scholarly journals Use of a novel ball-joint guide array for magnetic resonance imaging–guided cannula placement and convective delivery: technical note

2020 ◽  
pp. 1-7
Author(s):  
Krystof S. Bankiewicz ◽  
Tomasz Pasterski ◽  
Daniel Kreatsoulas ◽  
Jakub Onikijuk ◽  
Krzysztof Mozgiel ◽  
...  
Keyword(s):  
Technical Note ◽  
Acid Decarboxylase ◽  
Ball Joint ◽  
Imaging Data ◽  
Convection Enhanced Delivery ◽  
Amino Acid Decarboxylase ◽  
Radial Error ◽  
The Mean ◽  
Mri Guided ◽  
Cannula Placement

OBJECTIVEThe objective of this study was to assess the feasibility, accuracy, effectiveness, and safety of an MRI-compatible frameless stereotactic ball-joint guide array (BJGA) as a platform for cannula placement and convection-enhanced delivery (CED).METHODSThe authors analyzed the clinical and imaging data from consecutive patients with aromatic l-amino acid decarboxylase (AADC) deficiency who underwent infusion of adeno-associated virus (AAV) containing the AADC gene (AAV2-AADC).RESULTSEleven patients (7 females, 4 males) underwent bilateral MRI-guided BJGA cannula placement and CED of AAV2-AADC (22 brainstem infusions). The mean age at infusion was 10.5 ± 5.2 years (range 4–19 years). MRI allowed for accurate real-time planning, confirmed precise cannula placement after single-pass placement, and permitted on-the-fly adjustment. Overall, the mean bilateral depth to the target was 137.0 ± 5.2 mm (range 124.0–145.5 mm). The mean bilateral depth error was 0.9 ± 0.7 mm (range 0–2.2 mm), and the bilateral radial error was 0.9 ± 0.6 mm (range 0.1–2.3 mm). The bilateral absolute tip error was 1.4 ± 0.8 mm (range 0.4–3.0 mm). Target depth and absolute tip error were not correlated (Pearson product-moment correlation coefficient, r = 0.01).CONCLUSIONSUse of the BJGA is feasible, accurate, effective, and safe for cannula placement, infusion MRI monitoring, and cannula adjustment during CED. The low-profile universal applicability of the BJGA streamlines and facilitates MRI-guided CED.

scholarly journals Accuracy of direct magnetic resonance imaging-guided placement of drug infusion cannulae

2015 ◽  
Vol 122 (5) ◽  
pp. 1173-1179 ◽  
Author(s):  
Prashant Chittiboina ◽  
John D. Heiss ◽  
Russell R. Lonser
Keyword(s):  
Real Time ◽  
Brain Regions ◽  
Drug Infusion ◽  
Convection Enhanced Delivery ◽  
Radial Error ◽  
Selective Perfusion ◽  
Placement Accuracy ◽  
The Mean ◽  
Cannula Placement ◽  
Direct Placement

An intraoperative MRI (iMRI)–compatible system has been developed for direct placement of convection-enhanced delivery (CED) cannulae using real-time imaging. To establish the precision and feasibility of this technology, the authors analyzed findings in patients who underwent direct iMRI CED cannula placement. Three consecutive patients underwent iMRI-guided placement of CED infusion cannulae (6 cannulae) for treatment of diffuse intrinsic brainstem glioma (2 patients) or Parkinson's disease (1 patient). Convective infusion cannulae were guided to the target using the ClearPoint iMRI-based navigation platform (MRI Interventions, Inc.). Placement accuracy was analyzed. Real-time iMRI during infusion cannula insertion allowed for monitoring of trajectory accuracy during placement. During cannula insertion, no reinsertions or changes due to errors in targeting were necessary. The mean radial error was 1.0 ± 0.5 mm (± SD). There was no correlation between the total length of the planned trajectory and the radial error (Pearson's coefficient: −0.40; p = 0.5). The mean anteroposterior and lateral errors were 0.9 ± 0.5 and 0.3 ± 0.2 mm, respectively. The mean in-plane distance error was 1.0 ± 0.4 mm. The mean tip error (scalar distance between the planned target and actual tip) was 1.9 ± 0.9 mm. There was no correlation between the length of the planned trajectory and any of the measured errors. No complications were associated with cannula placement. Real-time iMRI-based targeting and monitoring of infusion cannula placement is a safe, effective, and accurate technique that should enable more selective perfusion of brain regions.

