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Limpo H, Díez R, Albisua J, Tejada S. Intraoperative high-field resonance: How to optimize its use in our healthcare system. ACTA ACUST UNITED AC 2021; 33:261-268. [PMID: 34625382 DOI: 10.1016/j.neucie.2021.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/18/2021] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND AIMS Intraoperative MRI (ioMRI) consists of performing a MRI during brain or spinal surgery. Although it is a safe and useful technique, it is available in a few hospitals. This means some aspects are not perfectly defined or standardized, forcing each center to develop its own solutions. Our goal is to describe the technique, evaluate the changes made to optimize its use and thus be able to facilitate the intraoperative resonance implementation in other neurosurgery departments. METHODS A prospective analysis of patients consecutively operated using high-field ioMRI guidance was carried out, describing the type of tumor, clinical data, time and sequences of ioMR, use of intraoperative neurophysiology, preoperative tumor volume, after ioMR, and postoperative, as well as complications. RESULTS ioMR was performed in 38 patients selected from among 425 brain tumors (9%) operated on in this interval. The tumor types were: 11 glioblastomas, 8 anaplastic astrocytomas, 5 diffuse astrocytomas, 4 meningiomas, 3 oligodendrogliomas, 2 metastases, 2 epidermoid cysts, 1 astroblastoma, 1 arachnoid cyst and 1 pituitary adenoma. The mean age was 45 years. The mean preoperative tumor volume was 45.22cc, after the ioMR 5.08cc and postoperative 1.28cc. Resection was extended after ioMR in 76%. Gross total resection was achieved in 15 patients and residual tumor of less than 1cc was observed in 8. An intentional tumor tissue was left in an eloquent brain region (mean volume 7cc) in 13 patients. Bleeding and ischemia complications were detected early on ioMR in 5%. MRI length was 47 min on average. CONCLUSIONS Intraoperative MRI was a useful and safe technique, and no associated complications were registered.
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Affiliation(s)
- Hiria Limpo
- Departamento de Neurocirugía, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain.
| | - Ricardo Díez
- Departamento de Neurocirugía, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Julio Albisua
- Departamento de Neurocirugía, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Sonia Tejada
- Departamento de Neurocirugía, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
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Resonancia intraoperatoria de alto campo: cómo optimizar su uso en nuestro modelo sanitario. Neurocirugia (Astur) 2021. [DOI: 10.1016/j.neucir.2021.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Englman C, Malpas CB, Harvey AS, Maixner WJ, Yang JYM. Intraoperative magnetic resonance imaging in epilepsy surgery: A systematic review and meta-analysis. J Clin Neurosci 2021; 91:1-8. [PMID: 34373012 DOI: 10.1016/j.jocn.2021.06.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/19/2021] [Indexed: 11/27/2022]
Abstract
This systematic review investigated the added value of intraoperative magnetic resonance imaging (iMRI)-guidance in epilepsy surgery, compared to conventional non-iMRI surgery, with respect to the rate of gross total resection (GTR), postoperative seizure freedom, neurological deficits, non-neurological complications and reoperations. A comprehensive literature search was conducted using Medline, Embase, PubMed, and Cochrane Reviews databases. Randomized control trials, case control or cohort studies, and surgical case series published from January 1993 to February 2021 that reported on iMRI-guided epilepsy surgery outcomes for either adults or children were eligible for inclusion. Studies comparing iMRI-guided epilepsy surgery to non-iMRI surgery controls were selected for meta-analysis using random-effects models. Forty-two studies matched the selection criteria and were used for qualitative synthesis and ten of these were suitable for meta-analysis. Overall, studies included various 0.2-3.0 Tesla iMRI systems, contained small numbers with heterogenous clinical characteristics, utilized subjective GTR reporting, and had variable follow-up durations. Meta-analysis demonstrated that the use of iMRI-guidance led to statistically significant higher rates of GTR (RR = 1.31 [95% CI = 1.10-1.57]) and seizure freedom (RR = 1.44 [95% CI = 1.12-1.84]), but this was undermined by moderate to significant statistical heterogeneity between studies (I2 = 55% and I2 = 71% respectively). Currently, there is only level III-2 evidence supporting the use of iMRI-guidance over conventional non-iMRI epilepsy surgery, with respect to the studied outcomes.
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Affiliation(s)
- Cameron Englman
- Department of Paediatrics, University of Melbourne, VIC, Australia
| | - Charles B Malpas
- Developmental Imaging, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Neurology, Royal Melbourne Hospital, Melbourne, VIC, Australia; Clinical Outcomes Research Unit, Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, VIC, Australia
| | - A Simon Harvey
- Neuroscience Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, VIC, Australia; Department of Neurology, Royal Children's Hospital, Melbourne, VIC, Australia
| | - Wirginia J Maixner
- Department of Neurosurgery, Neuroscience Advanced Clinical Imaging Service, Royal Children's Hospital, Melbourne, VIC, Australia; Neuroscience Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Joseph Yuan-Mou Yang
- Department of Neurosurgery, Neuroscience Advanced Clinical Imaging Service, Royal Children's Hospital, Melbourne, VIC, Australia; Neuroscience Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Developmental Imaging, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, VIC, Australia.
