The heroes return to earth.
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Education, Medical, Graduate↗
SEARCH · PubMed Health
Results for “Neuronavigation”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
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Intraoperative magnetic resonance imaging safety considerations.
Patient safety considerations are a priority for perioperative nurses. In the intraoperative magnetic resonance imaging (MRI) chamber, additional safety precautions for both patients and staff members must be taken. This article provides a brief overview of the intraoperative MRI environment and details safety considerations for surgical staff members and patients.
Brain Neoplasms↗
Combining magnetoencephalography and functional magnetic resonance imaging.
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Brain↗
A robust and automatic method for evaluating accuracy in 3-D ultrasound-based navigation.
We present a robust and automatic method for evaluating the 3-D navigation accuracy in ultrasound (US) based image-guided systems. The method is based on a precisely built and accurately measured phantom with several wire crosses and an automatic 3-D template matching by correlation algorithm. We investigated the accuracy and robustness of the algorithm and also addressed optimization of algorithm parameters. Finally, we applied the method to an extensive data set from an in-house US-based navigation system. To evaluate the algorithm, eight skilled observers identified the same wire crosses manually and the average over all observers constitutes our reference data set. We found no significant differences between the automatic and the manual procedures; the average distance between the point sets for one particular volume (27 point pairs) was 0.27 +/- 0.17 mm. Furthermore, the spread of the automatically determined points compared with the reference set was lower than the spread for any individual operator. This indicates that the automatic algorithm is more accurate than manual determination of the wire-cross locations, in addition to being faster and nonsubjective. In the application example, we used a set of 35 3-D US scans of the phantom under various acquisition configurations. The US frequency was 6.7 MHz and the average target depth was 6 cm. The accuracy, represented by the mean distance between automatically-determined wire-cross locations and physically measured locations, was found to be 1.34 +/- 0.62 mm.
Algorithms↗
Effect of bite tray impression technique on relocation accuracy in frameless stereotactic radiotherapy.
A previously developed method for achieving patient relocation in fractionated stereotactic radiotherapy (attachment of an infrared fiducial system to a bite tray) relies on the integrity of a bite tray system that incorporates moulding to the patient's upper dentition. Reproducible and accurate patient positioning requires stability of the bite tray and mould during the full treatment process, both during the time the bite tray is inserted in the patient's mouth, and between separate bite tray insertions. The optimum construction method for a stable reproducible tray has not been sufficiently investigated. We undertook a study to identify factors which might influence the integrity of the hard palate bite tray system. Reprosil Fast Set Putty was used to construct 3 impression conditions; teeth only; teeth and alveolar sulcus; and teeth, alveolar sulcus, and the hard palate. Reproducibility was assessed by volunteers inserting the impressions multiple times and recording the locations of 8 standard reference points. Our results showed the optimal impression technique (i.e., the one that led to the smallest ranges in positional and rotational errors) was that which incorporated the teeth, alveolar sulcus, and hard palate.
Brain Neoplasms↗
Chronometry of parietal and prefrontal activations in verbal working memory revealed by transcranial magnetic stimulation.
We explored the temporal dynamics of parietal and prefrontal cortex involvement in verbal working memory employing single-pulse transcranial magnetic stimulation (TMS). In six healthy volunteers the left or right inferior parietal and prefrontal cortex was stimulated with the aid of a frameless stereotactic system. TMS was applied at 10 different time points 140-500 ms into the delay period of a two-back verbal working memory task. A choice reaction task was used as a control task. Interference with task accuracy was induced by TMS earlier in the parietal cortex than in the prefrontal cortex and earlier over the right than the left hemisphere. This suggests a propagation of information flow from posterior to anterior cortical sites converging in the left prefrontal cortex. Significant interference with reaction time was observed after 180 ms with left prefrontal cortex stimulation. These effects were not observed in the control task, underlining the task specificity of our results. We propose that the interference with right-sided prefrontal cortex stimulation leads to impaired performance due to disturbed input into the left prefrontal cortex, whereas left-sided TMS interferes directly with the final information processing. Left- and right-sided brain areas might be involved in parallel processing of semantic and object features of the stimuli, respectively.
