This document discusses various brain tumors and their MRI appearances. It describes low-grade astrocytomas as focal or diffuse lesions with low to intermediate T1 signal and high T2 signal, sometimes with mild contrast enhancement. Grade III astrocytomas are described as often irregular lesions with low to intermediate T1 signal, high T2 signal, and heterogeneous contrast enhancement. Glioblastomas are said to occur in those over 50 years old and demonstrate irregular margins, necrosis, vascular proliferation, and heterogeneous contrast enhancement.

1. Dr. Prashant Pote
Jr.III
Department of Radiology
GMC Mumbai & JJ hospital

3.  Focal or diffuse mass lesion usually located in
white matter with low to intermediate signal
onT1WI and high signal onT2WI;
 with or without mild Gd-contrast
enhancement.
 Minimal associated mass effect
 Well-differentiated but infiltrating neoplasm,
slow growth pattern.

4. Fig. 1A.18 Low-grade astrocytoma.
a AxialT2WI shows a focal mass lesion in
left temporo-occipital region with
heterogeneous intermediate to high signal
Fig. 1A.18 b Postcontrast axialT1WI
shows a small zone of mild Gd-contrast
enhancement in only a small portion of the
lesion.

5.  20% involve deep gray matter structures-
thalamus, basal ganglia
 Ca++ and cysts uncommon.
 Hemorrhage or surrounding edema (rare)

6.  Grade III astrocytoma,malignant
astrocytoma, high grade astrocytoma :
 Often irregularly marginated lesion located in
white matter with low to intermediate signal
onT1WI and high signal onT2WI, with or
without Gd-contrast enhancement.
 DWI: No diffusion restriction is typical

7. a AxialT2WI shows an infiltrative
lesion with heterogenous high signal,
poorly defined margins with mass effect
located in the right frontoparietal region.
b Postcontrast axialT1WI shows irregular
Gd-contrast enhancement in a portion
of the neoplasm.

8. a AxialT2WI shows a large mass
lesion with heterogenous high signal containing
areas of necrosis, poorly defined
margins, and marked mass effect located
in the right temporal, frontal, and parietal
b Postcontrast axialT1WI shows
prominent irregular Gd-contrast enhancement
at the neoplasm.

9.  Above 50 years
 Most common primary CNS tumor. Highly malignant
neoplasms with necrosis and vascular proliferation
 Irregularly marginated mass lesion with necrosis or
cyst. Mixed signal onT1WI and heterogeneous high
signal onT2WI. Hemorrhage may be associated.
 Prominent heterogeneous Gd-contrast enhancement.
 Can cross corpus callosum- “butterfly glioma”
 DWI; Lower measured ADC than low grade gliomas
o No diffusion restriction typical
 Elevated maximum rCBV compared to low grade

10.  Brain-brain spread:
 White matter tracts,carpous callosum,
corticospinal tract
 Ependymal and subependymal spread-
creeping tm
 Drop mets in spine

11. a AxialT2WI shows an infiltrative lesion with
heterogenous high signal, poorly defined
margins with mass effect located in the left
frontal lobe extending through the corpus
callosum into the right frontal lobe
Fig. 1A.20b Postcontrast axialT1WI
shows no Gd-contrast enhancement at
neoplasm.

12.  Diffusely infiltrating glial tumor involving
three or more lobes.
 Infiltrative lesion with poorly defined margins
with mass effect located in the white matter.
 Low to intermediate signal onT1WI and high
signal onT2WI; usually no Gd-contrast
enhancement until late in disease

14. T2 cor Post contrast T1Cor

15.  Circumscribed lesion located near the
foramen ofMonro with mixed low to
intermediate or high signal onT1WI and on
T2WI.
 Cysts and/or calcifications may be associated.
 Heterogenous or homogenous Gd-contrast
enhancement

16.  Subependymal hamartoma near foramen of
Monro,occurs in 15% of patients with
tuberous sclerosisbelow 20 years of age.
 Slow-growing lesions thatcan progressively
cause obstruction of CSF flow through the
foramen of Monro.

