolati, Abdulkerim Gokoglu, Daniel Eichberg, Amir A Zamani, Alexandra J Golby, Ossama AlmeftyAbstract:Skull Base Tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal Tumor resection with incomplete knowledge of patient anatomy remains a challenge.To determine the accuracy and utility of image-Based preoperative segmentation in Skull Base Tumor resections, we performed a prospective study. Ten patients with Skull Base Tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured.Strong correspondence between image-Based segmentation and microscopic view was found at the surface of the Tumor and Tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases.Image-Based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during Skull Base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.
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ni 17multimodal navigated Skull Base Tumor resection using image Based vascular and cranial nerve segmentation a prospective validation study
Neuro-oncology, 2014Co-Authors: Parviz Dolati, Abdulkerim Gokoglu, Alexandra J Golby, Ossama AlmeftyAbstract:INTRODUCTION: Skull Base Tumors frequently encase or invade adjacent normal neural and vascular structures. Preoperative segmentation and planning to identify these anatomical landmarks are essentially important in complex Skull Base Tumor resection for minimizing surgical morbidities. METHODS: Ten patients with Skull Base Tumors underwent preoperative 3TMRI, which included thin sectioned 3D space T2, 3D Time of Flight and MPRAGE sequences. Images were reviewed by an expert independent neuroradiologist. Imaging sequences were loaded in BrainLab iPlanNet (8/10) and Stryker (2/10) for segmentation and pre-operative planning. After patient registration to the intra-op neuronavigation system and surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe. RESULTS: Perfect correspondence between image-Based segmentation and microscopic view was found at the surface of the Tumor and Tumor-normal brain interfaces in all cases. Pre-operative segmentation of the major arteries, veins, and venous sinuses matched with the intra-operative microscopic findings in all cases (Dice-coefficient =1). This information reassured the surgeon and prevented vascular tearing during different stages of Tumor resection. This also helped in preventing major intra-operative arterial or venous bleeding. Preoperative segmentation of the related cranial nerves was technically possible in only 80% of cases. However, Image-guidance helped the surgeon to localize the involved cranial nerves in all cases. CONCLUSION: Image-Based pre-operative vascular and neural element segmentation, especially with 3D reconstruction, is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing vascular and neural injury during Skull Base surgeries. This novel preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients.
Dan M Fliss - One of the best experts on this subject based on the ideXlab platform.
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comparison of quality of life after transnasal endoscopic vs open Skull Base Tumor resection
Archives of Otolaryngology-head & Neck Surgery, 2012Co-Authors: Avraham Abergel, Oren Cavel, Nevo Margalit, Dan M FlissAbstract:Objective To evaluate the impact of the open and endoscopic Skull Base surgery performed by the same team on patients' quality of life. Design Retrospective survey. Setting University-affiliated medical center. Patients The study included 78 patients who underwent surgery for removal of Skull Base neoplasms through an expanded endoscopic (n = 41) or a subcranial (n = 37) approach. Main Outcome Measure A multidimensional, disease-specific questionnaire with 36 items was used. Six relevant domains of QOL were assessed: role of performance, physical functioning, vitality, pain, specific symptoms, and impact on emotions. Results There were no significant clinical or demographic differences between the 2 study groups (P >> .06). Univariate and multivariate analyses showed that patients who underwent endoscopic surgery reported significantly better scores in the physical function and impact on emotions domains than the patients who underwent subcranial surgery (P Conclusion In certain domains, quality of life after endoscopic Skull Base surgery appears to be better than that after open approaches.
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pericranial wrapping of the frontal bone after anterior Skull Base Tumor resection
Plastic and Reconstructive Surgery, 2005Co-Authors: Dan M FlissAbstract:Background: Classic craniofacial resection and the subcranial approach are well-established techniques for the removal of Tumors involving the anterior Skull Base. These techniques require frontal craniotomy to allow broad exposure of the anterior cranial fossa, a procedure that may be further complicated by local infection and osteomyelitis or because of a reduction in tissue perfusion and direct communication between the osteotomy and the contaminated nasoethmoidal cavity. The authors present a new method for wrapping of the frontal bone segment with a pericranial flap with the intention of preventing these serious complications. Methods: By means of this new approach, the frontonaso-orbital bone segment is removed, the frontal sinus bone is cranialized, and the frontonaso-orbital segment is repositioned in its original anatomical place following Tumor extirpation. Wrapping is accomplished by a double-sided covering of the bone segment with the pericranial flap. This vascularized tissue is guided underneath the bony segment to cover the intranasal surface and then is externalized over the entire frontal area. The frontonaso-orbital segment and its overlying pericranial flap are fixed with the prebent titanium plates. Results: To date, the authors have performed 20 subcranial operations for resection of malignant Tumors of the anterior Skull Base using this technique. None of these patients developed bone flap necrosis or osteomyelitis following radiotherapy. In the authors' hands, the rate of osteoradionecrosis was significantly lower in patients undergoing malignant subcranial Tumor resection with pericranial wrapping than in those operated on before the study was activated (0 percent versus 20 percent, respectively; p = 0.056). Conclusions: Pericranial wrapping is suitable for patients undergoing extirpation of anterior Skull Base Tumors and for whom perioperative radiotherapy is recommended and for patients who have undergone multiple surgical procedures.
