Purpose: Our goals were to (a) develop and validate a sensitive measure of image registration, applicable between as well as within imaging modalities; and (b) quantify the accuracy of the automated image registration (AIR) algorithm in retrospectively registering MR and PET images of baboon brain.
Method: We studied five monkeys, each with a surgically implanted "cap" that was bolted to an acrylic headholder containing fiducial markers. Anatomic MRI and PET H2 15O blood flow images were aligned using AIR (ignoring the fiducials).
Results: (a) Fiducial points were localized to about one-tenth the voxel size. Distances computed from the fiducial points were correct to within 0.2% (MRI) and 1.4% (PET). (b) The mean error remaining after AIR, measured at the five fiducial points, varied from 2.9 to 5.3 mm. The average registration error within the brain was calculated to be 2.20 mm (maximum, 3.57 mm). This error was not primarily rotational about the center of the brain and was worsened by heavy smoothing of the PET images.
Conclusion: (a) We have defined a reliable, sensitive metric that can stringently test the accuracy of various image registration techniques. (b) The AIR algorithm leaves modest error after aligning PET blood flow and anatomic MR images of baboon brain.
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http://dx.doi.org/10.1097/00004728-199609000-00038 | DOI Listing |
Jpn J Radiol
January 2025
Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
Purpose: To evaluate the effects of four-dimensional noise reduction filtering using a similarity algorithm (4D-SF) on the image quality and tumor visibility of low-dose dynamic computed tomography (CT) in evaluating breast cancer.
Materials And Methods: Thirty-four patients with 38 lesions who underwent low-dose dynamic breast CT and were pathologically diagnosed with breast cancer were enrolled. Dynamic CT images were reconstructed using iterative reconstruction alone or in combination with 4D-SF.
Micron
December 2024
Material Measurement Laboratory, National Institute of Standards and Technology, 325 S Broadway, Boulder, CO 80305, USA.
Electron tomography is a powerful tool for the three-dimensional characterization of materials at the nano- and atomic-scales. A typical workflow for tomography involves several pre-processing steps that may include spatial binning, image registration, and tilt-axis alignment depending upon the nature of the acquired data. Here we describe the capabilities of a new, open-source software package named ETSpy that builds upon the widely used HyperSpy package.
View Article and Find Full Text PDFJ Neurooncol
January 2025
Department of Neurosurgery, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany.
Background And Objectives: Recently, reduction of transcallosal inhibition by contralateral navigated repetitive transcranial magnetic stimulation (nrTMS) improved neurorehabilitation of glioma patients with new postoperative paresis. This multicentric study examines the effect of postoperative nrTMS in brain tumor patients to treat surgery-related upper extremity paresis.
Methods: This is a secondary analysis of two randomized and three one-arm studies in brain tumor patients with new/progressive postoperative paresis.
J Neurol
January 2025
Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 18 Innovation Walk, Clayton, Victoria, 3800, Australia.
Background: Huntington's disease (HD) is a rare neurodegenerative disease that causes progressive cognitive, physical, and psychiatric symptoms. Computerised cognitive training (CCT) is a novel intervention that aims to improve and maintain cognitive functions through repeated practice. The effects of CCT have yet to be established in HD.
View Article and Find Full Text PDFOncologist
January 2025
HonorHealth Research Institute, Scottsdale, AZ, United States.
Lessons Learned: Intravenous paricalcitol did not improve the efficacy of pembrolizumab, likely related to the short half-life.
Background: Immunotherapy has limited benefit in the treatment of advanced pancreatic cancer with the tumor microenvironment playing a key role in immune resistance. In preclinical studies, vitamin D receptor (VDR) agonists have been shown to sensitize pancreatic tumors to PD-1 blockade.
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