In this work we propose the use of a modified version of the correlation coefficient as a performance criterion for the image alignment problem. The proposed modification has the desirable characteristic of being invariant with respect to photometric distortions. Since the resulting similarity measure is a nonlinear function of the warp parameters, we develop two iterative schemes for its maximization, one based on the forward additive approach and the second on the inverse compositional method. As it is customary in iterative optimization, in each iteration, the nonlinear objective function is approximated by an alternative expression for which the corresponding optimization is simple. In our case we propose an efficient approximation that leads to a closed-form solution (per iteration) which is of low computational complexity, the latter property being particularly strong in our inverse version. The proposed schemes are tested against the Forward Additive Lucas-Kanade and the Simultaneous Inverse Compositional (SIC) algorithm through simulations. Under noisy conditions and photometric distortions, our forward version achieves more accurate alignments and exhibits faster convergence whereas our inverse version has similar performance as the SIC algorithm but at a lower computational complexity.
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http://dx.doi.org/10.1109/TPAMI.2008.113 | DOI Listing |
Childs Nerv Syst
January 2025
Department of Neurosurgery, Hospital de São José, ULS São José, Lisbon, Portugal.
Background: Subdural hematoma (SDH) typically occurs due to traumatic brain injury but can arise as a rare complication of procedures like endoscopic third ventriculostomy (ETV).
Case Presentation: We report an unusual case in a 9-year-old male with previous resection of a fourth-ventricle ependymoma at 2 years of age. Seven years post-surgery, he presented with worsening hydrocephalus and underwent ETV.
Eur Arch Otorhinolaryngol
January 2025
Department of Radiology, Istanbul Training and Research Hospital, University of Health Sciences, Istanbul, Turkey.
Purpose: Cochlear implantation (CI) surgery is essential for restoring hearing in individuals with severe sensorineural hearing loss. Accurate placement of the electrode within the cochlea is essential for successful auditory outcomes and minimizing complications. This study aims to analyze the relationship between the round window niche (RWN) alignment, its visibility during surgery, and the impact on surgical techniques and outcomes.
View Article and Find Full Text PDFBehav Res Methods
January 2025
Department of Psychology, University of Quebec at Trois-Rivières, Trois-Rivières, Canada.
Frequently, we perceive emotional information through multiple channels (e.g., face, voice, posture).
View Article and Find Full Text PDFPLoS One
January 2025
Human Anatomy Teaching and Research Section (Digital Medical Center), Inner Mongolia Medical University Basic Medical College, Hohhot, China.
The cervical uncinate process is a unique structure of the cervical spine that undergoes significant changes in its morphological characteristics with age, and these changes may be related to osteoporosis. This study aimed to observe the distribution of cancellous bone in the cervical uncinate process and its morphological features using micro-computed tomography (Micro-CT) to gain a deeper understanding of the morphological characteristics of the uncinate microstructure. We performed Micro-CT scans on 31 sets of C3-C7 vertebrae, a total of 155 intact bone samples, and subsequently used the measurement software with the Micro-CT system to obtain parameters related to the cancellous bone of the uncinate process.
View Article and Find Full Text PDFJ Med Syst
January 2025
Department of Neurosurgery, University Medical Centre Utrecht, Utrecht, The Netherlands.
This study aimed to develop and validate a cost-effective, customizable patient-specific phantom for simulating external ventricular drain placement, combining image segmentation, 3-D printing and molding techniques. Two variations of the phantom were created based on patient MRI data, integrating a realistic skin layer with anatomical landmarks, a 3-D printed skull, an agarose polysaccharide gel brain, and a ventricular cavity. To validate the phantom, 15 neurosurgeons, residents, and physician assistants performed 30 EVD placements.
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