Adult↗
Intraoperative MR imaging.
Intraoperative MR imaging has become a safe and effective technology that has revolutionized the way neurosurgery is performed. Benefits include the ability to update data sets for navigational systems, to monitor tumor resections, to adjust the approach to intracranial lesions, and to guide functional and drug or cell delivery procedures. Use of this technique can help avoid inadvertent injury of important anatomic and vascular structures. In addition, complications such as ischemia or hemorrhage can be detected early. Intraoperative MR imaging is particularly useful for ensuring that brain biopsies yield diagnostic tissue and for assessing the completeness of tumor resection. As is true for any new technology, the benefits of intraoperative MR imaging must be examined carefully to guarantee appropriate use. Many neurosurgical procedures do not require real-time image guidance and can be performed safely using current surgical techniques, including microsurgical methods and frameless and frame-based stereotaxy. Other tumor resections, tumor biopsies, and surgical and interventional procedures distinctly benefit from the sophisticated information provided by intraoperative imaging techniques. In surgery for low-grade gliomas, intraoperative MR imaging has found general acceptance, whereas its usefulness to monitor the resection of high-grade gliomas remains controversial. The economic issues related to intraoperative MR imaging cannot be overlooked. The acquisition of an intraoperative MR imaging system is associated with considerable expense, and its performance increases the cost of equipment and the operating time. Despite these additional expenses, intraoperative MR imaging can lead to a potential overall cost reduction in the treatment of certain patients if long-term cure can be achieved, repeat resection can be avoided, or procedure-associated morbidity can be reduced. Although intraoperative MR imaging techniques hold tremendous potential, the definition of their appropriate role in the delivery of successful and cost-effective medical care awaits further study.
Brain↗
Shine the magnetic resonance light on neurosurgery.
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Brain Neoplasms↗
Functional MR imaging: from the BOLD effect to higher motor cognition.
The key contributions of functional imaging to our understanding of the human motor system and higher motor disorders are reviewed in this chapter. Following a short introduction into the method of functional magnetic resonance imaging (fMRI), some core aspects of the human motor system (multiple nonprimary motor areas, the mirror neuron system, intraparietal multimodal cortex) are highlighted. Finally, the convergence (and divergence) of functional imaging and neurological data from patients with lesions of the motor system is discussed with special emphasis to how this informs our current knowledge of the pathophysiology of higher motor disorders.
Brain Mapping↗
Endoscopic sinus surgery under navigation system--analysis report of 79 cases.
BACKGROUND: Functional endoscopic sinus surgery (FESS) is the most popular method for treating medicine-refractory sinonasal disease. However, there are some pitfalls with this technique that can result in serious complications. Under the assistance of a navigation system, surgeons can overcome such problems. This study aimed to evaluate the efficacy of FESS aided by a navigation system. METHODS: There were 79 patients who underwent FESS under the assistance of a navigation system in our department between September 2004 and September 2005. Data on preoperative setup time, accuracy of the navigation system, operative time, and amount of blood loss during the operation were collected and analyzed. RESULTS: Mean preoperative setup time and mean operative time were 10.6 minutes and 112.3 minutes, respectively. The mean number of paranasal sinuses operated on was 5.8. The mean accuracy of the navigator system was 1.08 mm. Mean blood loss was 102.5 mL. Compared with data collected 2 years ago, preoperative setup time and operative time had both shortened. In addition, the number of operated paranasal sinuses had increased. This indicates that operative skill had improved. Moreover, operative time, amount of blood loss during the operation, and number of operated paranasal sinuses presented positive associations and significant differences (p < 0.05). No major complications such as blindness or cerebral spinal fluid leakage were noted. CONCLUSION: The characteristics of FESS aided by a navigation system include: (1) being able to pilot the relative positions of the operative instruments correctly in 3 dimensions; (2) being able to remove lesions more thoroughly; and (3) its inability to disclose the positions of vessels. As the number of patients we operated on increased, operative time was reduced. On the other hand, blood loss increased when the operations became more aggressive. However, performing FESS with the assistance of a navigation system is a safe way to treat patients with chronic paranasal sinusitis.
Endoscopy↗
Applications of fMRI in translational medicine and clinical practice.
