Clinical Utility of SPECT Neuroimaging in the Diagnosis and Treatment of Traumatic Brain Injury: A Systematic Review

Cyrus A Raji,John Thornton,Dan Pavel,Theodore Henderson,Robert Tarzwell,Michael Uszler,Howard Schneider,Muriel Van Lierop,Daniel G Amen,Phil Cohen,Jie Tian

doi:10.1371/journal.pone.0091088

Abstract

PurposeThis systematic review evaluated the clinical utility of single photon emission computed tomography (SPECT) in traumatic brain injury (TBI).MethodsAfter defining a PICO Statement (Population, Intervention, Comparison and Outcome Statement), PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria were applied to identify 1600 articles. After screening, 374 articles were eligible for review. Inclusion for review was focus on SPECT in the setting of mild, moderate, or severe TBI with cerebral lobar specificity of SPECT findings. Other inclusion criteria were comparison modalities in the same subjects and articles in English. Foreign language articles, SPECT studies that did not include comparison modalities, and case reports were not included for review.ResultsWe identified 19 longitudinal and 52 cross-sectional studies meeting inclusion criteria. Three longitudinal studies examined diagnostic predictive value. The first showed positive predictive value increases from initial SPECT scan shortly after trauma to one year follow up scans, from 59% to 95%. Subsequent work replicated these results in a larger cohort. Longitudinal and cross sectional studies demonstrated SPECT lesion localization not detected by CT or MRI. The most commonly abnormal regions revealed by SPECT in cross-sectional studies were frontal (94%) and temporal (77%) lobes. SPECT was found to outperform both CT and MRI in both acute and chronic imaging of TBI, particularly mild TBI. It was also found to have a near 100% negative predictive value.ConclusionsThis review demonstrates Level IIA evidence (at least one non-randomized controlled trial) for the value of SPECT in TBI. Given its advantages over CT and MRI in the detection of mild TBI in numerous studies of adequate quality, and given its excellent negative predictive value, it may be an important second test in settings where CT or MRI are negative after a closed head injury with post-injury neurological or psychiatric symptoms.

Highlights

traumatic brain injury (TBI) is a complex clinical phenomenon lacking a rigorously specified taxonomy, clear natural history, or pathoanatomical diagnostic criteria
It is understood that those with mild TBI, repetitive mild TBI, can have underlying neuropathology, that contributes to long-term increases in morbidity and mortality [1,2,4,5,6]
With the consultation of an experienced health sciences librarian, a search of PubMed and Ovid MEDLINE was done in November of 2012. This was done using a series of search terms based upon the following Medical Subject Headings (MeSH) terms: (‘‘Tomography, Emission-Computed, Single-Photon’’ [MeSH] OR spect[tiab] OR ‘‘single photon emission computed tomography’’ [tiab] OR ‘‘Technetium Tc 99m Exametazime’’ [MeSH] OR hmpao[tiab] OR ecd[tiab] OR ‘‘Technetium Tc 99m Bicisate’’ [Supplementary Concept] OR ‘‘Cerebrovascular Circulation’’ [MeSH] OR ‘‘regional cerebral blood flow’’ [tiab] OR rcbf[tiab]) AND (‘‘brain injuries’’ [MeSH] OR tbi[tiab] OR ‘‘traumatic brain injury’’ [tiab] OR concussion[tiab]) NOT

Summary

Introduction

TBI is a complex clinical phenomenon lacking a rigorously specified taxonomy, clear natural history, or pathoanatomical diagnostic criteria. The classic designations of mild, moderate, or severe TBI are based on the acute presentation and do not necessarily predict the long-term outcome. The effects of several mechanisms for TBI (including impact, rotational and angular acceleration, and shear forces) lead to neurophysiological changes, cellular depolarization, and apoptosis that occur on a continuum and can progress over a protracted period of time [1]. It is understood that those with mild TBI, repetitive mild TBI, can have underlying neuropathology, that contributes to long-term increases in morbidity and mortality [1,2,4,5,6]. As the extent of undiagnosed or undertreated mild TBI becomes more evident [7], the endeavor of identifying TBI, mild TBI, and providing effective treatments becomes increasingly important

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