17.  Rare type of astrocytoma occurring in young
adults associated with seizure history
 Supratentorial cortical mass with adjacent
enhancing dural "tail"
 Cyst and enhancing mural nodule typical (50-
60%)
 Despite circumscribed appearance, tumor often
infiltrates into brain,VRSs
 Minimal or no edema is typical
 Ca++, hemorrhage, frank skull erosion rare

18. AxialT2WI shows a lesion
with heterogenous high signal, poorly defined
margins with mass
effect located in the right temporal lobe.
Postcontrast sagittalT1WI shows equivocal
minimal Gd-contrast enhancement at
neoplasm

19.  Usually in adults older than 35 years of age, 85%
supratentorial.
 Circumscribed lesion with mixed low to
intermediate signal on T1WI and mixed
intermediate to high signal on T2WI;
 areas of signal void at sites clump-like
calcification;
 heterogenous Gd-contrast enhancement.
 Involves white matter and cerebral cortex. Can
cause chronic eosion of inner table of calvaria.

20. Central neurocytoma. a Axial
T2WI shows a circumscribed lesion with
heterogenous high signal containing cystic
zones, involving the septum pellucidum
with extension into both lateral ventricles.
b Postcontrast coronal
T1WI shows irregular pattern of Gd-contrast
enhancement at neoplasm

21.  Age 20-40 yrs.
 Bubbly mass in the body or frontal horn of
lateral ventricle attached to septum pellucidum.
 Heterogeneous intermediate signal onT1WI;
heterogeneous high signal onT2WI.
 Calcifications and/or small cysts may be
associated. Heterogeneous Gd-contrast
enhancement.
 Slow growingTm ,rarely invades

22.  Imaging appearance similar to
intraventricular oligodendrogliomas.

23. AxialT2WI
shows a lesion with heterogenous high signal
containing small cystic zones in the
anterior right temporal lobe (arrows). No
Gd-contrast enhancement was seen
associated
with this lesion (images not
shown).

24.  Circumscribed tumor; usually supratentorial,
often temporal or frontal lobes. Low to
intermediate signal onT1WI, intermediate to
high signal onT2WI.
 Cysts may be present.With or without Gd-
contrast enhancement.

25.  Ganglioglioma (contains glial and neuronal
elements),
 Ganglioneuroma (contains only ganglion
cells). Uncommon tumors, below 30 years,
seizure presentation, slow-growing
neoplasms.
 Gangliocytoma (contains only neuronal
elements, dysplastic brain tissue). Favorable
prognosis if completely resected

26.  Circumscribed lesions involving the cerebral
cortex
 and subcortical white matter. Low signal on
T1WI;
 high signal onT2WI. Small cysts may be
associated.
 Usually no Gd-contrast enhancement.
 Benign superficial lesions commonly located
in the temporal or frontal lobes.

27. a AxialT2WI shows infiltrating lesions with high signal and mass effect located in the right
frontal and temporal lobes with involvement of the corpus callosum (arrows).
b, c Postcontrast axialT1WI shows Gd-contrast enhancement at two
sites of intra-axial lymphoma (arrows).

28.  Primary CNS lymphoma more common than
secondary, usually occurs in adults older than 40
yearsof age. B cell lymphoma more common
thanT cell lymphoma
 Primary CNS lymphoma: focal or infiltrating
lesion
 located in the basal ganglia, periventricular
regions, posterior fossa/brainstem.
 Low to intermediate signal onT1WI;
intermediate signal onT2WI.
Hemorrhage/necrosis may be associated in
immunocompromised patients.

29.  Usually Gd-contrast enhancement.
 Diffuse leptomeningeal enhancement is
another pattern of intracranial lymphoma.

30.  Circumscribed tumors usually located in the
cerebellum and/or brainstem.
 Small Gd-contrast-enhancing nodule with or
without cyst (60%), or larger solid lesion with
prominent heterogeneous enhancement (40%)
 with or without flow voids within lesion or at the
periphery.
 Intermediate signal onT1WI; intermediate to
high signal onT2WI.
 Occasionally lesions have evidence of recent or
remote hemorrhage.

31.  Rarely occur in cerebral hemispheres; occur in
adolescents, young and middle-aged adults.
 Lesions are typically multiple in patients with
von Hippel-Lindau disease.

33.  Circumscribed spheroid lesions in brain that
can have various intra-axial locations, often
at gray-white matter junctions.
 Usually low to intermediate signal onT1WI;
intermediate to high signal onT2WI.
 Hemorrhage, calcifications, cysts may be
associated.
 VariableGd-contrast enhancement,
peripheral to nodular enhancement.

34.  Extra-axial or intra-axial lesions usually less than
3 cm in diameter with irregular margins in the
leptomeninges or brain parenchyma/brainstem
(anterior temporal lobes, cerebellum, thalami,
inferior frontal lobes) with high signal onT1WI
secondary to increased melanin.
 Gdcontrast enhancement+/-
 No restriction on DWI, No blooming.
 Vermian hypoplasia,arachnoid cysts, Dandy-
Walker malformation may be associated.