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Feigl GC, Heckl S, Kullmann M, Filip Z, Decker K, Klein J, Ernemann U, Tatagiba M, Velnar T, Ritz R. Review of first clinical experiences with a 1.5 Tesla ceiling-mounted moveable intraoperative MRI system in Europe. Bosn J Basic Med Sci 2019; 19:24-30. [PMID: 30589401 PMCID: PMC6387677 DOI: 10.17305/bjbms.2018.3777] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 07/29/2018] [Indexed: 11/16/2022] Open
Abstract
High-field intraoperative MRI (iMRI) systems provide excellent imaging quality and are used for resection control and update of image guidance systems in a number of centers. A ceiling-mounted intraoperative MRI system has several advantages compared to a conventional iMRI system. In this article, we report on first clinical experience with using such a state-of-the-art, the 1.5T iMRI system, in Europe. A total of 50 consecutive patients with intracranial tumors and vascular lesions were operated in the iMRI unit. We analyzed the patients' data, surgery preparation times, intraoperative scans, surgical time, and radicality of tumor removal. Patients' mean age was 46 years (range 8 to 77 years) and the median surgical procedure time was 5 hours (range 1 to 11 hours). The lesions included 6 low-grade gliomas, 8 grade III astrocytomas, 10 glioblastomas, 7 metastases, 7 pituitary adenomas, 2 cavernomas, 2 lymphomas, 1 cortical dysplasia, 3 aneurysms, 1 arterio-venous malformation and 1 extracranial-intracranial bypass, 1 clival chordoma, and 1 Chiari malformation. In the surgical treatment of tumor lesions, intraoperative imaging depicted tumor remnant in 29.7% of the cases, which led to a change in the intraoperative strategy. The mobile 1.5T iMRI system proved to be safe and allowed an optimal workflow in the iMRI unit. Due to the fact that the MRI scanner is moved into the operating room only for imaging, the working environment is comparable to a regular operating room.
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Affiliation(s)
- Guenther C Feigl
- Department of Neurosurgery, University of Tuebingen Medical Center, Germany.
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5
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Nimsky C, Carl B. Historical, Current, and Future Intraoperative Imaging Modalities. Neurosurg Clin N Am 2017; 28:453-464. [DOI: 10.1016/j.nec.2017.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Roessler K, Hofmann A, Sommer B, Grummich P, Coras R, Kasper BS, Hamer HM, Blumcke I, Stefan H, Nimsky C, Buchfelder M. Resective surgery for medically refractory epilepsy using intraoperative MRI and functional neuronavigation: the Erlangen experience of 415 patients. Neurosurg Focus 2016; 40:E15. [DOI: 10.3171/2015.12.focus15554] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE
Intraoperative overestimation of resection volume in epilepsy surgery is a well-known problem that can lead to an unfavorable seizure outcome. Intraoperative MRI (iMRI) combined with neuronavigation may help surgeons avoid this pitfall and facilitate visualization and targeting of sometimes ill-defined heterogeneous lesions or epileptogenic zones and may increase the number of complete resections and improve seizure outcome.
METHODS
To investigate this hypothesis, the authors conducted a retrospective clinical study of consecutive surgical procedures performed during a 10-year period for epilepsy in which they used neuronavigation combined with iMRI and functional imaging (functional MRI for speech and motor areas; diffusion tensor imaging for pyramidal, speech, and visual tracts; and magnetoencephalography and electrocorticography for spike detection). Altogether, there were 415 patients (192 female and 223 male, mean age 37.2 years; 41% left-sided lesions and 84.9% temporal epileptogenic zones). The mean preoperative duration of epilepsy was 17.5 years. The most common epilepsy-associated pathologies included hippocampal sclerosis (n = 146 [35.2%]), long-term epilepsy-associated tumor (LEAT) (n = 67 [16.1%]), cavernoma (n = 45 [10.8%]), focal cortical dysplasia (n = 31 [7.5%]), and epilepsy caused by scar tissue (n = 23 [5.5%]).
RESULTS
In 11.8% (n = 49) of the surgeries, an intraoperative second-look surgery (SLS) after incomplete resection verified by iMRI had to be performed. Of those incomplete resections, LEATs were involved most often (40.8% of intraoperative SLSs, 29.9% of patients with LEAT). In addition, 37.5% (6 of 16) of patients in the diffuse glioma group and 12.9% of the patients with focal cortical dysplasia underwent an SLS. Moreover, iMRI provided additional advantages during implantation of grid, strip, and depth electrodes and enabled intraoperative correction of electrode position in 13.0% (3 of 23) of the cases. Altogether, an excellent seizure outcome (Engel Class I) was found in 72.7% of the patients during a mean follow-up of 36 months (range 3 months to 10.8 years). The greatest likelihood of an Engel Class I outcome was found in patients with cavernoma (83.7%), hippocampal sclerosis (78.8%), and LEAT (75.8%). Operative revisions that resulted from infection occurred in 0.3% of the patients, from hematomas in 1.6%, and from hydrocephalus in 0.8%. Severe visual field defects were found in 5.2% of the patients, aphasia in 5.7%, and hemiparesis in 2.7%, and the total mortality rate was 0%.
CONCLUSIONS
Neuronavigation combined with iMRI was beneficial during surgical procedures for epilepsy and led to favorable seizure outcome with few specific complications. A significantly higher resection volume associated with a higher chance of favorable seizure outcome was found, especially in lesional epilepsy involving LEAT or diffuse glioma.