Jeffrey H. Siewerdsen - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a system for high accuracy 3d image Based registration of endoscopic video to c arm cone beam ct for image guided Skull Base surgery
IEEE Transactions on Medical Imaging, 2013Co-Authors: Daniel J. Mirota, Ali Uneri, Sebastian Schafer, Sajendra Nithiananthan, Masaru Ishii, Gary L. Gallia, Russell H. Taylor, Gregory D. Hager, Douglas D Reh, Jeffrey H. SiewerdsenAbstract:The safety of endoscopic Skull Base surgery can be enhanced by accurate navigation in preoperative computed tomography (CT) or, more recently, intraoperative cone-beam CT (CBCT). The ability to register real-time endoscopic video with CBCT offers an additional advantage by rendering information directly within the visual scene to account for intraoperative anatomical change. However, tracker localization error (~1-2 mm ) limits the accuracy with which video and tomographic images can be registered. This paper reports the first implementation of image-Based video-CBCT registration, conducts a detailed quantitation of the dependence of registration accuracy on system parameters, and demonstrates improvement in registration accuracy achieved by the image-Based approach. Performance was evaluated as a function of parameters intrinsic to the image-Based approach, including system geometry, CBCT image quality, and computational runtime. Overall system performance was evaluated in a cadaver study simulating transsphenoidal Skull Base Tumor excision. Results demonstrated significant improvement (p <; 0.001) in registration accuracy with a mean reprojection distance error of 1.28 mm for the image-Based approach versus 1.82 mm for the conventional tracker-Based method. Image-Based registration was highly robust against CBCT image quality factors of noise and resolution, permitting integration with low-dose intraoperative CBCT.
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Evaluation of a System for High-Accuracy 3D Image-Based Registration of Endoscopic Video to C-Arm Cone-Beam CT for Image-Guided Skull Base Surgery
IEEE Transactions on Medical Imaging, 2013Co-Authors: Daniel J. Mirota, Ali Uneri, Sebastian Schafer, Sajendra Nithiananthan, Masaru Ishii, Gary L. Gallia, Russell H. Taylor, Gregory D. Hager, Jeffrey H. SiewerdsenAbstract:The safety of endoscopic Skull Base surgery can be enhanced by accurate navigation in preoperative computed tomography (CT) or, more recently, intraoperative cone-beam CT (CBCT). The ability to register real-time endoscopic video with CBCT offers an additional advantage by rendering information directly within the visual scene to account for intraoperative anatomical change. However, tracker localization error (~1-2 mm ) limits the accuracy with which video and tomographic images can be registered. This paper reports the first implementation of image-Based video-CBCT registration, conducts a detailed quantitation of the dependence of registration accuracy on system parameters, and demonstrates improvement in registration accuracy achieved by the image-Based approach. Performance was evaluated as a function of parameters intrinsic to the image-Based approach, including system geometry, CBCT image quality, and computational runtime. Overall system performance was evaluated in a cadaver study simulating transsphenoidal Skull Base Tumor excision. Results demonstrated significant improvement (p
Abdulkerim Gokoglu - One of the best experts on this subject based on the ideXlab platform.
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multimodal navigated Skull Base Tumor resection using image Based vascular and cranial nerve segmentation a prospective pilot study
Surgical Neurology International, 2015Co-Authors: Parviz Dolati, Abdulkerim Gokoglu, Daniel Eichberg, Amir A Zamani, Alexandra J Golby, Ossama AlmeftyAbstract:Skull Base Tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal Tumor resection with incomplete knowledge of patient anatomy remains a challenge.To determine the accuracy and utility of image-Based preoperative segmentation in Skull Base Tumor resections, we performed a prospective study. Ten patients with Skull Base Tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured.Strong correspondence between image-Based segmentation and microscopic view was found at the surface of the Tumor and Tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases.Image-Based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during Skull Base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.
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ni 17multimodal navigated Skull Base Tumor resection using image Based vascular and cranial nerve segmentation a prospective validation study
Neuro-oncology, 2014Co-Authors: Parviz Dolati, Abdulkerim Gokoglu, Alexandra J Golby, Ossama AlmeftyAbstract:INTRODUCTION: Skull Base Tumors frequently encase or invade adjacent normal neural and vascular structures. Preoperative segmentation and planning to identify these anatomical landmarks are essentially important in complex Skull Base Tumor resection for minimizing surgical morbidities. METHODS: Ten patients with Skull Base Tumors underwent preoperative 3TMRI, which included thin sectioned 3D space T2, 3D Time of Flight and MPRAGE sequences. Images were reviewed by an expert independent neuroradiologist. Imaging sequences were loaded in BrainLab iPlanNet (8/10) and Stryker (2/10) for segmentation and pre-operative planning. After patient registration to the intra-op neuronavigation system and surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe. RESULTS: Perfect correspondence between image-Based segmentation and microscopic view was found at the surface of the Tumor and Tumor-normal brain interfaces in all cases. Pre-operative segmentation of the major arteries, veins, and venous sinuses matched with the intra-operative microscopic findings in all cases (Dice-coefficient =1). This information reassured the surgeon and prevented vascular tearing during different stages of Tumor resection. This also helped in preventing major intra-operative arterial or venous bleeding. Preoperative segmentation of the related cranial nerves was technically possible in only 80% of cases. However, Image-guidance helped the surgeon to localize the involved cranial nerves in all cases. CONCLUSION: Image-Based pre-operative vascular and neural element segmentation, especially with 3D reconstruction, is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing vascular and neural injury during Skull Base surgeries. This novel preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients.