Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Focusing of Light in the Eye01:16

Focusing of Light in the Eye

Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
Interference and Diffraction02:18

Interference and Diffraction

Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
NMR Spectrometers: Resolution and Error Correction01:14

NMR Spectrometers: Resolution and Error Correction

When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
Aliasing01:18

Aliasing

Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency.
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal...
Distance Corrections01:15

Distance Corrections

To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to...
Convergence of Fourier Series01:21

Convergence of Fourier Series

The Fourier series is a powerful mathematical tool for representing periodic signals as an infinite sum of complex exponentials. In practice, this infinite series is truncated to a finite number of terms, yielding a partial sum. This truncation makes the approximation of the signal feasible but introduces certain challenges, particularly near discontinuities, known as the Gibbs phenomenon.
The Gibbs phenomenon refers to the persistent oscillations and overshoots that occur near discontinuities...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

[Allogeneic hematopoietic stem cell transplantation for RASGRP2 gene-related inherited platelet function disorders: a case report and literature review].

Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi·2026
Same author

Preclinical characterization and phase I results of TQB2102, a first-in-class HER2 biparatopic antibody-drug conjugate, in patients with advanced solid tumors.

Annals of oncology : official journal of the European Society for Medical Oncology·2026
Same author

Nutritional impacts of dietary selenium and iodine and their interaction on growth performance, antioxidant capacity and bone quality in Longyan ducklings.

British poultry science·2025
Same author

[A prospective birth cohort study on the association between gestational blood pressure and neurodevelopment in 2-year-old children].

Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine]·2024
Same author

[Study on the risk factors of coal workers' pneumoconiosis and the mechanism of pyroptosis in peripheral blood].

Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases·2024
Same author

Parent-child interaction, appetite self-regulation, and BMIz in Chinese preschoolers: a mediation analysis.

Public health·2024

Related Experiment Video

Updated: Jul 8, 2026

High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis
13:31

High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis

Published on: December 22, 2015

Fourier correction for spatially variant collimator blurring in SPECT.

W Xia1, R M Lewitt, P R Edholm

  • 1Dept. of Radiol., Pennsylvania Univ., Philadelphia, PA.

IEEE Transactions on Medical Imaging
|January 1, 1995
PubMed
Summary
This summary is machine-generated.

This study introduces a novel distance-dependent preprocessing method for single-photon emission computed tomography (SPECT) projection data. The technique effectively corrects blurring and distortion, improving image reconstruction quality for both circular and noncircular orbits.

More Related Videos

A Multimodal Wide-Field Fourier-Transform Raman Microscope
06:48

A Multimodal Wide-Field Fourier-Transform Raman Microscope

Published on: December 30, 2025

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis
07:55

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis

Published on: September 22, 2017

Related Experiment Videos

Last Updated: Jul 8, 2026

High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis
13:31

High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis

Published on: December 22, 2015

A Multimodal Wide-Field Fourier-Transform Raman Microscope
06:48

A Multimodal Wide-Field Fourier-Transform Raman Microscope

Published on: December 30, 2025

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis
07:55

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis

Published on: September 22, 2017

Area of Science:

  • Medical Imaging
  • Nuclear Medicine
  • Image Processing

Background:

  • Single-photon emission computed tomography (SPECT) relies on projection data acquisition.
  • Collimator point-response functions introduce blurring, which is often approximated as spatially invariant.
  • Existing deblurring methods struggle with the distance-dependent nature of collimator blurring.

Purpose of the Study:

  • To develop a distance-dependent preprocessing method for SPECT projection data.
  • To enable simultaneous processing of projection data across all views.
  • To improve image reconstruction accuracy by correcting spatially variant blurring.

Main Methods:

  • Utilized Fourier analysis of sinogram Fourier coefficients for distance-dependent characteristics.
  • Developed a spatially variant inverse filter for simultaneous projection data processing.
  • Extended the method to handle both circular and noncircular orbit geometries.

Main Results:

  • Experimental results with simulated and phantom data demonstrate the method's potential for circular orbits.
  • The spatial filtering approach successfully corrects spatially variant blurring and distortion.
  • Simulated elliptical orbit data show improved image reconstruction quality.

Conclusions:

  • The proposed distance-dependent preprocessing method offers a significant advancement for SPECT imaging.
  • This technique effectively addresses the limitations of spatially invariant deblurring approximations.
  • The method shows promise for enhancing image quality in various SPECT acquisition geometries.