The document discusses various neuroimaging techniques used to study the brain, including their basic principles and psychiatric applications. It describes CT, MRI, MRS, fMRI, and SPECT, explaining what each measures, how they work, and what tissues appear as on the images. It provides examples of structural images and contrasts the advantages and disadvantages of the different modalities. It also outlines specific indications for neuroimaging in clinical practice and research into psychiatric disorders.

2. Contents
Basic fundamentals about






CT scan
MRI
MRS
fMRI
SPECT
PET
Imaging in some specific psychiatric disorders





Imaging in Dementia
Imaging in OCD
Imaging in Depression & Bipolar disorders
Imaging in Schizophrenia
Imaging in Anxiety disorders & PTSD
Imaging in ADHD & Autism

3. NEUROIMAGING

Can allow measurement of the structure, function, &
chemistry of the living human brain

Has provided new information about the pathophysiology
of psychiatric disorders

Can be useful for diagnosing illness, predicting prognosis
& for developing new treatments

4. USES OF NEUROIMAGING
Indications in
Clinical Practice

Neurological Deficits

To rule out neurological
causes of psychiatric
illnesses

Dementia
Indications in Clinical
Research

Analysis of Clinically
Defined Groups of Patients

Analysis of Brain Activity
during Performance of
Specific Tasks

5. NEURO-IMAGING TECHNIQUES
1.
Structural




2.
Plain Skull Radiography
Pneumo-encephalography
CT scan
Structural MRI
Functional






Magnetic resonance spectroscopy (MRS)
Functional MRI (fMRI)
Positron emission tomography (PET)
Single photon emission computed tomography (SPECT)
Brain electrical activity mapping (BEAM)
Evoked Potential

6. COMPUTED TOMOGRAPHY (CT)

7. …Contd
CT Scanners take a
series of head X-ray
pictures from all
vantage points
The amount of radiation
that passes through, or is
not absorbed from, each
angle is digitized &
entered into a computer
When viewed in
sequence, the images
allow mental
reconstruction of the
structure of the brain
BASICS
360º around a
patient's head
The computer uses matrix algebra
calculations to assign a specific
density to each point within the head
& displays these data as a set of 2-D
images

8. Grey-scale Appearance on CT
Tissue
Appearance
Bone
White
Calcified Tissue
White
Clotted Blood
White
Grey Matter
Light Gray
White Matter
Medium Grey
CSF
Near Black
Water
Near Black
Air
Black

9. Points to remember

CT image is determined only by degree to which tissues absorb X-ray

Bony str. Absorb large amount of x-rays and tend to obscure the details
of neighboring structures poor visibility in brainstem.

Poor differentiation of grey-white pattern than compared to MRI.

Certain tumors may be invisible on CT because they absorb as much
irradiation than the surrounding brain visible on Contrast CT.

Bone, clotted blood, calcified tissue, contrast material all appear white
& CSF black

The only component of brain better seen on CT scan is
Calcification, which may be invisible on MRI

10. Normal CT Brain

11. 
Criteria for Contrast Patients with H/O seizure
 Patients with H/O cerebro-vascular accident
 Suspicion of intracranial SOLs including
granulomas, CNS tumours, metastatic lesions
¤ Plain CT
• Diagnostic accuracy 82%
¤ Contrast CT
• IV iodinated contrast medium
• Diagnostic accuracy 92%

12. Image showing enhancement after contrast administration

13. …Contd
ADVANTAGES v/s DISADVANTAGES of CT
ADVANTAGES

Simpler, cheaper, more accessible

Tolerated by claustrophobics

No absolute contraindications

Better than MR for bone detail &
Calcification
DISADVANTAGES

Ionizing radiation

IV contrast complications

Limited range of tissue
contrasts

15. CLNICAL INDICATIONS OF CT BRAIN IN
PSYCHIATRY










Confusion &/or dementias of unknown cause
First episode of psychosis
First episode of major affective disorder after 50 years of age
Personality changes after 50 years of age
Psychiatric symptoms following head injury
To rule out complications due to possible head trauma
Prolonged catatonia
Co existence of seizure with psychiatric symptoms
Movement disorders of unknown etiology
Focal neurological signs accompanying psychiatric symptoms
Weinberg 1984; Beresford et al 1986