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Affiliation(s)
| | | | | | | | | | | | - Hajo M. Hamer
- 3Neurology, Epilepsy Centre, University Hospital Erlangen; and
| | | | - Hermann Stefan
- 3Neurology, Epilepsy Centre, University Hospital Erlangen; and
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Sacino MF, Ho CY, Murnick J, Keating RF, Gaillard WD, Oluigbo CO. The role of intraoperative MRI in resective epilepsy surgery for peri-eloquent cortex cortical dysplasias and heterotopias in pediatric patients. Neurosurg Focus 2016; 40:E16. [DOI: 10.3171/2016.1.focus15538] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE
Previous studies have demonstrated that an important factor in seizure freedom following surgery for lesional epilepsy in the peri-eloquent cortex is completeness of resection. However, aggressive resection of epileptic tissue localized to this region must be balanced with the competing objective of retaining postoperative neurological functioning. The objective of this study was to investigate the role of intraoperative MRI (iMRI) as a complement to existing epilepsy protocol techniques and to compare rates of seizure freedom and neurological deficit in pediatric patients undergoing resection of perieloquent lesions.
METHODS
The authors retrospectively reviewed the medical records of pediatric patients who underwent resection of focal cortical dysplasia (FCD) or heterotopia localized to eloquent cortex regions at the Children's National Health System between March 2005 and August 2015. Patients were grouped into two categories depending on whether they underwent conventional resection (n = 18) or iMRI-assisted resection (n = 11). Patient records were reviewed for factors including demographics, length of hospitalization, postoperative seizure freedom, postoperative neurological deficit, and need for reoperation. Postsurgical seizure outcome was assessed at the last postoperative follow-up evaluation using the Engel Epilepsy Surgery Outcome Scale.
RESULTS
At the time of the last postoperative follow-up examination, 9 (82%) of the 11 patients in the iMRI resection group were seizure free (Engel Class I), compared with 7 (39%) of the 18 patients in the control resection group (p = 0.05). Ten (91%) of the 11 patients in the iMRI cohort achieved gross-total resection (GTR), compared with 8 (44%) of 18 patients in the conventional resection cohort (p = 0.02). One patient in the iMRI-assisted resection group underwent successful reoperation at a later date for residual dysplasia, compared with 7 patients in the conventional resection cohort (with 2/7 achieving complete resection). Four (36%) of the patients in the iMRI cohort developed postoperative neurological deficits, compared with 15 patients (83%) in the conventional resection cohort (p = 0.02).
CONCLUSIONS
These results suggest that in comparison with a conventional surgical protocol and technique for resection of epileptic lesions in peri-eloquent cortex, the incorporation of iMRI led to elevated rates of GTR and postoperative seizure freedom. Furthermore, this study suggests that iMRI-assisted surgeries are associated with a reduction in neurological deficits due to intraoperative damage of eloquent cortex.
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Winston GP. Epilepsy surgery, vision, and driving: what has surgery taught us and could modern imaging reduce the risk of visual deficits? Epilepsia 2013; 54:1877-88. [PMID: 24199825 PMCID: PMC4030586 DOI: 10.1111/epi.12372] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2013] [Indexed: 11/29/2022]
Abstract
Up to 40% of patients with temporal lobe epilepsy (TLE) are refractory to medication. Surgery is an effective treatment but may cause new neurologic deficits including visual field deficits (VFDs). The ability to drive after surgery is a key goal, but a postoperative VFD precludes driving in 4-50% of patients even if seizure-free. VFDs are a consequence of damage to the most anterior portion of the optic radiation, Meyer's loop. Anatomic dissection reveals that the anterior extent of Meyer's loop is highly variable and may clothe the temporal horn, a key landmark entered during temporal lobe epilepsy surgery. Experience from surgery since the 1940s has shown that VFDs are common (48-100%) and that the degree of resection affects the frequency or severity of the deficit. The pseudowedge shape of the deficit has led to a revised retinotopic model of the organization of the optic radiation. Evidence suggests that the left optic radiation is more anterior and thus at greater risk. Alternative surgical approaches, such as selective amygdalo-hippocampectomy, may reduce this risk, but evidence is conflicting or lacking. The optic radiation can be delineated in vivo using diffusion tensor imaging tractography, which has been shown to be useful in predicting the postoperative VFDs and in surgical planning. These data are now being used for surgical guidance with the aim of reducing the severity of VFDs. Compensation for brain shift occurring during surgery can be performed using intraoperative magnetic resonance imaging (MRI), but the additional utility of this expensive technique remains unproven.
