Use Of Intraoperative Magnetic Resonance Imaging Research Articles

Intraoperative Magnetic Resonance Imaging Assisted Endoscopic Endonasal Resection of Clival Chordomas.

BackgroundCranial base chordomas are typically indolent and usually appear as encapsulated tumors. They slowly grow by infiltrating the bone, along with the lines of least resistance. Due to its relationship with important neurovascular structures, skull base chordoma surgery is challenging.ObjectiveThe usefulness of intraoperative magnetic resonance imaging (IO-MRI) in achieving the goal of surgery, is evaluated in this study.MethodsBetween March 2018 and March 2020, 42 patients were operated on for resection of skull base chordomas in our institution. All of them were operated on under IO-MRI. Patients were analyzed retrospectively for identifying common residue locations, complications and early post-operative outcomes.ResultsIn 22 patients (52,4%) gross total resection was achieved according to the final IO-MRI. In 20 patients (47,6%) complete tumor removal was not possible because of extension to the petrous bone (8 patients), pontocerebellar angle (6 patients), prepontine cistern (4 patients), temporobasal (1 patient), cervical axis (1 patient). In 13 patients, the surgery was continued after the first IO-MRI control was performed, which showed a resectable residual tumor. 7 of these patients achieved total resection according to the second IO-MRI, in the other 6 patients all efforts were made to ensure maximal resection of the tumor as much as possible without morbidity. Repeated IO-MRI helped achieve gross total resection in 7 patients (53.8%).ConclusionsOur study proves that the use of IO-MRI is a safe method that provides the opportunity to show the degree of resection in skull base chordomas and to evaluate the volume and location of the residual tumor intraoperatively. Hence IO-MRI can improve the life expectancy of patients because it provides an opportunity for both gross total resection and maximal safe resection in cases where total resection is not possible.

INNV-09. SURGICAL STRATEGIES FOR OLDER PATIENTS WITH GLIOBLASTOMA

Abstract OBJECTIVE Though image-guided surgery with intraoperative magnetic resonance imaging (IoMRI) is associated with higher extent of resection, we aimed to determine the clinical outcome of its use, compared to other less time-consuming intraoperative ultrasound (IoUS), in this patient population. METHODS Clinical data of 221 consecutive patients aged 70 years or older, who underwent surgical resection for GBM with intraoperative ultrasonography (IoUS) alone or combination of IoMRI + IoUS at Yale New Haven Hospital and Memorial Sloan Kettering Cancer Center were retrospectively reviewed. Variables were analyzed, and comparative analyses were performed, including predictors of overall survival. RESULTS The addition of IoMRI was not superior to IoUS alone in terms of overall survival (OS) (HR=0.85, 95% CI 0.49-1.47; P= 0.56) or Karnofsky Performance Score (KPS) at 6 weeks postoperatively (OR=0.51, 95% CI 0.22-1.15; P= 0.102). On the contrary, the length of surgery (LOSx) was significantly longer (P< 0.0001) in the IoMRI group. Postoperative complications were significantly less in the IoUS-only group (OR=0.17, 95% CI 0.3-0.46; P=0.002) and in patients who had a preoperative KPS score of 70 or higher (OR=0.092, 95% CI 0.018-0.47; P=0.004). Patients with relatively lower preoperative KPS scores (< 70) showed significant clinical improvement at 6 weeks postoperatively (P=0.0002). Patients with postoperative complications were more likely to have lower KPS scores at 6 weeks postoperatively (OR=0.30, 95% CI 0.10-0.89; P= 0.031), while increased extent of resection was associated with improved KPS scores at 6 weeks postoperatively (OR=2.171, 95% CI 1.22-3.87; P= 0.009). CONCLUSION Aggressive management with surgical resection should be considered in older patients with GBM, even those with relatively poor KPS scores. The use of IoMRI in this patient population does not appear to yield any survival benefit over IoUS but instead significantly prolongs the length of surgery, increasing the risk for potential postoperative complications.