16. MRI
Liquid Helium Cooled
1.5 Tesla Solenoid Magnet
Radiofrequency
Transmitter/Reciever
Coil
Patient Platform

17. …Contd
Nuclei of all atoms are
thought to spin about an
axis randomly oriented in
space
When the pulse terminates, the
axis of the spinning nucleus
realigns itself with the magnetic
field
During this
realignment, it emits its
own radiofrequency
signal
Placed in magnetic Field 
axis of all odd-numbered
nuclei (mainly Hydrogen)
align with the magnetic field
When exposed to a pulse of
radiofrequency waves Axis of nucleus deviates
away from the magnetic field
MRI scanners collect the emissions of
individual, realigning nuclei & use
computer analysis to generate a
series of 2-D images that represent
the brain

18. 
Radiofrequency and magnetic field pulses
manipulated to create different pulse sequences.

Based on the duration of RF pulse & the length of
time - different pulse sequences are obtained.

Examples: T1, T2, FLAIR, DWI etc.

19. T1 Weighted MRI

Best for visualizing normal
neuroanatomy

Sharp boundaries between
grey matter, white matter, and
CSF

Useful in evaluation of
cerebro-pontine angle cistern
& pituitary fossa

Bone white
white matter light grey
grey matter medium grey
water/CSF/air- Black



•T1 is the only sequence that allows
contrast enhancement with Gadolinium.
•Contrast enhanced structures on T1
appears white.

20. T2 Weighted MRI

Less distinct boundaries
between white and grey matter

Best for displaying pathology

Useful in demyelination, edema
& tumour infiltration

Gray matter medium gray

white matter dark grey

CSF and water White

21. …Contd
T1 WEIGHTED IMAGES
T2 WEIGHTED IMAGES

22. Fluid Attenuated Inversion Recovery
(FLAIR)

Special type of MRI scan

T1 image is inverted & added to
the T2 image

Contrast between grey & white
matter is doubled & the normal
CSF signal is suppressed.

Special indications
1.
To detect Sclerosis of
hippocampus in Temporal lobe
epilepsy.
2.
To Localize the areas of
abnormal metabolism in
degenerative neurological
diseases.

23. Diffusion-Weighted Imaging (DWI)

Sensitive to speed of
water diffusion

Visualizes area of
ischemic stroke in 1st
few hours- earliest to
detect ischemia.

24. IMPORTANT POINTS
•MRI magnets used in clinical practice ranges from 0.3 to 2.0 Tesla strength.
•Higher field-strength scanners produce image of higher resolution.
INDICATIONS



To rule out organic
cause of
psychiatric illness
Abrupt change in
mental state
DISADVANTAGES
ADVANTAGES

Does not expose the
patient to ionizing
radiations

Demyelinating
disease can be
assessed reliably
New onset memory
loss or dementia

better study of
posterior fossa
structures

Avoided in patients
wearing metallic
devices

Claustrophobia

Does not pick up
bony abnormalities

Difficult in
uncooperative
patients

25. IV CONTRAST IN NEURO-IMAGING

CT  Iodine based
 Iodine is highly attenuating of X-ray beam (bright on CT)

MRI  Gadolinium based (Gadolinium DTPA)
 Gadolinium is a paramagnetic metal that hastens T1 relaxation of
nearby water protons (bright on T1-weighted images)

Tissue that gets brighter with IV contrast is said to be ―enhanced‖

Enhancement reflects the vascularity of tissue,
 The blood-brain barrier keeps IV contrast out of the brain
 Enhancement implies BBB is absent or dysfunctional

