18F-FDG-PET and MRI in autoimmune encephalitis: a systematic review of brain findings

Silvia Morbelli, Marco Zoccarato, Matteo Bauckneht, Mariagiulia Anglani, Diego Cecchin

Research output: Contribution to journalReview article

Abstract

Introduction: In the diagnostic assessment of autoimmune encephalitis (AE) associated with antineural antibody (Ab) imaging with 18F-fluorodeoxyglucose (FDG), positron emission tomography (PET) was initially only used to screen for occult malignancies in paraneoplastic cases. Today accumulating evidence also supports the use of PET imaging for the objective assessment of metabolic changes in the brain of patients with AE. On the other hand, magnetic resonance imaging (MRI) of the brain reveals a variable picture depending on the specific syndrome and associated antibody, and may be normal in a sizable proportion of patients. Acquisition of evidence: Among all the articles retrieved, we selected only studies and case series describing 18F-PET/CT, or multimodal imaging assessments (with both PET/CT and MRI performed in the same patient) on at least five patients with AE confirmed by the presence of antineural Ab. Studies describing MRI but not PET/CT findings on at least 20 cases were also included to strengthen the morphological considerations. Summary of evidence: We summarize the findings in the literature, commenting on studies involving the use of FDG-PET/CT in patients with AE, focusing on the added value and unsolved issues of using FDG-PET as opposed to MRI, and discussing them in the context of the available diagnostic criteria for AE. We also describe neuroimaging (PET and MRI) differences between AE with Ab against surface antigens vs AE with Ab against intracellular antigens. The timing of neuroimaging after the onset of symptoms is also considered. Conclusions: From a systematic review of the literature, it seems that some specific metabolic patterns correlate with the presence of specific Ab, such as a cerebral posterior hypometabolism in anti-NMDAR encephalitis, and a mesiotemporal hypermetabolism (associated with hyperintensities and swollen structures on MRI T2) in encephalitis with LGI1 and onconeural Ab. To ascertain the prognostic value of FDG-PET and its role in driving therapy, larger (preferably longitudinal) studies are needed on age-matched, untreated patients with the same Ab status, who undergo imaging at a similar time after the onset of their symptoms. This would enable a systematic correlation between MRI and FDG-PET findings, and help to clarify a number of unsolved clinical and technical issues.

LanguageEnglish
Pages151-168
Number of pages18
JournalClinical and Translational Imaging
Volume6
Issue number3
DOIs
Publication statusPublished - Jun 1 2018

Fingerprint

Fluorodeoxyglucose F18
Positron-Emission Tomography
Magnetic Resonance Imaging
Brain
Antibodies
Neuroimaging
Anti-N-Methyl-D-Aspartate Receptor Encephalitis
Multimodal Imaging
Hashimoto's encephalitis
Encephalitis
Surface Antigens
Longitudinal Studies
Antigens

Keywords

  • Autoimmune encephalitis
  • MRI
  • Paraneoplastic
  • PET/CT
  • PET/MRI

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

18F-FDG-PET and MRI in autoimmune encephalitis : a systematic review of brain findings. / Morbelli, Silvia; Zoccarato, Marco; Bauckneht, Matteo; Anglani, Mariagiulia; Cecchin, Diego.

In: Clinical and Translational Imaging, Vol. 6, No. 3, 01.06.2018, p. 151-168.

Research output: Contribution to journalReview article

Morbelli, Silvia ; Zoccarato, Marco ; Bauckneht, Matteo ; Anglani, Mariagiulia ; Cecchin, Diego. / 18F-FDG-PET and MRI in autoimmune encephalitis : a systematic review of brain findings. In: Clinical and Translational Imaging. 2018 ; Vol. 6, No. 3. pp. 151-168.
@article{24a47a199ea645b38a8e4bfbb4f8d189,
title = "18F-FDG-PET and MRI in autoimmune encephalitis: a systematic review of brain findings",
abstract = "Introduction: In the diagnostic assessment of autoimmune encephalitis (AE) associated with antineural antibody (Ab) imaging with 18F-fluorodeoxyglucose (FDG), positron emission tomography (PET) was initially only used to screen for occult malignancies in paraneoplastic cases. Today accumulating evidence also supports the use of PET imaging for the objective assessment of metabolic changes in the brain of patients with AE. On the other hand, magnetic resonance imaging (MRI) of the brain reveals a variable picture depending on the specific syndrome and associated antibody, and may be normal in a sizable proportion of patients. Acquisition of evidence: Among all the articles retrieved, we selected only studies and case series describing 18F-PET/CT, or multimodal imaging assessments (with both PET/CT and MRI performed in the same patient) on at least five patients with AE confirmed by the presence of antineural Ab. Studies describing MRI but not PET/CT findings on at least 20 cases were also included to strengthen the morphological considerations. Summary of evidence: We summarize the findings in the literature, commenting on studies involving the use of FDG-PET/CT in patients with AE, focusing on the added value and unsolved issues of using FDG-PET as opposed to MRI, and discussing them in the context of the available diagnostic criteria for AE. We also describe neuroimaging (PET and MRI) differences between AE with Ab against surface antigens vs AE with Ab against intracellular antigens. The timing of neuroimaging after the onset of symptoms is also considered. Conclusions: From a systematic review of the literature, it seems that some specific metabolic patterns correlate with the presence of specific Ab, such as a cerebral posterior hypometabolism in anti-NMDAR encephalitis, and a mesiotemporal hypermetabolism (associated with hyperintensities and swollen structures on MRI T2) in encephalitis with LGI1 and onconeural Ab. To ascertain the prognostic value of FDG-PET and its role in driving therapy, larger (preferably longitudinal) studies are needed on age-matched, untreated patients with the same Ab status, who undergo imaging at a similar time after the onset of their symptoms. This would enable a systematic correlation between MRI and FDG-PET findings, and help to clarify a number of unsolved clinical and technical issues.",
keywords = "Autoimmune encephalitis, MRI, Paraneoplastic, PET/CT, PET/MRI",
author = "Silvia Morbelli and Marco Zoccarato and Matteo Bauckneht and Mariagiulia Anglani and Diego Cecchin",
year = "2018",
month = "6",
day = "1",
doi = "10.1007/s40336-018-0275-x",
language = "English",
volume = "6",
pages = "151--168",
journal = "Clinical and Translational Imaging",
issn = "2281-5872",
publisher = "Springer-Verlag Italia s.r.l.",
number = "3",