35.  Neuroectodermal dysplasia with proliferation
of melanocytes in leptomeninges associated
with large and/or numerous cutaneous nevi.
 Maychange into CNS melanoma.

36.  Focal lesion with or without associated mass effect,or poorly
defined zone of low to intermediate signal onT1WI and
intermediate to high signal onT2WI, with or without Gd-
contrast enhancement.
 involving tissue (gray matter and/or white matter) in field of
treatment.
 Usually occurs from 4−6 months to 10 years after radiation
treatment.
 May be difficult to distinguish from neoplasm.
 Positron emission tomography (PET) and MR spectroscopy
(MRS), pMR might be helpful for evaluation.

37. a AxialT2WI shows poorly defined
zones of heterogeneous high signal involving
the cerebral cortex and white matter at
the anterior portions of both temporal
lobes (arrows). Mild localized mass effect is
. b Postcontrast axialT1WI
shows Gd-contrast enhancement involving
tissue (gray and/or white matter) in the
field of treatment (arrows).

39. a AxialT2WI shows a large, well-
circumscribed, extra-axial dural-based lesion
at the anterior falx with heterogeneous
intermediate to slightly high signal that results
in prominent compression of both frontal
lobes.
b Postcontrast axialT1WI shows prominent,
slightly heterogenous Gd-contrast
enhancement

40.  Extra-axial, well-circumscribed, dural-based
lesions.
 Locations in order of decreasing frequency:
supratentorial,infratentorial, parasagittal,
convexity, sphenoid ridge, parasellar, posterior
fossa, optic nerve sheath, intraventricular.
 Intermediate signal onT1WI and intermediate to
slightly high signal onT2WI.
 Usually prominent Gd-contrast enhancement.
 Calcifications may be associated.

41.  Most common extra-axial tumor. Usually benign
neoplasms, typically occurring in adults above
40 years of age,
 in women more commonly than men.
 Multiple meningiomas seen with
neurofibromatosis type 2.
 Can result in compression of adjacent brain
parenchyma, encasement of arteries, and
compression of dural venous sinuses.
 Rarely invasive/malignant.

42. a Postcontrast coronal
GRE)T1WI shows a large, slightly lobulated,
prominently enhancing extra-axial
dural-based lesion at the tentorium that results
in prominent compression of the right
cerebral hemisphere superiorly and right
cerebellar hemisphere inferiorly.
. b Axial
T2WI shows the large extra-axial lesion to
have heterogeneous intermediate signal
(arrows).

43.  Extra-axial mass lesions, often well-
circumscribed.
 Intermediate signal onT1WI and
intermediate to slightly high signal onT2WI;
 prominent Gd-contrast enhancement (may
resemble meningiomas).
 Withor without associated erosive bone
changes.

44.  Rare neoplasms in young adults
 sometimes referred to as angioblastic
meningioma or meningeal
hemangiopericytoma.

45. a Postcontrast
axialT1WI shows abnormal curvilinear
dural enhancement on the right with
two zones of nodular thickening representing
metastatic breast carcinoma (arrows).
b AxialT2WI shows the two zones
of dural thickening have intermediate signal,
which can also be seen with meningiomas
(arrows).

46.  Single or multiple well-circumscribed or poorly
defined lesions involving the skull, dura,
leptomeninges,and/or choroid plexus.
 Low to intermediate signal onT1WI and intermediate
to high signal onT2WI; usually Gd-contrast
enhancement.
 Bone destructionand compression of neural tissue or
vessels may be present.
 Leptomeningeal tumor often best seen on
postcontrast images
 Metastatic tumor may have variable destructive or
infiltrative changes involving single or multiple sites of
involvement.

47. a SagittalT1WI
shows a circumscribed, slightly lobulated
tumor with intermediate signal in the
pineal recess (arrows).
AxialT2WI shows the lesion
to have heterogeneous,
intermediate to high signal with
a thin rim of low signal
(arrows).
Postcontrast axialT1WI
shows prominent Gd-
contrast enhancement
of tumor (arrows).