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Affiliation(s)
- Gavin P Winston
- Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, United Kingdom
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Abernethy LJ, Avula S, Hughes GM, Wright EJ, Mallucci CL. Intra-operative 3-T MRI for paediatric brain tumours: challenges and perspectives. Pediatr Radiol 2012; 42:147-57. [PMID: 22286342 DOI: 10.1007/s00247-011-2280-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Revised: 07/13/2011] [Accepted: 08/04/2011] [Indexed: 10/14/2022]
Abstract
MRI is the ideal modality for imaging intracranial tumours. Intraoperative MRI (ioMRI) makes it possible to obtain scans during a neurosurgical operation that can aid complete macroscopic tumour resection—a major prognostic factor in the majority of brain tumours in children. Intraoperative MRI can also help limit damage to normal brain tissue. It therefore has the potential to improve the survival of children with brain tumours and to minimise morbidity, including neurological deficits. The use of ioMRI is also likely to reduce the need for second look surgery, and may reduce the need for chemotherapy and radiotherapy. Highfield MRI systems provide better anatomical information and also enable effective utilisation of advanced MRI techniques such as perfusion imaging, diffusion tensor imaging, and magnetic resonance spectroscopy. However, high-field ioMRI facilities require substantial capital investment, and careful planning is required for optimal benefit. Safe ioMRI requires meticulous attention to detail and rigorous application of magnetic field safety precautions. Interpretation of ioMRI can be challenging and requires experience and understanding of artefacts that are common in the intra-operative setting.
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Affiliation(s)
- L J Abernethy
- Department of Radiology, Alder Hey Children’s NHS Foundation Trust, Eaton Road, Liverpool L12 2AP, UK.
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Ng WH, Mukhida K, Rutka JT. Image guidance and neuromonitoring in neurosurgery. Childs Nerv Syst 2010; 26:491-502. [PMID: 20174925 DOI: 10.1007/s00381-010-1083-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 01/18/2010] [Indexed: 11/24/2022]
Abstract
INTRODUCTION The localization of tumors and epileptogenic foci within the somatosensory or language cortex of the brain of a child poses unique neurosurgical challenges. In the past, lesions in these regions were not treated aggressively for fear of inducing neurological deficits. As a result, while function may have been preserved, the underlying disease may not have been optimally treated, and repeat neurosurgical procedures were frequently required. Today, with the advent of preoperative brain mapping, image guidance or neuronavigation, and intraoperative monitoring, peri-Rolandic and language cortex lesions can be approached directly and definitively with a high degree of confidence that neurosurgical function will be maintained. METHODS AND RESULTS The preoperative brain maps can now be achieved with magnetic resonance imaging (MRI), functional MRI, magnetoencephalography, and diffusion tensor imaging. Image guidance systems have improved significantly and include the use of the intraoperative MRI. Somatosensory, motor, and brainstem auditory-evoked potentials are used as standard neuromonitoring techniques in many centers around the world. Added to this now is the use of continuous train-of-five monitoring of the integrity of the corticospinal tract while operating in the peri-Rolandic region. CONCLUSION We are in an era where continued advancements can be expected in mapping additional pathways such as visual, memory, and hearing pathways. With these new advances, neurosurgeons can expect to significantly improve their surgical outcomes further.
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Affiliation(s)
- Wai Hoe Ng
- Department of Neurosurgery, National Neuroscience Institute, Singapore, Singapore
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Pamir MN, Ozduman K, Dinçer A, Yildiz E, Peker S, Ozek MM. First intraoperative, shared-resource, ultrahigh-field 3-Tesla magnetic resonance imaging system and its application in low-grade glioma resection. J Neurosurg 2010; 112:57-69. [PMID: 19480544 DOI: 10.3171/2009.3.jns081139] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The authors describe the first shared-resource, 3-T intraoperative MR (ioMR) imaging system and analyze its impact on low-grade glioma (LGG) resection with an emphasis on the use of intraoperative proton MR spectroscopy. METHODS The Acibadem University ioMR imaging facility houses a 3-T Siemens Trio system and consists of interconnected but independent MR imaging and surgical suites. Neurosurgery is performed using regular ferromagnetic equipment, and a patient can be transferred to the ioMR imaging system within 1.5 minutes by using a floating table. The ioMR imaging protocol takes < 10 minutes including the transfer, and the authors obtain very high-resolution T2-weighted MR images without the use of intravenous contrast. Functional sequences are performed when needed. A new 5-pin headrest-head coil combination and floating transfer table were specifically designed for this system. RESULTS Since the facility became operational in June 2004, 56 LGG resections have been performed using ioMR imaging, and > 19,000 outpatient MR imaging procedures have been conducted. First-look MR imaging studies led to further resection attempts in 37.5% of cases as well as a 32.3% increase in the number of gross-total resections. Intraoperative ultrasonography detected 16% of the tumor remnants. Intraoperative proton MR spectroscopy and diffusion weighted MR imaging were used to differentiate residual tumor tissue from peritumoral parenchymal changes. Functional and diffusion tensor MR imaging sequences were used both pre- and postoperatively but not intraoperatively. No infections or other procedure-related complications were encountered. CONCLUSIONS This novel, shared-resource, ultrahigh-field, 3-T ioMR imaging system is a cost-effective means of affording a highly capable ioMR imaging system and increases the efficiency of LGG resections.