Functional MRI (fMRI) has had a major impact in cognitive neuroscience. fMRI now has a small but growing role in clinical neuroimaging, with initial applications to neurosurgical planning. Current clinical research has emphasized novel concepts for clinicians, such as the role of plasticity in recovery and the maintenance of brain functions in a broad range of diseases. There is a wider potential for clinical fMRI in applications ranging from presymptomatic diagnosis, through drug development and individualization of therapies, to understanding functional brain disorders. Realization of this potential will require changes in the way clinical neuroimaging services are planned and delivered.
Animals↗
Mini-incision technique for total hip arthroplasty with navigation.
This prospective study compares a mini-incision technique and traditional posterior approach for total hip arthroplasty (THA). Thirty-three patients who had undergone a mini-incision THA were matched by diagnosis, gender, average age, and preoperative Harris Hip Score (HHS) to 33 patients who had undergone THA using the traditional posterior approach. The average length of the incision for group 1 was 11.7 cm (range, 7.3-13.0) and for group 2 was 20.2 cm (range, 14.8-26.0). At the 3-month follow-up, patients in the mini-incision group had significant improvement in limp (P<.05) and ability to climb stairs (P <.01) compared with the traditional group. At the 6 month follow-up, the mini-incision group was significantly better in terms of limp (P <.05), distance walked (P<.001), and stairs (P < 0.001). There was no significant difference between groups for pain, function, or range of motion at the 1-year follow-up examination.
Aged↗
Improving planning procedure in brain biopsy: coupling frame-based stereotaxy with navigational device STP 4.0.
37 consecutive patients with space-occupying intracerebral lesions were operated via frame-based stereotaxy. After CT-localizing of suspect lesions and computer-supported definition of entry and target coordinates a serial stereotactic biopsy was performed. Biopsy specimens allowed a satisfactory neuropathological examination and diagnostic result in 36 cases (97 %). Only three patients (8.1 %) showed an intraoperative bleeding, which was not associated with any postoperative CT-detectable hematoma, neurosurgical intervention nor with any neurological deficits. In summary we described the method of a computerized planning technique for stereotactic biopsy with the use of a special stereotactic planning program. High percentage of satisfactory neuropathological diagnoses and comfortable and accurate definition of target and entry coordinates justify computer support as a routine method.
Adolescent↗
Image-guided transsphenoidal surgery for pituitary lesions using Mehrkoordinaten Manipulator (MKM) navigation system.
Twenty-five patients with pituitary lesions were operated on by image-guided transsphenoidal surgery (TSS) using the Mehrkoordinaten Manipulator (MKM) navigation system. The cases included 21 cases of pituitary adenomas, 2 cases of craniopharyngioma and 2 cases of Rathke's cleft cyst. All operations were performed through the sublabial approach under an operative microscope. In some cases, an endoscope was used for the observation of the residual tumor and surrounding structures. The tumors and surrounding important structures such as the internal carotid arteries, the basilar artery, and the optic nerves were precisely localized, and mechanical error was less than 2 mm in almost all cases. In 3 early cases of pituitary adenoma, the patient's head was moved slightly during the insertion of the nasal speculum; in these cases, the resulting error was more than 2 mm. In evaluating the procedures, we determined that the most useful benefit of the MKM system compared with other systems is that the navigation information is not only displayed on the monitor, but also presented in the operative field under the microscope. Therefore, the surgeon can obtain the navigation information without removing his eyes from the operative field under the microscope. The most important drawback to the system is its bulky size.
Adenoma↗
Frameless stereotactic radiosurgery with mobile CT, mask immobilization and micro-multileaf collimators.