26. Amygdala

27. Hippocampus

28. Caudate
Head

29. Putamen

30. Globus
Pallidus

31. Magnetic Resonance Spectroscopy
(MRS)

32. PRINCIPLE
Basic principle similar to MRI
MRS can detect several odd-numbered nuclei
Permits study of many metabolic processes
φ
Nuclei align themselves in the strong mag. field
φ
A radiofrequency pulse causes the nuclei of interest to absorb & then emit
energy
φ
Readout on MRS  in the form of a spectrum  Can be converted into a
pictorial image of the brain

34. NUCLEI USED IN MRS
& Their uses in Psychiatry
NUCLEI
USES
H¹
Decreased aspartate (NAA) in dementia & other
neurological conditions
Li 7
Pharmacokinetics of Lithium
C¹³
Study of metabolic pathway
F 19
•
•
P³¹
Pharmacokinetics of certain drugs like SSRIs
(Fluoxetine, Fluoxamine)
Analysis of glucose metabolism
Tissue metabolism (compound containing high energy
phosphates like ATP, ADP etc.)

35. Significance of MRS in psychiatry

MRS has revealed decreased NAA conc. in temporal
lobes & increased conc. of Inositol in occipital lobes of
pts with Alzheimer dementia.

MRS has revealed decreased NAA conc. In temporal
& frontal lobes of pts with Schizophrenia.

Also it has shown elevated brain Lactate levels during
panic attacks in pts with panic disorder.

36. Functional Magnetic Resonance Imaging
(fMRI)

37. 
ADVANTAGES
A sub-type of MRI scan

Uses the New T2 or the Blood-Oxygen
Level Dependent (BOLD) sequence
Detects levels of oxygenated Hb in
the blood  Maps brain function

Detects not the brain activity per se, but
the blood flow
Neuronal
activity
within the
brain
Local
increase
in blood
flow
Increases
the local
Hb conc.
• Possible to study both
cerebral anatomy &
functional
neurophysiology using
a single technique
(Bullmore & Fletcher
2003)
• No radio active
exposure
Which
reflects the
func. activity
of brain on
T2 sequence

38. Limitations of fMRI

fMRI asseses neuronal activity indirectly by
measuring blood flow (or tissue perfusion)  this
limits its resolution.
 Two tasks that activates clusters of neurons 5 mm apart
will yield overlapping signals on fMRI & thus are
indistinguishable by this technique.
 Sensitivity & resolution can be improved by using ultrasmall non toxic iron oxide particles.

Acquisition of sufficient images for study can
require 20 minutes to 3 hours, during which the
subject’s head must remain in exactly the same
position.

39. fMRI
Healthy Controls
Depression group

40. Healthy Controls
fMRI
Schizophrenia group

41. SPECT
SPECT
SPECT

42. …Contd
BASICS
A type of Nuclear Imaging that shows how blood flows to tissues & organs
 Integrates : CT + Radioactive Material (Tracer)
 SPECT uses compounds labeled with single photon-emitting isotopes: iodine123, technetium-99m, and xenon-133

Inject with radiolabelled material
Gamma rays
emitted detected
by scanner
Translated into
2-D image
These images
added together
to get a 3-D
image

43. USES

Regional cerebral blood flow
 Tc 99 is most commonly used for deeper structures of brain
 Xe 133 for superficial structures of brain (rCBF Technique)

Muscarinic cholinergic system
 I 123

Dopaminergic system
 Radiolabelled receptor binding agents I123, IBZM (Iodobenzamide) for
D2 receptors

Adrenergic system

Early diagnosis of Alzheimer's disease

44. What SPECT can measure

Regional brain function: perfusion

Dopamine D2 receptor availability

Dopamine transporter function

M1 muscarinic receptors

Nicotinic receptors
Same scanner: different radiopharmaceuticals

45. PET

46. …Contd
BASIC PRINCIPLE
-ray
detector
+
Radioactive nucleus
•
•
Most Commonly Used Isotopes
• F 18
• N 13
• O 15
A radioactive isotope is injected &
decays, emitting a β + particle.
Within a short distance, the β + particle
bumps into an electron & the two
annihilate, producing a pair of - rays.
•
By detecting & reconstructing where the rays come from, we can measure the
location & conc of radio-isotope.

