CT-MR image data fusion for computer assisted navigated neurosurgery of temporal bone tumors.
OBJECTIVE
To demonstrate the value of multi detector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative work up of temporal bone tumors and to present, especially, CT and MR image fusion for surgical planning and performance in computer assisted navigated neurosurgery of temporal bone tumors.


METHODS
Fifteen patients with temporal bone tumors underwent MDCT and MRI. MDCT was performed in high-resolution bone window level setting in axial plane. The reconstructed MDCT slice thickness was 0.8 mm. MRI was performed in axial and coronal plane with T2-weighted fast spin-echo (FSE) sequences, un-enhanced and contrast-enhanced T1-weighted spin-echo (SE) sequences, and coronal T1-weighted SE sequences with fat suppression and with 3D T1-weighted gradient-echo (GE) contrast-enhanced sequences in axial plane. The 3D T1-weighted GE sequence had a slice thickness of 1mm. Image data sets of CT and 3D T1-weighted GE sequences were merged utilizing a workstation to create CT-MR fusion images. MDCT and MR images were separately used to depict and characterize lesions. The fusion images were utilized 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.


RESULTS
Tumorous lesions of bone and soft tissue were well delineated and characterized by CT and MR images. The images played a crucial role in the differentiation of benign and malignant pathologies, which consisted of 13 benign and 2 malignant tumors. The CT-MR fusion images supported the surgeon in preoperative planning and improved surgical performance. The mean intraoperative accuracy of the navigation system was 1.25 mm.


CONCLUSIONS
CT and MRI are essential in the preoperative work up of temporal bone tumors. CT-MR image data fusion presents an accurate tool for planning the correct surgical procedure and is a benefit for the operational results in computer assisted navigated neurosurgery of temporal bone tumors.
Nemec
Stefan Franz
SF
Department of Radiology/Osteology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria. stefan.nemec@meduniwien.ac.at
Donat
Markus Alexander
MA
Mehrain
Sheida
S
Friedrich
Klaus
K
Krestan
Christian
C
Matula
Christian
C
Imhof
Herwig
H
Czerny
Christian
C
D000328:Adult; D000368:Aged; D002813:Chondrosarcoma / Q000473:pathology / Q000601:surgery; D005260:Female; D005918:Glomus Tumor / Q000473:pathology / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007432:Intraoperative Period; D008279:Magnetic Resonance Imaging; D008297:Male; D008545:Melanoma / Q000473:pathology / Q000601:surgery; D008579:Meningioma / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery; D038361:Neuronavigation / Q000379:methods*; D019635:Neurosurgical Procedures; D012680:Sensitivity and Specificity; D012888:Skull Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D025321:Surgery, Computer-Assisted; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed