Analytical, Diagnostic and Therapeutic Techniques, and Equipment

Emission-Computed Single-Photon Tomography

A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.

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MeSH Record

Synonyms

19 entry terms
  • CAT Scan, Single-Photon Emission
  • CT Scan, Single-Photon Emission
  • Radionuclide Tomography, Single-Photon Emission-Computed
  • SPECT
  • Single-Photon Emission CT Scan
  • Single-Photon Emission Computer-Assisted Tomography
  • Single-Photon Emission Computerized Tomography
  • Single-Photon Emission-Computed Tomography
  • Tomography, Emission-Computed, Single-Photon
  • Tomography, Single-Photon, Emission-Computed
  • CAT Scan, Single Photon Emission
  • CT Scan, Single Photon Emission
  • Emission-Computed Tomography, Single-Photon
  • Radionuclide Tomography, Single Photon Emission Computed
  • Single Photon Emission CT Scan
  • Single Photon Emission Computed Tomography
  • Single Photon Emission Computer Assisted Tomography
  • Single Photon Emission Computerized Tomography
  • Tomography, Single-Photon Emission-Computed

MeSH Record

Aspects Covered

14 allowable subheadings

Indexed with the subheadings adverse effects, classification, economics, ethics, history, instrumentation, methods, mortality, nursing, psychology, standards, statistics & numerical data, trends, veterinary.

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History Note

90; was SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY & SPECT see TOMOGRAPHY, EMISSION-COMPUTED 1989

MeSH Record

Previous Indexing

  • Tomography, Emission-Computed (1980-1989)
  • Tomography, X-Ray Computed (1977-1979)

MeSH Hierarchy

Tree Numbers

  1. E01w.370.350w.350.800w.800w
  2. E01w.370.350w.600w.350.800w.800w
  3. E01w.370.350w.710.800w.800w
  4. E01w.370.350w.825w.800w.800w
  5. E01w.370.384.730.800w.800w

MeSH Record

NLM Classification

WN 206

AMA Style

References

  1. National Library of Medicine. Emission-Computed Single-Photon Tomography. Medical Subject Headings (MeSH). 2026. Unique ID D015899. http://id.nlm.nih.gov/mesh/2026/D015899
  2. Emission-Computed Single-Photon Tomography. In: Wikipedia. https://en.wikipedia.org/wiki/Single-photon_emission_computed_tomography
  3. Emission-Computed Single-Photon Tomography. In: Wikidata. https://www.wikidata.org/wiki/Q849737