CT–MR image data fusion for computer-assisted navigated surgery of orbital tumors

Nemec, Stefan Franz; Peloschek, Philipp; Schmook, Maria Theresa; Krestan, Christian Robert; Hauff, Wolfgang; Matula, Christian; Czerny, Christian

doi:10.1016/j.ejrad.2008.11.003

« Previous Next »European Journal of Radiology
Volume 73, Issue 2 , Pages 224-229, February 2010

CT–MR image data fusion for computer-assisted navigated surgery of orbital tumors

Stefan Franz Nemec
- Department of Radiology/Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria
- Corresponding author. Tel.: +43 1404007609; fax: +43 1404003777.
Philipp Peloschek
- Department of Radiology/Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria
Maria Theresa Schmook
- Department of Radiology/Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria
Christian Robert Krestan
- Department of Radiology/Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria
Wolfgang Hauff
- Department of Ophthalmology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria
Christian Matula
- Department of Neurosurgery, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria
Christian Czerny
- Department of Radiology/Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria

Received 27 October 2008; received in revised form 2 November 2008; accepted 5 November 2008.

Abstract

Purpose

To demonstrate the value of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative assessment of orbital tumors, and to present, particularly, CT and MR image data fusion for surgical planning and performance in computer-assisted navigated surgery of orbital tumors.

Materials and methods

In this retrospective case series, 10 patients with orbital tumors and associated complaints underwent MDCT and MRI of the orbit. MDCT was performed at high resolution, with a bone window level setting in the axial plane. MRI was performed with an axial 3D T1-weighted (w) gradient-echo (GE) contrast-enhanced sequence, in addition to a standard MRI protocol. First, MDCT and MR images were used to diagnose tumorous lesions compared to histology as a standard of reference. Then, the image data sets from CT and 3D T1-w GE sequences were merged on a workstation to create CT–MR fusion images that were used for interventional planning and intraoperative image guidance. The intraoperative accuracy of the navigation unit was measured, defined as the deviation between the same landmark in the navigation image and the patient. Furthermore, the clinical preoperative status was compared to the patients’ postoperative outcome.

Results

Radiological and histological diagnosis, which revealed 7 benign and 3 malignant tumors, were concordant in 7 of 10 cases (70%). The CT–MR fusion images supported the surgeon in the preoperative planning and improved the surgical performance. The mean intraoperative accuracy of the navigation unit was 1.35mm. Postoperatively, orbital complaints showed complete regression in 6 cases, were ameliorated notably in 3 cases, and remained unchanged in 1 case.

Conclusion

CT and MRI are essential for the preoperative assessment of orbital tumors. CT–MR image data fusion is an accurate tool for planning the correct surgical procedure, and can improve surgical results in computer-assisted navigated surgery of orbital tumors.

Keywords: Computed tomography, Magnetic resonance imaging, Image fusion, Neuronavigation, Orbital tumors