scholarly journals Real-time magnetic resonance imaging-guided frameless stereotactic brain biopsy: technical note

2016 ◽  
Vol 124 (4) ◽  
pp. 1039-1046 ◽  
Author(s):  
Ahmed Mohyeldin ◽  
Russell R. Lonser ◽  
J. Bradley Elder
Keyword(s):  
Real Time ◽  
Brain Biopsy ◽  
Technical Note ◽  
Dysembryoplastic Neuroepithelial Tumor ◽  
Stereotactic Brain Biopsy ◽  
Real Time Imaging ◽  
Radial Error ◽  
Histological Data ◽  
The Mean ◽  
Target Depth

OBJECT The object of this study was to assess the feasibility, accuracy, and safety of real-time MRI-compatible frameless stereotactic brain biopsy. METHODS Clinical, imaging, and histological data in consecutive patients who underwent stereotactic brain biopsy using a frameless real-time MRI system were analyzed. RESULTS Five consecutive patients (4 males, 1 female) were included in this study. The mean age at biopsy was 45.8 years (range 29–60 years). Real-time MRI permitted concurrent display of the biopsy cannula trajectory and tip during placement at the target. The mean target depth of biopsied lesions was 71.3 mm (range 60.4–80.4 mm). Targeting accuracy analysis revealed a mean radial error of 1.3 ± 1.1 mm (mean ± standard deviation), mean depth error of 0.7 ± 0.3 mm, and a mean absolute tip error of 1.5 ± 1.1 mm. There was no correlation between target depth and absolute tip error (Pearson product-moment correlation coefficient, r = 0.22). All biopsy cannulae were placed at the target with a single penetration and resulted in a diagnostic specimen in all cases. Histopathological evaluation of biopsy samples revealed dysembryoplastic neuroepithelial tumor (1 case), breast carcinoma (1 case), and glioblastoma multiforme (3 cases). CONCLUSIONS The ability to place a biopsy cannula under real-time imaging guidance permits on-the-fly alterations in the cannula trajectory and/or tip placement. Real-time imaging during MRI-guided brain biopsy provides precise safe targeting of brain lesions.

scholarly journals Gene therapy for aromatic L-amino acid decarboxylase deficiency by MR-guided direct delivery of AAV2-AADC to midbrain dopaminergic neurons

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Toni S. Pearson ◽  
Nalin Gupta ◽  
Waldy San Sebastian ◽  
Jill Imamura-Ching ◽  
Amy Viehoever ◽  
...  
Keyword(s):  
Amino Acid ◽  
Motor Function ◽  
Viral Vector ◽  
Genetic Disorder ◽  
Dopamine Metabolism ◽  
Acid Decarboxylase ◽  
Convection Enhanced Delivery ◽  
Amino Acid Decarboxylase ◽  
Post Surgery ◽  
Midbrain Dopaminergic Neurons