48.  More common in males than females (10−30
years);
 Circumscribed tumors.With or without
disseminated disease.
 Pineal region, suprasellar region, third
ventricle/basal ganglia.
 Low to intermediate signal onT1WI, occasionally
high signal onT1WI;
 variable low, intermediate, high signal onT2WI.
 Gd-contrast enhancement of tumor and
leptomeninges if disseminated

49. a SagittalT1WI shows a pituitary
macroadenoma with intermediate signal
measuring 18mm in height (arrows).
b Postcontrast coronalT1WI
shows prominent enhancement of the lesion,
which extends upward into the suprasellar
cistern (arrows).

50.  Macro adenomas (>10mm):. Extension into
suprasellar cistern with waist at diaphragma
sella, with or without extension into
cavernous sinus.
 Occasionally invades skull base.

51.  Microadenomas (<10mm): Commonly have
intermediate signal onT1WI andT2WI.
 Cysts, hemorrhage,necrosis may be
associated.
 Typically enhance less than normal pituitary
tissue–often best seen with dynamic early
phase imaging.

52.  Common benign slow-growing tumors
representing approximately 50% of
sellar/parasellar neoplasms in adults.
 Can be associated with endocrine abnormalities
related to oversecretion of hormones(prolactin,
nonsecretory type, growth hormone,ACTH, and
others).
 Prolactinomas: more common in females than
males;
 growth hormone tumors:more common in
males.

53. Craniopharyngioma. a Sagittal
T1WI shows a lobulated lesion with
mixed low, intermediate, and high signal in
the sella and suprasellar cistern with d
Fig. 1A.62b Postcontrast sagittalT1WI
shows enhancement in portions of the lesion
(arrows).

54.  Circumscribed lobulated lesions; both
suprasellar and intrasellar location, less
commonly suprasellar or intrasellar only.
Variable low, intermediate, and/or high signal
onT1WI andT2WI.
 With or without nodular or rim Gd-contrast
enhancement.
 May contain cysts, lipid components, and
calcifications.

55.  Usually histologically benign but locally
aggressive lesions arising from squamous
epithelial rests along Rathke’s cleft.
 Occurs in children (10 years) and adults
(above 40 years).

56. • Pineal parenchymal tumors
(pineocytoma/blastoma)
• Germ cell tumors (germinoma, teratoma)

57.  Pineocytomas can be encountered at any age
but mostly occur in young adults in the
second decade of life
 obstructive hydrocephalus secondary to
compression of the tectum of the midbrain
and obstruction of the aqueduct

59.  Slow growing and well circumscribed
tumours (compared to pineoblastomas which
tend to be larger, and less well
circumscribed).
 They tend to be solid, although focal areas of
cystic change, or haemorrhage do occur.
 Pineal calcifications tend to be dispersed
peripherally.
 T1 C+ (Gd): solid components vividly
enhance.

61.  Pineoblastomas tend to be large poorly
defined masses, with frequent CSF seeding.
 directly involve adjacent brain structures.
 The solid component tends to be slightly
hyperdense compared to adjacent brain due
to high cellularity.
 "exploded" calcification.
 T1 C+ (Gd): vivid heterogenous enhancement
DWI/ADC restricted diffusion due to dense
cellular packing

63.  Germinomas are soft tissue density,
enhancing masses.
 When present in the pineal region they
appear to "engulf" normal pineal tissue

65. a SagittalT1WI shows a
circumscribed,
slightly lobulated lesion with
intermediate
signal located in the atrium of the
right lateral ventricle (arrows).
Hydrocephalus
is also present.
b Postcontrast sagittalT1WI
shows prominent Gd-contrast
enhancement
of the lesion (arrows).

66.  Circumscribed and/or lobulated lesions with
papillary projections. Intermediate signal on
T1WI and mixed intermediate to high signal on
T2WI;
 usually prominent Gd-contrast enhancement.
May contain calcifications.
 Locations: atrium of lateral ventricle (children)
more common than fourth ventricle (adults),
rarely other locations such as third ventricle.
 Associated with hydrocephalus.

67. a Sagittal
T1WI shows a large lesion with low and intermediate
signal involving the nasal cavity,
ethmoidal and sphenoidal sinuses, anterior
and mid skull base.The lesion extends into
the anterior cranial fossa, displacing the inferior
b.AxialT2WI shows the lesion
to have mixed intermediate to high signal.
The lesion encases portions of the carotid
arteries (arrows).

68.  Multiple (myeloma) or single (plasmacytoma)
wellcircumscribed or poorly defined lesions
involving the skull and dura.
 Low to intermediate signal onT1WI and
intermediate to high signal onT2WI,
 usually with Gd-contrast enhancement and
with bone destruction.

