, the computer display cursor showed the position of the pointer tip on the corresponding plane of the CT scans or MR images. Kosugi, et al. , 8 also envisioned the use of intraoperative ultrasound imaging with the neuronavigator. Based on previous experience with stereotactic surgery and intraoperative ultrasound imaging at our clinic, 5–7 a neuronavigation system was independently specified in our group in 1987. We describe the first clinical experiences with this system. Description of the Neuronavigation System Our computer-assisted neuronavigation
John Koivukangas, Yrjö Louhisalmi, Jyrki Alakuijala and Jarkko Oikarinen
Iain H. Kalfas, Donald W. Kormos, Michael A. Murphy, Rick L. McKenzie, Gene H. Barnett, Gordon R. Bell, Charles P. Steiner, Mary Beth Trimble and Joseph P. Weisenberger
screw breakage or dislodgment. Discussion Frameless stereotaxy for intracranial localization was pioneered by Roberts, et al. , 11 who used a stereotactic microscope, and by Watanabe and coworkers, 14 who used a mechanical multiarticulated neuronavigation arm. Several groups have expanded this technology to localize intracranial lesions more effectively and directly; 1, 2, 8, 13, 17 however, little exploration has been done regarding the application of this technology to spinal surgery. Nolte reported a preliminary use of an optical-based system for
therefore important to be cautious when advancing the stylet, particularly in patients in whom the surgeon doing the revision did not place the original shunt. One adjuvant that may facilitate this is the use of the neuronavigation neuroview endoscope, with which one can simultaneously see the end of the ventricular catheter and coagulate through the body of the scope itself, thereby reducing the risk of injury to intraventricular structures. Neurosurgical Forum: Letters to the Editor Response Peter C. Whitfield , F
Michael R. Gaab and Henry W. S. Schroeder
25 34, M headache aqueduct, midbrain + 3rd ventriculostomy, microsurgery & radiation low-grade astrocytoma 9 transient trochlear palsy, headache tumor biopsy of a frontal low-grade unchanged, no tumor progression, astrocytoma ventricles unchanged 26 11, F headache, nausea, vomiting pineal region + partial cyst resection, — pineal cyst 7 no complaints, residual cyst, smaller neuronavigation ventricles 27 9, M headache, vomiting, diplopia
, and impact on neuronavigation Neil L. Dorward Olaf Alberti Binti Velani Frans A. Gerritsen William F. J. Harkness Neil D. Kitchen David G. T. Thomas April 1998 88 4 656 662 10.3171/jns.1998.88.4.0656 Computerized tomography angiography of ruptured cerebral aneurysms: factors affecting time to maximum contrast concentration Yoshikazu Nakajima Toshiki Yoshimine Hiroyoshi Yoshida Keiji Sakashita Mitsutoyo Okamoto Masanobu Kishikawa Keiichi Yagi Junichiro Yokota Toru
Neil L. Dorward, Olaf Alberti, Binti Velani, Frans A. Gerritsen, William F. J. Harkness, Neil D. Kitchen and David G. T. Thomas
. The findings are discussed in relation to the impact of postimaging brain distortion on the reliability of neuronavigation for different surgically treated tumors and for the prediction of error in individual cases. Clinical Material and Methods Patient Population During the period between June 1996 and April 1997 a total of 93 image-guided operations were performed at our institution. The male/female ratio of the patients in whom these operations were performed was 1.5:1 and the mean age was 44.7 years ( Table 1 ). Cases were selected on the basis of a
Claudia Martin, Eben Alexander III, Terry Wong, Richard Schwartz, Ferenc Jolesz and Peter McL. Black
Radical resection of low-grade gliomas can decrease the incidence of recurrence, the time to tumor progression, and the incidence of malignant transformation. The authors present a series of 25 patients who underwent craniotomy and resection of low-grade tumor in an intraoperative magnetic resonance (MR) imager. This is an open configuration 0.5-tesla imager developed by The Brigham and Women's Hospital and General Electric, in which a patient can be placed to undergo surgery. Gross-total removal was accomplished under real-time image guidance. These intraoperative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery. The authors consistently found that the extent of abnormality seen on the intraoperatively obtained films of resection was larger than that apparent in the surgical field of view alone. Intraoperative imaging made accurate surgical identification of these abnormal areas and subsequent resection possible. Patients with tumors adjacent to or within motor or language cortex underwent resection while awake, with monitoring of neurological function. In these cases, an aggressive resection without increased neurological morbidity was accomplished using the image guidance in conjunction with serial testing. A 1-month postoperative MR image was obtained in all patients. These correlated with the final intraoperative images obtained after the resection was completed. Only one patient had a mild postoperative deficit that remained at the 1-month follow-up examination. As the long-term outcome in patients with low-grade gliomas has been shown to correspond to the degree of resection, surgical resection in which intraoperative MR imaging guidance is used can be an invaluable modality in the treatment of these tumors.
P. Charles Garell, Roman Mirsky, M. Daniel Noh, Christopher M. Loftus, Patrick W. Hitchon, M. Sean Grady, Ralph G. Dacey and Matthew A. Howard III
✓ Proper ventricular catheter placements are associated with improved shunt performance. When placing ventricular catheters via the posterior approach, the surgeon must determine an optimum trajectory and then pass a catheter along that trajectory. The incidence of optimal posterior catheter placements is increased by using a posterior catheter guide (PCG); however, errors may still occur because of poor selection of a posterior burr-hole site. In this report an easy-to-use posterior burr-hole localizer (Localizer) is described that defines the optimum burr-hole location based on geometric relationships involving the ear and supraorbital rims.
The basic design principle of the Localizer was formulated and tested by using neuronavigational imaging tools to examine normal adult ventricular anatomy in relation to surface landmarks and by reviewing imaging studies obtained in 50 adult patients with hydrocephalus. Subsequently, the Localizer was used in 28 consecutive patients scheduled to undergo shunt surgery performed by using the PCG. In all cases the catheter entered the ventricle on the first pass and postoperative imaging studies demonstrated successful placement in the ipsilateral anterior horn. There were no catheter-related complications. These early results indicate that the Localizer and PCG devices may be safe and effective when used in combination for placement of posterior ventricular catheters.
Neil L. Dorward, Olaf Alberti, James D. Palmer, Neil D. Kitchen and David G. T. Thomas
C ontemporary imaging of individual neuroanatomy has achieved such exquisite detail that mental transposition of imaging information to a surgical field necessarily loses much of this information. Neuronavigation has successfully overcome this difficulty; considerable experience has now accrued with image guidance systems, 10, 13, 14, 23, 25, 28 and there is increasing evidence of their clinical benefit. 2, 7, 15, 18, 26, 28 In contrast with its use in open neurosurgical operations, image guidance has had little impact on the traditional frame
Rudolf Fahlbusch, Jürgen Honegger, Werner Paulus, Walter Huk and Michael Buchfelder
ventricle in relation to the precise location of tumor attachment. It remains to be seen how much the surgeon can benefit by introduction of intraoperative endoscopy, neuronavigation, and intraoperative resection control by MR imaging. This could improve the extent of resection but also demonstrates the limitations of surgical resection. On the basis of our present knowledge of hypothalamic functions in humans, possibilities of functional monitoring of the hypothalamus, which could guide surgical maneuvers, are not anticipated. New aspects of predicting outcome could