AbstractAromatic L-amino acid decarboxylase (AADC) deficiency is a rare genetic disorder characterized by deficient synthesis of dopamine and serotonin. It presents in early infancy, and causes severe developmental disability and lifelong motor, behavioral, and autonomic symptoms including oculogyric crises (OGC), sleep disorder, and mood disturbance. We investigated the safety and efficacy of delivery of a viral vector expressing AADC (AAV2-hAADC) to the midbrain in children with AADC deficiency (ClinicalTrials.gov Identifier NCT02852213). Seven (7) children, aged 4–9 years underwent convection-enhanced delivery (CED) of AAV2-hAADC to the bilateral substantia nigra (SN) and ventral tegmental area (VTA) (total infusion volume: 80 µL per hemisphere) in 2 dose cohorts: 1.3 × 1011 vg (n = 3), and 4.2 × 1011 vg (n = 4). Primary aims were to demonstrate the safety of the procedure and document biomarker evidence of restoration of brain AADC activity. Secondary aims were to assess clinical improvement in symptoms and motor function. Direct bilateral infusion of AAV2-hAADC was safe, well-tolerated and achieved target coverage of 98% and 70% of the SN and VTA, respectively. Dopamine metabolism was increased in all subjects and FDOPA uptake was enhanced within the midbrain and the striatum. OGC resolved completely in 6 of 7 subjects by Month 3 post-surgery. Twelve (12) months after surgery, 6/7 subjects gained normal head control and 4/7 could sit independently. At 18 months, 2 subjects could walk with 2-hand support. Both the primary and secondary endpoints of the study were met. Midbrain gene delivery in children with AADC deficiency is feasible and safe, and leads to clinical improvements in symptoms and motor function.

scholarly journals Gene Therapy for Aromatic L-Amino Acid Decarboxylase Deficiency by MR-Guided Direct Delivery of AAV2-AADC to Midbrain Dopaminergic Neurons

2020 ◽  
Author(s):  
Toni Pearson ◽  
Nalin Gupta ◽  
Waldy San Sebastian ◽  
Jill Imamura-Ching ◽  
Amy Viehoever ◽  
...  
Keyword(s):  
Amino Acid ◽  
San Francisco ◽  
Viral Vector ◽  
Genetic Disorder ◽  
Dopamine Metabolism ◽  
Acid Decarboxylase ◽  
Convection Enhanced Delivery ◽  
Amino Acid Decarboxylase ◽  
Post Surgery ◽  
The Ohio State University

Abstract Background: Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare genetic disorder characterized by deficient synthesis of dopamine and serotonin. It presents in early infancy, and causes severe developmental disability and lifelong motor, behavioral, and autonomic symptoms including oculogyric crises (OGC), sleep disorder, and mood disturbance.Objective: We investigated the safety and efficacy of delivery of a viral vector expressing AADC (AAV2-hAADC) to the midbrain in children with AADC deficiency. Design, Setting and Participants: Seven (7) children, aged 4-9 years underwent convection-enhanced delivery (CED) of AAV2-hAADC to the bilateral substantia nigra (SN) and ventral tegmental area (VTA) (total infusion volume: 80 µL per hemisphere) in 2 dose cohorts: 1.3 x 1011 vg (n=3), and 4.2 x 1011 vg (n=4). Six (6) subjects were treated at UCSF Benioff Children’s Hospital in San Francisco and 1 at The Ohio State University.Results: Direct bilateral infusion of AAV2-hAADC was well-tolerated and achieved target coverage of 98% and 70% of the SN and VTA, respectively. Dopamine metabolism was increased in all subjects and FDOPA uptake was enhanced within the midbrain and the striatum. OGC resolved completely in 6 of 7 subjects by Month 3 post-surgery. Eighteen (18) months after surgery (n=5), 4/5 subjects gained the ability to sit independently and 2/5 could walk with 2-hand support.Conclusion: Midbrain gene delivery in children with AADC deficiency is feasible and safe, and leads to substantial clinical improvements in symptoms and motor function.Trial Registration: ClinicalTrials.gov Identifier NCT02852213

Development of a novel frameless skull-mounted ball-joint guide array for use in image-guided neurosurgery