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Affiliation(s)
- M Necmettin Pamir
- Department of Neurosurgery, Acibadem University, School of Medicine, Istanbul, Turkey
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12
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Lumenta CB, Gumprecht H, Krammer MJ. Image-Guided Neurosurgery. Neurosurgery 2010. [DOI: 10.1007/978-3-540-79565-0_36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Levy R, Cox RG, Hader WJ, Myles T, Sutherland GR, Hamilton MG. Application of intraoperative high-field magnetic resonance imaging in pediatric neurosurgery. J Neurosurg Pediatr 2009; 4:467-74. [PMID: 19877782 DOI: 10.3171/2009.4.peds08464] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Over the past decade, the use of intraoperative MR (iMR) imaging in the pediatric neurosurgical population has become increasingly accepted as an innovative and important neurosurgical tool. The authors summarize their experience using a mobile 1.5-T iMR imaging unit with integrated neuronavigation with the goal of identifying procedures and/or pathologies in which the application of this technology changed the course of surgery or modified the operative strategy. METHODS A database has been prospectively maintained for this patient population. The authors reviewed the hospital charts and imaging results for all patients in the database. This review revealed 105 neurosurgical procedures performed in 98 children (49 male and 49 female) between March 1998 and April 2008. Intradissection (ID) and/or quality assurance images were obtained at the discretion of the surgeon. RESULTS The median age at surgery was 12 years (4 months-18 years). One hundred intracranial and 5 spinal procedures were performed; 22 of these procedures were performed for recurrent pathology. Surgical planning scans were obtained for 102 procedures, and neuronavigation was used in 93 patients. The greatest impact of iMR imaging was apparent in the 55 procedures to resect neoplastic lesions; ID scans were obtained in 49 of these procedures. Further surgery was performed in 49% of the procedures during which ID scans had been obtained. A smaller proportion of ID scans in the different cranial pathology groups (5 of 21 epilepsy cases, 4 of 9 vascular cases) resulted in further resections to meet the surgical goal of the surgeon. Two ID scans obtained during 5 procedures for the treatment of spinal disease did not lead to any change in surgery. Postoperative scans did not reveal any acute adverse events. There was 1 intraoperative adverse event in which a Greenberg retractor was inadvertently left on during ID scanning but was removed after the scout scans. CONCLUSIONS The application of iMR imaging in the pediatric neurosurgical population allows, at minimum, the opportunity to perform less invasive surgical exposures. Its potential is greatest when its high-quality imaging ability is coupled with its superior neuronavigation capabilities, which permits tracking of the extent of resection of intracranial tumors and, to a lesser extent, other lesions during the surgical procedure.
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Affiliation(s)
- Ron Levy
- Division of Neurosurgery, Department of Clinical Neuroscience, Faculty of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
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Wheatley BM. Selective amygdalohippocampectomy: the trans-middle temporal gyrus approach. Neurosurg Focus 2008; 25:E4. [DOI: 10.3171/foc/2008/25/9/e4] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The most common surgical procedure for the mesial temporal lobe is the standard anterior temporal resection or what is commonly called the anterior temporal lobectomy. There are, however, a number of other more selective procedures for removal of the mesial temporal lobe structures (amygdala, hippocampus, and parahippocampal gyrus) that spare much of the lateral temporal neocortex. Included in these procedures collectively referred to as selective amygdalohippocampectomy are the transsylvian, subtemporal, and transcortical (trans-middle temporal gyrus) selective amygdalohippocampectomy. In this manuscript the author reviews some of the surgical details of the trans-middle temporal gyrus approach to the mesial temporal structures.
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Stone SSD, Rutka JT. Utility of neuronavigation and neuromonitoring in epilepsy surgery. Neurosurg Focus 2008; 25:E17. [DOI: 10.3171/foc/2008/25/9/e17] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The management of medically refractory epilepsy poses both a valuable therapeutic opportunity and a formidable technical challenge to epilepsy surgeons. Recent decades have produced significant advancements in the capabilities and availability of adjunctive tools in epilepsy surgery. In particular, image-based neuronavigation and electrophysiological neuromonitoring represent versatile and informative modalities that can assist a surgeon in performing safe and effective resections. In the present article the authors discuss these 2 subjects with reference to how they can be applied and what evidence supports their use. As technologies evolve with demonstrated and potential utility, it is important for all clinicians who deal with epilepsy to understand where neuronavigation and neuromonitoring stand in the present and what avenues for improvement exist for the future.
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Nimsky C, Ganslandt O, Fahlbusch R. Comparing 0.2 tesla with 1.5 tesla intraoperative magnetic resonance imaging analysis of setup, workflow, and efficiency. Acad Radiol 2005; 12:1065-79. [PMID: 16099691 DOI: 10.1016/j.acra.2005.05.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2004] [Revised: 05/02/2005] [Accepted: 11/26/2004] [Indexed: 11/20/2022]
Abstract
RATIONALE AND OBJECTIVES To compare low-field with high-field intraoperative magnetic resonance imaging (MRI) in respect to setup, workflow, and efficiency. MATERIALS AND METHODS A total of 750 patients were investigated either with a 0.2 T (March 1996-July 2001) or a 1.5 T (April 2002-August 2004) MRI system adapted for intraoperative use. RESULTS With the low-field setup, 330 patients were examined in 65 months; with the high-field setup, 420 patients were examined in 29 months, which is a 2.8-fold increase in cases per month (14.5 versus 5.1) reflecting improved ease of use. Concerning intraoperative workflow, the time for preparation to start intraoperative imaging decreased fivefold (2 minutes instead of 10 minutes); navigation was applied more often with 57% versus 51% (240/420 versus 167/330), whereas functional data were integrated in 35% versus 39% (84/240 versus 65/167). Application of navigation updates was doubled (22% versus 11%; 53/240 versus 18/167). Image acquisition time was reduced by a factor of two, allowing a more detailed imaging protocol, whereas the image quality is clearly improved in the high-field setup, where there was no difference between the standard preoperative image quality compared with the intraoperative quality. This contributed to an increased detection of tumor remnants and extended resections in pituitary (36% versus 29%; 47/129 versus 17/59) and glioma surgery (41% versus 26%; 38/93 versus 28/106). CONCLUSION Compared with the low-field setup, the high-field setup results not only in clearly superior image quality and increased imaging armamentarium, contributing to increased rates of detected tumor remnants, but also in a distinct improvement of intraoperative workflow. Furthermore, intraoperative high-field MRI offers various modalities beyond standard anatomic imaging, such as magnetic resonance spectroscopy, diffusion tensor imaging, and functional MRI.
