scholarly journals Optimization of Curvilinear Needle Trajectories for Transforamenal Hippocampotomy

2016 ◽  
Vol 13 (1) ◽  
pp. 15-22 ◽  
Author(s):  
David B. Comber ◽  
E. Bryn Pitt ◽  
Hunter B. Gilbert ◽  
Matthew W. Powelson ◽  
Emily Matijevich ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Medial Axis ◽  
Tumor Resection ◽  
Percutaneous Treatment ◽  
Thermal Therapy ◽  
Foramen Ovale ◽  
Worst Case ◽  
Seizure Disorders ◽  
Thermal Therapies ◽  
Concentric Tube Robot

Abstract BACKGROUND: The recently developed magnetic resonance imaging–guided laser-induced thermal therapy offers a minimally invasive alternative to craniotomies performed for tumor resection or for amygdalohippocampectomy to control seizure disorders. Current laser-induced thermal therapies rely on linear stereotactic trajectories that mandate twist-drill entry into the skull and potentially long approaches traversing healthy brain. The use of robotically driven, telescoping, curved needles has the potential to reduce procedure invasiveness by tailoring trajectories to the curved shape of the ablated structure and by enabling access through natural orifices. OBJECTIVE: To investigate the feasibility of using a concentric tube robot to access the hippocampus through the foramen ovale to deliver thermal therapy and thereby provide a percutaneous treatment for epilepsy without drilling the skull. METHODS: The skull and both hippocampi were segmented from dual computed tomography/magnetic resonance image volumes for 10 patients. For each of the 20 hippocampi, a concentric tube robot was designed and optimized to traverse a trajectory from the foramen ovale to and through the hippocampus from head to tail. RESULTS: Across all 20 cases, the mean distances (errors) between the hippocampus medial axis and backbone of the needle were 0.55, 1.11, and 1.66 mm for the best, mean, and worst case, respectively. CONCLUSION: These curvilinear trajectories would provide accurate transforamenal delivery of an ablation probe to typical hippocampus volumes. This strategy has the potential both to decrease the invasiveness of the procedure and to increase the completeness of hippocampal ablation.

Percutaneous Treatment of Congenital Defects of the Inter-atrial Septum in Adults – Recent Advances and Persistent Pitfalls

2009 ◽  
Vol 4 (1) ◽  
pp. 76
Author(s):  
James Slater ◽  
Mark Fisch ◽  
◽  
Keyword(s):  
Atrial Septal Defect ◽  
Adult Patient ◽  
Patent Foramen Ovale ◽  
Septal Defect ◽  
Percutaneous Treatment ◽  
Atrial Septum ◽  
Congenital Defects ◽  
Foramen Ovale ◽  
Anatomy And Physiology ◽  
Specific Tissue

William Harvey was the first scientist to describe the heart as consisting of separate right- and left-sided circulations. Our understanding of the heart’s anatomy and physiology has grown significantly since this landmark discovery in 1628. Today, we recognise not only the importance of these separate systems, but also the specific tissue that divides them. Our growing understanding of the inter-atrial septum has allowed us to identify defects within this structure and develop effective percutaneous devices for closure of these defects in the adult patient. This article discusses the formation of a patent foramen ovale (PFO) and atrial septal defect (ASD). In addition, we describe the medical illnesses caused by these defects and summarise the indications and risks related to percutaneous closure of these defects. We also report the most up-to-date transcatheter therapeutic options for closure of these common congenital defects in the adult patient.

scholarly journals NI-01 Usefulness of preoperative evaluation of glioma elasticity by the magnetic resonance elastography

2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii12-ii13
Author(s):  
Shinichiro Koizumi ◽  
Kazuhiko Kurozumi
Keyword(s):  
Elastic Modulus ◽  
Magnetic Resonance ◽  
Preoperative Evaluation ◽  
Tumor Resection ◽  
High Grade Glioma ◽  
Magnetic Resonance Elastography ◽  
Low Grade ◽  
Intracranial Tumors ◽  
Grade 3 ◽  
Malignant Grade