We present frameless stereotactic radiosurgery using mobile CT, thermal plastic mask fixation, a vacuum-form body immobilizer and micro-multileaf collimators. A linear accelerator and a self-moving helical CT scanner gantry were installed in the same room. The isocenter of irradiation can be also aligned with the center of the CT gantry by rotating the couch. A thermal plastic mask and vacuum-form body immobilizer was used for registration and immobilization. The advantages of this system are as follows: 1) Accurate and painless frameless fractionated irradiation can be performed smoothly, as the patient's head is fixed without exchanging the couch from CT scanning to irradiation system. 2) This mask system can be applied to children, infants or adults with a previous craniotomy bone flap that must have a fixation pin placed into it. This system can be also used for fractionated radiotherapy without painful skull pin-fixed frame. 3) 1 mm micro-multileaf collimators enable irregular contour irradiation. 4) Image fusion (among CT, MRI, angiography, and PET) and 3D images can be used for irradiation planning. 5) This system can be used on any part of the body. 6) This system can be installed in any irradiation room without any extension or new construction.
Brain Neoplasms↗
Neuroendoscopic surgery for intracerebral haemorrhage--comparison with traditional therapies.
Endoscopy is a new therapeutic option for hypertensive intracerebral haemorrhage. Although it has the advantages of being less invasive than craniotomy and more effective than conservative treatment, not all patients are candidates for it. Since it is important to clarify which characteristics of patients are indications for this operation, we retrospectively evaluated the role of endoscopic surgery in comparison with traditional treatments for hypertensive intracerebral haemorrhage. Seven patients were treated with endoscopic surgery in our institution between January 2000 and November 2001. Two had thalamic haemorrhage, 4 putaminal haemorrhage, and 1 intracerebral haemorrhage. The average age of patients was 55 years. Endoscopic operation was mainly selected for haematomas more than 20 ml and less than 40 ml in volume. Generally, endoscopy yielded good outcomes with GR in 50 % of patients. Adequate indications for endoscopic operation may be the following; 1) Putaminal haematoma of small-intermediate size, 2) Haematoma situated deep in the brain, e. g., thalamic haemorrhage, 3) Intraventricular haematoma, 4) High-risk patients who cannot tolerate general anaesthesia.
Adult↗
Adaptation of a hexapod-based robotic system for extended endoscope-assisted transsphenoidal skull base surgery.
OBJECTIVE: To adapt a hexapod-based robotic system for use in extended endoscope-assisted transsphenoidal skull base surgery. METHODS: A robotic system (Evolution 1, Universal Robot Systems, Schwerin, Germany) based on a hexapod design with an attached seventh axis is used as instrument holder. The instrument interface is operated via a joystick control. An endoscope is applied to the instrument interface, which is tracked by a navigation system (Stealth, Medtronic, USA). RESULTS: The instrument holder was modified so that it could be applied in transsphenoidal surgery. Furthermore, translation and pivoting movements of the system were implemented, also a quick change between microscope and robotic-controlled endoscope was made possible. After extensive phantom testing two patients with large invasive pituitary adenomas were operated on using the robotic endoscope assistance during transsphenoidal surgery. The robotic assistance allowed the use of two additional instruments under endoscopic view. For example, drilling, suctioning, application of punches, as well as microsurgical tumor removal could be performed under endoscopic view. CONCLUSION: A robotic system could be adapted for use in endoscope-assisted transsphenoidal skull base surgery allowing simultaneous use of two instruments under endoscopic view. This opens new possibilities to extend transsphenoidal skull base surgery.
Adenoma↗
Fluoroscopic frameless computer-assisted navigation for transsphenoidal surgery: a clinical assessment of accuracy in spatial position and trajectory.
OBJECTIVE: Fluoroscopic navigation technique in transsphenoidal surgery on the one hand provides multi-planar (antero-posterior and lateral views) navigation while on the other hand it does not need any preoperative preparation. To assess the clinical accuracy of the above technique in the transsphenoidal surgery, we performed this study. METHODS: 5 patients undergoing transsphenoidal surgery were assessed. Fluoroscopic images were compared with C-arm X-ray images for difference in spatial position and trajectory. RESULTS: 26 sets of data were collected for analysis. Mean pointer tip difference was 0.6 mm. The 95 % confidence interval was 1.3 mm. Mean trajectory difference was 1.2 degree. The 95 % confidence interval was 2.7 degree. CONCLUSION: With a good clinical accuracy, fluoroscopic navigation offers a distinct advantage to replace the traditional fluoroscopic approach for transsphenoidal surgery for its low X-ray exposure and multi-planar (antero-posterior and lateral views) navigation.
Adenoma↗