47. …Contd
APPLICATIONS

To estimate regional cerebral blood flow

To estimate regional cerebral glucose metabolism
(regional cerebral metabolic rate for glucose - rCMRglu)

For receptor imaging

To study normal brain development

48. SPECT v/s PET
SPECT
PET
Single photon
Positron
99mTc or I 123
11C or 18F
Short half life
Longer half life
Less sensitive
Highly sensitive (100 times more than
SPECT)
Can buy isotopes
Local cyclotron
Low spatial resolution
Superior spatial resolution
Cheaper and easily available than PET
Costly, not easily available

49. PET scan
Increased loss of gray
matter in adolescence
between the ages of
12-16 compared to
healthy adolescence.
Red—Gray Matter Gain
Blue—Gray Matter Loss

50. PET Scan
Not Depressed vs. Depressed

51. PET scans of a 45 year old woman
with recurrent depression
pre and post treatment.

52. PET Scan
ADHD vs. Normal
NORMAL
ADHD
White, Red, Orange = higher glucose metabolism
Blue, Green, Purple = lower glucose metabolism

53. IMAGING IN SPECIFIC
PSYCHIATRIC DISORDERS

54. IMAGING IN DEMENTIA

56. ALZHEIMER’S DEMENTIA

57. Structural imaging

Cerebral atrophy (typical dilatation of lateral
ventricles & widening of cortical sulci) particularly in posterior temporal & parietal regions &
 specific brain regions like hippocampus and medial
temporal lobe.

Volumetric MRI reveals shrinkage in vulnerable
brain regions, particularly the medial temporal lobe
& Hippocampus.

59. Measurements of hippocampus is the most sensitive marker of
pathology of AD early in disease

62. Functional imaging

Early studies using PET or SPECT revealed a
characteristic pattern of hypometabolism in the posterior
parietal lobes.

MRS in AD revealed- Decreased conc of NAA in the
temporal lobes & increased conc of inositol in the
occipital lobes

64. SPECT of rCBF in AD
(Cummings and Mega, 2003)

65. PET of
Glucose
Metabolism
in normal vs.
Alzheimer’s
Disease

66. Recent..

Most recent development in brain imaging in AD is
the development of radio-labelled ligands that can
bind with amyloid, and then can be visualised with
PET.
 This technique is currently under investigation.

67. FRONTO-TEMPORAL
DEMENTIA

68. Structural imaging reveals
Severe sharply localised atrophy – bilaterally symmetric
―KNIFE-BLADE ATROPHY‖

Hyper-intense signal in the cortex & underlying white
matter of the affected areas

Areas involved- dorsolateral prefrontal cortex & medial
temporal lobes
Areas spared- posterior parietal and occipital cortices.

Functional imaging reveals
Fronto-temporal hypometabolism

71. Frontal lobe dementia
• Frontal hypo-perfusion sometimes including
temporal lobes
Alzheimer’s disease
Bi-lateral temporo-parietal
deficits
Frontal lobe dementia
Bi-lateral frontal lobe
deficits

72. LEWY BODY DEMENTIA

73. 
To date, no MRI features have been identified to
characterize DLB.

The absence of significant Medial Temporal lobe
atrophy in an elderly demented patient suggests
DLB etiology rather than AD.

PET or SPECT may reveal reduced occipital
function with generalized reduction of cortical
activity.