Abstract Introduction: The elasticity of intracranial tumors is difficult to assess non-invasively because the lesion is surrounded by the skull. Therefore, intracranial tumors have not been verified before surgery in terms of elastic modulus. Magnetic resonance elastography (MRE) is an epoch-making method capable of non-invasively imaging the elasticity of internal organs. We have examined the elasticity of meningiomas and pituitary adenomas and reported their usefulness. This time, we measured the glioma elasticity and verified usefulness of MRE. Method: Twenty-four gliomas (mean age 51.8±15.7 years, male: female = 17: 7) who underwent tumor resection after MRE imaging from July 2017 to May 2020 were targeted. The average elasticity was measured as an evaluation of tumor elastic modulus by MRE. Gliomas were divided into a low-grade glioma group (LGG: Grade 1, 2) and a high-grade glioma group (HGG: Grade 3, 4). Then, a comparative statistical study was conducted. Results: The average values of the average elasticity of LGG group (9 cases) and HGG group (15 cases) were 1.8±0.8 kPa and 2.5±0.8 kPa, respectively. The average elasticity was significantly higher in the HGG group (p=0.023). In the ROC analysis, the cutoff value was 2.1 kPa (sensitivity 70%, specificity 70%). Therefore, it was suggested that the tumor is likely to be HGG when the average elasticity is 2.1 kPa or more. Discussion: The glioma elasticity by preoperative MRE was significantly higher in the HGG group. Based on actual surgical experience, the tumor seems to be hard in the HGG group, and it was judged to be consistent with this our MRE research. The preoperative evaluation of glioma elasticity by MRE was considered useful, and it might help in planning a surgical strategy considering malignant grade.

scholarly journals Safety aspects of the PiCCO thermodilution-cardiac output catheter during magnetic resonance imaging at 3 Tesla

2021 ◽  
Author(s):  
Marieke Voet ◽  
Christiaan G. Overduin ◽  
Ernst L. Stille ◽  
Jurgen J. Fütterer ◽  
Joris Lemson
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiac Output ◽  
Magnetic Resonance ◽  
Critically Ill ◽  
Cardiac Output Monitoring ◽  
Measured Temperature ◽  
Resonance Imaging ◽  
Worst Case ◽  
Thermodilution Cardiac Output ◽  
3T Mri

AbstractThermodilution cardiac output monitoring, using a thermistor-tipped intravascular catheter, is used in critically ill patients to guide hemodynamic therapy. Often, these patients also need magnetic resonance imaging (MRI) for diagnostic or prognostic reasons. As thermodilution catheters contain metal, they are considered MRI-unsafe and advised to be removed prior to investigation. However, removal and replacement of the catheter carries risks of bleeding, perforation and infection. This research is an in vitro safety assessment of the PiCCO™ thermodilution catheter during 3 T Magnetic Resonance Imaging (3T-MRI).  In a 3T-MRI environment, three different PiCCO™ catheter sizes were investigated in an agarose-gel, tissue mimicking phantom. Two temperature probes measured radiofrequency-induced heating; one at the catheter tip and one at a reference point. Magnetically induced catheter dislocation was assessed by visual observation as well as by analysis of the tomographic images. For all tested catheters, the highest measured temperature increase was 0.2 °C at the center of the bore and 0.3 °C under “worst-case” setting for the tested MRI pulse sequences. No magnetically induced catheter displacements were observed. Under the tested circumstances, no heating or dislocation of the PiCCO™ catheter was observed in a tissue mimicking phantom during 3T-MRI. Leaving the catheter in the critically ill patient during MRI investigation might pose a lower risk of complications than catheter removal and replacement.

Quantification of Glioma Removal by Intraoperative High-Field Magnetic Resonance Imaging: An Update

Neurosurgery ◽  
2011 ◽  
Vol 69 (4) ◽  
pp. 852-863 ◽  
Author(s):  
Daniela Kuhnt ◽  
Oliver Ganslandt ◽  
Sven-Martin Schlaffer ◽  
Michael Buchfelder ◽  
Christopher Nimsky
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Field ◽  
Tumor Volume ◽  
Tumor Resection ◽  
World Health ◽  
Incomplete Resection ◽  
Resonance Imaging ◽  
Glioma Surgery ◽  
Who Grade