First application of intraoperative MRI of the liver during ALPPS procedure for colorectal liver metastases

PurposeIntraoperative detection of intrahepatic lesions can be demanding. The use of preoperative contrast-enhanced magnetic resonance imaging (MRI) or computer tomography (CT) combined with intraoperative ultrasound of the liver is state of the art. Near totally regressed colorectal liver metastases (CRLM) after neoadjuvant chemotherapy or nodules in severely altered liver tissue as steatosis or cirrhosis are often hard to detect during the operative procedure. Especially differentiation between benign atypical nodules and malignant tumors can be very difficult. The intraoperative use of contrast-enhanced ultrasound or intraoperative navigation are helpful tools. However, both methods show relevant limitations.The use of intraoperative MRI (ioMRI) can overcome this problem. Relevant structures can be marked within the operative site or immediate control of complete tumor resection can be achieved. This might allow immediate surgical optimization in case of failure.MethodsWe report the intraoperative application of ioMRI in a case of a 61-year-old male patient suffering from rectal cancer with 10 synchronous bilobar CRLM who was treated stepwise by multimodal treatment and staged hepatectomy. Intraoperative contrast-enhanced MRI of the liver was used during completion procedure of an extended right hemihepatectomy performed as “Associating Liver Partition and Portal vein Ligation for Staged hepatectomy (ALPPS)”.ResultsioMRI provided excellent images and showed absence of liver metastases in the liver remnant. Procedure of ioMRI was safe, fast and feasible.ConclusionTo the best of our knowledge, we describe the first case of intraoperative application of a contrast-enhanced MRI during open liver surgery at the University Hospital of Dresden.

Survival trends in glioma: Experience at a tertiary care centre.

Even after decades of research in the field of gliomas, the overall prognosis is still quite dismal. Several factors have been proposed that affect the outcome and survival length of patients with a glioma. Here, we present a series of 471 patients, who underwent surgical resection of their glioma at a tertiary level neurosurgical centre. We noted retrospective data of patients' age, histological tumor grade, and whether or not intraoperative magnetic resonance imaging (MRI) was used, and assessed the survival length of these patients from the day of surgery. The overall survival in our series was approximately 14 months. Predictably, those with age less than 40 years and those with Karnofsky performance score (KPS) ≥80 had longer survival than those with a higher age and KPS <80; those with World Health Organisation (WHO) grade IV lesions had the shortest survival length compared to all the other grades. However, while comparing survival among other tumor grades, we did not find significant difference. Further, use of intraoperative MRI did not offer any statistically significant difference in survival. In addition to the conventional prognostic factors we need more definate ways to accurately predict survival in patients harbouring a glioma. Probably, assessing molecular characteristics of the individual tumors, such as presence of isocitrate dehydrogenase (IDH) mutation versus wild-type IDH, would help us in predicting survival more accurately.

Randomized trial for superiority of high field strength intra-operative magnetic resonance imaging guided resection in pituitary surgery

Till date there are no randomized trials to suggest the superiority of intra-operative magnetic resonance imaging (IOMRI) guided trans-sphenoidal pituitary resection over two dimensional fluoroscopic (2D-F) guided resections. We conducted this trial to establish the superiority of IOMRI in pituitary surgery. Primary objective was to compare extent of tumor resection between the two study arms. It was a prospective, randomized, outcome assessor and statistician blinded, two arm (A: IOMRI, n=25 and B: 2D-F, n=25), parallel group clinical trial. 4 patients from IOMRI group cross-over to 2D-F group and were consequently analyzed in latter group, based on modified intent to treat method. A total of 50 patients were enrolled till completion of trial (n=25 in each study arm). Demographic profile and baseline parameters were comparable among the two arms (p>0.05) except for higher number of endoscopic procedures and experienced neurosurgeons (>10years) in arm B (p=0.02, 0.002 respectively). Extent of resection was similar in both study arms (A, 94.9% vs B, 93.6%; p=0.78), despite adjusting for experience of operating surgeon and use of microscope/endoscope for surgical resection. We observed that use of IOMRI helped optimize the extent of resection in 5/20 patients (25%) for pituitary tumor resection in-group A. Present study failed to observe superiorty of IOMRI over conventional 2D-F guided resection in pituitary macroadenoma surgery. By use of this technology, younger surgeons could validate their results intra-operatively and hence could increase EOR without causing any increase in complications.

