scholarly journals A technical note on the geometric effects of volume to surface mapping of fMRI data

2020 ◽  
Author(s):  
Keith George Ciantar ◽  
Ting Xu ◽  
Claude J. Bajada
Keyword(s):  
Technical Note ◽  
Fmri Data ◽  
Volumetric Data ◽  
Surface Mesh ◽  
Surface Mapping ◽  
Uncorrelated Noise ◽  
Local Neighborhood ◽  
Technical Report ◽  
Geometric Effects

AbstractIn this technical report we identify and report a problem with the process of volume to surface mapping that has potentially impacted studies that focus upon local neighborhood connectivity. We show that neighborhood correlations vary spatially with anatomical patterns (gyral structure) even when the underlying volumetric data is uncorrelated noise. We explore the effects of this anomaly across varying data resolutions and surface mesh densities. We finally propose an approach to mitigate these unwanted effects.

scholarly journals A Hilbert-based method for processing respiratory timeseries

2020 ◽  
Author(s):  
Samuel J. Harrison ◽  
Samuel Bianchi ◽  
Jakob Heinzle ◽  
Klaas Enno Stephan ◽  
Sandra Iglesias ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Time Resolution ◽  
Technical Note ◽  
Fmri Data ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Physiological Noise ◽  
Noise Correction ◽  
The Hilbert Transform

In this technical note, we introduce a new method for estimating changes in respiratory volume per unit time (RVT) from respiratory bellows recordings. By using techniques from the electrophysiological literature, in particular the Hilbert transform, we show how we can better characterise breathing rhythms, with the goal of improving physiological noise correction in functional magnetic resonance imaging (fMRI). Specifically, our approach leads to a representation with higher time resolution and better captures atypical breathing events than current peak-based RVT estimators. Finally, we demonstrate that this leads to an increase in the amount of respiration-related variance removed from fMRI data when used as part of a typical preprocessing pipeline. Our implementation will be publicly available as part of the PhysIO package, which is distributed as part of the open-source TAPAS toolbox (https://translationalneuromodeling.org/tapas).

scholarly journals Stereotactic navigation for the prepsoas oblique lateral lumbar interbody fusion: technical note and case series

2017 ◽  
Vol 43 (2) ◽  
pp. E14 ◽  
Author(s):  
Anthony M. DiGiorgio ◽  
Caleb S. Edwards ◽  
Michael S. Virk ◽  
Praveen V. Mummaneni ◽  
Dean Chou
Keyword(s):  
Interbody Fusion ◽  
Case Series ◽  
Psoas Muscle ◽  
Technical Note ◽  
Invasive Technique ◽  
Lumbar Interbody Fusion ◽  
Lateral Lumbar Interbody Fusion ◽  
Transpsoas Approach ◽  
Technical Report ◽  
Stereotactic Navigation

The prepsoas retroperitoneal approach is a minimally invasive technique used for anterior lumbar interbody fusion. The approach may have a more favorable risk profile than the transpsoas approach, decreasing the risks that come with dissecting through the psoas muscle. However, the oblique angle of the spine in the prepsoas approach can be disorienting and challenging. This technical report provides an overview of the use of navigation in prepsoas oblique lateral lumbar interbody fusion in a series of 49 patients.

SACRAL NERVE STIMULATION (SNS) FOR PUDENDAL NEURALGIA VIA THE SACROCOCCYGEAL APPROACH: A TECHNICAL NOTE

2017 ◽  
pp. 153-157
Author(s):  
Kenneth Candido
Keyword(s):  
Pain Management ◽  
Pelvic Pain ◽  
Nerve Stimulation ◽  
Sacral Nerve Stimulation ◽  
Technical Note ◽  
Treatment Modalities ◽  
Pudendal Neuralgia ◽  
Sacral Nerve ◽  
Technical Report