Abstract BACKGROUND: The beneficial role of the extent of resection (EOR) in glioma surgery in correlation to increased survival remains controversial. However, common literature favors maximum EOR with preservation of neurological function, which is shown to be associated with a significantly improved outcome. OBJECTIVE: In order to obtain a maximum EOR, it was examined whether high-field intraoperative magnetic resonance imaging (iMRI) combined with multimodal navigation contributes to a significantly improved EOR in glioma surgery. METHODS: Two hundred ninety-three glioma patients underwent craniotomy and tumor resection with the aid of intraoperative 1.5 T MRI and integrated multimodal navigation. In cases of remnant tumor, an update of navigation was performed with intraoperative images. Tumor volume was quantified pre- and intraoperatively by segmentation of T2 abnormality in low-grade and contrast enhancement in high-grade gliomas. RESULTS: In 25.9% of all cases examined, additional tumor mass was removed as a result of iMRI. This led to complete tumor resection in 20 cases, increasing the rate of gross-total removal from 31.7% to 38.6%. In 56 patients, additional but incomplete resection was performed because of the close location to eloquent brain areas. Volumetric analysis showed a significantly (P < .01) reduced mean percentage of tumor volume following additional further resection after iMRI from 33.5% ± 25.1% to 14.7% ± 23.3% (World Health Organization [WHO] grade I, 32.8% ± 21.9% to 6.1% ± 18.8%; WHO grade II, 24.4% ± 25.1% to 10.8% ± 11.0%; WHO grade III, 35.1% ± 27.3% to 24.8% ± 26.3%; WHO grade IV, 34.2% ± 23.7% to 1.2% ± 16.2%). CONCLUSION: MRI in conjunction with multimodal navigation and an intraoperative updating procedure enlarges tumor-volume reduction in glioma surgery significantly without higher postoperative morbidity.

The percutaneous treatment of Patent Foramen Ovale, an effective and safe therapeutic choice

Open Medicine ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. 638-643
Author(s):  
S. Evola ◽  
R. Trovato ◽  
B. Kauroo ◽  
L. Alioto ◽  
V. Sucato ◽  
...  
Keyword(s):  
Patent Foramen Ovale ◽  
Percutaneous Treatment ◽  
Foramen Ovale ◽  
Therapeutic Choice

Abstract

Does the Modified Arrhenius Model Reliably Predict Area of Tissue Ablation After Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Pediatric Lesional Epilepsy?

2021 ◽  
Author(s):  
Kelsey D Cobourn ◽  
Imazul Qadir ◽  
Islam Fayed ◽  
Hepzibha Alexander ◽  
Chima O Oluigbo
Keyword(s):  
Magnetic Resonance ◽  
Linear Regression ◽  
Magnetic Resonance Images ◽  
Thermal Therapy ◽  
Invasive Technique ◽  
Hypothalamic Hamartoma ◽  
Arrhenius Model ◽  
Laser Interstitial Thermal Therapy ◽  
Accuracy And Precision

Abstract BACKGROUND Commercial magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) systems utilize a generalized Arrhenius model to estimate the area of tissue damage based on the power and time of ablation. However, the reliability of these estimates in Vivo remains unclear. OBJECTIVE To determine the accuracy and precision of the thermal damage estimate (TDE) calculated by commercially available MRgLITT systems using the generalized Arrhenius model. METHODS A single-center retrospective review of pediatric patients undergoing MRgLITT for lesional epilepsy was performed. The area of each lesion was measured on both TDE and intraoperative postablation, postcontrast T1 magnetic resonance images using ImageJ. Lesions requiring multiple ablations were excluded. The strength of the correlation between TDE and postlesioning measurements was assessed via linear regression. RESULTS A total of 32 lesions were identified in 19 patients. After exclusion, 13 pairs were available for analysis. Linear regression demonstrated a strong correlation between estimated and actual ablation areas (R2 = .97, P < .00001). The TDE underestimated the area of ablation by an average of 3.92% overall (standard error (SE) = 4.57%), but this varied depending on the type of pathologic tissue involved. TDE accuracy and precision were highest in tubers (n = 3), with average underestimation of 2.33% (SE = 0.33%). TDE underestimated the lesioning of the single hypothalamic hamartoma in our series by 52%. In periventricular nodular heterotopias, TDE overestimated ablation areas by an average of 13% (n = 2). CONCLUSION TDE reliability is variably consistent across tissue types, particularly in smaller or periventricular lesions. Further investigation is needed to understand the accuracy of this emerging minimally invasive technique.

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