74. VASCULAR DEMENTIA

79. Vascular dementia

Multiple regions of focally reduced perfusion

80. NORMAL PRESSURE
HYDROCEPHALUS

82. MRI findings include
Ventricular enlargement out of proportion to sulcal
atrophy.

Prominent periventricular hyperintensity (halo).

Prominent flow void in the aqueduct and third
ventricle, the so-called jet sign, (presents as a dark
aqueduct and third ventricle on a T2-weighted image
where remainder of CSF is bright)

Thinning and elevation of corpus callosum on sagittal
images

84. IMAGING IN OCD
-Frontal lobe
-Caudate
-Cingulate gyrus

85. CT & MRI IN OCD

Bilaterally smaller caudate in OCD pts.

Significantly more Cerebral Grey matter & Less white matter volume
than normal controls.

Decreased volume of Left orbital frontal cortex.

Abnormality in length of Corpus callosum.

Abnormality in Pituitary volume may also be noted.

Larger anterior cingulate volumes (ACV)  a/w increased OCD
symptoms severity but not duration of illness

86. MRS IN OCD

OCD patients were divided into three
groups
 Responders to a SSRI
 Responders to a SSRI + an Atypical
Antipsychotic
 Non-Responders to either SSRI or
SSRI + an Atypical Antipsychotic
Greater Glutamatergic
conc. in caudate, as
measured by ¹H-MRS in
comparison to controls

MRS was used to measure NAA
concentrations in the anterior
cingulate, the left basal ganglia & the
left prefrontal lobe of the subjects

Significantly lower NAA concentrations
in responders to SSRI + AAP in
Sumitani S et al (2007) Psychiatry Res; 154: 85-92
anterior cingulate gyrus

87. SPECT & PET in OCD

In a resting SPECT study, OCD pts has increased mesial frontal
perfusion, which normalised with fluoxetine Rx.
PET have shown- Increased activity (eg. Metabolism & blood
flow) in the frontal lobes, basal ganglia(sp. caudate), and the
cingulate gyrus in OCD pts. (findings consistent with the MRI
findings)
 Head of the caudate 

 PET : Greater activity
 SPECT : Decreased activity

Pharmalcological and behavioral Rx reportedly reverse these
abnormalities.

88. IMAGING IN DEPRESSION
& BIPOLAR DISORDER
-Left Prefrontal cortex
-Subcortical nuclei

89. CT & MRI in Depression

Smaller volumes of frontal cortex, cerebellum, caudate &
putamen.

Ventricular enlargement, cortical atrophy, and sulcal widening
also have been reported in some studies.

The most consistent abnormality observed in depression isIncreased frequency of abnormal hyperintensities in subcortical
regions including periventricular regions, basal ganglia, and
thalamus.
 These hyperintensities may reflect the deleterious effects of recurrent
affective episodes. (specially in bipolar I disorder and among elderly)

90. 
Some depressed pts may also have specifically
reduced hippocampal or caudate nucleus volumes,
suggesting presence of more focal defects.
 Focal areas of atrophy have been associated with increased
illness severity, bipolarity and increased cortisol levels.

91. fMRI IN DEPRESSION

Bilateral anterior cingulate cortex & Right amygdala
significantly smaller in size.
Tang Y et al (2007) Psychiatry Res.

Inactivation of Left prefrontal cortex in Depressed
Inactivation of Right prefrontal cortex in Mania

92. fMRI
Healthy Controls
Depression group

93. SPECT in Depression

Baseline cerebral blood flow (CBF)
was lower in depressed patients –
in frontal cortex & subcortical nuclei
bilaterally

Medication response –
normalization of CBF deficit.
Joensuu M et al (2007) Psychiatry Res. 154(2): 125-31

94. PET in Depression

The most widely replicated PET
finding in depression is- Decreased
anterior brain (frontal / prefrontal
cortex) metabolism specially on
dominant hemisphere (LEFT side).
 Reversal of this hypofrontality occurs when
pt. shifts from depression into mania (i.e.
decrease RIGHT frontal lobe function seen
in mania)

It has been seen that
antidepressants at least partially
NORMALISES these changes.

