Research Article From: PMC, US National Library of Medicine National Institutes of Health. Open Neuroimag J. 2011; 5: 40–48. Published online 2011 Jul 28. doi:  10.2174/1874440001105010040

By: Daniel G AmenManuel TrujilloAndrew NewbergKristen WilleumierRobert TarzwellJoseph C Wu and Barry Chaitin

Abstract

Over the past 20 years brain Single Photon Emission Computed Tomography (SPECT) imaging has developed a substantial, evidence-based foundation and is now recommended by professional societies for numerous indications relevant to psychiatric practice. Unfortunately, SPECT in clinical practice is utilized by only a handful of clinicians. This article presents a rationale for a more widespread use of SPECT in clinical practice for complex cases, and includes seven clinical applications where it may help optimize patient care.

Keywords: Brain SPECT, evidence based, brain trauma, dementia, toxicity, complex cases.

Introduction

“SPECT techniques provide a powerful window into the function of the brain and promise to become an important component of the routine clinical evaluation of patients with neurological and psychiatric diseases”[1].

This opening sentence to Holman and Devous’ 1992 article “Functional Brain SPECT: The Emergence of a Powerful Clinical Method,” highlighted the hope held for functional neuroimaging nearly two decades ago. A consistently growing body of research supports SPECT’s clinical utility. Fourteen years ago, Vasile wrote in the Harvard Review of Psychiatry [2], “The clinical utility of SPECT in neuropsychiatry is well established.” Nearly a decade ago, Camargo [3] wrote, “Brain SPECT … is rapidly becoming a clinical tool in many places. The importance of this technique should not be overlooked, particularly in cerebrovascular diseases, dementias, epilepsy, head injury, obsessive-compulsive disorder, Gilles de la Tourette’s syndrome, schizophrenia, depression, panic disorder, and drug abuse.” Despite its evidence-base for multiple areas relevant to diagnosis and treatment few psychiatrists have adopted SPECT or other functional neuroimaging techniques in clinical practice.

This article lays out the evidence-based argument for the addition of SPECT for patients with complex presentations or who are treatment resistant. The article focuses on SPECT for three reasons. First, SPECT cameras are available in every major North American, European and Asian hospital making it the most widely available imaging modality available today. Second, SPECT has extensive research validating its usefulness for problems often faced by psychiatrists and is endorsed by scientific review bodies for many indications relevant to psychiatry. And, third, SPECT is among the least expensive neuroimaging tools and has had insurance reimbursement codes for greater than 20 years.

SPECT’s prolific use in peer-reviewed research supports that it is a well-established and reliable measure of brain function (regional cerebral blood flow—rCBF) [4]. Both the American College of Radiology [5] and the European Society of Nuclear Medicine (ESNM) [6] have published similar evidence-based guidelines for using SPECT to enhance patient care. Commonly accepted clinical indications for SPECT include:

  • Evaluating patients for cerebrovascular disease.
  • Evaluating patients with suspected dementia including early detection, differential diagnosis, and in the pre-dementia phase.
  • Presurgical localization of epileptic foci.
  • Evaluation of traumatic brain injury, especially in the absence of computed tomography (CT) and/or magnetic resonance imaging (MRI) findings.
  • Evaluation of suspected inflammation to provide helpful information in progressive inflammatory disorders including viral encephalitis, vasculitis, and HIV-encephalopathy.
  • Assessing brain death.

It is obvious to practicing psychiatrists that all of these indications, except perhaps brain death and the pre-surgical location of epileptic foci, are potentially valuable in clinical practice. Psychiatrists commonly evaluate and treat dementia and the consequences of brain trauma, cerebral vascular disease, inflammation and infections. Besides these common indications, the ESNM guidelines also state, “SPECT can be useful in other indications such as movement disorders and psychiatric diseases (e.g. for follow-up of depression).”

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