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Affiliation(s)
- Christopher Nimsky
- Department of Neurosurgery, University Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany.
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Nimsky C, Ganslandt O, Fahlbusch R. 1.5 T: intraoperative imaging beyond standard anatomic imaging. Neurosurg Clin N Am 2005; 16:185-200, vii. [PMID: 15561538 DOI: 10.1016/j.nec.2004.07.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Intraoperative high-field MRI with integrated microscope-based neuronavigation is a safe and reliable technique providing immediate intraoperative quality control. Major indications are pituitary tumor, glioma, and epilepsy surgery. Intraoperative high-field MRI provides intraoperative anatomic images at high quality that are up to the standard of pre- and postoperative neuroradiologic imaging. Compared with previous low-field MRI systems used for intraoperative imaging, not only is the image quality is clearly superior but the imaging spectrum is much wider and the intraoperative work flow is improved. Furthermore, high-field MRI offers various modalities beyond standard anatomic imaging, such as magnetic resonance spectroscopy, diffusion tensor imaging, and functional MRI.
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Affiliation(s)
- Christopher Nimsky
- Department of Neurosurgery, University Erlangen-Nuremberg, Schwabachanlage 6 91054 Erlangen, Germany.
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Oh DS, Black PM. A low-field intraoperative MRI system for glioma surgery: is it worthwhile? Neurosurg Clin N Am 2005; 16:135-41. [PMID: 15561533 DOI: 10.1016/j.nec.2004.07.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As intraoperative MRI expands its presence, its use will undoubtedly increase in glioma surgery. The foregoing discussion makes it clear that its benefits are unsurpassed by any other existing system. Because of their radiographic characteristics and gross appearance, gliomas are particularly suited for intraoperative MRI-guided surgery. It enables us to localize gliomas and define tumor margins precisely when, during surgery, the difference between tumor and brain is not easy to discern. The images generated during surgery serve as a detailed and updated map within which navigation is performed with utmost precision. Its significance is further highlighted when dealing with tumors in eloquent areas of the brain, where uncertainties over the location of tumor in relation to important brain structures can hinder the removal of tumor. By providing accurate positional information and in conjunction with cortical mapping techniques, intraoperative MRI enhances the confidence of the surgeon to go forward with resection or to stop when reaching important cortex. It allows us to perform the resection to the desired limit without causing injury to nearby important structures, thereby preventing postoperative neurologic deficits. The tracking system guides us in targeting each minute part of the tumor with unprecedented accuracy, and the ability to update images makes possible the constant evaluation of the progress of surgery. This near-real-time imaging can eliminate the errors brought about by the brain shifting that occurs throughout surgery. It also serves the important purpose of verifying the presence and position of any remaining tumor in the operative field. By means of sequential imaging, additional resection can be performed on any remaining tumor until imaging shows completion. The unwanted occurrence of finding residual tumor on a postoperative scan is thus practically eliminated. As a result, the surgical goal of complete or optimal resection can be achieved without any guesswork. Ultimately, what this means for the glioma patient is increased likelihood of longer survival brought about by a more thorough tumor resection. Intraoperative MRI addresses many of the surgical challenges posed by gliomas. As it becomes more available, there will come a point when the prevailing persuasion will be that some poorly defined tumors near eloquent cortex should not be operated on without intraoperative MRI. In the final analysis, not only is intraoperative MRI worthwhile but it will, in all likelihood, become a standard of care for many glioma cases.
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Affiliation(s)
- Dennis S Oh
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
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Kelly JJ, Hader WJ, Myles ST, Sutherland GR. Epilepsy surgery with intraoperative MRI at 1.5 T. Neurosurg Clin N Am 2005; 16:173-83. [PMID: 15561537 DOI: 10.1016/j.nec.2004.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Despite the infancy of iMRI in epilepsy surgery and the paucity of literature on this topic, some conclusions may be reached. Although iMRI is a useful adjunct during epilepsy procedures, a randomized control trial is necessary to determine its true impact.
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Affiliation(s)
- John J Kelly
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, 1403 29th Street NW, Calgary, T2N 2T9 Alberta, Canada
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Schulz T, Puccini S, Schneider JP, Kahn T. Interventional and intraoperative MR: review and update of techniques and clinical experience. Eur Radiol 2004; 14:2212-27. [PMID: 15480689 DOI: 10.1007/s00330-004-2496-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Revised: 08/12/2004] [Accepted: 08/16/2004] [Indexed: 11/30/2022]
Abstract
The concept of interventional magnetic resonance imaging (MRI) is based on the integration of diagnostic and therapeutic procedures, favored by the combination of the excellent morphological and functional imaging characteristics of MRI. The spectrum of MRI-assisted interventions ranges from biopsies and intraoperative guidance to thermal ablation modalities and vascular interventions. The most relevant recently published experimental and clinical results are discussed. In the future, interventional MRI is expected to play an important role in interventional radiology, minimal invasive therapy and guidance of surgical procedures. However, the associated high costs require a careful evaluation of its potentials in order to ensure cost-effective medical care.