69.  Myeloma may have variable destructive or
infiltrative changes involving the axial and/or
appendicular skeleton.

70.  Well-circumscribed lobulated lesions with low to
intermediate signal onT1WI and high signal on
T2WI;
 Gd-contrast enhancement (usually
heterogeneous).
 Locally invasive associated with bone
erosion/destruction,
 encasement of vessels and nerves
 Skull base and clivus common location, usually
in the midline.

71.  Lobulated lesions with low to intermediate
signal onT1WI and high signal onT2WI.
 With or without matrix mineralization: low
signal onT2WI.
 With Gdcontrast enhancement (usually
heterogeneous).
 Locally invasive associated with bone
erosion/destruction, encasement of vessels and
nerves.
 Skull base and petro-occipital synchondrosis
common location, usually off midline.

72. SagittalT1WI shows a large destructive lesion involving the
skull with intracranial and extracranial soft-tissue components.
These have intermediate signal containing irregular zones of
low signal, representing matrix mineralization/ ossification.
Postcontrast sagittalT1WI shows prominent
enhancement at the soft-tissue portions of the lesion.

73.  Destructive lesions involving the skull base.
Low tointermediate signal onT1WI and
mixed low, intermediate,high signal onT2WI.
 Usually wit matrix mineralization/ossification:
low signal onT2WI.
 With Gd-contrast enhancement (usually
heterogeneous).

74.  Rare lesions involving the endochondral
bone-forming portions of the skull base.
More common than chodrosarcomas and
Ewing sarcoma.
 Locally invasive,high metastatic potential.
 Occurs in children as primary tumors and
adults (associated with Paget disease,
irradiated bone, chronic osteomyelitis,
osteoblastoma, giant cell tumor, fibrous
dysplasia).

75.  Destructive lesions in the nasal cavity,
paranasal sinuses, nasopharynx.
 With or without intracranial extension via
bone destruction or perineural spread.
 Intermediate signal onT1WI and
intermediate to slightly high signal onT2WI;
 Mild Gd-contrast enhancement. Large lesions
(necrosis and/or hemorrhage may be
associated).

76.  Occurs in adults, more common in males than
 females, usually above 55 years. Associated
withoccupational or other exposure to nickel,
chromium, mustard gas, radium,
manufacture of wood products.

77. a.Postcontrast FS coronalT1WI shows an
enhancing lesion in the nasopharynx
extending superiorly through a widened left
foramen ovale (perineural spread) into the
left trigeminal cistern and medial left
middle cranial fossa (arrows).
b AxialT2WI shows that the lesion also
extends into the sphenoidal and ethmoidal
sinuses and has heterogeneous intermediate
and high signal (arrows). A left middle ear
effusion is also present.

78.  Destructive lesions in the paranasal sinuses,
nasal cavity, nasopharynx.
 With or without intracranial extension via
bone destruction or perineural spread.
 Intermediate signal onT1WI and
intermediate to high signal onT2WI; variable
mild, moderate, or prominent Gd-contrast
enhancement.

79.  Tumors also referred to as olfactory
neuroblastoma.
 Arise from olfactory epithelium in the
superior nasal cavity.
 Occurs in adolescents and adults,
 more common in males than females.

80. After intravenous administration of Gd-DTPA,
considerable
enhancement of an inhomogeneous
lesion (arrow) originating in the
nasal vault is seen

81.  Single or mutiple circumscribed soft-tissue lesions
in the marrow of the skull associated with focal
bony destruction/erosion with extension
extracranially, intracranially, or both.
 Lesions usually have low to intermediate signal on
T1WI and mixed intermediate to slightly high signal
onT2WI, with Gd-contrast enhancement.
 With or without enhancement of the adjacent dura.

82. a CoronalT2WI shows a
soft-tissue lesion with mixed intermediate
to high signal in the marrow of the skull,
associated with focal bony destruction/erosion
(arrows).
b Postcontrast FS coronal
T1WI shows heterogeneous enhancement
of the lesion as well as enhancement of
the adjacent dura (arrows).

83.  Single lesion: Commonly seen in males more than
females (below 20 years).
 Proliferation of histiocytes in medullary cavity with
localized destruction of bone with extension into
adjacent soft tissues.
 Multiple lesions: Associated with syndromes such as:
Letterer-Siwe disease (lymphadenopathy
hepatosplenomegaly), children below 2 years; Hand-
Schüller-Christian disease (lymphadenopathy,
exophthalmos,diabetes insipidus) children aged
5−10years.