2020 ◽  
Vol 132 (2) ◽  
pp. 595-604
Author(s):  
Vivek Sudhakar ◽  
Amin Mahmoodi ◽  
John R. Bringas ◽  
Jerusha Naidoo ◽  
Adrian Kells ◽  
...  
Keyword(s):  
Topological Analysis ◽  
Correlation Coefficients ◽  
Brain Structures ◽  
Neurosurgical Procedures ◽  
Ball Joint ◽  
Convection Enhanced Delivery ◽  
Directional Bias ◽  
Subcortical Brain ◽  
Subcortical Brain Structures ◽  
Mri Guided

OBJECTIVESuccessful convection-enhanced delivery of therapeutic agents to subcortical brain structures requires accurate cannula placement. Stereotactic guiding devices have been developed to accurately target brain nuclei. However, technologies remain limited by a lack of MRI compatibility, or by devices’ size, making them suboptimal for direct gene delivery to brain parenchyma. The goal of this study was to validate the accuracy of a novel frameless skull-mounted ball-joint guide array (BJGA) in targeting the nonhuman primate (NHP) brain.METHODSFifteen MRI-guided cannula insertions were performed on 9 NHPs, each targeting the putamen. Optimal trajectories were planned on a standard MRI console using 3D multiplanar baseline images. After cannula insertion, the intended trajectory was compared to the final trajectory to assess deviation (euclidean error) of the cannula tip.RESULTSThe average cannula tip deviation was 1.18 ± 0.60 mm (mean ± SD) as measured by 2 independent reviewers. Topological analysis showed a superior, posterior, and rightward directional bias, and the intra- and interclass correlation coefficients were > 0.85, indicating valid and reliable intra- and interobserver evaluation.CONCLUSIONSThe data demonstrate that the BJGA can be used to reliably target subcortical brain structures by using MRI guidance, with accuracy comparable to current frameless stereotactic systems. The size and versatility of the BJGA, combined with a streamlined workflow, allows for its potential applicability to a variety of intracranial neurosurgical procedures, and for greater flexibility in executing MRI-guided experiments within the NHP brain.

scholarly journals Technical note: Inherent benchmark or not? Comparing Nash–Sutcliffe and Kling–Gupta efficiency scores

2019 ◽  
Vol 23 (10) ◽  
pp. 4323-4331 ◽  
Author(s):  
Wouter J. M. Knoben ◽  
Jim E. Freer ◽  
Ross A. Woods
Keyword(s):  
Time Series ◽  
Coefficient Of Variation ◽  
Ad Hoc ◽  
Model Performance ◽  
Technical Note ◽  
Mean Flow ◽  
Model Adequacy ◽  
Robust Model ◽  
The Mean ◽  
Adequacy Assessment

Abstract. A traditional metric used in hydrology to summarize model performance is the Nash–Sutcliffe efficiency (NSE). Increasingly an alternative metric, the Kling–Gupta efficiency (KGE), is used instead. When NSE is used, NSE = 0 corresponds to using the mean flow as a benchmark predictor. The same reasoning is applied in various studies that use KGE as a metric: negative KGE values are viewed as bad model performance, and only positive values are seen as good model performance. Here we show that using the mean flow as a predictor does not result in KGE = 0, but instead KGE =1-√2≈-0.41. Thus, KGE values greater than −0.41 indicate that a model improves upon the mean flow benchmark – even if the model's KGE value is negative. NSE and KGE values cannot be directly compared, because their relationship is non-unique and depends in part on the coefficient of variation of the observed time series. Therefore, modellers who use the KGE metric should not let their understanding of NSE values guide them in interpreting KGE values and instead develop new understanding based on the constitutive parts of the KGE metric and the explicit use of benchmark values to compare KGE scores against. More generally, a strong case can be made for moving away from ad hoc use of aggregated efficiency metrics and towards a framework based on purpose-dependent evaluation metrics and benchmarks that allows for more robust model adequacy assessment.