95. PET scans of a 45 year old woman
with recurrent depression
pre and post treatment.

96. Bipolar disorder

PET studies in depressed BPI, bipolar II, and manic
individuals have shown increased amygdala and
ventral striatal limbic subcortical activity compared
with healthy controls

In adults, there are findings of enlarged (or shrunken)
amygdalae, decreased dorsal and ventral prefrontal
cortices, and smaller or no change in hippocampi.
Altshuler LL, Bartzokis G, Grieder T, et al. An MRI study of temporal lobe structures in men with
bipolar disorder or schizophrenia. Biol Psychiatry. 2000;48:147–162.
Blumberg et al. 2003 "Amygdala and hippocampal volumes in adolescents and adults with bipolar
disorder". Arch Gen Psychiatry 60 (12): 1201–8.

97. IMAGING IN SCHIZOPHRENIA

98. Structural imaging

Enlargement of lateral & third ventricles may be static or
progressive.

Frontal lobe abnormalities, particularly prefrontal gray matter
and orbitofrontal regions.

Parietal lobe abnormalities, particularly of the inferior parietal
lobule which includes both supramarginal and angular gyri.

Subcortical abnormalities i.e. cavum septi pellucidum, basal
ganglia, corpus callosum, and thalamus.

All these structural abnormalities may be static or progressive.

99. 
Decreased size of medial temporal lobe structures (which
include the amygdala, hippocampus, and parahippocampal
gyrus), and abnormalities of neocortical temporal lobe regions
(superior temporal gyrus).

Hippocampus is not only smaller in size but also functionally
abnormal (disturbed glutamate transmission in functional
scans)

Reduced symmetry in various brain areas may be indicative
of disruption of brain lateralisation during neurodevelopment.

Anatomical & functional deficits in prefrontal cortex.

Volume shrinkage or neuronal loss in medial dorsal nucleus of
thalamus.

100. 
Positive symptoms  Decreased volume of
Superior temporal gyrus

Negative symptoms  Enlarged lateral ventricle &
decreased volume of medial temporal lobe
structures

Typical Anti-psychotics  increases the size of the
basal ganglia

101. Ventriculomegaly in discordant monozygotic twins seen on T2-weighted MRI scans.
Woolley J , and McGuire P APT 2005;11:195-202
©2005 by The Royal College of Psychiatrists

102. Functional imaging

Hypofrontality

Functional scans have also revealed lower levels of
phosphomonoester & inorganic phosphate and higher
levels of phophodiester in schiz pts.

NAA levels were also lower in hippocampus and frontal
lobes in pts with schiz.

103. Scan showing Increased loss of gray matter in adolescence between
the ages of 12-16 compared to healthy adolescence.
Red—Gray Matter Gain ;
Blue—Gray Matter Loss

105. IMAGING IN ANXIETY D/Os

106. 
Structural imaging (CT & MRI) Occasional increase in size of ventricles.
 Abnormalities in RIGHT hemisphere but not in the left
hemisphere.
○ This finding suggests that some type of cerebral
asymmetry may be important in the development of
anxiety disorder.

Functional imaging (fMRI, SPECT, PET) Abnormalities in frontal cortex, occipital & temporal
areas in pts. with anxiety disorder &
Abnormalities in parahippocampal gyrus in pts with
panic disorder.

107. 
MRS –
 In panic d/o  used to record the levels of
lactate, whose IV infusion can ppt. panic episodes in
~ 3/4th of the pts. with either Panic D/o or Major
Depression
 Brain lactate conc. were found to be elevated during
panic attacks, even without provocative infusion in
panic disorder pts.