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Affiliation(s)
- Thomas Schulz
- Department of Diagnostic Radiology, Leipzig University Hospital, Liebigstrasse 20, 04103 Leipzig, Germany.
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Abstract
Our concept of computer assisted surgery is based on the combination of intraoperative magnetic resonance (MR) imaging with microscope-based neuronavigation, providing anatomical and functional guidance simultaneously. Intraoperative imaging evaluates the extent of a resection, while the additional use of functional neuronavigation, which displays the position of eloquent brain areas in the operative field, prevents increasing neurological deficits, which would otherwise result from extended resections. Up to mid 2001 we performed intraoperative MR imaging using a low-field 0.2 Tesla scanner in 330 patients. The main indications were the evaluation of the extent of resection in gliomas, pituitary tumours, and in epilepsy surgery. Intraoperative MR imaging proved to serve as intraoperative quality control with the possibility of an immediate modification of the surgical strategy, i.e. extension of the resection. Integrated use of functional neuronavigation prevented increased neurological deficits. Compared to routine pre- or postoperative imaging being performed with high-Tesla machines, intraoperative image quality and sequence spectrum could not compete. This led to the development of the concept to adapt a high-field MR scanner to the operating environment, preserving the benefits of using standard microsurgical equipment and microscope-based neuronavigational guidance with integrated functional data, which was successfully implemented by April 2002. Up to the end of 2002, 95 patients were investigated with the new setup. Improved image quality, intraoperative workflow, as well as enhanced sophisticated intraoperative imaging possibilities are the major benefits of the high-field setup.
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Affiliation(s)
- C Nimsky
- Department of Neurosurgery, University Erlangen-Nürnberg, Erlangen, Germany
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Abstract
Minimally invasive interventional radiological procedures, such as balloon angioplasty, stent placement or coiling of aneurysms, play an increasingly important role in the treatment of patients suffering from vascular disease. The non-destructive nature of magnetic resonance imaging (MRI), its ability to combine the acquisition of high quality anatomical images and functional information, such as blood flow velocities, perfusion and diffusion, together with its inherent three dimensionality and tomographic imaging capacities, have been advocated as advantages of using the MRI technique for guidance of endovascular radiological interventions. Within this light, endovascular interventional MRI has emerged as an interesting and promising new branch of interventional radiology. In this review article, the authors will give an overview of the most important issues related to this field. In this context, we will focus on the prerequisites for endovascular interventional MRI to come to maturity. In particular, the various approaches for device tracking that were proposed will be discussed and categorized. Furthermore, dedicated MRI systems, safety and compatibility issues and promising applications that could become clinical practice in the future will be discussed.
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Affiliation(s)
- L W Bartels
- Department of Radiology, Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, Room E.01.335, 3584 CX Utrecht, The Netherlands.
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Schmitz B, Nimsky C, Wendel G, Wienerl J, Ganslandt O, Jacobi K, Fahlbusch R, Schüttler J. Anesthesia during high-field intraoperative magnetic resonance imaging experience with 80 consecutive cases. J Neurosurg Anesthesiol 2003; 15:255-62. [PMID: 12826974 DOI: 10.1097/00008506-200307000-00014] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Intraoperative magnetic resonance imaging (MRI) has been used for years to update neuronavigation and for intraoperative resection control. For this purpose, low-field (0.1-0.2 T) MR scanners have been installed in the operating room, which, in contrast to machines using higher magnetic field strength, allowed the use of standard anesthetic and surgical equipment. However, these low-field MR systems provided only minor image quality and a limited battery of MR sequences, excluding functional MRI, diffusion-weighted MRI, or MR angiography and spectroscopy. Based on these advantages, a concept using high-field MRI (1.5 T) with intraoperative functional neuronavigational guidance has been developed that required adaptation of the anesthetic regimen to working in the close vicinity to the strong magnetic field. In this paper the authors present their experience with the first 80 consecutive patients who received anesthesia in a specially designed radio frequency-shielded operating room equipped with a high-field (1.5 T) MR scanner. We describe the MR-compatible anesthesia equipment used including ventilator, monitoring, and syringe pumps, which allow standard neuroanesthesia in this new and challenging environment. This equipment provides the use of total intravenous anesthesia with propofol and remifentanil allowing rapid extubation and neurologic examination following surgery. In addition, extended intraoperative monitoring including EEG monitoring required for intracranial surgery is possible. Moreover, problems and dangers related to the effects of the strong magnetic field are discussed.