scholarly journals Massive haemorrhagic complications of ruptured pulmonary arteriovenous malformations: outcomes from a 12 years’ retrospective study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xu Ma ◽  
Bing Jie ◽  
Dong Yu ◽  
Ling-Ling Li ◽  
Sen Jiang
Keyword(s):  
Arteriovenous Malformations ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Hereditary Haemorrhagic Telangiectasia ◽  
Pulmonary Arteriovenous Malformations ◽  
Imaging Data ◽  
Peripheral Lung ◽  
Life Threatening ◽  
The Mean

Abstract Background The life-threatening haemorrhagic complications of pulmonary arteriovenous malformations (PAVMs) are extremely rare, and only described in isolated cases. This study was designed to comprehensively investigate management of ruptured PAVMs. Methods We retrospectively assessed clinical and imaging data of ruptured PAVMs to summarize incidence, clinical characteristics, and outcomes following embolisation between January 2008 and January 2021. Results Eighteen of 406 (4.4%) patients with PAVMs developed haemorrhagic complications. Twelve of 18 patients were clinically diagnosed with hereditary haemorrhagic telangiectasia (HHT). Haemorrhagic complications occurred with no clear trigger in all cases. Eight of 18 patients (44.4%) were initially misdiagnosed or had undergone early ineffective treatment. 28 lesions were detected, with 89.3% of them located in peripheral lung. Computed tomography angiography (CTA) showed indirect signs to indicate ruptured PAVMs in all cases. Lower haemoglobin concentrations were associated with the diameter of afferent arteries in the ruptured lesions. Successful embolotherapy was achieved in all cases. After embolotherapy, arterial oxygen saturation improved and bleeding was controlled (P < 0.05). The mean follow-up time was 3.2 ± 2.5 years (range, 7 months to 10 years). Conclusions Life threatening haemorrhagic complications of PAVMs are rare, they usually occur without a trigger and can be easily misdiagnosed. HHT and larger size of afferent arteries are major risk factors of these complications. CTA is a useful tool for diagnosis and therapeutic guidance for ruptured PAVMs. Embolotherapy is an effective therapy for this life-threatening complication.

scholarly journals Aromatic L-amino Acid Decarboxylase (AADC) deficiency: results from an Italian modified Delphi consensus

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Carlo Fusco ◽  
◽  
Vincenzo Leuzzi ◽  
Pasquale Striano ◽  
Roberta Battini ◽  
...  
Keyword(s):  
Amino Acid ◽  
Diagnostic Delay ◽  
Steering Committee ◽  
Outcome Data ◽  
Diagnosis And Treatment ◽  
Acid Decarboxylase ◽  
Delphi Consensus ◽  
Amino Acid Decarboxylase ◽  
Modified Delphi ◽  
Number Of Patients

Abstract Background Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare and underdiagnosed neurometabolic disorder resulting in a complex neurological and non-neurological phenotype, posing diagnostic challenges resulting in diagnostic delay. Due to the low number of patients, gathering high-quality scientific evidence on diagnosis and treatment is difficult. Additionally, based on the estimated prevalence, the number of undiagnosed patients is likely to be high. Methods Italian experts in AADC deficiency formed a steering committee to engage clinicians in a modified Delphi consensus to promote discussion, and support research, dissemination and awareness on this disorder. Five experts in the field elaborated six main topics, each subdivided into 4 statements and invited 13 clinicians to give their anonymous feedback. Results 100% of the statements were answered and a consensus was reached at the first round. This enabled the steering committee to acknowledge high rates of agreement between experts on clinical presentation, phenotypes, diagnostic work-up and treatment strategies. A research gap was identified in the lack of standardized cognitive and motor outcome data. The need for setting up an Italian working group and a patients’ association, together with the dissemination of knowledge inside and outside scientific societies in multiple medical disciplines were recognized as critical lines of intervention. Conclusions The panel expressed consensus with high rates of agreement on a series of statements paving the way to disseminate clear messages concerning disease presentation, diagnosis and treatment and strategic interventions to disseminate knowledge at different levels. Future lines of research were also identified.

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