108. IMAGING IN PTSD

109. Structural imaging in PTSD
Studies in PTSD Vietnam combat
veterans revealed:
 Reduced left and right hippocampal
volume
 Volume reductions were associated
with severity of combat exposure.
 A similar study was undertaken with Gulf
war veterans in Israel, and these data are
have shown similar findings

Hippocampus (green), Fornix
(blue)
and Mammilary Bodies (gray) are
shown in 3D.
Boone, Omar et al. Longitudinal MRI Study of Hippocampal Volume
in Trauma Survivors With PTSD. Am J Psychiatry 2001; 158:1248–1251

110. 
Smaller hippocampal volume is not a necessary
risk factor for developing PTSD and does not
occur within 6 months of expressing the disorder
 This brain abnormality might occur in individuals with
chronic or complicated PTSD.
Boone, Omar et al. Longitudinal MRI Study of Hippocampal Volume
in Trauma Survivors With PTSD. Am J Psychiatry 2001; 158:1248–1251

111. Twin studies in PTSD

A study reported in Nature-Neuroscience evaluated MR brain
morphometry of the hippocampus in monozygotic twins
discordant for PTSD. The PTSD twin was diagnosed with
PTSD as a result of combat exposure in the Vietnam War.

The twin aspect of this study was important as it showed that
individuals discordant for PTSD showed reduced hippocampal
volume compared with twins where PTSD was present in
neither twin.

This finding suggests that there may be a predisposition or
vulnerability factor involved in the genesis of PTSD
Gilberson, MW et al. Smaller hippocampal volume predicts pathologic vulnerability to
psychological trauma. Nature-Neuroscience, October 2002

112. Functional imaging in PTSD

fMRI studies have found increased activity in
Amygdala, a brain region associated with fear.

113. IMAGING IN ADHD

114. Structural imaging (CT & MRI)

Shows no consistent findings.

Increased cortical grey & white matter volumes from 5
yrs of age with peak at 12-15 yrs of age.

Early onset ADHD may be associated with smaller
total brain volume in- 4% cases.

Decrease in the volume of posterior inferior cerebellar
vermis may be noted.(region involved in attention
processing)

115. Functional imaging (fMRI, SPECT, PET)

PET has shown that adolescent females with ADHD have
globally lower glucose metabolism that both normal
controls & males with ADHD.

PET scan has also shown lower CBF and metabolic rates
in the frontal lobes of children with ADHD.

This may be because frontal lobes in children with ADHD are not
adequately performing their inhibitory mechanism on lower
structures, leading to disinhibition.

Less striatal activation during cognition inhibition tasks.

117. PET Scan
ADHD vs. Normal
White, Red, Orange = higher glucose metabolism
Blue, Green, Purple = lower glucose metabolism

118. IMAGING IN AUTISM

119. Structural imaging

Significant DECREASE of grey matter concentration in superior
temporal sulcus bilaterally, an area which is critical for
perception of key social stimuli.

Also a decrease of white matter concentration in the right
temporal pole and in cerebellum compared to normal children.

INCREASE in total cerebral volume, both in grey and white
matter, mostly in the occipital, temporal and parietal lobes.

Brain enlargement has been considered as a possible biomarker for
autistic disorder.

121. Functional imaging

Bilateral hypoperfusion of the temporal lobes in autistic
children.

In addition, activation abnormalities may be observed
in the temporal lobes and amygdala, which are
involved in language and social cognition.

An increase in visual cortex activity was also reported

123. Message…

Neuroimaging can be structural / functional

Functional imaging more useful than structural in psychiatry

Neuroimaging in psychiatry is presently used mainly to rule
out neurological causes, and in evalulation of dementia

Sensitiviy & specifity of imaging in psychiatry is not much

Still various studies and their findings and newer
developments holds a promising future for neuroimaging in
psychiatric diagnosis & managements.

125. Presented and Made by-
Dr.Swapnil Agrawal
Resident- Psychiatry
Govt. Medical College, Kota (Raj)
dr.swapnil@yahoo.co.in