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Affiliation(s)
- Bernd Schmitz
- Department of Anesthesiology, University of Erlangen-Nuremberg, Erlangen, Germany
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Nimsky C, Ganslandt O, Buchfelder M, Fahlbusch R. Glioma surgery evaluated by intraoperative low-field magnetic resonance imaging. ACTA NEUROCHIRURGICA. SUPPLEMENT 2003; 85:55-63. [PMID: 12570138 DOI: 10.1007/978-3-7091-6043-5_8] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To give an overview on intraoperative magnetic resonance (MR) imaging in glioma surgery. MATERIAL AND METHODS MR imaging was performed using a 0.2T scanner, located in a radiofrequency-shielded operating theatre. Two setups were used: surgery either in a neighbouring operating theatre, or directly at the 5G line. Additionally, in gliomas adjacent to eloquent brain areas microscope- or pointer-based neuronavigation with integrated functional data was applied. 106 gliomas were among the 330 patients investigated in the last 5 years. RESULTS We did not observe complications attributable to intraoperative MR imaging. Image quality was sufficient to evaluate the extent of the tumour resection in the majority of cases. Intraoperative imaging revealed remaining tumour in 63%. In a total of 26% patients further tumour could be removed due to the results of intraoperative imaging, increasing the rate of complete tumour removal especially in the low-grade tumours. The additional use of functional neuronavigation prevented an increased morbidity. CONCLUSION Intraoperative MR imaging offers the possibility of further tumour removal during the same surgical procedure in case of tumour remnants, increasing the rate of complete tumour removal. The effects of brain shift can be compensated for using intraoperative image data for updating.
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Affiliation(s)
- C Nimsky
- Department of Neurosurgery, University Erlangen-Nürnberg, Erlangen, Germany
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Nimsky C, Ganslandt O, Gralla J, Buchfelder M, Fahlbusch R. Intraoperative low-field magnetic resonance imaging in pediatric neurosurgery. Pediatr Neurosurg 2003; 38:83-9. [PMID: 12566841 DOI: 10.1159/000068046] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2002] [Accepted: 09/04/2002] [Indexed: 11/19/2022]
Abstract
BACKGROUND Since the mid-1990s, the feasibility and indications of intraoperative magnetic resonance (MR) imaging have been investigated by different groups. The majority of examinations were carried out in adults. The aim of this study was to summarize our experience of over 5 years of intraoperative MR imaging in pediatric neurosurgery. METHODS For scanning, we used a 0.2-Tesla Magnetom Open, which was placed in a radiofrequency-shielded twin operating theater, allowing surgery with standard instruments and additional neuronavigational guidance either in an adjacent operating room or directly in the radiofrequency cabin on the extended MR table, at the 5-G line. RESULTS In total, 330 patients were investigated, among them 33 children who were younger than 17 years. We found four main indications for intraoperative MR imaging: the evaluation of cyst drainage (n = 9), of the extent of resection in epilepsy surgery (n = 6) and of the removal of pituitary tumors (n = 6) and gliomas and other brain tumors (n = 12). Intraoperative MR imaging allowed us to evaluate the extent of the resection or to monitor catheter placements and consecutive cyst alterations in all cases. In 2 tumor cases and 3 catheter placements, intraoperative imaging resulted in a modification of the surgical strategy. CONCLUSIONS Intraoperative low-field MR imaging is a safe procedure; we did not encounter an increased morbidity in the children investigated. It serves as intraoperative quality control documenting the effects of surgery, e.g. the extent of a resection, which can then be compared to the treatment plan. Besides its most essential application in brain tumors, it also proved to be particularly helpful in children undergoing complicated catheter placements for cyst drainage, as well as in pituitary and epilepsy surgery.
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Affiliation(s)
- Christopher Nimsky
- Department of Neurosurgery, University Erlangen-Nuremberg, Erlangen, Germany.
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From Intraoperative Patient Transport to Surgery in the Fringe Field–Intraoperative Application of Magnetic Resonance Imaging Using a 0.2-Tesla Scanner: The Erlangen Experience. ACTA ACUST UNITED AC 2002. [DOI: 10.1097/00127927-200207040-00004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hodaie M, Musharbash A, Otsubo H, Snead OC, Chitoku S, Ochi A, Holowka S, Hoffman HJ, Rutka JT. Image-guided, frameless stereotactic sectioning of the corpus callosum in children with intractable epilepsy. Pediatr Neurosurg 2001; 34:286-94. [PMID: 11455228 DOI: 10.1159/000056040] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Corpus callosotomy is an effective neurosurgical procedure for children with intractable atonic or drop attack seizures. While this procedure has not changed significantly over the past three decades, some technical issues remain to be resolved. These include the intraoperative determination of the extent of the callosotomy, the need to stage the procedure, as well as side of approach of craniotomy. We report our 8-year experience with corpus callosotomy using a frameless stereotactic image-guided system (ISG Viewing Wand). Seventeen children with atonic seizures underwent sectioning of the corpus callosum. The mean patient age was 10.5 years. Six children underwent complete callosotomy while 11 underwent resection of the anterior two-thirds. MRI 3D reconstruction of the sagittal sinus and draining cerebral veins was undertaken in all cases. The side of the craniotomy was determined on the basis of favorability of the draining veins with respect to the extent of the callosotomy. The extent of the callosotomy was determined by intraoperative feedback using the ISG Viewing Wand((R)). Nine of 11 patients in the partial callosotomy group and 4 of 6 patients in the complete callosotomy group showed significant improvement in atonic seizures. We conclude that the use of frameless stereotaxy can function as an important adjunct in the planning and conduction of successful sectioning of the corpus callosum in children with intractable seizures.
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Affiliation(s)
- M Hodaie
- Division of Neurosurgery, Hospital for Sick Children and University of Toronto, Ont., Canada
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