Publications by authors named "Andreas Gierich"
Background: The development of robotic systems has provided an alternative to frame-based stereotactic procedures. The aim of this experimental phantom study was to compare the mechanical accuracy of the Robotic Surgery Assistant (ROSA) and the Leksell stereotactic frame by reducing clinical and procedural factors to a minimum.
Methods: To precisely compare mechanical accuracy, a stereotactic system was chosen as reference for both methods.
Background: Directional deep brain stimulation (DBS) allows steering the stimulation in an axial direction which offers greater flexibility in programming. However, accurate anatomical visualization of the lead orientation is required for interpreting the observed stimulation effects and to guide programming.
Objectives: In this study we aimed to develop and test an accurate and robust algorithm for determining the orientation of segmented electrodes based on standard postoperative CT imaging used in DBS.
Objectives: The aim of this study was to evaluate the reduction of artifacts from deep brain stimulation electrodes (DBS) using an iterative metal artifact reduction algorithm (O-MAR), virtual monoenergetic images (VMI), and both in combination in postoperative spectral detector computed tomography using a dual-layer detector (spectral detector computed tomography [SDCT]) of the head.
Material And Methods: Nonanthropomorphic phantoms with different DBS leads were examined on SDCT; in 1 phantom periprocedural bleeding was simulated. A total of 20 patients who underwent SDCT after DBS implantation between October 2016 and April 2017 were included in this institutional review board-approved retrospective study.
Article Synopsis
- Scientists want to create a way to predict how much of the brain gets damaged when treating tumors with a special kind of radiation therapy called Cyberknife.
- They made a model that figures out the best plan to minimize damage while still treating the tumor effectively, using past information and testing it on fake (phantom) cases.
- The model worked well, showing that with better planning, like using smaller tools and changing treatment settings, they could reduce damage to the brain during treatment.
Purpose: Orientating the angle of directional leads for deep brain stimulation (DBS) in an axial plane introduces a new degree of freedom that is indicated by embedded anisotropic directional markers. Our aim was to develop algorithms to determine lead orientation angles from computed tomography (CT) and stereotactic x-ray imaging using standard clinical protocols, and subsequently assess the accuracy of both methods.
Methods: In CT the anisotropic marker artifact was taken as a signature of the lead orientation angle and analyzed using discrete Fourier transform of circular intensity profiles.
Background And Purpose: Stereotactic radiosurgery of intracranial tumors and vascular malformations can be performed by either a linear accelerator (Linac) or gamma knife. The aim of this first study on patients was to determine the radiation exposure of organs at risk and assess the risk for late effects including secondary tumors and/or hereditary disorders after stereotactic Linac radiosurgery.
Material And Methods: Thermoluminescent dosimetry (TLD) measurements were done on 21 consecutively admitted patients with various intracranial lesions scheduled for Linac radiosurgery.