Artikel
Tumor origin in acoustic neuromas: The value of 3D CISS MRT sequences
Tumorursprung bei Akustikusneurinomen: Die Wertigkeit von 3D-CISS-MRT-Sequenzen
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Autoren
Veröffentlicht: | 23. April 2004 |
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Gliederung
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Objective
The technique of three-dimensional MRT-CISS sequences has been advocated for preoperative evaluation of tumor origin in acoustic neuromas. A prospective study comparing preoperative imaging and intraoperative findings has not been published so far.
Methods
The prospective study included 15 patients with histologically proven vestibular schwannomas, who were operated in 2003. The average tumor size measured 20 mm. In 5 patients the tumor filled the internal auditory canal almost completely. In the remaining patients, the fundus was free of tumor. Patients underwent 3D CISS MRT to evaluate tumor origin. Intraoperative findings were documented by the surgeon. Both investigators were blinded regarding the results of neuroradiological and surgical findings.
Results
In 11 cases radiological evaluation resulted in a definite identification of tumor origin (inferior vestibular nerve: 5 patients; superior vestibular nerve : 6 patients) In 4 of 5 patients, in whom the tumor reached the fundus, tumor origin could not be identified. Surgical identification of tumor origin was obtained in all but 1 case (superior vestibular nerve:12 cases, inferior vestibular nerve: 2 cases). Summarizing the results, a positive match was obtained in 8 of 15 patients, a definite mismatch was documented in 3 cases.
Conclusions
The technique of 3D CISS MRT can add valuable information regarding tumor origin in acoustic neuroma surgery, based upon appropriate patient selection. When the fundus of the internal auditory canal is not completely obliterated by tumor a positive match of neuroradiological and operative findings could be obtained in 66.6%. Advanced imaging processing using segmentation and visualisation may further increase the reliability.