Brain imaging in epilepsy

2019 ◽  
Vol 19 (5) ◽  
pp. 438-443 ◽  
Author(s):  
John S Duncan
Keyword(s):  
Brain Imaging ◽  
Epilepsy Surgery ◽  
Single Photon ◽  
Photon Emission ◽  
Ct Scanning ◽  
Three Dimensions ◽  
Epileptic Focus ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Cerebral Pathology

Brain imaging with MRI identifies structural cerebral pathology that may give rise to seizures. The greatest yield is from MRI at 3T using epilepsy protocols, and reported by expert neuroradiologists who possess the full clinical data. X-ray CT scanning has a role in assessing patients with seizures in the context of an acute neurological illness. Identifying a relevant structural lesion with MRI is fundamental in the consideration of epilepsy surgery; it is crucial to establish if a lesion is relevant to the epilepsy or not. If no lesion is identified, developmental MRI and image processing may identify a subtle abnormality. Positron-emission tomography (PET) and single-photon emission computed tomography (SPECT) may identify focal functional abnormalities that infer the location of an epileptic focus. Functional MRI is useful for localising eloquent cortex, and tractography delineates crucial white matter tracts, so that these may be avoided in epilepsy surgery. Reviewing data in three dimensions aids visualisation of structural relationships and helps surgical planning.

Advanced Neuroimaging for Modern Epilepsy Surgery

2011 ◽  
Vol 6 (4) ◽  
pp. 257
Author(s):  
Doris D Wang ◽  
Carlos Santos-Sanchez ◽  
Paul A Garcia ◽  
Edward F Chang ◽  
◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Single Photon ◽  
Imaging Techniques ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Neurological Morbidity ◽  
Surgical Evaluation ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Localising the onset of seizures to guide epilepsy surgery can be notoriously difficult. Modern neuroimaging has revolutionised the field by improving the diagnosis and treatment of epilepsy. In order to ameliorate seizures without causing new neurological morbidity, many imaging tools have been developed to guide safe and effective resective surgery. In this article, we discuss recent advances in structural imaging using ultrahigh-field magnetic resonance imaging, metabolic functional imaging techniques of positron emission tomography and single photon emission computed tomography and electrophysiological imaging using magnetoencephalography. Our goal is to provide an overview of these state-of-the-art imaging modalities, their role in guiding surgery, and how they are incorporated into the pre-surgical evaluation of epilepsy.

Neuroimaging technologies

2020 ◽  
pp. 101-112
Author(s):  
Mark Woolrich ◽  
Mark Jenkinson ◽  
Clare Mackay
Keyword(s):  
Brain Imaging ◽  
Single Photon ◽  
Photon Emission ◽  
Experimental Medicine ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Brain Structure And Function ◽  
Magnetic Resonance Imaging Mri ◽  
And Function ◽  
The Brain

The brain is a highly complex system that is inaccessible to biopsy, which puts human brain imaging at the heart of our attempts to understand psychiatric disorders. Imaging has the potential to uncover the pathophysiology, provide biomarkers for use in the development and monitoring of treatments, and stratify patients for studies and trials. This chapter introduces the three main brain imaging technologies that are used to assay brain structure and function: magnetic resonance imaging (MRI), molecular imaging positron emission tomography (PET), and single-photon emission computed tomography (SPECT); electrophysiology [electroencephoaography (EEG)]; and magnetoencephalograpy (MEG). The chapter outlines the principles behind their use and the nature of the information that can be extracted. Together, these brain imaging methods can provide complementary windows into the living brain as an increasingly essential suite of tools for experimental medicine in psychiatry.

Brain Imaging In Obsessive-Compulsive Disorder: Evidence for the Involvement of Frontal-Subcortical Circuitry in the Mediation of Symptomatology

CNS Spectrums ◽  
1996 ◽  
Vol 1 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Arthur L. Brody ◽  
Sanjaya Saxena
Keyword(s):  
Computed Tomography ◽  
Brain Imaging ◽  
Obsessive Compulsive Disorder ◽  
Functional Neuroimaging ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Positron Emission

AbstractRecent brain-imaging studies have examined the neuroanatomy and pathophysiology of obsessive-compulsive disorder (OCD). Researchers have used computed tomography and magnetic resonance imaging to look at brain structure and single-photon emission computed tomography and positron emission tomography scanning to look at brain function in OCD subjects. In this article, we review these studies and discuss their methodology. We then present a theoretical model derived from these studies for how the brain mediates OCD symptomatology.Functional neuroimaging studies have pointed to hyperactivity of orbitofrontal-basal ganglionic–thalamic circuitry in patients with OCD. Our model posits an imbalance between the classical “direct” and “indirect” orbitofrontal–basal ganglionic–thalamic pathways in OCD subjects. The direct circuit appears to function as a positive feedback loop and may “capture” or “lock in” symptomatic OCD subjects. The indirect circuit, which usually provides tonic inhibition to the direct circuit, may be relatively weak.Finally, we discuss how frontal-subcortical brain circuitry may be involved in other neuropsychiatric illnesses, and we describe how monoamines, such as serotonin and dopamine, may be involved in regulating these circuits in OCD and other illnesses.

scholarly journals A Nordic survey of CT doses in hybrid PET/CT and SPECT/CT examinations

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Natalie A. Bebbington ◽  
Bryan T. Haddock ◽  
Henrik Bertilsson ◽  
Eero Hippeläinen ◽  
Ellen M. Husby ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Positron Emission ◽  
Pet Ct ◽  
Clinical Purpose ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Abstract Background Computed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose. Results Data were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8). Conclusions Suggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.

Neuroimaging and the Origin of Psychiatric Symptoms in Dementia

1997 ◽  
Vol 8 (S3) ◽  
pp. 239-243 ◽  
Author(s):  
David L. Sultzer
Keyword(s):  
Computed Tomography ◽  
Density Functional ◽  
Psychiatric Symptoms ◽  
Functional Neuroimaging ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Neuroimaging studies have contributed greatly to our understanding of Alzheimer's disease and other dementias. Computed tomography and magnetic resonance imaging reveal brain structure and aid in the diagnostic evaluation of patients with cognitive impairment. Functional neuroimaging studies use positron emission tomography, single-photon emission computed tomography, and other methods to measure regional cerebral activity, including metabolic rate, blood flow, and neuroreceptor density. Functional neuroimaging results can be useful clinically and have also been used in a variety of research applications to examine physiologic variables in neuropsychiatric illnesses.

Sign in / Sign up

Export Citation Format

Share Document