Background: Pudendal neuralgia is a debilitating pain syndrome, and fi nding long-lasting treatment modalities has been challenging in pain management. Sacral nerve stimulation (SNS) has emerged as a treatment option for pudendal neuralgia but the correct placement of SNS leads can be challenging. Previously described techniques include placing the stimulator at the conus, as well as retrograde and transforaminal approaches. Objective: We aim to describe the relevant anatomy and technique for precise SNS lead placement using a sacrococcygeal approach. Study Design: A technical report. Setting: An interventional pain management practice. Methods: Description with accompanying fl uoroscopic and anatomical images; this technical report describes the specifi c technique we employed in 7 patients suffering from intractable pelvic pain as a result of pudendal neuralgia. Results: Successful placement of percutaneous SNS leads using a sacrococcygeal approach in all 7 patients suffering from pudendal neuralgia. Six of the 7 patients experienced a decrease in the visual analog scale (VAS) pain score (> 50%), improvement in function during the trial period, and proceeded with permanent neurosurgical implantation. Four out of 6 patients that underwent permanent implantation reported persistent pain relief and improvement in the activities of daily living at long-term follow-up (range: 12–33 months). Limitations: The design of this study limits the ability to determine the defi nitive risks, potential complications, and long-term benefi ts. The precise clinical value of this approach remains to be determined in larger prospective studies. Conclusions: Although infrequently performed, the sacrococcygeal approach may represent a more successful and safe alternative method for the placement of SNS leads for a SNS trial. Key words: Technical note, neuromodulation, sacral nerve stimulation, pudendal neuralgia, pelvic pain, SCS, SNS

scholarly journals Endonasal Endoscopic Pituitary Adenoma Resection in light of the COVID-19 Pandemic: A Technical Report

2020 ◽  
Author(s):  
Danilo Talacimon Barbosa ◽  
Dan Zimelewicz Oberman ◽  
Alick Durão Moreira ◽  
Luisa Borges ◽  
Felipe Gonçalves ◽  
...  
Keyword(s):  
Pituitary Adenoma ◽  
Low Cost ◽  
Technical Note ◽  
Surgical Instruments ◽  
Direct Access ◽  
Subtotal Resection ◽  
Anatomical Landmarks ◽  
Endoscopic Endonasal ◽  
Severe Visual Loss ◽  
Technical Report

Abstract Introduction The endoscopic endonasal transsphenoidal approach (EETA) is routinely used to treat sellar and suprasellar tumors. It provides safe and direct access to tumors in these locations, with wide visualization of anatomical landmarks and great surgical results. With the COVID-19 pandemic, despite the high risk of transmission involved, various surgical procedures cannot be postponed due to their emergency. Case Report A 62-year-old female presented in the previous two months with headaches, followed by bilateral severe visual loss. In 2016, she was submitted to subtotal resection of a non-secretory macroadenoma. Because of the progressive visual deficits, the EETA was used to the resect the pituitary adenoma. Technical Note We developed a low-cost adaptation to the surgical fields, covering the patient's head and superior trunk with a regular surgical microscope bag with a tiny slit to enable the endoscope and surgical instruments to enter the nose, thus protecting the personnel in the operating room from the aerosolization of particles. This makes surgery safer for the surgical team and for the patient. Conclusion In view of the lack of literature on this subject, except for some reports of experiences from some services around the world, we describe the way we have adjusted the EETA in the context of the COVID-19 pandemic.

NEEDLE TIP DEPTH ASSESSMENT ON FORAMINAL OBLIQUE FLUOROSCOPIC VIEWS DURING CERVICAL RADIOFREQUENCY NEUROTOMY. A TECHNICAL NOTE

2018 ◽  
pp. 127-131
Author(s):  
Robin Raju
Keyword(s):  
Radiofrequency Ablation ◽  
Epidural Injection ◽  
Lateral View ◽  
Technical Note ◽  
Single Subject ◽  
Oblique Angle ◽  
Radiofrequency Neurotomy ◽  
Technical Report ◽  
Neurovascular Structures ◽  
Interlaminar Epidural Injection

Background: Precise needle tip visualization using fluoroscopy is critical to avoid injury to nearby neurovascular structures during cervical radiofrequency neurotomy (RFN). The contralateral oblique (CLO) view has been shown to be superior to the lateral view for needle tip visualization during cervical interlaminar epidural injection (CESI). It has been demonstrated that increasing the angle of obliquity during CESI causes the needle tip to appear to move dorsal and superficial on contralateral oblique views. Needle tip visualization for cervical RFN has been described using a foraminal oblique (FO) view, but the technique and effect of angle on needle tip depth have not been studied. Objective: To analyze how the needle tip depth changes with varying oblique angles of FO views during cervical RFN. Methods: Fluoroscopic views during cervical RFN between lateral and 50 degrees FO in a single subject were analyzed. Results: The needle tip appears to move ventral and deeper with increasing angle of obliquity with respect to the lamina. Conclusion: Contrary to the phenomenon noticed with contralateral oblique views in CESI, in this case the needle tip appears to move ventral and deeper with increasing angle of obliquity on foraminal oblique views during cervical RFN. It becomes crucial for practitioners to understand that during cervical RFN, with inadequate foraminal oblique angle, needle tip looks artificially superficial, which in turn may cause one to advance the needle to a dangerous depth. Limitation: This is an observational study in a single subject; hence further larger studies are needed to confirm the findings in this technical report. Key words: contralateral oblique, needle depth assessment, cervical radiofrequency neurotomy, cervical radiofrequency ablation, foraminal oblique, fluoroscopy views, fluoroscopy angles

