Original scientific paper
Virtual endoscopy and 3D volume rendering in the management of maxillary sinus cancer
Višeslav Ćuk
; Department of Otorhinolaryngology, General Hospital Zabok, Zabok, Croatia
Stanko Belina
; Department of Radiology, Special Hospital for Medical Rehabilitation, Krapinske Toplice, Croatia
Abstract
Objectives: To find out advantages and disadvantages of virtual endoscopy (VE) and 3D volume rendering (3DVR),
helical CT data postprocessing methods, that might be useful in diagnostics and preoperative management of maxillary sinus cancer.
Methods: High-resolution helical CT scan (HRCT) of paranasal sinuses (slice thicknes 1.2 and 0.6 mm) was performed in a 41-year-old female with cancer of the right maxillary sinus. Siemens Somatom Emotion 16 scanner was used for data collection. Acquired images were stored in DICOM format. Ray casting fly-through algorithm was applied as well as 3D In-space volume rendering. The processing was done using a professional 3D Syngo CT 2006G software package.
Results: During the post-processing of data we made virtual sinusoscopy, virtual rhinoscopy and 3DVR. Image analysis was performed by one radiologist, one ENT specialist and one maxillofacial surgeon. Fly-through of virtual endocamera within the maxillary sinus and nasal cavity was manually driven. Using a mouse pointing device, we interactively changed the camera 3D position and focus. We also controlled the field of view of the camera. We found that inside the sinus, cancer was located on the floor and posterior wall. The surface involved by cancer was uneven, thickened and elevated in comparison to areas covered by healthy sinus mucosa. 3DVR showed cancer advance through the eroded posterior maxillary sinus wall towards the retromaxillary space. Reconstructed virtual images were comparable with those obtained by classical sinusoscopy. CT showed destruction of the posterior wall of the maxillary sinus and further tumor advance to the retromaxillary space. Parts of the hard palate were also involved. There were no cancer spread to other parts of the body.
Conclusion: VE accompanied with 3D In space analysis has several advantages in comparison to classical endoscopy.
It is completely non-invasive. It is possible to repeat the same procedure hundreds of times, therefore it may be a valuable tool for training. Interactive control of all virtual camera parameters, including the field-of-view is possible. Endoscopic viewing as opposed to real endoscopy is not restricted to the spaces defined by inner surfaces. The viewer may penetrate the walls and see the extent of lesions within and beyond the wall. Finally, it has a potential to stage tumors by determining the location and the extent of transmural extension.
Keywords
high resolution computed tomography; virtual endoscopy; 3D volume rendering; maxillary sinus cancer
Hrčak ID:
280411
URI
Publication date:
22.11.2007.
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