0
0

Sections

Excerpt

SPECT provides images of cerebral blood flow and brain activity. For this particular scan, a radioactive tracer attached to a drug, generally Technetium-99m-HMPAO (hexamethylpropylene amine oxime) or technetium-99m-ECD (ethyl cysteinate dimer), is administered intravenously. HMPAO and ECD are lipophilic drugs and are able to diffuse across the blood-brain barrier and into neurons. Once inside the cell, they are converted into hydrophilic compounds and are unable to diffuse out of the cell. Physical decay of the radionuclide attached to HMPAO or ECD leads to high-energy photon emissions that are measured by a SPECT detector. A computer creates visual images from this information, using various algorithms and filtering techniques to correct background noise and motion. Tracer uptake and cerebral blood flow are high in the gray matter, where neuronal bodies and synapses reside, and are low in the white matter, which is composed of metabolically less active axons. Thus, the cortex and subcortical structures will appear bright, or "hot," on SPECT, whereas white matter will appear "cold" and dark. The ventricles will appear even darker.

Your session has timed out. Please sign back in to continue.
Sign In Your Session has timed out. Please sign back in to continue.
Sign In to Access Full Content
 
Username
Password
Sign in via Athens (What is this?)
Athens is a service for single sign-on which enables access to all of an institution's subscriptions on- or off-site.
Not a subscriber?

Subscribe Now/Learn More

PsychiatryOnline subscription options offer access to the DSM-5 library, books, journals, CME, and patient resources. This all-in-one virtual library provides psychiatrists and mental health professionals with key resources for diagnosis, treatment, research, and professional development.

Need more help? PsychiatryOnline Customer Service may be reached by emailing PsychiatryOnline@psych.org or by calling 800-368-5777 (in the U.S.) or 703-907-7322 (outside the U.S.).

References

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Related Content
Articles
Books
Textbook of Traumatic Brain Injury, 2nd Edition > Chapter 6.  >
Psychiatric News
PubMed Articles
Regional and inter-regional theta oscillation during episodic novelty processing. Brain Cogn 2014;90C():70-75.doi:10.1016/j.bandc.2014.06.009.
Motor Imagery Learning Induced Changes in Functional Connectivity of the Default Mode Network. IEEE Trans Neural Syst Rehabil Eng 2014;():.doi:10.1109/TNSRE.2014.2332353.
 
  • Print
  • PDF
  • E-mail
  • Chapter Alerts
  • Get Citation