}

TY - JOUR

T1 - 18F-FDG-PET and MRI in autoimmune encephalitis

T2 - Clinical and Translational Imaging

AU - Morbelli, Silvia

AU - Zoccarato, Marco

AU - Bauckneht, Matteo

AU - Anglani, Mariagiulia

AU - Cecchin, Diego

PY - 2018/6/1

Y1 - 2018/6/1

N2 - Introduction: In the diagnostic assessment of autoimmune encephalitis (AE) associated with antineural antibody (Ab) imaging with 18F-fluorodeoxyglucose (FDG), positron emission tomography (PET) was initially only used to screen for occult malignancies in paraneoplastic cases. Today accumulating evidence also supports the use of PET imaging for the objective assessment of metabolic changes in the brain of patients with AE. On the other hand, magnetic resonance imaging (MRI) of the brain reveals a variable picture depending on the specific syndrome and associated antibody, and may be normal in a sizable proportion of patients. Acquisition of evidence: Among all the articles retrieved, we selected only studies and case series describing 18F-PET/CT, or multimodal imaging assessments (with both PET/CT and MRI performed in the same patient) on at least five patients with AE confirmed by the presence of antineural Ab. Studies describing MRI but not PET/CT findings on at least 20 cases were also included to strengthen the morphological considerations. Summary of evidence: We summarize the findings in the literature, commenting on studies involving the use of FDG-PET/CT in patients with AE, focusing on the added value and unsolved issues of using FDG-PET as opposed to MRI, and discussing them in the context of the available diagnostic criteria for AE. We also describe neuroimaging (PET and MRI) differences between AE with Ab against surface antigens vs AE with Ab against intracellular antigens. The timing of neuroimaging after the onset of symptoms is also considered. Conclusions: From a systematic review of the literature, it seems that some specific metabolic patterns correlate with the presence of specific Ab, such as a cerebral posterior hypometabolism in anti-NMDAR encephalitis, and a mesiotemporal hypermetabolism (associated with hyperintensities and swollen structures on MRI T2) in encephalitis with LGI1 and onconeural Ab. To ascertain the prognostic value of FDG-PET and its role in driving therapy, larger (preferably longitudinal) studies are needed on age-matched, untreated patients with the same Ab status, who undergo imaging at a similar time after the onset of their symptoms. This would enable a systematic correlation between MRI and FDG-PET findings, and help to clarify a number of unsolved clinical and technical issues.

AB - Introduction: In the diagnostic assessment of autoimmune encephalitis (AE) associated with antineural antibody (Ab) imaging with 18F-fluorodeoxyglucose (FDG), positron emission tomography (PET) was initially only used to screen for occult malignancies in paraneoplastic cases. Today accumulating evidence also supports the use of PET imaging for the objective assessment of metabolic changes in the brain of patients with AE. On the other hand, magnetic resonance imaging (MRI) of the brain reveals a variable picture depending on the specific syndrome and associated antibody, and may be normal in a sizable proportion of patients. Acquisition of evidence: Among all the articles retrieved, we selected only studies and case series describing 18F-PET/CT, or multimodal imaging assessments (with both PET/CT and MRI performed in the same patient) on at least five patients with AE confirmed by the presence of antineural Ab. Studies describing MRI but not PET/CT findings on at least 20 cases were also included to strengthen the morphological considerations. Summary of evidence: We summarize the findings in the literature, commenting on studies involving the use of FDG-PET/CT in patients with AE, focusing on the added value and unsolved issues of using FDG-PET as opposed to MRI, and discussing them in the context of the available diagnostic criteria for AE. We also describe neuroimaging (PET and MRI) differences between AE with Ab against surface antigens vs AE with Ab against intracellular antigens. The timing of neuroimaging after the onset of symptoms is also considered. Conclusions: From a systematic review of the literature, it seems that some specific metabolic patterns correlate with the presence of specific Ab, such as a cerebral posterior hypometabolism in anti-NMDAR encephalitis, and a mesiotemporal hypermetabolism (associated with hyperintensities and swollen structures on MRI T2) in encephalitis with LGI1 and onconeural Ab. To ascertain the prognostic value of FDG-PET and its role in driving therapy, larger (preferably longitudinal) studies are needed on age-matched, untreated patients with the same Ab status, who undergo imaging at a similar time after the onset of their symptoms. This would enable a systematic correlation between MRI and FDG-PET findings, and help to clarify a number of unsolved clinical and technical issues.

KW - Autoimmune encephalitis

KW - MRI

KW - Paraneoplastic

KW - PET/CT

KW - PET/MRI

UR - http://www.scopus.com/inward/record.url?scp=85048720957&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85048720957&partnerID=8YFLogxK

U2 - 10.1007/s40336-018-0275-x

DO - 10.1007/s40336-018-0275-x

M3 - Review article

VL - 6

SP - 151

EP - 168

JO - Clinical and Translational Imaging

JF - Clinical and Translational Imaging

SN - 2281-5872

IS - 3

ER -