Catheter exchange technique for the Wingspan stent: technical note

2009 ◽  
Vol 10 (4) ◽  
pp. e4-e4
Author(s):  
W S Lesley ◽  
R Rangaswamy
Keyword(s):  
Vertebral Artery ◽  
Drug Administration ◽  
Balloon Angioplasty ◽  
Clinical Result ◽  
Technical Note ◽  
Single Patient ◽  
Catheter Exchange ◽  
Guide Catheter ◽  
Technical Report ◽  
Exchange Technique

Background and purposeThe only Food and Drug Administration-approved implant for managing intracranial stenosis is the Wingspan stent. Modification of the standard Wingspan stent delivery procedure has not been previously reported.Material and methodsRetrospective, single-patient, technical report.ResultsFollowing uneventful balloon angioplasty, a symptomatic intracranial vertebral artery stenosis was inaccessible to Wingspan stent delivery using standard procedural protocol because of poor proximal guide catheter purchase. After placing a Renegade Hi-Flo microcatheter across the stenosis, the Wingspan stent was transferred to this catheter and advanced to the lesion using a Neuroform stabilizer. Unsheathing of the stent yielded uncomplicated, precise placement of the stent with a good clinical result.ConclusionThe Wingspan stent transfer technique can be used successfully in the management of intracranial stenotic disease.

scholarly journals Percutaneous transforaminal endoscopic discectomy in a nine-year-old patient with sciatica: case report, technical note and overview of the literature

2021 ◽  
Author(s):  
P. S. Gadjradj ◽  
B. S. Harhangi
Keyword(s):  
Pediatric Population ◽  
Technical Note ◽  
Disk Herniation ◽  
Lumbar Disk Herniation ◽  
Endoscopic Techniques ◽  
Lumbar Disk ◽  
Technical Report ◽  
Endoscopic Discectomy ◽  
Percutaneous Transforaminal Endoscopic Discectomy ◽  
Robust Evidence

AbstractPercutaneous transforaminal endoscopic discectomy (PTED) is an alternative procedure to open microdiscectomy (OM) to treat sciatica caused by lumbar disk herniation. Even though robust evidence comparing PTED with OM is lacking, PTED is becoming increasingly popular to treat spinal disorders. In this technical report, the surgical technique and outcomes of PTED in a 9-year-old patient are described. Furthermore, an overview of the literature on full-endoscopic techniques to treat sciatica is given, showing that PTED is feasible, safe and effective to treat lumbar disk herniation in the pediatric population.

New AAC Access Strategy for Gesture Tracking: A Technical Note

2012 ◽  
Vol 21 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Susan Fager ◽  
Tom Jakobs ◽  
David Beukelman ◽  
Tricia Ternus ◽  
Haylee Schley
Keyword(s):  
Augmentative And Alternative Communication ◽  
Technical Note ◽  
Head Tracking ◽  
Alternative Communication ◽  
Access Methods ◽  
Cord Injury ◽  
Physical Limitations ◽  
Gesture Tracking ◽  
Communication Needs ◽  
Tracking Device

Abstract This article summarizes the design and evaluation of a new augmentative and alternative communication (AAC) interface strategy for people with complex communication needs and severe physical limitations. This strategy combines typing, gesture recognition, and word prediction to input text into AAC software using touchscreen or head movement tracking access methods. Eight individuals with movement limitations due to spinal cord injury, amyotrophic lateral sclerosis, polio, and Guillain Barre syndrome participated in the evaluation of the prototype technology using a head-tracking device. Fourteen typical individuals participated in the evaluation of the prototype using a touchscreen.

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