Intraoperative Magnetic Resonance Imaging in Intracranial Glioma Resection: A Single-Center, Retrospective Blinded Volumetric Study

Intraoperative magnetic resonance imaging (IoMRI) was devised to overcome brain shifts during craniotomies. Yet, the acceptance of IoMRI is limited. To evaluate impact of IoMRI on intracranial glioma resection outcome including overall patient survival. A retrospective review of records was performed on a cohort of 164 consecutive patients who underwent resection surgery for newly diagnosed intracranial gliomas either with or without IoMRI technology performed by 2 neurosurgeons in our center. Patient follow-up was at least 5 years. Extent of resection (EOR) was calculated using pre- and postoperative contrast-enhanced and T2-weighted MR-images. Adjusted analysis was performed to compare gross total resection (GTR), EOR, permanent surgery-associated neurologic deficit, and overall survival between the 2 groups. Overall median EOR was 92.1%, and 97.45% with IoMRI use and 89.9% without IoMRI, with crude (unadjusted) P < 0.005. GTR was achieved in 49.3% of IoMRI cases, versus in only 21.4% of no-IoMRI cases, P < 0.001. GTR achieved was more with the use of IoMRI among gliomas located in both eloquent and noneloquent brain areas, P = 0.017 and <0.001, respectively. Permanent surgery-associated neurologic deficit was not (statistically) more significant with no-IoMRI, P = 0.284 (13.8% vs. 6.7%). In addition, the IoMRI group had better 5-year overall survival, P < 0.001. This study shows that the use of IoMRI was associated with greater rates of EOR and GTR, and better overall 5-year survival in both eloquent brain areas located and non-eloquent brain areas located gliomas, with no increased risk of neurologic complication.

Intraoperative MRI for neurosurgical and general surgical interventions.

The use of intraoperative magnetic resonance imaging (IMRI) during surgeries and procedures has expanded in the last decade. Not only is it becoming more commonly used for a variety of adult and pediatric neurosurgical procedures, but also its use has expanded to other types of surgeries. Along with using IMRI for removing tumors of the spinal cord, surgeons are now using it for other types of surgical operations of the kidney and liver. The increased utilization during the intraoperative period warrants the anesthesia provider to assure that patients and staff are unharmed because of increased risk of the powerful magnet. Recent literature is reviewed regarding the expansive use of IMRI in the operating and procedure room. Safety issues and anesthetic implications are also addressed. IMRI is becoming increasingly more popular, especially with neurosurgeons, but its use is also expanding to other types of surgeries. Because of the increased use, the anesthesia provider must be aware of the dangers that it imposes to those involved and take necessary safety precautions. This will help assure that no one is harmed during the operation or procedure.

Use of Intraoperative MRI for Functional Preservation in Neurosurgical Procedures

From March 1996 until July 2008, 1540 patients were examined at the Department of Neurosurgery at the University of Erlangen with intraoperative magnetic resonance imaging (MRI). The low-field (n = 330) and high-field (n = 1210) experiences are summarized. Intraoperative MRI is a safe and reliable procedure, whatever system is used. In the low-field system, there was a distinct difference in image quality between pre- and intraoperative imaging. Intraoperative high-field MRI results in images with the same quality as in standard preoperative neuroradiological routine diagnostics.

Craniotomy for tumor treatment in an intraoperative magnetic resonance imaging unit.

The complex three-dimensional anatomic features of the brain and its vulnerability to surgical intervention make the surgical treatment of intracranial tumors challenging. We evaluated the surgical treatment of supratentorial tumors using intraoperative magnetic resonance imaging (MRI), which provides real-time guidance, allows localization of intracranial tumors and their margins, and facilitates continuous assessment of surgical progress. Sixty patients underwent craniotomies for tumor treatment in the General Electric intraoperative MRI unit at the Brigham and Women's Hospital (Boston, MA) during a 1-year period. The patients selected were those with intracranial tumors that were considered difficult to resect because of their locations or previous incomplete operations. Twenty-nine low-grade and 19 high-grade gliomas, 8 metastatic lesions, 2 meningiomas, 1 pineoblastoma, and 1 astroblastoma were resected. Tumors were accurately localized and targeted, and the extent of resection, as well as any intraoperative complications, could be immediately assessed during surgery. Marked brain shifting occurred during the procedures, and repeated intraoperative imaging allowed surgical accommodation for this shifting. In more than one-third of the cases, intraoperative imaging showed residual tumor when resection appeared complete on the basis of surgical observation alone. Intraoperative MRI is a revolutionary tool for the surgical treatment of brain tumors, providing observation of the procedure as it is being performed. With intraoperative MRI, tumor resection is safer, the extent of resection can be directly evaluated, and intraoperative complications can be noted if they occur. Outcomes after resection depend on minimizing injury to normal brain tissue and achieving maximal tumor resection. The use of intraoperative MRI directly affects these factors.